The Prolongation of Life - Optimistic Studies

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Title: The Prolongation of Life - Optimistic Studies
Author: Metchnikoff, Elie
Language: English
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THE PROLONGATION
OF LIFE

OPTIMISTIC STUDIES

ÉLIE METCHNIKOFF

SUB-DIRECTOR OF THE PASTEUR INSTITUTE, PARIS

THE ENGLISH TRANSLATION

EDITED BY

P. CHALMERS MITCHELL

M.A., D.SC. OXON., HON. LL.D., F.R.S.

_Secretary of the Zoological Society of London; Corresponding Member
of the Academy of Natural Sciences of Philadelphia_

G. P. PUTNAM’S SONS
NEW YORK & LONDON
The Knickerbocker Press
1908

EDITOR’S INTRODUCTION

Élie Metchnikoff has carried on the high purpose of the Pasteur
Institute by devoting his genius for biological inquiry to the service
of man. Some years ago, in a series of Essays which were intended to
be provocative and educational, rather than expository, he described
the direction towards which he was pressing. I had the privilege of
introducing these Essays to English readers under the title _The Nature
of Man_, a Study in Optimistic Philosophy. In that volume, Professor
Metchnikoff recounted how sentient man, regarding his lot in the world,
had found it evil. Philosophy and literature, religion and folk-lore,
in ancient and modern times have been deeply tinged with pessimism. The
source of these gloomy views lies in the nature of man itself. Man has
inherited a constitution from remote animal ancestors, and every part
of his structure, physical, mental and emotional, is a complex legacy
of diverse elements. Possibly at one time each quality had its purpose
as an adaptation to environment, but, as man, in the course of his
evolution, and the environment itself have changed, the old harmonious
intercourse between quality and circumstances has been dislocated in
many cases. And so there have come into existence many instances of
what the Professor calls “disharmony,” persistences of structures,
or habits, or desires that are no longer useful, but even harmful,
failures of parallelism between the growth, maturity and decay of
physical and mental qualities and so forth. Religions and philosophies
alike have failed to find remedies or efficient anodynes for these
evils of existence, and, so far, man is justified of his historical and
actual pessimism.

Metchnikoff, however, was able to proclaim himself an optimist, and
found, in biological science, for the present generation a hope, or,
at the least, an end towards which to work, and for future generations
a possible achievement of that hope. Three chief evils that hang over
us are disease, old age, and death. Modern science has already made
vast strides towards the destruction of disease, and no one has more
right to be listened to than a leader of the Pasteur Institute when he
asserts his confidence that rational hygiene and preventive measures
will ultimately rid mankind of disease. The scientific investigation
of old age shows that senility is nearly always precocious and
that its disabilities and miseries are for the most part due to
preventable causes. Metchnikoff showed years ago that there exists in
the human body a number of cells known generally as phagocytes, the
chief function of which is to devour intruding microbes. But these
guardians of the body may turn into its deadly enemies by destroying
and replacing the higher elements, the specific cells of the different
tissues. The physical mechanism of senility appears to be in large
measure the result of this process. Certain substances, notably the
poisons of such diseases as syphilis and the products of intestinal
putrefaction, stimulate the activity of the phagocytes and so encourage
their encroachment on the higher tissues. The first business of science
is to remove these handicaps in favour of the wandering, corroding
phagocytes. Specific poisons must be dealt with separately, by
prevention or treatment, and it is well known that Metchnikoff has
made great advances in that direction. The most striking practical
side of _The Nature of Man_, however, was the discussion of the cause
and prevention of intestinal putrefaction. Metchnikoff believes that
the inherited structure of the human large intestine and the customary
diet of civilised man are specially favourable to the multiplication
of a large number of microbes that cause putrefaction. The avoidance
of alcohol and the rigid exclusion from diet of foods that favour
putrefaction, such as rich meats, and of raw or badly cooked substances
containing microbes, do much to remedy the evils. But the special
introduction of the microbes which cause lactic fermentation has
the effect of inhibiting putrefaction. By such measures Metchnikoff
believes that life will be greatly prolonged and that the chief evils
of senility will be avoided. It may take many generations before the
final result is attained, but, in the meantime, great amelioration is
possible. There remains the last enemy, death. Metchnikoff shows that
in the vast majority of cases death is not “natural,” but comes from
accidental and preventable causes. When diseases have been suppressed
and the course of life regulated by scientific hygiene, it is probable
that death would come only at an extreme old age. Metchnikoff thinks
that there is evidence enough at least to suggest that when death comes
in its natural place at the end of the normal cycle of life, it would
be robbed of its terrors and be accepted as gratefully as any other
part of the cycle of life. He thinks, in fact, that the instinct of
life would be replaced by an instinct of death.

Metchnikoff’s suggestion, then, was that science should be encouraged
and helped in every possible way in its task of removing the diseases
and habits that now prevent human life from running its normal course,
and his belief is that were the task accomplished, the great causes of
pessimism would disappear.

In this new volume, _The Prolongation of Life_, the main thesis is
carried further, and a number of criticisms and objections are met.
The latter, so far as they relate to technical details, I need say
nothing of here, as Metchnikoff and his staff at the Pasteur Institute
are the most skilled existing technical experts on these matters, but
I cannot refrain from a word of comment on the brilliant treatment
of the objection to the suggested amelioration of human life that it
considered only the individual and neglected the just subordination
of the individual to society. In the sixth Part of this volume,
Metchnikoff discusses the relation of the individual to the species,
society or colony, from the general point of view of comparative
biology, and shows that as organisation progresses, the integrity of
the individual becomes increasingly important. Were orthobiosis, the
normal cycle of life, attained by human beings, there still would be
room for specialisation of individuals and for differentiation of the
functions of individuals in society, but instead of the specialisation
and differentiation making individuals incomplete throughout their
whole lives, they would be distributed over the different periods of
the life of each individual.

As these lines are intended to be an introduction, not a commentary, I
will now leave the reader to follow the argument in the book itself.

P. CHALMERS MITCHELL.

LONDON, _August, 1907_.

PREFACE

It is now four years since I wrote a volume, the English translation
of which was called _The Nature of Man_, and which was an attempt to
frame an optimistic conception of life. Human nature contains many
very complex elements, due to its animal ancestry, and amongst these
there are some disharmonies to which our misfortunes are due, but also
elements which afford the promise of a happier human life.

My views have encountered many objections, and I wish to reply to some
of these by developing my arguments. This was my first task in this
book, but I have also brought together a series of studies on problems
which closely affect my theory.

Although it has been possible to support my conception by new facts,
some of which have been established by my fellow-workers, others
by myself, there still remain many sides of the subject where it
is necessary to fall back on hypotheses. I have accepted such
imperfections instead of delaying the publication of my book.

Even at present there are critics who regard me as incapable of sane
and logical reasoning. The longer I postpone publication, the longer
would I leave the field open to such persons. What I have been saying
may serve also as a reply to the remark of one of my critics, that my
ideas have been “suggested by self-preoccupation.”

It is, of course, quite natural that a biologist whose attention had
been aroused by noticing in his own case the phenomena of precocious
old age should turn to study the causes of it. But it is equally plain
that such a study could give no hope of resisting the decay of an
organism which had already for many years been growing old. If the
ideas which have come out of my work bring about some modification in
the onset of old age, the advantage can be gained only by those who are
still young, and who will be at the pains to follow the new knowledge.
This volume, in fact, like my earlier one on the “Nature of Man,” is
directed much more to the new generation than to that which has already
been subjected to the influence of the factors which produce precocious
old age. I think that thus the experience of those who have lived and
worked for long can be made of service to others.

As this volume is a sequel to _The Nature of Man_, I have tried as much
as possible to avoid repetition of what was fully explained in the
earlier volume.

Here I bring together the results of work that has been done since the
publication of _The Nature of Man_. Some of the chapters relate to
subjects upon which I have lectured, or which, in a different form,
have been printed before. For instance, the section on the psychic
rudiments of man appeared in the _Bulletin de l’Institut général
psychologique_ of 1904, the essay on Animal Societies was published in
the _Revue Philomatique de Bordeaux et du Sud-Ouest_ of 1904, and in
the _Revue_ of J. Finot of the same year, whilst a German translation
of it appeared in Prof. Ostwald’s _Annalen der Naturphilosophie_. The
chapter on soured milk first appeared as a pamphlet, published in
1905. The substance of my views on natural death was published in June
last in “Harper’s Monthly Magazine” of New York, while the chapter on
natural death in animals appeared in the first number of the _Revue du
Mois_ for 1906.

I have to thank most sincerely the friends and pupils who have helped
me by bringing before me new facts, or other materials; the names
of these will appear in their proper places in the volume. I have
not mentioned by name, however, Dr. J. Goldschmidt, whose continual
encouragement and practical sympathy have made my work much easier.

Finally, my special thanks are due to Drs. Em. Roux and Burnet, and
M. Mesnil, who have been so good as to correct my manuscript and the
proofs of this volume.

É. M.

PARIS, _Feb. 7, 1907_.

CONTENTS

PAGE

EDITOR’S INTRODUCTION v

PREFACE ix

PART I

THE INVESTIGATION OF OLD AGE

THE PROBLEMS OF SENILITY

Treatment of old people in uncivilised
countries.—Assassination of old people in civilised
countries.—Suicide of old people.—Public assistance in
old age.—Centenarians.—Mme. Robineau, a lady of 106
years of age.—Principal characters of old age.—Examples
of old mammals.—Old birds and tortoises.—Hypothesis of
senile degeneration in the lower animals 1

THEORIES OF THE CAUSATION OF SENILITY

Hypothesis of the causation of senility.—Senility
cannot be attributed to the cessation of the power of
reproduction of the cells of the body.—Growth of the
hair and the nails in old age.—Inner mechanism of
the senescence of the tissues.—Notwithstanding the
criticisms of M. Marinesco, the neuronophags are true
phagocytes.—The whitening of hair, and the destruction
of nerve cells as arguments against a theory of old age
based on the failure of the reproductive powers of the
cells 15

III

MECHANISM OF SENILITY

Action of the macrophags in destroying the higher
cells.—Senile degeneration of the muscular
fibres.—Atrophy of the skeleton.—Atheroma and arterial
sclerosis.—Theory that Old Age is due to alteration
in the vascular glands.—Organic tissues that resist
phagocytosis. 25

PART II

LONGEVITY IN THE ANIMAL KINGDOM

THEORIES OF LONGEVITY

Relation between longevity and size.—Longevity and
the period of growth.—Longevity and the doubling
in weight after birth.—Longevity and rate of
reproduction.—Probable relations between longevity and
the nature of the food 39

LONGEVITY IN THE ANIMAL KINGDOM

Longevity in the lower animals.—Instances of long life
in sea-anemones and other vertebrates.—Duration of
life of insects.—Duration of life of “cold-blooded”
vertebrates.—Duration of life of birds.—Duration of
life of mammals.—Inequality of the duration of life
in males and females.—Relations between longevity and
fertility of the organism 47

III

THE DIGESTIVE SYSTEM AND SENILITY

Relations between longevity and the structure of
the digestive system.—The cæca in birds.—The
large intestine of mammals.—Function of the large
intestine.—The intestinal microbes and their agency in
producing auto-intoxication and auto-infection in the
organism.—Passage of microbes through the intestinal
wall 59

MICROBES AS THE CAUSE OF SENILITY

Relations between longevity and the intestinal
flora.—Ruminants.—The horse.—Intestinal flora of
birds.—Intestinal flora of cursorial birds.—Duration
of life in cursorial birds.—Flying mammals.—Intestinal
flora and longevity of bats.—Some exceptions to the
rule.—Resistance of the lower vertebrates to certain
intestinal microbes 73

DURATION OF HUMAN LIFE

Longevity of man.—Theory of Ebstein on the normal
duration of human life.—Instances of human
longevity.—Circumstances which may explain the long
duration of human life 84

PART III

INVESTIGATIONS ON NATURAL DEATH

NATURAL DEATH AMONGST PLANTS

Theory of the immortality of unicellular
organisms.—Examples of very old trees.—Examples of
short-lived plants.—Prolongation of the life of some
plants.—Theory of the natural death of plants by
exhaustion.—Death of plants from auto-intoxication 94

NATURAL DEATH IN THE ANIMAL WORLD

Different origins of death in animals.—Examples of
natural death associated with violent acts.—Examples
of natural death in animals without digestive
organs.—Natural death in the two sexes.—Hypothesis as
to the cause of natural death in animals 109

III

NATURAL DEATH AMONGST HUMAN BEINGS

Natural death in the aged.—Analogy of natural death and
sleep.—Theories of sleep.—Ponogenes.—The instinct
of sleep.—The instinct of natural death.—Replies to
critics.—Agreeable sensation at the approach of death 119

PART IV

SHOULD WE TRY TO PROLONG HUMAN LIFE?

THE BENEFIT TO HUMANITY

Complaints of the shortness of our life.—Theory of
“medical selection” as a cause of degeneration of the
race.—Utility of prolonging human life 132

SUGGESTIONS FOR THE PROLONGATION OF LIFE

Ancient methods of prolonging human life.—Gerokomy.—The
“immortality draught” of the Taoists.—Brown-Séquard’s
method.—The spermine of Poehl.—Dr. Weber’s
precepts.—Increased duration of life in historical
times.—Hygienic maxims.—Decrease in cutaneous cancer 136

III

DISEASES THAT SHORTEN LIFE

Measures against infectious diseases as aiding in the
prolongation of life.—Prevention of syphilis.—Attempts
to prepare serums which could strengthen the higher
elements of the organism 145

INTESTINAL PUTREFACTION SHORTENS LIFE

Uselessness of the large intestine in man.—Case of
a woman whose large intestine was inactive for six
months.—Another case where the greater part of the
large intestine was completely shut off.—Attempts to
disinfect the contents of the large intestine.—Prolonged
mastication as a means of preventing intestinal
putrefaction 151

LACTIC ACID AS INHIBITING INTESTINAL PUTREFACTION

The development of the intestinal flora in
man.—Harmlessness of sterilised food.—Means
of preventing the putrefaction of food.—Lactic
fermentation and its anti-putrescent action.—Experiments
on man and mice.—Longevity in races which used
soured milk.—Comparative study of different soured
milks.—Properties of the Bulgarian Bacillus.—Means
of preventing intestinal putrefaction with the help of
microbes 161

PART V

PSYCHICAL RUDIMENTS IN MAN

RUDIMENTARY ORGANS IN MAN

Reply to critics who deny the simian origin of
man.—Actual existence of rudimentary organs.—Reductions
in the structure of the organs of sense in man.—Atrophy
of Jacobson’s organ and of the Harderian gland in the
human race 184

HUMAN TRAITS OF CHARACTER INHERITED FROM APES

The mental character of anthropoid apes.—Their muscular
strength.—Their expression of fear.—The awakening of
latent instincts of man under the influence of fear 191

III

SOMNAMBULISM AND HYSTERIA AS MENTAL RELICS

Fear as the primary cause of hysteria.—Natural
somnambulism.—Doubling of personality.—Some examples
of somnambulists.—Analogy between somnambulism and
the life of anthropoid apes.—The psychology of
crowds.—Importance of the investigation of hysteria for
the problem of the origin of man 200

PART VI

SOME POINTS IN THE HISTORY OF SOCIAL ANIMALS

THE INDIVIDUAL AND THE RACE

Problem of the species in the human race.—Loss
of individuality in the associations of lower
animals.—Myxomycetes and Siphonophora.—Individuality in
Ascidians.—Progress in the development of the individual
living in a society 212

INSECT SOCIETIES

Social life of insects.—Development and preservation of
individuality in colonies of insects.—Division of labour
and sacrifice of individuality in some insects 220

III

SOCIETY AND THE INDIVIDUAL IN THE HUMAN RACE

Human societies.—Differentiation in the human
race.—Learned women.—Habits of a bee, Halictus
quadricinctus.—Collectivist theories.—Criticisms by
Herbert Spencer and Nietzsche.—Progress of individuality
in the societies of higher beings 223

PART VII

PESSIMISM AND OPTIMISM

PREVALENCE OF PESSIMISM

Oriental origin of pessimism.—Pessimistic
poets.—Byron.—Leopardi.—Poushkin.—Lermontoff.—Pessimism
and suicide 233

ANALYSIS OF PESSIMISM

Attempts to assign reasons for the pessimistic conception
of life.—Views of E. von Hartmann.—Analysis of
Kowalevsky’s work on the psychology of pessimism 239

III

PESSIMISM IN ITS RELATION TO HEALTH AND AGE

Relation between pessimism and the state of the
health.—History of a man of science who was pessimistic
when young and who became an optimist in old
age.—Optimism of Schopenhauer when old.—Development of
the sense of life.—Development of the senses in blind
people.—The sense of obstacles 247

PART VIII

GOETHE AND FAUST

GOETHE’S YOUTH

Goethe’s youth.—Pessimism of youth.—Werther.—Tendency
to suicide.—Work and love.—Goethe’s conception of life
in his maturity 261

GOETHE AND OPTIMISM

Goethe’s optimistic period.—His mode of life
in that period.—Influence of love in artistic
production.—Inclinations towards the arts must be
regarded as secondary sexual characters.—Senile love
of Goethe.—Relation between genius and the sexual
activities 270

III

GOETHE’S OLD AGE

Old age of Goethe.—Physical and intellectual vigour of
the old man.—Optimistic conception of life.—Happiness
in life in his last period 279

GOETHE AND “FAUST”

_Faust_ the biography of Goethe.—The three monologues in
the first Part.—Faust’s pessimism.—The brain-fatigue
which finds a remedy in love.—The romance with
Marguerite and its unhappy ending 283

THE OLD AGE OF FAUST

The second Part of _Faust_ is in the main a description
of senile love.—Amorous passion of the old man.—Humble
attitude of the old Faust.—Platonic love for
Helena.—The old Faust’s conception of life.—His
optimism.—The general idea of the play 290

PART IX

SCIENCE AND MORALITY

UTILITARIAN AND INTUITIVE MORALITY

Difficulty of the problem of morality.—Vivisection
and anti-vivisection.—Enquiry into the possibility of
rational morality.—Utilitarian and intuitive theories of
morality.—Insufficiency of these 301

MORALITY AND HUMAN NATURE

Attempts to found morality on the laws of human
nature.—Kant’s theory of moral obligation.—Some
criticisms of the Kantian theory.—Moral conduct must be
guided by reason 309

III

INDIVIDUALISM

Individual morality.—History of two brothers brought
up in the same circumstances, but whose conduct was
quite different.—Late development of the sense of
life.—Evolution of sympathy.—The sphere of egoism in
moral conduct.—Christian morality.—Morality of Herbert
Spencer.—Danger of exalted altruism 316

ORTHOBIOSIS

Human nature must be modified according to an
ideal.—Comparison with the modification of the
constitution of plants and of animals.—Schlanstedt
rye.—Burbank’s plants.—The ideal of orthobiosis.—The
immorality of ignorance.—The place of hygiene in
the social life.—The place of altruism in moral
conduct.—The freedom of the theory of orthobiosis from
metaphysics 325

THE PROLONGATION OF LIFE

PART I

THE INVESTIGATION OF OLD AGE

THE PROBLEMS OF SENILITY

Treatment of old people in uncivilised
countries—Assassination of old people in civilised
countries—Suicide of old people—Public assistance in
old age—Centenarians—Mme. Robineau, a lady of 106 years
of age—Principal characters of old age—Examples of old
mammals—Old birds and tortoises—Hypothesis of senile
degeneration in the lower animals

In the “Nature of Man” I laid down the outlines of a theory of the
actual changes which take place during the senescence of our body.
These ideas, on the one hand, have raised certain difficulties, and, on
the other, have led to new investigations. As the study of old age is
of great theoretical importance, and naturally is of practical value, I
think that it is useful to pursue the subject still further.

Although there exist races which solve the difficulty of old age by
the simple means of destroying aged people, the problem in civilised
countries is complicated by our more refined feelings and by
considerations of a general nature.

In the Melanesian Islands, old people who have become incapable of
doing useful work are buried alive.

In times of famine, the natives of Tierra del Fuego kill and eat the
old women before they touch their dogs. When they were asked why they
did this, they said that dogs could catch seals, whilst old women could
not do so.

Civilised races do not act like the Fuegians or other savages; they
neither kill nor eat the aged, but none the less life in old age often
becomes very sad. As they are incapable of performing any useful
function in the family or in the village, the old people are regarded
as a heavy burden. Although they cannot be got rid of, their death is
awaited with eagerness, and is never thought to come soon enough. The
Italians say that old women have seven lives. According to a Bergamask
tradition, old women have seven souls, and after that an eighth soul,
quite a little one, and after that again half a soul; whilst the
Lithuanians complain that the life of an old woman is so tough that it
cannot be crushed even in a mill. We may take it as an echo of such
popular ideas that murders of old people are extremely common even
in the most civilised European countries. I have been astonished in
looking through criminal records to see how many cases there are of the
murder of old people, specially of old women. It is easy to divine the
motives of these acts. A convict of the Island of Saghalien, condemned
for the assassination of several old persons, declared naïvely to the
prison doctor: “Why pity them? They were already old, and would have
died in any case in a few years.”

In the celebrated novel of Dostoiewsky, “Crime and Punishment,” there
is a tavern scene where young people discuss all sorts of general
topics. In the middle of the conversation a student declares that he
would “murder and rob any cursed old woman without the least remorse.”
“If the truth were told,” he goes on to say, “this is how I look at
the thing. On the one hand a stupid old woman, childish, worthless,
ill-tempered, and in bad health; no one would miss her, indeed she is
a nuisance to everyone. She does not even herself know any reason why
she should live, and perhaps to-morrow death will make a good riddance
of her. On the other hand, there are fresh and vigorous young people
who are dying in their thousands, in the most senseless way, no one
troubling about them, and everywhere the same thing is going on.”

Old people not only run the risk of murder; they very often end their
own lives prematurely by suicide.

They prefer death to a life oppressed by material hardships or burdened
by diseases. The daily papers give many instances of old people who,
tired of suffering, asphyxiate themselves by their charcoal stoves.

The frequency of suicide in the case of the old has been established
by numerous statistics, and the new facts which I now cite do no more
than confirm it. In 1878, in Prussia, amongst 100,000 individuals there
were 154 cases of suicide of men between the ages of 20 and 50, but
295, that is to say, nearly twice as many of men between the ages of 50
and 80. In Denmark, a country in which suicide is notoriously common, a
similar proportion exists. Thus, in Copenhagen, in the ten years from
1886 to 1895, there were 394 suicides of men between 50 and 70. These
figures relate to 100,000 individuals. Of the suicides 36-1/2 per cent.
were those of people in the prime of life, 63-1/2 per cent. those of
the aged.[1]

In such circumstances, it is natural that politicians and
philanthropists have made many attempts to ameliorate the old age of
the poor. In some countries laws have been passed to bring about this.
For instance, a Danish law of June 27th, 1891, established compulsory
aid for the aged, enacting that every person more than 60 years old was
to have the legal right to aid if required. In 1896 more than 36,000
people (36,246) were pensioned under this law, at a cost of nearly
£200,000. In Belgium, the indigent old people are not pensioned until
they reach the age of 65. In France, until recently, the aged poor
could be supported at the public expense only by prosecuting them and
sending them to prison for begging. This state of affairs, however,
ceased with the application of the law of July 15th, 1905, according to
which any French subject without resources, unable to support himself
by work, and either more than 70 years of age, or suffering from some
incurable infirmity or disease, is to receive public assistance.

It has been thought the proper course to make such laws, and to lay
the burden on the general population, without inquiring if it may not
be possible to retard the debility of old age to such an extent that
very old people might still be able to earn their livelihood by work.
Old age can be studied by the methods of exact science, and there may
yet be established some regimen by which health and vigour will be
preserved beyond the age where now it is generally necessary to resort
to public charity. With this object, a systematic investigation of
senescence should be made in institutions for the aged, where there
are always a large number of people from 75 to 90 years old, although
centenarians are extremely rare. I know many institutions for aged
men where, from their first foundation, there has been no case of an
inhabitant reaching the age of 100, and even in similar institutions
for women, although women live to much greater ages than men,
centenarians are very rare. At the Salpêtrière, for instance, where
there is always a large number of old women, it is the rarest chance to
find a centenarian. Opportunity for the study of the extremely aged is
to be found only in private families.

Most of the centenarians whom I have been able to see have been so
defective mentally that all that can be studied in them are the
physical qualities and functions. A few years ago an old woman who
had reached her 100th year was the pride of the Salpêtrière. She was
bedridden and extremely feeble physically and mentally. She replied
briefly when she was asked questions, but apparently without any idea
of what they meant.

Not long ago, a lady who lived in a suburb of Rouen reached her 100th
birthday. The local newspapers wrote exaggerated articles about her,
praising the integrity of her mind and her physical strength. I paid
a visit to her myself, hoping to make a detailed investigation, but
I found at once that the journalists had completely misrepresented
her condition. Although her physical health was fairly good, her
intelligence had degenerated to such an extent that I had to abandon
the idea of any serious investigation.

The most interesting of all the centenarians with whom I have become
acquainted had reached an extremely advanced age, having entered upon
her 107th year. It is about two years ago that a journalist, Monsieur
Flamans, took me to see this Mme. Robineau who lived in a suburb of
Paris. I found her a very old-looking lady, rather short, thin, with a
bent back, and leaning heavily on a cane when she walked. The physical
condition (Mme. Robineau was born on January 12th, 1800), of this
woman of more than 106 years, showed extreme decay. She had only one
tooth; she had to sit down after every few steps, but, once comfortably
seated, she could remain in that position for quite a long time. She
went to bed early and got up very late. Her features displayed very
great age (see Fig. 1), although her skin was not extremely wrinkled.

[Illustration: FIG. 1.—Mme. Robineau, a centenarian. From a photograph
taken on her one hundred and fifth birthday.]

The skin of her hands had become so transparent that one could see
the bones, the blood-vessels, and the tendons. Her senses were very
feeble; she could see only with one eye; taste and smell were extremely
rudimentary; her hearing was her best means of relation with the
external world. None the less, Dr. Löwenberg, a well-known aurist,
had assured himself that her auditory organs showed in a most marked
degree, the usual signs of old age, such as complete insensibility to
high notes and slight deafness for low notes. Dr. Löwenberg attributed
these changes to senile degeneration of the ear which affected more
and more seriously the nervous mechanism although it had caused little
change in the conducting apparatus. Notwithstanding her physical
weakness, Mme. Robineau retained her intelligence fully, her mind
remained delicate and refined and the goodness of her heart was
touching. In contrast with the usual selfishness of old people, Mme.
Robineau took a vivid interest in those around her. Her conversation
was intelligent, connected, and logical. Examination of the physical
functions of this old lady revealed facts of great interest. Dr.
Ambard found that the sounds of the heart were normal, but perhaps a
little accentuated. The pulse was regular, 70 to 84 a minute, and its
tension was normal. The arterial pressure was 17. The lungs were sound.
All these facts testify to her general health. The most remarkable
circumstance was the absence of sclerosis of the arteries, although
such degeneration is usually believed to be a normal character of old
age.

Analysis of the urine, made on several occasions, showed that the
kidneys were affected with a chronic disease, which, however, was not
serious.[2]

Although the sense of taste was weak, Madame Robineau had a fair
appetite. She ate and drank little, but her diet was varied. She
took butcher’s meat or chicken extremely seldom, but ate eggs, fish,
farinaceous food, vegetables, and stewed fruit, and drank sweetened
water with a little white wine, and sometimes, after a meal, a small
glass of dessert wine. The processes of alimentary digestion and
excretion were normal.

It has sometimes been thought that duration of life is a hereditary
property. There was no evidence for this in the present case. Madame
Robineau’s relatives had died comparatively early in life, and a
centenarian was unknown in her family. Her great age was an acquired
character. Her whole life had been extremely regular. She had married a
timber merchant, and had lived for many years in a suburb of Paris in
comfortable circumstances. Her character was gentle and affectionate;
she was thoroughly domesticated, and had been devoted to home life with
very few distractions.

At the age of 106 years, her intelligence suddenly became weak. She
lost her memory almost completely, and sometimes wandered. But her
gentle and affectionate disposition remained unaltered.

The appearance of aged persons is too well known to make detailed
description necessary. The skin of the face is dry and wrinkled and
generally pale; the hairs on the head and the body are white; the back
is bent, and the gait is slow and laborious, whilst the memory is weak.
Such are the most familiar traits of old age. Baldness is not a special
character; it often begins during youth and naturally is progressive,
but if it has not already appeared, it does not come on with old age.

The stature diminishes in old age. As the result of a series of
observations, it has been established that a man loses more than an
inch (3·166 cm.), and a woman more than an inch and a half (4·3 cm.),
between the ages of fifty and eighty-five years. In extreme cases,
the loss may be nearly three inches. The weight also becomes less.
According to Quételet, males attain their maximum weights at the age of
forty, females at that of fifty. From the age of sixty years onwards,
the body becomes lighter, the loss at eighty being as much as thirteen
pounds.

Such losses of height and weight are signs of the general atrophy of
the aged organism. Not merely the soft parts, such as the muscles and
viscera, but even the bones lose weight, in the latter case the loss
being of the mineral constituents. This process of decalcification
makes the skeleton brittle, and is sometimes the cause of fatal
accidents.

The loss of muscular tissue is specially great. The volume diminishes,
and the substance becomes paler; the fat between the fibres is
absorbed, and may disappear completely. Movements are slower, and
the muscular force is abated. This progressive degeneration has been
examined by dynamometrical measurements of the hand and the trunk, and
is greater in males than in females.

The volumes and weights of the visceral organs similarly become
smaller, but the diminution is not uniform.

The old age of lower mammals presents characters similar to those found
in man. I can now give other instances than the case of the old dog
which I described in the “Nature of Man.”

I will first take the case of old elephants, described by a competent
observer. “The general appearance is wretched, the skull being often
hardly covered with skin; there are deep abrasions under the eyes, and
smaller ones on the cheeks, whilst the skin of the forehead is very
often deeply fissured or covered with lumps. The eyes are usually dim,
and discharge an abnormal quantity of water. The margin of the ears,
specially on the lower side, is usually frayed. The skin of the trunk
is roughened, hard, and warty, so that the organ has lost much of its
flexibility. The skin on the body generally is worn and wrinkled; the
legs are thinner than in maturity, the huge mass of muscles being much
shrunken, whilst the circumference, especially just above the feet, is
considerably reduced. The skin round the toe-nails is roughened and
frayed. The tail is scaly and hard, and the tip is often hairless.

[Illustration: FIG. 2.—A Mare, thirty-seven years old.]

[Illustration: FIG. 3.—A White Duck, which lived for more than a
quarter of a century.]

Horses begin to grow old much sooner than elephants. I reproduce (Fig.
2) the photograph of a rare instance of longevity, a mare 37 years
old, which belonged to M. Métaine, in the department of Mayenne. The
skin, bare in places, but elsewhere covered with long hairs, shows
considerable atrophy. The general attitude reveals the feebleness
of the whole body. Many birds, on the other hand, show at similar
ages very slight external change, as may be seen from the photograph
of a duck more than 25 years old (Fig. 3) which belonged to Dr.
Jean Charcot. At a still greater age, as may be seen occasionally
in parrots, the general debility of the body reveals itself in the
attitude, in the condition of the feathers, and in the swelling of the
joints. On the other hand, the oldest reptiles which have been observed
do not differ in appearance from normal adults of the same species. I
have in my possession a male tortoise (_Testudo mauritanica_) given me
by my friends MM. Rabaud and Caullery, and which is at least 86 years
old. It shows no sign of old age, and in all respects behaves like
any other individual of this species. More than 31 years ago it was
wounded by a blow, the traces of which remain visible on the right side
of the carapace (Fig. 4). In the last three years the tortoise lived in
a garden at Montauban, along with two females which laid fertile eggs.
The old male, although, as I have said, probably at least 86 years of
age, was still sexually healthy.

[Illustration: FIG. 4.—An Old Land-tortoise.]

I have borrowed from the interesting volume of Prof. Sir E. Ray
Lankester[3] the figure (Fig. 5) and description of a giant tortoise
from the island of Mauritius, which is probably the oldest of all
living animals. It was brought to Mauritius from the Seychelles in
1764, and has lived since then in the garden of the Governor, and as it
has thus already been 140 years in captivity, its age must be at least
150 years, although we have not exact information. Notwithstanding
this, it shows no signs of old age.

The examples which I have brought together show that often amongst
vertebrates there are some animals the organisms of which withstand
the ravages of time much better than that of man. I think it a fair
inference that senility, the precocious senescence which is one of
the greatest sorrows of humanity, is not so profoundly seated in the
constitution of the higher animals as has generally been supposed. It
is not necessary, therefore, to discuss at length the general question
as to whether senile degeneration is an inevitable event in living
organisms.

[Illustration: FIG. 5.—A Water-tortoise, more than 150 years old.

(After Prof. Sir E. Ray Lankester.)]

I have already shown, in the “Nature of Man,” the difference which
exists between senile degeneration in our own bodies and the phenomena
of senescence amongst Infusoria which, as M. Maupas described, are
followed by a process of rejuvenescence. According to the more recent
results of several investigators, the difference is still greater than
I had supposed. Enriquez[4] has been able to propagate Infusoria to
the 700th generation without any sign of senility being displayed. Here
we are far from the condition in the human race.

R. Hertwig,[5] one of the best observers of the lower animals, has
recently attempted to show that the very simple animalculæ of the genus
_Actinosphærium_ are subject to true physiological degeneration. He
has several times seen cultures of this Rhizopod degenerate, until all
the individuals had died, notwithstanding the presence of abundant
food. Prof. Hertwig attributed this to the “constitution of the
_Actinosphærium_ having been weakened by too great vital activity
at an earlier stage.” I should have thought that it was a much more
natural explanation to suppose that the culture had undergone infection
by one of the contagious diseases which so often destroy cultures of
different kinds of lower animals and plants. As this idea had not
occurred to the observer, he had not searched for parasitic microbes
amongst the granulations which are always present in the body of an
_Actinosphærium_. However this may be, I cannot accept the facts
brought forward by this distinguished German as a valid proof of the
existence of senile degeneration in these lowly creatures.

The facts that I have brought together in this chapter justify the
conclusion that human beings who reach extreme old age may preserve
their mental qualities notwithstanding serious physical decay.
Moreover, it is equally plain that the organism of some vertebrates is
able to resist the influence of time much longer than is the case with
man under present conditions.

THEORIES OF CAUSATION OF SENILITY

Hypothesis of the causation of senility—Senility
cannot be attributed to the cessation of the power
of reproduction of the cells of the body—Growth of
the hair and the nails in old age—Inner mechanism of
the senescence of the tissues—Notwithstanding the
criticisms of M. Marinesco, the neuronophags are true
phagocytes—The whitening of hair and the destruction of
nerve cells, as arguments against a theory of old age
based on the failure of the reproductive powers of the
cells

Although it has not been proved that living matter must inevitably
undergo senile decrepitude, it is none the less true that man and his
nearest allies generally exhibit such degeneration. It is therefore
extremely important to recognise the real causes of our senescence.
There have been many hypotheses on the subject, but there are
comparatively few definite facts known.

Bütschli has supposed that the life of cells is maintained by a
specific vital ferment which becomes feebler in proportion to the
extent of cellular reproduction, but I cannot regard this as more than
a pious opinion. The ferment has never been seen, and we do not know
of its actual existence. According to the better-known theory of Prof.
Weismann, old age depends on a limitation in the power of cells to
reproduce, so that a time comes when the body can no longer replace
the wastage of cells which is an inevitable accompaniment of life. As
old age appears at different times in different species and different
individuals, Weismann has concluded that the possible number of cell
generations differs in different cases. He has not found, however,
a solution of the problem as to why multiplication of cells should
cease in one individual, whereas it proceeds much further in other
individuals. Prof. Minot,[6] the American zoologist, has developed
a similar theory, and has employed an exact method to determine the
gradual diminution in the rate of growth of an animal from its birth
onwards. According to him, the power of reproduction of the cells
weakens progressively during life, until a point is necessarily reached
at which the organism, no longer capable of repairing itself, begins to
atrophy and degenerate. Dr. Buehler[7] has recently laid stress upon
this theory.

There is no doubt that cells reproduce much more actively during the
embryonic period. The process becomes slower later on, but, none the
less, continues to display itself throughout the whole period of life.
Buehler attributes the difficulty with which certain wounds heal in the
case of old people to the insufficiency of cellular reproduction. He
thinks in particular that the proliferation of the cells of the skin,
to replace those which are worn off from the surface, becomes less
active with age. According to him, it is theoretically obvious that a
time must come when the replacement of the epidermic cells completely
ceases. As the superficial layers of the skin continue to dry up and
be cast off, it is plain that the epidermis must disappear completely.
Buehler thinks that there must be a similar fate for the genital
glands, the muscles, and all the other organs.

These theoretical considerations, however, are not compatible with
certain well-known facts indicating that there is no general cessation
of the power of cell reproduction in old age. The hairs and the nails,
which are epidermic outgrowths, continue to grow throughout life, their
growth being due to the proliferation of their constituent cells. There
is no sign of any arrest in the development of these structures, even
in the most advanced old age. The reverse is true. It is well known
that the hairs on some parts of the body increase in number and in
length in old people. In some lower races, for instance in the Mongols,
the moustache and the beard grow vigorously in old age, whilst young
people of the same race have only very small moustaches and practically
no trace of beard. So also in white women the fine and almost invisible
down which covers the upper lip, the chin, and the cheeks in the young
may become replaced by long hairs which form a moustache or beard.

Dr. Pohl, a specialist in the growth of hair, has measured the rate of
growth in different circumstances. He has shown that in an old man of
61 the hair on the temple grew 11 mm. in a month; on the other hand,
the hair on the same region in boys of 11 to 15 years old grew in
the same time only from 11 to 12 mm. Plainly, there is no case here
of a progressive diminution of cell-proliferation with age. The same
observer, it is true, has shown that the hair of young men of between
21 and 24 years grew at the rate of 15 mm. a month, whilst in the same
individuals, at the age of 61 years, the rate of growth was only 11
mm.; but this diminution in the rate of growth is only apparent. The
first figure concerned the hair taken from different regions of the
scalp, whilst the second related only to the hair on the temples, and
Dr. Pohl himself has shown that, in the latter region, the hair grows
slower than in other regions. Moreover, in many boys of 11 to 15 years
old, studied by this observer, the rate of growth was always less than
15 mm., and often less even than the 11 mm. recorded in the old man of
61.

I have been able to note that the nails grow even in very old people.
In the case of Mme. Robineau, the centenarian, the nail of the middle
finger of the left hand grew 2-1/2 mm. in three weeks. In the case of a
lady of 32 years old, the corresponding nail grew 3 mm. in two weeks,
the difference being out of all proportion to the enormous difference
in the age. The centenarian’s nails had to be cut from time to time.

Although the hairs of old people grow, they become white, which is a
phenomenon of senile degeneration. Although they increase in length,
the colouring matter in them becomes reduced and finally disappears.
In the “Nature of Man” I described the process by which this blanching
takes place, and which may now be regarded as definitely proved. It is
useful as a means of interpreting the real nature of the process of
senescence. In several published works, I have explained my belief that
just as the pigment of the hair is destroyed by phagocytes, so also the
atrophy of other organs of the body, in old age, is very frequently
due to the action of devouring cells which I have called macrophags.
These are the phagocytes that destroy the higher elements of the body,
such as the nervous and muscular cells, and the cells of the liver and
kidneys. This part of my theory has encountered very strong criticism,
especially with regard to the part played by the macrophags in the
senescence of nervous tissue.

Neurologists in particular, have criticised my interpretation. For
several years M. Marinesco[8] has attacked my theory of the atrophy
of the nerve-cells in old age. In the first place, he has stated that
in old people, and even if these are very old, it is rare to find
phagocytes surrounding and devouring the cells of the brain. In support
of this contention, he has been good enough to send me two preparations
made from the brains of two very old persons. After careful examination
I was convinced that my opponent had been inexact. In the brain of the
two centenarians (one of whom died at the age of 117 years) there were
very many nerve-cells surrounded by phagocytes and in process of being
destroyed by them. It happened, however, that as the sections were very
weakly stained, it was more difficult to observe the facts than in the
preparations upon which I had made my own observations. I have already
recorded this fact in the second and third French editions of the
“Nature of Man.”

Without taking notice of my reply, M. Marinesco has published another
criticism of my theory in an article[9] entitled “Histological
Investigations into the Mechanism of Senility.” In that work, although
he himself had invented the designation “neuronophag” for a phagocyte
that devours nerve-cells, he denies the existence of such a power.
He thinks that nerve-cells atrophy independently of the cells that
surround them. The latter, the so-called neuronophags, only contribute
to the atrophy inasmuch as they press against the nerve-cells and
deprive them of nutrition. He is confident that the constituent parts
of nerve-cells are never found in the neuronophags. There is no
question of phagocytosis, of the existence of cells that devour their
neighbours.

M. Léri has taken a similar view in a Report on the Senile Brain[10]
presented to a recent congress of alienists and neurologists.
According to him “the nuclei which surround some of the atrophying
nerve-cells do not play the part of neuronophags.” In his monograph
“La Neuronophagie,”[11] M. Sand elaborates the same view. He relies
on his observation that “neuronophags are usually either devoid
of protoplasm or display only a very thin layer of it. They never
exhibit protoplasmic outgrowths, and they never have granules in their
cellular bodies (p. 86).” Still more recently MM. Laignel-Lavastine and
Voisin[12] have taken the same view, maintaining that the neuronophags
do not display phagocytosis.

Although I cannot undertake here to give a detailed reply to the
arguments of my critics, I may point out a fallacy that vitiates
their reasoning. The study of the intimate structure of nervous
tissue involves the treatment of that very delicate substance by
numerous active reagents. It is extremely important not to forget the
possibility of alterations which may be produced in the processes of
preparation and which are extremely difficult to avoid. A glance at
the figures given by my critics shows me that the neuronophags in
their preparations had been subjected to violent treatment. When M.
Léri speaks of “the nuclei which surround some of the nerve-cells,”
and M. Sand of “cells without protoplasm,” it is clear that they had
been observing cells destroyed by the processes of the laboratory.
The illustrations in the memoir of M. Marinesco show that in his
preparations, too, the neuronophags had been very greatly altered.

It is well known that nuclei do not exist free in tissues, and that
when they appear devoid of protoplasm, there has been some defect in
the technical methods of preparing them for examination. As a matter
of fact, neuronophags do not consist of nuclei with at the most a
pellicle of protoplasm; like other cells, they have protoplasmic bodies
which, however, are frequently destroyed by the violent processes of
histological preparation.

The arguments of my critics recall to me the words of a medical
student, who, on being asked to describe the microbe of tuberculosis,
said that it was a little red bacillus. The bacillus in question, like
most bacilli, is colourless, but it is usual to stain it so that it
may be visible under the microscope. The student, knowing it only in
particular preparations, had a false idea of its appearance.

In well-made preparations, neuronophags are typical cells with abundant
protoplasm. When they have been preserved by a process that does
not dissolve their contents, they show granules like those found in
nerve-cells.

To study neuronophagy, M. Manouélian,[13] in the laboratory of the
Pasteur Institute in Paris, set himself to improve the technical
methods of preparation. He succeeded in showing first that in the
destruction of nerve-cells that occurs in cases of hydrophobia, the
contents of these cells are absorbed by the surrounding neuronophags.
“My observations on the cerebro-spinal ganglia of human cases of
hydrophobia,” he wrote, “show clearly that the macrophags act as
phagocytes of the nerve-cells.” “Most of the cells in the nerve-ganglia
contain yellow, brown, and black pigmented granules, usually united
in small masses. What becomes of these granulations on the destruction
and disappearance of the nerve-cell? If, as M. Marinesco has it, there
is no phagocytosis by the surrounding cells, but merely a mechanical
interference, then the granules, on the destruction of the nerve-cells
that contained them, should be found lying in the interstitial tissue.
But this does not happen. The granules are ingested by cells which are
true macrophags.”

By the aid of a very delicate mode of preparation, M. Manouélian has
shown that in the case of senile brains the granules of the nerve-cells
are absorbed by neuronophags. I have myself studied M. Manouélian’s
preparations and can testify to the accuracy of his observations (Figs.
6 and 7).

Doubt is no longer possible. In senile degeneration the nerve-cells are
surrounded by neuronophags which absorb their contents and bring about
more or less complete atrophy. It has been supposed that in order to
devour their contents, the neuronophags must penetrate the nerve-cells,
and such an event has rarely been seen. But it is well known, the
phagocytosis of red blood corpuscles being a typical instance, that
to absorb a cell a phagocyte does not necessarily engulf it bodily or
penetrate it, but may gradually denude it of its contents merely by
resting in contact with it.

There has been some discussion as to the condition of nerve-cells which
are on the point of being devoured by neuronophags. It has been noticed
that such cells may display a considerable amount of degeneration
without being devoured, whilst, on the other hand, cells apparently
normal have been found undergoing phagocytosis. As I cannot state
definitely what are the conditions that induce the phagocytosis of
nerve-cells, I shall not attempt a discussion of the problem.

Although the destruction of nerve-cells by neuronophags is a general
occurrence in senile brains, one may conceive of cases where this does
not occur. And so, in old people who have preserved their faculties,
it may well be that the neuronophags have refrained from attacking the
nerve-cells. But as such instances are rare, so also phagocytosis is
usually found in senile brains, and I cannot accept M. Sand’s denial of
its existence, based on his study of two cases.

[Illustration: FIG. 6.]

[Illustration: FIG. 7.

FIGS. 6. & 7.—Two nerve-cells from the cortex of the brain of an old
dog aged fifteen years.

The neuronophags surrounding the nerve-cells contain numerous
granulations.

(From preparations made by M. Manouélian.)]

The general result of my investigation into the criticisms that
have been published on this matter has confirmed me in my belief
that neuronophagy plays a most important part in senescence, and
recent observations that I have made with M. Weinberg have completely
supported this view.

The bleaching of hair and the atrophy of the brain in old age thus
furnish important arguments against the view that senescence is the
result of arrest of the reproductive powers of cells. Hairs grow old
and become white without ceasing to grow. The cessation of the power of
reproduction cannot be the cause of the senescence of brain-cells, for
these cells do not reproduce even in youth.

III

MECHANISM OF SENILITY

Action of the macrophags in destroying the higher
cells—Senile degeneration of muscular fibres—Atrophy
of the skeleton—Atheroma and arterial sclerosis—Theory
that old age is due to alteration in the vascular
glands—Organic tissues that resist phagocytosis

The instances which I have selected in attempting to describe the
mechanism of senescence of the tissues are not the only cases in which
the importance of phagocytosis is evident. The blanching of hair is
due to the destructive agency of chromophags; in atrophy of the brain
neuronophags destroy the higher nerve-cells. In addition to these
instances of phagocytosis, in which the active agents belong to the
category of macrophags, there are many other devouring cells, adrift
in the tissues of the aged, and ready to cause destruction of other
cells of the higher type. The phagocytic action is not so manifest as
in the case of infectious diseases, partly because it is the method of
macrophags to absorb the contents of the higher cells extremely slowly.
The mode of action is well seen in the atrophy of an egg-cell (Fig. 8),
where the surrounding macrophags gradually seize hold of the granules
within it and carry these off. As the process goes on, the ovum becomes
reduced to a shapeless mass, and finally leaves only a few fragments,
or disappears completely. M. Matchinsky[14] has studied the series of
events in my laboratory, and I am myself well assured of the importance
of the action of macrophags in the atrophy of the ovary.

[Illustration: FIG. 8.—Ovum of a Bitch in process of destruction by
Phagocytes, which are full of fatty granules.

(After M. Matchinsky.)]

The phenomena of atrophy in general and of senile decay afford other
cases of tissue destruction in which the phagocytic character of the
process is more modified and obscure than in nerve-cells and ova.

It is well known that progressive muscular debility is an accompaniment
of old age. Physical work is seldom given to men over sixty years
of age, as it is notorious that they are less capable of it. Their
muscular movements are feebler and soon bring on fatigue; their actions
are slow and painful. Even old men whose mental vigour is unimpaired
admit their muscular weakness. The physical correlate of this
condition is an actual atrophy of the muscles, and has for long been
known to observers. More than half a century ago, Kölliker,[15] one of
the founders of histology, devoted some attention to this matter, and
described the senile modification of muscular tissue in the following
words:—“In old age there is a true atrophy of the muscles. The fibres
are much more slender; there are deposited in their substance numerous
yellow or brown granules and many globular nuclei. These nuclei are
frequently arranged in longitudinal series and present such signs of
active division as are found in embryonic tissue.”

Other investigators afterwards made similar observations. Vulpian[16]
and Douaud[17] have stated that a multiplication of nuclei takes places
in the atrophying muscles of the old.

As the senile degeneration of muscular tissue appeared to be important
in my study of the mechanism of senescence, M. Weinberg and I
examined several cases of muscular atrophy in old human beings and
lower animals. We were able to recognise the phenomena observed by
our predecessors. In senile atrophy the muscular fibres contain many
nuclei, and these, increasing rapidly, bring about an almost complete
disappearance of the contractile substance (Fig. 9). The fibres
preserve their striation for a certain time but eventually lose it and
appear to contain an amorphous mass with numerous, rapidly multiplying
nuclei.

[Illustration: FIG. 9.—Degeneration of striated muscle Fibres from the
auricular muscle of a man aged 87 years.

(From a preparation made by Dr. Weinberg.)]

The investigators who had recorded these facts thought of them only as
curious. It is plain, in the first place, however, that this remarkable
and rapid multiplication is a proof that senile atrophy is not due to
failure of cell proliferation, although the latter has frequently been
suggested as the mechanism of senescence. In muscular atrophy, cell
multiplication, so far from failing, greatly increases. We may add
muscular atrophy to the blanching of hair and the decay of nerve-cells
as another instance showing that senile degeneration is not the result
of cells ceasing to be able to multiply. Just as in the atrophy
of the brain there is an increase in the volume of neuroglœa,
the substance in which the neuronophags are found, so also in the
atrophy of the muscles there is an increase of muscular nuclei. Along
with the increase of nuclei, however, there is an increase of the
protoplasmic substance of the fibres known as sarcoplasm. The latter
replaces the myoplasm, the specific striated substance of muscles, by
a process which must be regarded as parallel with phagocytosis. In a
normal muscle the two substances and the sarcoplasmic nuclei are in
equilibrium, but in old age the sarcoplasm and its nuclei increase at
the expense of the myoplasm. The equilibrium is destroyed with the
result that the muscular power is weakened. In these conditions the
sarcoplasm acts phagocytically with regard to the myoplasm, just as the
chromophag becomes the phagocyte of the pigment of the hair, or the
neuronophag devours the nerve-cell.

The investigation of other cases of muscular atrophy, as, for instance,
that of the caudal muscles of frog-tadpoles, confirms the significance
of the process that I have observed in old age. In the two cases, what
takes place is the destruction of the contractile material of the
muscles by myophags, a special kind of phagocyte.

It is one of the curiosities of senile atrophy that whilst there is
hardening or sclerosis of so many organs, the skeleton, the most
solid part of our frame-work, becomes less dense, so that the bones
are friable, the condition often leading to serious accidents in old
people. The bones become porous, and lose weight. It is difficult to
believe that macrophags, although they destroy softer elements such
as nerve-cells or muscle fibres, can be able to gnaw through a hard
material like bone impregnated with mineral salts. As a matter of fact,
the mechanism of bone atrophy must be placed in a different category
from the phagocytosis of other organs. It is brought about, however,
by the agency of cells very like some of the macrophags. These cells
contain many nuclei, and are known as osteoclasts. They form round
about the bony lamellæ and lead to their destruction, but are incapable
of breaking off fragments of bone and dissolving them in their
interiors. Although the intimate mechanism of this destructive action
is not thoroughly understood, it seems probable that the cells secrete
some acid which softens bone by dissolving the lime salts. The process
can be observed in the different varieties of caries of the bone, and
in the bony atrophy of old age as is represented in Fig. 10.

By the action of the osteoclasts, which themselves are macrophags, part
of the lime in the skeleton is dissolved during old age and passes into
the general circulation. This is probably a source of the lime which is
deposited so readily in the different tissues of old people. Whilst the
bones become lighter, the cartilages become bony, the inter-vertebrate
discs in particular becoming impregnated with salts, so that the
well-known senile malformation of the backbone is produced.

[Illustration: FIG. 10.—Destruction by osteoclasts of bony matter in
the sternum of a man aged 81 years.

(From a preparation made by Dr. Weinberg.)]

As a result of this displacement of lime in old age, the blood-vessels
become modified in a distinctive fashion. Atheroma of the arteries
is not invariable in old people, but it occurs extremely frequently.
In this form of degeneration, lime salts are deposited in the walls
of the cells, so that they become hard and friable. Several others,
among whom I may mention Durand-Fardel and Sauvage, have laid stress
on the coincidence of atheromatous lesions of the arteries and senile
degeneration of the bones. The relations between the two alterations
are very evident in the skull; the meningeal artery becomes sinuous and
atheromatous, and the grooves on the inner side of the bones of the
skull in which it runs, flatten out, and become larger because of other
malformations.[18]

There is no disharmony in the nature of old people so striking as this
transference of the lime salts from the skeleton to the blood-vessels,
producing as it does a dangerous softening of the former, and a
hardening of the latter that interferes with their function of carrying
nutrition to the organs. It is the manifestation of an extraordinary
disturbance of the properties of the cells that compose the body. The
atheromatous condition of the arteries is closely linked with arterial
sclerosis, an affection which is very common, although not constant,
in the aged. The whole question of these vascular alterations is
extremely complex, and before it can be cleared up, a number of special
investigations must be made.

Probably diseases of the arteries of different kinds, and arising from
different causes, are grouped under the terms atheroma and sclerosis.
In some cases the lesions are inflammatory and are due to the poisons
of microbes. An example of such an origin is the case of syphilitic
sclerosis, in which the specific microbes (spirilla of Schaudinn) lead
to precocious senescence. In other cases the arteries show phenomena of
degeneration resulting in the formation of calcareous platelets which
interfere with the circulation of the blood.

Investigations which have been made in recent years have led to very
interesting results concerning the origin of atheroma of the arteries.
In most cases, attempts to produce such lesions of the arteries by
experimental methods have not succeeded, but M. Josué[19] has been
able to produce true arterial atheroma in rabbits by injecting into
them adrenaline, the secretion of the supra-renal capsules.

This experiment has been repeated many times and is now well known.
Later on, M. Boveri[20] obtained a similar result by injecting
nicotine, the poison of tobacco. It is obvious, therefore, that amongst
the arterial diseases which play so great a part in senescence, some
are chronic inflammations produced by microbes, whilst others are
brought about by poisons introduced from without.

It is easy to understand, therefore, why these diseases of the arteries
are not always present in old age, although they are very common.

The part played by the secretion of the supra-renal glands in the
production of arterial disease has brought renewed attention to a
theory which supposed that certain glandular organs in the body play
a preponderating part in senile degeneration. Dr. Lorand[21] in
particular has argued that “senility is a morbid process due to the
degeneration of the thyroid gland and of other ductless glands which
normally regulate the nutrition of the body.” It has long been noticed
that persons affected with myxodema, as a result of the degeneration
of the thyroid gland, look like very old people. Everyone who has seen
the cretins in Savoy, Switzerland, or the Tyrol, must have noticed the
aged appearance of these victims, although very often they are quite
young. The condition of cretinism, with its profound bodily changes,
is the result of degeneration of the thyroid gland. On the other hand,
it is well known that in old people the thyroid and the suprarenals
frequently show cystic degeneration. It is quite probable, therefore,
that these so-called vascular glands have their share in producing
senility. Many facts show that they destroy certain poisons which have
entered the body, and it is easy to see that, if they have become
functionless, the tissues are threatened with poisoning. It does not
follow, however, that their action in producing senility is exclusive,
or even preponderating. M. Weinberg, at the Pasteur Institute, made
special investigations on this point, and found that the thyroid gland
and the supra-renal capsules were almost invariably normal in old
animals (cat, dog, horse), although the latter showed unmistakable
signs of senility. Similarly in an old man of 80 years, who died from
pneumonia, the thyroid gland was quite normal.

It must not be forgotten that the aged very often die from infectious
diseases such as pneumonia, tuberculosis, and erysipelas. In these
diseases the vascular glands generally, and the thyroid gland in
particular, are very often affected, with the result that what is due
to infection has been set down as a symptom of old age.[22]

Although the appearance of patients from whom the thyroid gland has
been removed, or in whom it has degenerated spontaneously, recalls
that of old people, it is possible to exaggerate the similarity. In
the masterly accounts of such unfortunates, recently compiled by
the well-known surgeon Kocher[23] there are many points which are
characteristic, without being typical, of old people.

Oedema of the skin which characterises thyroid patients is by no
means usual in old age. The loss of hair, normal in the patients, is
not a character of old age. In myxedematous women, menstruation is
very active; it ceases in old women. The great muscular development of
myxedematous patients distinguishes them from old people.

Physiological investigation does not support the existence of any
strong affinity between old age and affection of the thyroid gland. It
is known that removal of the thyroid is followed by cachexia only in
young subjects, MM. Bourneville and Bricon[24] having shown that the
tendency to cachexia after extirpation of the thyroid ceases almost
abruptly at the age of thirty. That age may be taken as the limit of
youth, of the time when growth is vigorous and the function of the
thyroid most active. Cases of cachexia, where the thyroid gland has
been removed in old persons from fifty to seventy, are very rare.

Rodents (rats, rabbits) support the removal of the thyroid extremely
well, without signs of cachexia, although these are normally
short-lived creatures. According to Horsley[25] extirpation of the
thyroid is not followed by cachexia in birds or rodents and is followed
by it only very slowly in ruminants and horses; it produces the
condition invariably but slightly in man and monkeys and extremely
seriously in carnivora. If this series be compared with the information
given in the next section of this volume on the relative ages which
the animals in question attain, it will be seen that there is no
correspondence.

In short, whilst I do not deny that the vascular glands may take a
share in the causation of senility, in so far as they are destroyers
of poisons, I cannot agree with the theory of Dr. Lorand.

[Illustration: FIG. 11.—Testis tissue from a dog aged twenty-two years.

(From a preparation made by Dr. Weinberg.)]

I think it indubitable that in senescence the most active factor is
some alteration in the higher cells of the body, accompanied by a
destruction of these by macrophags which gradually usurp the places of
the higher elements and replace them by fibrous tissue. Such a process
affects the organs of secretion (kidneys), the reproductive organs, and
in a modified form the skin, the mucous membranes, and the skeleton.
The testes are amongst the organs which resist invasion by macrophags.
I have already given an example (“The Nature of Man,” p. 98) of an old
man of 94 in whom active spermatozoa were produced. I know of a similar
case, the age being 103 years. Such cases are not rare, and not only
in old men, but in old animals, the testes continue to be active. Dr.
Weinberg and I have investigated these organs in a dog which died at
the age of 22 years after several years of pronounced senility. Many of
the organs of the animal exhibited serious invasions by macrophags but
the testes were extremely active, the cells being in free proliferation
and producing abundant spermatozoa (Fig. 11). In harmony with this
condition of the sexual organs, the sexual instincts of the animal
remained normal. We have investigated another dog which died at the age
of eighteen years. In this case the testes were cancerous and there was
no possibility of the production of spermatozoa. None the less, this
dog although markedly senile (Fig. 12) still showed sexual instincts
until shortly before it died.

[Illustration: FIG. 12.—An old dog, aged eighteen years.]

It is manifest that the tissues do not invariably degenerate in
old age, nor do all the organs that are modified in old age show
destruction by phagocytes and replacement by connective tissue. Organs
which produce phagocytes, such as the spleen, the spinal marrow and
the lymphatic glands, certainly show traces in old age of fibrous
degeneration but remain sufficiently active to produce macrophags which
destroy the higher cellular elements of the body. I have frequently
noticed cell division in such organs, and as an example may give the
case of the bone marrow taken from a man of 81 years (Fig. 13).

The eye is an organ that is modified in old age without the action of
macrophags. Cataract and the senile arc which appears as a milky ring
at the edge of the cornea are frequent in old age. These modifications
are due to impregnation of the parts affected by fatty matter which
makes them opaque. This deposition of fat[26] has been attributed to
defective nutrition. In most organs such fatty degeneration is followed
by phagocytosis, but the cornea and the crystalline lens are exempt
from this consequence for anatomical reasons. Most organs possess in
addition to their higher elements a constant source of macrophags.
Such a source of phagocytosis is the neuroglœa in nervous tissues,
the sarcoplasm in muscular tissues; the bones contain osteoclasts and
the liver and the kidneys are readily invaded by phagocytes from the
blood. The lens and the cornea have no cells that are able to become
macrophags.

[Illustration:

FIG. 13.—Bone marrow from the sternum of a man aged
eighty-one years.

(From a preparation made by Dr. Weinberg.)]

Some infectious diseases bring about precocious senility. A syphilitic
child is “a miniature old man, with wrinkled face, skin dull and
discoloured and flabby and hanging in folds as if it were too
large.”[27] In such a case the active agent is the microbe of syphilis
which has poisoned the child on the breast of its mother. It is no
mere analogy to suppose that human senescence is the result of a slow
but chronic poisoning of the organism. Such poisons, if not completely
destroyed or eliminated, weaken the tissues, the functions of which
become altered or enfeebled, so that, amongst other changes, there
is deposition of fatty matter. The phagocytes resist the influence of
invading poisons better than any of the other cells of the body and
sometimes are stimulated by them. The general result of such conditions
is that there comes to be a struggle between the higher cells and the
phagocytes in which the latter have the advantage.

The answer to the question as to whether our senescence can be
ameliorated must be approached from several points of view. This course
I shall now follow.

PART II

LONGEVITY IN THE ANIMAL KINGDOM

THEORIES OF LONGEVITY

Relation between longevity and size—Longevity and the
period of growth—Longevity and the doubling in weight
after birth—Longevity and rate of reproduction—Probable
relation between longevity and the nature of the food

The duration of the life of animals varies within very wide limits.
Some, as for instance, the males of certain wheel animalculæ (Rotifera)
complete their cycle of life from birth to death in 50 or 60 hours,
whilst others, like some reptiles, live more than 100 years, and quite
possibly may live for two or three centuries.

Enquiry has been made for many years as to whether there are laws
governing these different durations of life. Even the most casual
observation of domesticated animals has shown that, as a general rule,
small animals do not live so long as large ones; mice, guinea pigs, and
rabbits for instance, have shorter lives than geese, ducks, and sheep,
whilst these again are survived by horses, deer, and camels. Of all the
mammals which have lived under the protection of man, the elephant is
at once the largest, and the most long-lived.

However, it is not difficult to show that there is no absolute relation
between size and longevity, since parrots, ravens, and geese live much
longer than many mammals, and than some much larger birds.

As a general rule it may be said that a large animal takes more time
than a small one to reach maturity, and it has been inferred from this
that the length of the periods of gestation and of growth were in
proportion to the longevity. Buffon[28] long ago stated his opinion
that the “total duration of life bore some definite relation to the
length of the period of growth.” Therefore, as the period of growth is,
so to say, inherent in the species, longevity would have to be regarded
as a very stable phenomenon. Just as any species has acquired a fixed
and practically invariable size, so it would have acquired a definite
longevity. Buffon, therefore, thought that the duration of life did
not depend on habits or mode of life, or on the nature of food, that,
in fact, nothing could change its rigid laws, except an excess of
nourishment.

Taking as his standard the total period of development of the body,
Buffon came to the conclusion that the duration of life is six or seven
times that of the period of growth. Man, for instance, he said, who
takes 14 years to grow, can live 6 or 7 times that period, that is
to say, 90 or 100 years. The horse, which reaches its full size in 4
years, can live 6 or 7 times that length of time, that is to say from
25 to 30 years. The stag takes 5 or 6 years to grow, and reckoned in
the same way, its longevity should be 35 to 40 years.

Flourens[29] although supporting his principle, thought that Buffon
had been inexact in calculating the period of growth. In his opinion
a better result can be obtained by taking the limit of growth as that
age at which the epiphyses of the long bones unite with the bones
themselves. Using such a mode of computation, Flourens laid down that
an animal lived 5 times the length of its period of growth. Man, for
instance, takes 20 years to grow, and he can live for 5 times that
space, that is to say, 100 years; the camel takes 8 to grow, and lives
5 times as long, _i.e._, 40 years; the horse, 5 to grow, and lives 25
years.

However, even if we consider only the mammalia, it is impossible to
accept Flourens’ law, without considerable reserve. Weismann[30] has
referred to the case of the horse, which is completely adult at 4, but
lives not merely 5 times that period, but 10 or even 12 times. Mice
grow extremely quickly, so that they are able to reproduce at the age
of 4 months. Even if we take 6 months as their period of growth, their
longevity of 5 years is twice as long as it would be according to the
rule of Flourens. Amongst domesticated animals, the sheep is slow in
reaching maturity; it does not acquire its adult set of teeth until it
is 5 years old, and cannot be regarded as adult until then. None the
less, at the age of 8 or 10 years, it loses its teeth and begins to
grow old, whilst by 14 it is quite senile.[31] The longevity of the
sheep, therefore, is not quite three times its period of growth.

If we turn to other vertebrates, the variations in the relation of
growth and the duration of life are still greater. Parrots, for
instance, the longevity of which is extremely great, grow very quickly.
At the age of 2 years, they have acquired the adult plumage and are
able to reproduce, whilst the smaller species are in the same condition
at the age of one. Incubation, moreover, is very short, not more than
25 days, and in some species not three weeks. None the less, parrots
are birds which enjoy a quite remarkable longevity. The incubation
period of domestic geese is 30 days, and their period of growth is
also short. However, they may reach a great age, cases of 80 years and
of 100 years being on record. In contrast with these, ostriches, the
incubation period of which is 42 to 49 days, and which take 3 years to
become adult, have a relatively short life.

H. Milne-Edwards[32] many years ago contended that there was no
importance in the supposed law of relation between gestation and
longevity. He sums up his criticism as follows: “Although the period of
uterine life is longer in the horse, that animal does not live so long
as a human being; and some birds, the incubation of which only lasts a
few weeks, can live more than a century.”

Bunge[33] has recently taken up the study of the relations between the
duration of growth and longevity, and has suggested a new means of
investigation. He has observed that the period in which the new-born
mammal doubles its weight is a good index of the rapidity of its
growth. He has shown that whilst a human child requires 180 days to
reach double its weight at birth, the horse, the longevity of which is
very much less, doubles its weight in 60 days; a calf takes only 47
days for this; a kid 15 days; a pig 14 days; a cat 9-1/2; and a dog
only 9 days. Although these facts are very interesting, the exceptions
are too great to make it possible to base a law of longevity upon them.
The period of weight-doubling in the horse is nearly 7 times longer
than that in the dog, and yet the longevity of the horse is not more
than 3 times that of the dog. The goat, which takes much longer than
the dog to double its weight, has a shorter total life.

I observed myself that new-born mice quadruple their weight in the
first 24 hours. The doubling of weight in their case requires a time
36 times less long than that of the cat, and yet the cat lives only 5
times as long as the mouse.

It is fair to say, however, that Bunge himself does not draw a definite
conclusion from these figures and has published them only to stimulate
interest in the subject. He is against the view of Flourens, and points
out that although the multiple 5 is valid for man, it is not so in the
case of the horse which finishes its growth in 4 years and yet reaches
the age of 40 much less often than human beings attain that of 100
years.

Although it is impossible to admit the existence of exact relations
between size and the period of growth on the one side, and longevity
on the other, in the mode which Buffon and Flourens have followed,
it is none the less true that there is something intrinsic in each
kind of animal which sets a definite limit to the length of years it
can attain. The purely physiological conditions which determine this
limit leave room for a considerable amount of variation in longevity.
Duration of life therefore, is a character which can be influenced by
the environment. Weismann in his well-known essay on the duration of
life, has laid stress on this side of the problem. Longevity, according
to him, although in the last resort depending on the physiological
properties of the cells of which the organism is composed, can be
adapted to the conditions of existence and influenced by natural
selection, like other characters useful for the existence of the
species.

If a species is to remain in existence, its members must be able to
reproduce and the progeny must be able to reach adult life so that
they in their turn may reproduce. Now, it happens that there are some
animals the fecundity of which is extremely limited. Most birds which
are adapted to aerial life, and the weight of which is therefore to
be kept down, lay very few eggs. This happens in the case of birds
of prey, such as eagles and vultures. These birds nest only once a
year, and generally rear two or frequently only a single nestling.
In such circumstances the duration of life becomes a factor in the
preservation of the species, more important since eggs and chicks are
subject to many dangers. Eggs are devoured by many kinds of animals,
whilst unseasonable cold may kill the chicks. If the members of such
a species were incapable of living long, the unfavourable conditions
of life would soon lead to extinction. Those animals which reproduce
rapidly generally have a relatively brief duration of life. Mice, rats,
rabbits, and many other rodents seldom live more than 5 or 10 years,
but reproduce with enormous rapidity. It is almost possible to imagine
that there is some sort of intimate link, possibly physiological,
between longevity and low fertility. It is a current opinion that
reproduction wastes the maternal organism and that mothers of many
children grow old prematurely and seldom reach an advanced age.
This would seem to mean that fecundity was the cause of the short
duration of life. However, we must guard ourselves against such a
theory. Longevity, at least in the case of vertebrate animals, differs
extremely little in the two sexes, although the cost of the new
generation to the adult organism is very much greater in the case of
the female than of the male parent. None the less, females frequently
reach a great age, especially in the human race where women reach 100
years, or live beyond that time, much more often than men.

Low fertility, however, cannot itself be regarded as a cause of
longevity, as there are some very fertile animals which none the less
attain great ages. There are parrots which lay two or three times a
year, producing six to nine eggs in each clutch. The ducks (Anatidæ)
are distinguished for considerable longevity and very high fertility,
each nest containing rarely less than six and sometimes as many as
sixteen eggs. The common Sheldrake lays from twenty to thirty eggs.
Tame ducks, in some parts of the tropics, lay an egg daily throughout
the season. Wild ducks lay from seven to fourteen eggs in one nest.
Ducks and geese, none the less, frequently attain considerable ages,
ducks having been known to live for 29 years. Even the common fowl,
which is a notoriously prolific bird, may reach an age of twenty to
thirty years.

It will be said, however, that these birds are exposed to many enemies
during youth. Chickens, ducklings, and goslings are ready prey for
hawks, foxes and small carnivora. The longevity is possibly to be
explained as an adaptation for the preservation of the species by
compensating for the great destruction of the young. Weismann explains
in this way the longevity of many aquatic birds and other creatures
that are much preyed on. It must be noted, however, that the longevity
cannot depend on the risks run by the young birds, but must have arisen
independently. If this had not occurred, creatures, the young of which
are destroyed in great numbers, would have ceased to exist, as many
species have disappeared in geological time. The longevity of prolific
animals, the young of which are destroyed in numbers, must be due to
some cause which is neither fertility nor the destruction of their
offspring. This cause must be sought in the physiological processes of
the organism and can be attributed neither to the length of the period
of growth nor to the size attained by the adults.

After having discussed various theories of the cause of the duration of
life, M. Oustalet,[34] in a most interesting essay on the longevity of
vertebrates, came to the conclusion that diet was the chief factor. He
thinks that there is a “definite relation between diet and longevity.
For the most part herbivorous animals live longer than carnivorous
forms, probably because the former find their food with ease and
regularity, whilst the latter alternate between semi-starvation and
repletion.” There are certainly many instances which give support to
the view. Elephants and parrots, for instance, are vegetarian and reach
very great ages. On the other hand, there exist long-living carnivorous
animals. Many observations have made it certain that owls and eagles
reach great ages, and these birds live on animal food. Ravens, which
live on carrion, are also notorious for the duration of their lives.
There is no exact knowledge as to the ages reached by crocodiles, but
although these live on flesh, it is certain that their longevity is
great.

We must seek elsewhere for the real factors that control duration of
life. Before stating my conclusion, I will review what is known as to
the duration of life of different animals.

II.

LONGEVITY IN THE ANIMAL KINGDOM

Longevity in the lower animals—Instances of long life
in sea-anemones and other invertebrates—Duration of
life of insects—Duration of life of “cold-blooded”
vertebrates—Duration of life of birds—Duration of life
of mammals—Inequality of the duration of life in males
and females—Relations between longevity and fertility of
the organism

It is wonderful to what an extent the duration of life varies amongst
animals, the slightest examination of the facts showing that very many
factors must be involved.

As the higher animals are nearly always larger than invertebrates, if
there be a definite relation between longevity and size, one would
expect to find that vertebrates live longer than invertebrates.
However, this is not the case. Amongst animals of extremely simple
organisation, there are some which reach a great age. A striking
example of this is found in sea-anemones. These animals have a very
simple structure, without a separate digestive canal, and with a
badly developed, diffused nervous system, and yet have lived very
long in captivity. More than forty years ago, I remember having
seen in the possession of M. Lloyd, the Director of the Aquarium at
Hamburg, an anemone that he had kept alive for several dozen years in
a glass bowl. Another sea-anemone, belonging to the species _Actinia
mesembryanthemum_, is known to have lived 66 years. It was captured in
1828 by Dalyell, a Scottish zoologist, and was then quite adult, and
probably about 7 years old. It survived its owner for 36 years, and
died in Edinburgh in 1887, the cause of death being unknown. Although
they are thus capable of living so long, the rate of growth of members
of this species is rapid, and their fertility is very high. According
to Dalyell, these anemones reach the adult condition in 15 months. The
specimen in his possession, in the 20 years from 1828 to 1848 produced
334 larvæ, then after a period of sterility it gave birth, in one night
(1857) to 230 young anemones. This extraordinary prolificness decreased
with age, but even when it was 58 years old it used to produce from 5
to 20 at a time. In the seven years from 1872 onwards, it gave birth to
150 young anemones.[35] This animal, which certainly was not more than
the fortieth or the fiftieth of the weight of an adult rabbit, lived
six or seven times as long.

Ashworth and Nelson Annandale have published their observations on
another sea-anemone, of the species _Sagartia troglodytes_, which was
50 years old. It differed from younger examples only in being less
prolific.

There are other polyps, such as _Flabellum_, which do not live more
than 24 years, although we have no knowledge as to the cause of the
different duration of life.

The variation in the length of the life of molluscs and insects is
extremely great. Some species of gasteropods (_Vitrina_, _Succinea_)
live only a very few years, whilst others (_Natica heros_) can reach
thirty years. Some of the marine bivalves, as for instance, _Tridacna
gigas_, can live to sixty or a hundred years.[36]

Insects are animals as variable in their duration of life as they are
in other respects. Some live only a few weeks; some of the plant-lice,
for instance, die in a month. In the same order of Insects, however,
(Hemiptera) there are species of cicada which live thirteen to
seventeen years, that is to say, much longer than such little Rodents
as rats, mice, and guinea-pigs. The larva of an American species spends
seventeen years buried in the ground in orchards, where it feeds on the
roots of apple trees, and the species is known as _Cicada septemdecim_,
because of this duration of life. In the adult stage the insect lives
little more than a month, just time enough to lay the eggs, and bring
into the world the new generation, which in its turn will not appear
above ground until after another period of seventeen years.

Between these extremes of long and short life, there is to be found
amongst insects almost every gradation of longevity. Science, in its
present state, has failed to find any law governing these facts. Rules
which hold good up to a certain point in the case of the higher animals
break down in their application to insects. The large grasshoppers
and locusts, for instance, live a much shorter time than many minute
beetles. Queen bees, the fertility of which is very great, live two
or three years and may reach a fifth year, whilst worker bees, which
are infertile, die in the first year of their existence. Female ants,
although these are small and extremely prolific, reach the age of seven
years.[37]

We know so little about the physiological processes of insects, that we
cannot as yet make even a guess at the cause of this great variation
in their longevity. It is more probable that we shall find some
explanation in the case of vertebrates concerning which we know much
more.

Analysis of the facts shows that whilst in the evolution from fish to
mammal there has been a great increase in complexity of organisation,
there has at the same time been a reduction in the duration of life.
As a general rule, it may be laid down that the lower vertebrates live
longer than mammals.

The facts about the longevity of fish are not very numerous, but it
seems clear that these animals reach a great age. The ancient Romans,
who used to keep eels in aquaria, have noted that these fish would
live for more than sixty years. There is reason to believe that salmon
can live for a century, whilst pike live much longer. There is, for
instance, the much quoted instance of the pike stated by Gessner to
have been captured in 1230 and to have lived for 267 years afterwards.
Carps are regarded as equally long lived, Buffon setting down their
period of life as 150 years. There is a popular idea that the carp in
the lakes at Fontainebleau and Chantilly are several centuries old, but
E. Blanchard throws doubt on the accuracy of this estimate, inasmuch
as during revolutionary times most of the carp were eaten when the
palaces were overrun by the populace. There is no doubt, however, that
the life of carp may be very long indeed. Not very much is known about
the duration of life in batrachians, but it is certain at least that
some small frogs may live twelve or sixteen years, and toads as many as
thirty-six years.

More is known about the life of reptiles. Crocodiles and caymans,
which are large and which grow very slowly, attain great ages. In the
Paris Museum of Natural History there are crocodiles which have been
kept for more than forty years without showing signs of senescence.
Turtles, although they are smaller than crocodiles, live still longer.
A tortoise has lived for eighty years in the garden of the Governor
of Cape Town, and is believed to have reached the age of two hundred
years. Another tortoise, a native of the Galapagos Islands, is known to
be 175 years old, whilst a specimen in the London Zoological Gardens is
150 years old. A land tortoise (_Testudo marginata_) has been kept in
Norfolk, England, for a century. I am informed that in the Archbishop’s
palace at Canterbury, there is to be seen the carapace of a tortoise
which was brought to the Palace in 1623 and which lived there for
107 years.[38] Another tortoise, brought to Fulham by Archbishop
Laud, lived in the Palace for 128 years. I have already referred to a
specimen of _Testudo mauritanica_, the history of which is known for 86
years, but which is probably much older.

Very little is known as to the longevity of lizards and serpents, but
it may be inferred from what I have said about other reptiles that
reptiles as a class are able to reach great ages.

It is an easy inference that the great duration of life in cold-blooded
animals is associated with the slowness of the physiological processes
in these creatures. The circulation, for instance, is so slow, that the
heart of a tortoise beats only 20 to 25 times in a minute. Weismann has
suggested that one of the factors influencing the duration of life is
the rapidity or slowness of the vital activities, the times taken by
the processes of absorption and nutrition.

On the other hand, the blood is hot and the vital activities are rapid
in birds, and yet birds may attain great ages. Although in the last
chapter I gave a number of examples, the subject is so important that I
propose to go further into details. The possibility of this is due to
an admirable set of details brought together by Mr. J. H. Gurney.[39]
In his list, in which are included more than fifty species of birds, the
lowest figures are from eight and a half to nine years (_Podargus
cuvieri_, _Chelidon urbica_), and a duration of life so short is an
exception, a period of from fifteen to twenty years being more common.
Canaries have lived in captivity from 17 to 20 years, and goldfinches
up to 23 years. Field larks have lived for 24 years, the Lesser
Black-backed Gull 31 years and the Herring Gull 44 years. Birds of
medium size may live for several dozens of years, whether they live
on animal or on vegetable food, whether they are prolific or lay very
few eggs. I will quote only a few instances. Of forty parrots the
minimum and maximum ages were respectively 15 and 81 years, and the
average 43 years. Without accepting the truth of the story mentioned by
Humboldt according to which certain parrots survived an extinct race
of Indians, at least we may be certain that great ages have sometimes
been reached by these birds. Levaillant mentions a parrot (_Psittacus
erithaceus_) which lost its memory at the age of 60 years, its sight at
90 years, and which died aged 93 years. Another individual, probably
of the same species, is reported by J. Jennings to have reached the
age of 77. Jones, Layard, and Butler are the authorities for instances
of Sulphur-crested Cockatoos having reached respectively 30, 72 and
81 years. M. Abrahams states that an Amazon (_Chrysotis amasonica_)
lived 102 years. I myself have observed two cases of great longevity
in the same species of parrot. One of these birds died at the age of
82 years, apparently simply from old age, whilst the other, which was
in my possession for several years before it died at the age of 70
to 75 years, was vigorous, showing no signs of senility, but died of
pneumonia.

Mr. Gurney found that parrots were not the only birds capable of
reaching a great age. One raven reached 69 years and another 50, an
Eagle-owl (_Bubo maximus_) 68 years, another 53, a condor 52, an
imperial eagle 56, a common heron 60, a wild goose 80, and a common
swan 70 years. None of these examples approaches the legendary
three centuries attributed to the swan, but it is evident that many
different kinds of birds may attain great age. I can add some cases
to those of Mr. Gurney. In the Royal Park at Schönbrunn, near Vienna,
a white-headed vulture (_Neophron percnopterus_) died aged 118 years,
a golden eagle (_Aquila chrysaëtus_) aged 104, and another aged 80
(according to Oustalet). Mr. Pycraft (_Country Life_, June 25th, 1904)
reported that a female eagle, captured in Norway in 1829, had been
brought to England and had lived for 75 years. In the last thirty years
of its life, it had produced ninety eggs. The same writer mentions the
case of a falcon having lived to 162 years.

The collection of facts that I have passed in review make it manifest
that birds may have a great duration of life, but that reptiles surpass
them in this respect. Birds certainly do not reach the very great ages
of crocodiles and tortoises.

Longevity, therefore, is reduced as we ascend in the scale of
vertebrate life. We find a still greater reduction when we turn from
birds to mammals. Some mammals, it is true, may live as long as birds.
Elephants are a good instance. It used to be thought that these
giant mammals could live three or four centuries, but I can find no
confirmation of the legend, which seems as mythical as that relating to
the life of swans. There are no exact data as to the ages reached by
wild elephants, but it has been stated that in captivity an elephant
rarely but occasionally has completed its century. In zoological
gardens and in good menageries, where elephants are well cared for,
they seldom live more than 20 to 25 years. Chevrette, an African
elephant presented to the Jardin des Plantes by Mehemet Ali, in 1825,
lived for only 30 years. In the official list of the Indian Government,
which gives the deaths of elephants, it appears that of 138 examples,
only one lived more than 20 years after it had been purchased (Brehm’s
_Mammals_).

Flourens, using his own formula, assigned the age of 150 years to
elephants as their epiphyses do not fuse with the long bones until
the age of 30. So far, I know of no fact to support the conclusion,
although it seems fairly well established that occasionally an elephant
may reach a century. It is stated that one elephant was in service
throughout the whole period of more than 140 years in which Ceylon was
occupied by the Dutch. This elephant was found in the stables in 1656.
Natives with special knowledge of elephants set down their duration of
life as from 80 to 150 years, but say that they begin to grow old at
from 50 to 60 years of age. My general conclusion from the facts is
that the life of these very large mammals is about the same as that of
man who is very much smaller.

Centenarians, extremely rare amongst elephants, do not appear to exist
in any other kind of mammals except man. The rhinoceros, another large
mammal which is a native of the same countries as the elephant, does
not reach a great age. According to Oustalet an Indian rhinoceros died
in the menagerie of the Paris Museum at about the age of 25 years,
and showed all the signs of senility. Another Indian rhinoceros lived
for 37 years in the London Zoological Gardens. Grindon has stated his
opinion that the rhinoceros may live for 70 or 80 years, but this
seems rather an inference from the slowness of growth than a statement
of observed fact.

Horses and cattle are large animals, but do not enjoy very long lives.
The usual duration of life in horses is from 15 to 30 years. They begin
to grow old about 10 years, and in very rare cases may reach 40 or
more. A Welsh pony is said to have reached the age of sixty, but such a
case is excessively rare. Two other extreme cases are that of a horse
belonging to the Bishop of Metz which died at the age of 50 years, and
the charger of Field-Marshal Lacy which died at 46.

The duration of life of cattle is still shorter. Domestic cattle show
the first sign of age, a yellow discoloration of the teeth, when five
years old. In the sixteenth to eighteenth year the teeth fall out,
or break, and the cow ceases to give milk, whilst the bull has lost
reproductive power. According to Brehm, cattle live for 25 to 30
years or more. Although the duration of life is short, cattle are not
prolific. The gestation period of a cow approaches that of the human
race (242-287 days), and there is only one birth a year. The total
period of reproductivity lasts only a few years.

The sheep, another domesticated Ruminant, has a life even shorter.
According to Grindon, sheep do not live longer than 12 years as a rule,
but may reach 14 years, which in their case would be extreme age, as
they generally lose their teeth at from 8 to 10 years.

Some Ruminants, such as camels and deer, apparently live longer than
sheep or cattle, but I do not know exact facts about them.

The short life of domesticated carnivorous animals is well known. Dogs
seldom live more than 16 or 18 years, and even before that, at an age
of from 10 to 12, they usually show plain signs of senility. Jonatt
has mentioned as an extreme rarity a dog of 22 years of age, and Sir E.
Ray Lankester (_Comparative Longevity_, p. 60) cites another instance,
in this case the age being 34 years. The oldest dog that I have been
able to procure died at the age of 22.

It is generally believed that cats do not live so long as dogs. The
average age which they may attain is usually thought to be 10 or 12
years, but certainly a cat of that age has not the decrepid appearance
of an old dog. Thanks to the kindness of M. Barrier, the Director of
the Ecole d’Alfort, I have had in my possession a cat 23 years old. It
appeared to be quite vigorous, and died from cancer in the liver.

Most rodents, particularly the domesticated kinds, are extremely
prolific and very short lived. It is extremely rare for a rabbit to
reach the age of 10 years, whilst 7 years is the utmost limit for a
guinea-pig. Mice, so far as I can ascertain, do not live more than 5 or
6 years.

It is plain from the facts that I have brought together, that mammals,
whether they are large or small, as a rule, have shorter lives than
birds. It is probable, therefore, that there is something in the
structure of mammals which has brought about a shortening in the
duration of their lives.

Whilst most of the lower vertebrates, and all birds, reproduce by
laying eggs, the vast majority of mammals are viviparous. As the tax
on the parent organism is greater when the young are produced alive
than when eggs are laid, it might be thought that in this difference
lay the cause of the shorter life of mammals. It is well known that an
animal may be made feeble by too great fecundity, and it is conceivable
that the kind of parasitic life of the embryos within the body of the
mother may weaken her system.

There are many facts, however, which make it impossible to accept such
a view. The longevity of mammals is nearly equal in the two sexes,
although the tax on the organism caused by reproduction is much greater
in the case of females than in males. Longevity, however, cannot
be regarded as a character stable in each species and necessarily
identical in the two sexes. The animal kingdom presents many cases of
disparity in this respect, the difference in longevity in the two sexes
being specially striking in species of insects. Generally, the females
live longer than the males, as, for instance, amongst the Strepsiptera,
where the females have 64 times the duration of life of the males. On
the other hand, amongst butterflies, there are cases (_e.g._, _Aglia
tau_) where the males live longer than the females. In the human race,
there is a difference in the longevity of the sexes, the females having
the advantage.

As in most cases of disparity in the duration of life the female
lives longer than the male, it is plain that the difference cannot be
assigned to the drain on the organism caused by reproduction, which, of
course, is much greater in females.

Moreover, a closer scrutiny of the facts shows that although mammals
do not live so long as birds, the reproductive drain is greater in the
case of birds.

It is well known that the productivity of an animal is not necessarily
identical with its fecundity. Fish or frogs which lay thousands of
eggs at a time (a pike, for example, produces 130,000) are obviously
more prolific than, for instance, a sparrow which lays only 18 eggs in
a year, or than a rabbit, which in the same time gives birth to from
25 to 50. However, to produce this much smaller quantity of eggs or of
young, the sparrow and the rabbit (I have chosen the most prolific bird
and mammal) expend a much larger quantity of material than the frog or
the fish. The sparrow and the rabbit employ in producing their progeny
a bulk of material greater than the weight of their body, whilst the
enormous quantity of eggs laid by the frog does not weigh more than
one-seventh part of the body of the frog. It may be laid down, as a
general rule, that although fecundity, that is to say the number of
eggs or of young which are produced, diminishes as the organism becomes
more complex, the productivity on the other hand increases, expressed
in percentage of weight. The productivity, which is not more than 18
per cent. in batrachia, reaches 50 per cent. in reptiles, 74 per cent.
in mammals, and 82 per cent. in birds.

It is plain that if reproduction shortens the life of mammals by
weakening the organism, it must be the productivity, not the fecundity,
which is the important factor. I have just shown that productivity
is greater in birds than in mammals, and in consequence it cannot be
on account of any greater burden of reproduction that mammals have a
shorter life than birds. The shortness of mammalian life, again, cannot
be attributed to the fact that mammals give birth to young, whilst
the long-lived reptiles and birds produce eggs, because the longevity
of the males, which produce neither young nor eggs, is none the less
practically equal to that of the females of the same species. The
reason of the short life of mammals must be sought for elsewhere.

III

THE DIGESTIVE SYSTEM AND SENILITY

Relations between longevity and the structure
of the digestive system—The Cæca in birds—The
large intestine of mammals—Function of the large
intestine—The intestinal microbes and their agency in
producing auto-intoxication and auto-infection in the
organism—Passage of microbes through the intestinal wall

We have seen that the duration of life in mammals is relatively shorter
than that in birds, and in the so-called “cold-blooded” vertebrates.
No indication as to the cause of this difference can be found in
the structure of the organs of circulation, respiration, or urinary
secretion, or in the nervous or sexual apparatus. The key to the
problem is to be found in the organs of digestion.

In reviewing the anatomical structure of the digestive apparatus in the
vertebrate series, one soon comes to the striking fact that mammals
are the only group in which the large intestine is much developed. In
fish, the large intestine is the least important part of the digestive
tube, being little wider in calibre than the small intestine. Amongst
batrachia, where it is a relatively wide sack, it has begun to assume
some importance. In several reptiles it is still larger, and may be
provided with a lateral out-growth, which is to be regarded as a cæcum.
In birds, the large intestine still remains relatively badly developed;
it is short and straight. In most birds, at the point where the large
intestine passes into the small intestine, there is a pair of cæca,
more or less developed. These cæca are absent in climbing birds, such
as the wood-pecker, the oriole, and many others. They are reduced to
a pair of tiny outgrowths in the eagles, sparrow-hawks, and other
diurnal birds of prey, and in pigeons, and perching birds. These organs
are larger in the nocturnal birds of prey, in gallinaceous birds, and
in ducks, etc.[40]

In the large running birds, such as ostriches, rheas, and tinamous,
the cæca are relatively largest. Thus, for instance, in a rhea (_Rhea
americana_) which I dissected, the cæca were nearly two-thirds as long
as the small intestine. The latter was 1·65 m. in length, whereas one
of the cæca was 1·01 m., and the other 0·95 m. The weight of the two
cæca with their contents was more than 10 per cent. of the total weight
of the bird.

Notwithstanding the exceptions, which are relatively rare, the large
intestine is badly developed in the case of birds. On the other hand,
it reaches its largest size amongst mammals. In these animals, “only
the posterior portion of the latter, or rectum, which passes into the
pelvic cavity, corresponds to the large intestine of lower Vertebrates;
the remaining, and far larger part, must be looked upon as a neomorph,
and is called the colon.”[41]

Gegenbaur,[42] another well-known authority on comparative anatomy,
writes as follows on this subject:—“The hind-gut is longest in the
Mammalia, where it forms the large intestine, and is distinguished
as such, from the mid-gut, or small intestine. Owing to its greater
length, it is arranged in coils, so that the terminal portion only has
the straight course taken by the hind-gut of other Vertebrata.”

The two series of facts are not to be disputed. On the one hand mammals
are shorter lived than birds and lower vertebrates, on the other
hand the large intestine is much longer in them than in any other
vertebrates. Is there here any link of causality, binding the two
characters, or is it a mere coincidence?

To answer the question we must turn to the function of the large
intestine in vertebrates. In the lower members of the group (fish,
batrachia, reptiles, birds, etc.), the large intestine is not more
than a mere reservoir for the waste matter in the food. It takes no
share in digestion, as that is the function of the stomach and the
small intestine. Only the cæcum can be thought to have some digestive
property. In reptiles, the lowest vertebrates in which the cæcum is
present, it is so little differentiated from the large intestine
itself, that it is difficult to assign to it any specialised function.
In very many birds, however, the cæca are well separated from the main
digestive tube. The food material passes into them in considerable
quantities, and is retained there sufficiently long for some digestive
process to take place. M. Maumus has found, in the cæca of birds,
secretions which can dissolve albumen and invert sugar cane, but he has
been unable to make out that the cæcal juice has any action upon fatty
matter. Such digestive power, however, is slight, and when M. Maumus
removed the cæca in fowls and ducks, no evil consequences followed.
As in many birds the cæca are rudimentary and in others absent, it
may be inferred that these organs are useless, and are in process
of degeneration in the class. The cæca can be regarded as playing
an important part in the organism only in the case of large running
birds, where they are very highly developed, but we have not precise
information as to their digestive function.

The variations in the structure in the large intestine are greater
in mammals than in birds. In some mammals, the large intestine is a
simple prolongation of the small intestine, similar in calibre and
in structure. In these conditions it may fulfil a definite digestive
function. Th. Eimer[43] has determined that in insectivorous bats the
large intestine digests insects like the small intestine. Such cases,
however, are rare. In most mammals the large intestine is sharply
separated from the small intestine by a valve, and opens directly
into the cæcum which may be very large. In the horse, the cæcum is an
enormous bag, cylindrical and tapering, generally well filled, and
holding on an average 35 litres. It is equally large in many other
herbivorous animals, such as the tapir, the elephant, and most rodents.
In such cases, the food remains for a considerable time in the organ
and without doubt undergoes some digestive changes. In many other
mammals, particularly carnivorous forms, the cæcum may be quite absent,
whilst in some, as for instance, the cat and dog, it is very small;
in the latter cases its digestive function must be non-existent or
insignificant.[44]

As for the large intestine itself, apart from the special cases, such
as bats, it cannot fulfil any notable digestive function. Th. Eimer was
unable to find a proof of any such action in rats and mice, and the
very many investigations that have been made in the case of man seem to
have established the absence of digestive power in the colon.

Dr. Stragesco,[45] in a recent investigation carried out under the
direction of the famous Russian physiologist Pawloff, established that,
in normal conditions, digestion and assimilation of food are confined
almost exclusively to the small intestine in mammals, and that the
large intestine plays only the smallest part. It is only in certain
diseases of the digestive tract, in which, on account of increased
peristaltic action, the contents of the intestine with the digestive
juices are passed quickly from the small intestine to the large
intestine, that some digestive work is done in the latter organ.

The large intestine (excluding the cæcum), then, cannot be regarded as
an organ of digestion, although absorption of the liquids which have
been formed in the small intestine, may take place within its walls. It
is known that in the large intestine the contents of the gut give up
their water and assume the solid form of fæcal matter. However, whilst
the mucous membrane of the large intestine rapidly absorbs water, it
has not a similar action on other substances.

The question of the extent to which the large intestine can absorb
has been closely investigated, because of its practical importance.
It sometimes happens that invalids cannot take food by the mouth, so
that their life would be in danger if it were not possible to supply
them with food otherwise. Attempts have been made to inject nutritive
substances through the skin, or, and this is a more usual procedure, by
the rectum. By such means the organism can be kept alive for a certain
time, but the absorbing power of the large intestine is extremely
small. According to Czerny and Lautschenberger[46] the entire colon
of the human being can absorb no more than 6 grammes of albumen in 24
hours, an amount which, from the point of view of nutrition, is very
small. It was thought that the large intestine might more rapidly
absorb albuminous material which had been previously digested and
transformed to peptones, but the experiments of Ewald[47] showed that
even in that case the absorption was very small. According to more
recent experiments of Heile,[48] carried out upon dogs which had cæcal
fistulas, and in the case of a man who had an artificial aperture in
the colon, the large intestine does not absorb undigested white of
egg, and absorbs water, cane sugar, and glucose only very imperfectly.
The only substances which are rapidly absorbed through the wall of
the colon are the alkaline fluids from fæcal matter. It is possible,
however, to nourish invalids by rectal injections of certain nutritious
substances, the most important of which is milk.[49]

The large intestine, which has really very slight digestive properties
and cannot absorb any considerable bulk of nutriment, is an organ which
secretes mucus. The latter serves to moisten the solid fæcal material,
so aiding in its expulsion.

We must conclude, therefore, that the large intestine, the organ so
highly developed in mammals, is an apparatus the general function
of which is the preparation and elimination of the waste products
of digestion. Why should such an organ be so much more developed in
mammals than in the other vertebrates?

In answer to the question, I have formed the theory that the large
intestine has been increased in mammals to make it possible for
these animals to run long distances without having to stand still
for defæcation. The organ, then, would simply have the function of a
reservoir of waste matter.

Batrachia and reptiles lead a very idle life, and can move slowly,
sometimes because they are protected by poison (toads, salamanders,
serpents), sometimes because they have a very hard shell (turtles),
sometimes because they are extremely powerful (crocodiles). Mammals, on
the other hand, have to move very actively to catch their prey, or to
escape from their enemies. Such activity has become possible because
of the high development of the limbs, and because the capacity of the
large intestine makes possible the accumulation of waste matter for a
considerable time.

In order to void the contents of the intestines, mammals have to stand
still and assume some particular position. Each act of this kind is
a definite risk in the struggle for existence. A carnivorous mammal
which, in the process of hunting its prey, had to stop from time to
time, would be inferior to one which could pursue its course without
pausing. So, also, a herbivorous mammal, escaping from an enemy by
flight, would have the better chance of surviving the less it was
necessary for it to stand still.

According to such a view, the extreme development of the large
intestine would supply a real want in the struggle for existence. M.
Yves Delage,[50] the well-known biologist, is unable to accept this
hypothesis. He thinks that the rectal enlargement would fulfil the
purpose, and adds that everyone has seen herbivorous animals pass their
excretions whilst running. The rectum of mammals, however, cannot
serve as a reservoir for waste matter, because as soon as such matter
reaches the rectum it excites the need of excretion. The waste matter
accumulates in the large intestine, from which it passes into the
rectum at intervals. When it has reached that region, a sensation is
caused which leads to defæcation.

M. Delage is not quite definite when he speaks of mammals voiding their
excretions whilst they are in motion. A horse, harnessed to a vehicle,
may defæcate whilst it is walking or even running slowly. But these
animals cannot defæcate when in rapid motion, and competent observers
state that horses never do so whilst racing. In zoological gardens,
where animals have room to run about, they stand still before emptying
the rectum. M. Ch. Debreuil, who keeps antelopes in a very large park
at Melun, has noticed that the excreta are always to be found in masses
and not scattered about as if they had been discharged by animals
in motion. Antelopes, which are animals that run and leap extremely
actively, have to come to a standstill before discharging their small
pellets of deer-like excreta.

In the struggle for existence, when a mammal is pursuing its prey or
escaping its enemy, there is no question of the leisurely movement
of a horse harnessed to an omnibus or cab, but the greatest possible
activity is necessary. In such circumstances the possession of an
organ within which the excreta could accumulate would be of real
importance. My theory of the origin of the mammalian large intestine is
intrinsically probable.

Although the capacity of the large intestine may preserve a mammal in
emergencies, it is attended with disadvantages that may shorten the
actual duration of life.

The accumulation of waste matter, retained in the large intestine
for considerable periods, becomes a nidus for microbes which produce
fermentations and putrefaction harmful to the organism. Although our
knowledge of the subject is far from complete, it is certain that the
intestinal flora contains some microbes which damage health, either by
multiplying in the organism, or by poisoning it with their secretions.
Most of our knowledge on this matter has come from the study of human
patients.

Persons have been known who do not defæcate except at intervals of
several days, and who, none the less, do not seem to suffer in health.
But the opposite result is more common. The retention of fæcal matter
for several days very often brings harmful consequences. Organisms
which are in a feeble state from some other cause are specially
susceptible to damage of the kind referred to. Infants are frequently
seriously ill as the result of constipation. Dr. du Pasquier[51]
describes such cases in the following words:—“The infant is leaden
in hue, with sunken eyes, dilated pupils, and pinched nostrils. The
temperature may reach nearly 104° Fahr.; the pulse is rapid, feeble,
and often irregular. Restlessness, insomnia, sometimes convulsions,
stiffness of the neck and strabism show that the nervous system is
being poisoned by toxins, and even collapse may be reached. The foul
and dry tongue, the vomiting and fetid discharges show the disturbance
of the digestive tract. Very often an eruption appears, as described
by Hutinel, chiefly on the back and buttocks, the front of the thighs
and fore-arms.” The illness may lead to death but is generally cured by
simple purging.

Women in pregnancy and child-birth frequently suffer much as the
result of retention of fæcal matter, and physicians are familiar
with the symptoms, which have been described as follows by M.
Bouchet[52]:—“After normal parturition, in the course of which the
usual antiseptic precautions have been fully pursued, and where
delivery has been complete and natural, occasionally the patient is
seized with chill and headache. The breath is fetid and the tongue
foul. The temperature, taken in the axilla, is nearly 101° Fahr. The
abdomen is inflated and painful in the umbilical region. Palpation in
the iliac fossæ reveals lumps or consolidations along the colon. Thirst
is intense, and there is complete anorexy. On questioning, it is found
that there has not been defæcation for several days. The treatment
consists of purgatives, enemas, and milk diet. In the next few days the
bowels are emptied freely, the abdominal pain ceases, the temperature
becomes lower, appetite is restored, and the patient recovers.”

Those who suffer from affections of the heart, liver, or kidneys are
specially susceptible to the evil results of retained fæcal matter. In
such patients an error of diet or constipation may bring about most
serious consequences.

Such facts are well known to physicians, and it has been established
that complete emptying of the lower bowels leads at once to favourable
symptoms. From the other side, it has been shown by experiment that
artificial retention of the fæces by ligature of the rectum puts the
body in a grave condition.

If we collect our knowledge of all the facts, we cannot doubt but that
the cause of the evil is multiplication of microbes in the contents of
the large intestine. When the fæcal matter is free from microbes, as
is the case with the meconium of the fœtus or new-born infant, it
is not a source of danger to the organism. The waste of cells and the
secretions which are added to the undigested food cannot do any harm.
Amongst the microbes of the gut, there are some that are inoffensive,
but others are known to have pernicious properties.

The ill-health which follows retention of fæcal matter is certainly
due to the action of some of the microbes of the gut. There are
difficulties, however, in determining the precise mode of action of
these microbes. It is generally believed that they form poisonous
substances which are absorbed by the walls of the intestine and so pass
into the system. The phrase auto-intoxication as applied to infants,
women in labour, and patients affected with diseases of the heart,
liver, or kidneys, is based on this interpretation of the morbid
processes involved. Attempts have been made to isolate and study the
poisons in question, but there are many difficulties in the way. To
distinguish between the actions of the poisons and of the microbes
themselves, the latter have been destroyed by heat or by antiseptics,
or been removed by filtration. Such methods, however, may alter the
poisons and so are inconclusive. MM. Charron and Le Play[53] have
tried to obtain exact results by heating the intestinal microbes to
a temperature of about 136° Fahr., a process which probably does not
seriously deteriorate the microbial poisons. Such material, injected
into the veins of rabbits in large quantities, rapidly produced death,
or in smaller quantities, proportionate ill-health.

Kukula[54] has tried to produce this toxic action in animals,
employing microbial secretions obtained from cases of intestinal
obstruction. He succeeded in producing serious symptoms, such as
vomiting and curvature of the neck and back, in fact, precisely the
sequence of events familiar in cases of obstruction of the bowels or
other retentions of fæcal matter.

Some of the products of the intestinal flora are undoubtedly toxic,
such as the benzol derivatives (phenol, etc.) ammonium and other
salts. Many of these toxins have been insufficiently studied, but it
is well known that certain of them can be absorbed by the wall of the
gut and act as poisons. A well known case is the toxin of botulism
which was isolated and studied by M. van Ermenghem.[55] The poison,
the product of a microbe which causes serious intestinal disturbance,
is so fatal that a single drop given to a rabbit produces death after
symptoms similar to those observed in cases of human beings poisoned by
stale food. Butyric acid and the products of albuminous putrefaction
are amongst the most pernicious of the microbial poisons produced
in the large intestine. It is familiar that digestive disturbance
is frequently associated with discharges of sulphuretted hydrogen
and putrid excreta, and there is no doubt but that the microbes of
putrefaction are the cause of these symptoms.

It has been assumed for long that the retention of fæcal matter
tends to putrefactive changes in the intestines, and that the evil
consequences of constipation are due to this. Recently, however,
bacteriologists have criticised this accepted view, on account of the
small number of microbes found in the excreta of constipated persons.
Strasburger was the first to establish the fact, and his associate,
Schmidt, showed that putrefaction did not follow when readily
putrescible substances were infected with material taken from cases of
constipation. However, notwithstanding the exactness of these facts,
I cannot accept the inference which has been drawn from them. The
excreta discharged naturally in cases of constipation do not give a
correct indication of the conditions inside the gut; whilst such matter
contains few microbes, the substance removed after injection by an
enema is extremely rich in bacteria. Moreover, analysis of the urine,
in cases of constipation, shows an excess of the sulpho-conjugate
ethers which are known to be products of intestinal putrefaction.

Not only is there auto-intoxication from the microbial poisons absorbed
in cases of constipation, but microbes themselves may pass through the
walls of the intestine and enter the blood. In the maladies that are
the result of constipation some of the symptoms recall those of direct
infection, and it is highly probable that, if special investigations
were made, microbes of intestinal origin would be found in the blood of
the sick children and the pregnant or parturient women whose symptoms I
have described above.

The question as to the passage of microbes through the intestinal walls
is one of the most controversial of bacteriological problems, and there
is little agreement in the numerous publications regarding it. None the
less, it is far from impossible to get a general idea of what goes on
in an intestinal tract richly charged with microbes.

Although the intestinal wall in an intact state offers a substantial
obstacle to the passage of bacteria, it is incontestable that some
of these pass through it into the organs and the blood. Numerous
experiments performed on different kinds of animals (horses, dogs,
rabbits, etc.) show that some of the microbes taken with food traverse
the wall of the alimentary canal and come to occupy the adjacent
lymphatic glands, the lungs, the spleen and the liver, whilst they
are occasionally found in the blood and lymph. Discussion has taken
place as to whether the passage takes place when the wall of the gut
is absolutely intact or only when it is injured to however small
an extent. It would be extremely difficult to settle the question
definitely, but it is easy to see that it has little practical bearing.
It is known that the wall of the gut is damaged extremely easily, so
that the bluntest sound can hardly be passed into the stomach without
making a wound through which microbes can pass into the tissues and
blood. In the ordinary course of life, the delicate wall of the gut
must often undergo slight wounding, and the frequent presence of
microbes in the mesenteric ganglia of healthy animals shows clearly
what takes place.[56]

It is indubitable, therefore, that the intestinal microbes or their
poisons may reach the system generally and bring harm to it. I infer
from the facts that the more a digestive tract is charged with
microbes, the more it is a source of harm capable of shortening life.

As the large intestine not only is the part of the digestive tube most
richly charged with microbes, but is relatively more capacious in
mammals than in any other vertebrates, it is a just inference that the
duration of life of mammals has been notably shortened as the result of
chronic poisoning from an abundant intestinal flora.

MICROBES AS THE CAUSE OF SENILITY

Relations between longevity and the intestinal
flora—Ruminants—The Horse—Intestinal flora of
birds—Intestinal flora of cursorial birds—Duration
of life in cursorial birds—Flying mammals—Intestinal
flora and longevity of bats—Some exceptions to the
rule—Resistance of the lower vertebrates to certain
intestinal microbes

In the actual state of our knowledge it is impossible to make a final
examination of my hypothesis, as there are many factors about which we
are incompletely informed. Nevertheless, it is possible to confront the
hypothesis with a large number of accurately established facts.

Although the life of most mammals is relatively short, there are to be
found in the group some which live relatively long, as well as others
whose life is short. The elephant is an example of the long-lived
mammals, whilst ruminants are short-lived forms. In the last chapter, I
stated that sheep and cattle became senile at an early age, and did not
live long. They are striking exceptions to the rule according to which
the duration of life is in direct relation with the size and length of
the period of growth. The cow, which is much larger than a woman, and
the time of gestation of which is about the same, or a little longer,
acquires its teeth at four years old, and becomes senile at an early
age; it is quite old at between sixteen and seventeen, an age when a
woman is hardly adult; at the age of thirty, practically the extreme
limit for bovine animals, a woman is in full vigour.

The precocious old age of ruminants, the constitution of which is
well understood, and which are carefully tended, coincides with an
extraordinary richness of the intestinal flora. Food remains for a long
time in the complicated stomach of these animals, and afterwards the
digested masses remain still longer in the large intestine. According
to Stohmann and Weiske,[57] in the case of sheep it is a week until
the remains of a particular meal have finally left the body of the
animal. The excreta of sheep, normally solid, do not betray any special
putrefaction in the intestine, but if the body is opened there is
abundant evidence of the process. The intestinal contents are richly
charged with microbes and give off a strong odour of putrefaction. It
is not surprising that under these conditions, the life of sheep should
be short.

Another large herbivorous animal, the horse, also dies young, after a
premature old age. Although it does not ruminate and possesses a simple
stomach, the process of digestion is slow, and enormous masses of
nutritive material accumulate in the huge large intestine. Ellenberger
and Hofmeister[58] have shown that food remains in the alimentary canal
for nearly four days. It remains in the stomach and the small intestine
only 24 hours, but about three times as long in the large intestine.
This is remarkably different from what happens in the case of birds,
in which there is no stagnation during the passage of food through the
digestive canal.

The structure of birds is adapted for flight, the body being as light
as possible, many of the bones and the cavities of the body containing
air-sacs. The absence of a bladder and of a true large intestine
prevents the accumulation of excreta, these being ejected almost as
rapidly as they are formed. The process of ejection, which takes place
often in birds, is not so inconvenient as in mammals. The hind limbs
are not used in flight, so that they offer no obstacle to evacuation.
Thus birds may discharge their droppings while flying.

Such structure and habits make it not surprising that the alimentary
canal of many birds contains only a scanty intestinal flora. Parrots,
for instance, which are remarkably long-lived birds, harbour very few
microbes in the intestine. The small intestine contains almost none,
the rectum so few that the fæcal matter appears to be formed of mucus,
the waste of the food, and only a very few microbes. M. Michel Cohendy,
who has examined the intestinal flora at the Pasteur Institute, was
unable to isolate more than five different species of microbes living
in the alimentary canal of parrots.

Even in birds of prey which feed upon putrid flesh, the number of
microbes in the intestine is remarkably limited. I have investigated
the case of ravens which I fed on flesh which was putrid and swarming
with microbes. The droppings contained very few bacteria, and it was
specially remarkable that the intestines had not the slightest smell of
putrefaction. Although the opened body of a herbivorous mammal, such as
a rabbit, gives off a strong smell of putrefaction, the body of a raven
with the digestive tube exposed has no unpleasant smell. This absence
of putrefaction in the intestine is probably the reason of the great
longevity of such birds as parrots, ravens, and their allies.

It might be said, however, that the long duration of life in birds is
due to the organisation of these animals, rather than to the scantiness
of their intestinal flora. To meet this objection, it is necessary to
turn to the case of cursorial birds.

There are some birds incapable of flight, the wings of which are
badly developed, but which have strong limbs, and can run with great
rapidity. Ostriches, cassowaries, rheas, and tinamous, are well known
examples of cursorial birds. They live on the surface of the ground,
and their habits resemble those of mammals. When they are attacked
by enemies, they escape by running so quickly that some of them
(ostriches and rheas) outstrip even a horse. However, like mammals,
they cannot discharge their secretions when they are running quickly.
Tinamous (_Rhynchotus rufescens_), which I have observed in captivity,
however quickly they may be running, stop abruptly to discharge their
excretions. M. Debreuil, at my request, made observations on this
matter, and assured me that the tinamous and rheas (_Rhea americana_)
in his park always stood still for this purpose. He has noticed that
the droppings, however abundant, were always deposited in heaps.
With regard to ostriches, M. Rivière, director of the experimental
Gardens at Hamma, Algeria, has been kind enough to give me the
following information. “The discharge of excreta,” he said in a letter
in January, 1901, “is less frequent than in other birds, but the
comparatively small size of the enclosures here makes it impossible for
me to assert that the animal could discharge its droppings if it were
running for a length of time; _a priori_ I should think that this did
not happen. Normally the bird stands still for defæcation, the tuft of
feathers on the tail is lifted up, and there is a violent contraction
of the abdominal muscles before the sphincters of the cloaca are
suddenly opened to discharge the excrement with violence.”

I believe that the remarkable development of the large intestine in
these running birds has been acquired to obviate the danger which is
caused by the animal having to stop for defæcation. Although the huge
cæca of these birds have a digestive function, particularly on plants
rich in cellulose, I cannot think that the cæca of cursorial birds have
been developed for digestion. As a matter of fact, some birds which
are not cursorial live on the same kind of food (herbage, seeds, and
insects) and have much smaller cæca, the cæca indeed, in some, for
instance, the pigeons, being quite rudimentary.

[Illustration: FIG. 14.—Intestinal microbes from the cæca of a Rhea.]

It is not surprising that the accumulation of food material in the
large intestine of running birds is associated with the presence of
an extremely rich intestinal flora. Microscopic examination of the
excrement of such birds shows this at once. Although the intestinal
contents and excrement of many other birds show the presence of
very few microbes, belonging to a small number of species, the same
materials taken from running birds show enormous quantities of
microbes, belonging to a large number of species. In the cæcum of
the rhea (Fig. 14) there are bacterial threads, spirilla, bacilli,
vibrios, and many kinds of cocci. In the tinamous, the intestinal flora
is if possible even richer. According to the statistical investigations
of M. Michel Cohendy, the quantity of intestinal microbes in cursorial
birds is not less than that found in mammals, even in man.

If I am correct in the view that I have been explaining, cursorial
birds, on account of their rich intestinal flora, ought to have a
shorter duration of life than that of flying birds. I will now turn to
this side of the question. Amongst cursorial forms, there are some of
the largest living birds, ostriches being actually the largest living
birds, whilst an extinct running bird, the _Aepyornis_ of Madagascar,
was the largest known bird. According to the rule that large animals
live longer than small animals, ostriches should be able to reach a
great age. The facts, however, are against this. M. Rivière, who rears
ostriches in Algeria, and has a great experience of them, writes to me
as follows: “I have no confidence in the stories about the longevity of
the ostrich which were told me in the Sahara; they rest on no facts.
My personal observation is not very large, but it is quite exact. Some
of the ostriches which have been hatched here have lived for 26 years.
I do not estimate the duration of life of this bird at more than 35
years, and only one case of this age have I seen myself in 20 years.
The bird was a female, a good layer and sitter; she died of old age,
showing all the signs of decrepitude, the skin excoriated and lumpy,
the feathers degenerate and dry. The bird laid eggs until nearly the
end of her life, but at irregular intervals, and the shells were
granular instead of being smooth and polished.”

In a farm near Nice, where ostriches are reared, there was recently an
old male called “Kruger,” which was supposed to be 50 years old.[59]
Countess Stackelberg has been good enough to try to get information
for me about this, and informs me that although they have not exact
knowledge at the farm, they believe that it must be 50 years old. M.
Rivière thinks this statement very surprising, and has nothing in his
own long experience to confirm it.

The facts which I have been able to get together do not attribute a
long life to other running birds. Gurney mentions that a cassowary
(_Casuarius westermanni_) lived 26 years in the Zoological Gardens of
Rotterdam, and that three Australian emus (_Dromaeus novae-hollandiae_)
had lived in the same Gardens for 28, 22, and 20 years. M. Oustalet
(_Ornis_, 1899, vol. x, p. 62) mentions another emu of the same
species which died in London at the age of over 23 years. The rhea
(_Rhea americana_), another large running bird, does not live so long.
“Boecking thinks that its duration of life should be set down at from
14 to 15 years. According to him, many of these birds die of old age.”
(Brehm, _Oiseaux_, vol. ii, p. 517).

It is striking to compare the short life of cursorial birds, which
nevertheless thrive and reproduce in captivity, with the remarkable
longevity of so many other birds (parrots, birds of prey) which,
although they are much smaller, have been kept alive for from 80 to
100 years. It would be difficult to find a more striking argument in
favour of the view that richness of the intestinal flora shortens life.
When birds become adapted to terrestrial life and acquire a huge large
intestine in which microbes can abound, their duration of life is
diminished.

Just as some birds, losing the aerial mode of life, have come to
resemble mammals, so also some mammals have become flying animals,
provided with wings and in some respects resembling birds. Bats are
the most familiar instance. The large intestine, which is extremely
useful to running animals, not only ceases to be an advantage but is
harmful to flying creatures, insomuch as it increases the weight of
the body uselessly. Bats, accordingly, have no cæcum whilst the large
intestine is changed in structure and function. Instead of being a
capacious tube, serving as a reservoir for the refuse of the food, the
large intestine of bats has the same diameter as the small intestine.
Its structure is nearly identical. It is provided with glands, and
as I have already mentioned in the last chapter, it digests the food
in the same way as the small intestine. In fact, the large intestine
has become simply a part of the small intestine, the total length of
the gut being reduced. Bats, therefore, can no longer retain their
secretions but have to empty the intestine almost as often as most
birds. I find that Indian fruit bats (_Pteropus medius_) discharge
their excreta very often. Microscopic examination shows that there
is an absence of microbes quite unusual in the case of a mammal.
The alimentary canal of bats is nearly aseptic, containing only a
few single bacteria. I have fed these fruit bats with the same food
(carrots) which I have given to rabbits, guinea pigs, and mice; whilst
the bats accomplished the process of digestion in 1-1/2 hours, and
deposited excreta containing fragments of carrot, the rodents took
very much longer for digestion and large quantities of waste matter
accumulated in the cæca. The intestinal flora too, although the food
in each case was the same, showed remarkable differences in these
animals. It was almost absent in the bats, whilst in the rabbits,
guinea-pigs and mice it consisted of a mass of microbes of different
species. The excrement of the bats had no unpleasant odour, and the
digestive canal of these bird-like mammals was free from putrefaction.
Fruit bats fed upon fruit discharged excreta with a pleasant odour of
apples and bananas. We have seen that birds which live a life similar
to that of mammals acquire a rich intestinal flora and do not live so
long as aerial birds. It would be extremely interesting to ascertain
the duration of life of bats, mammals which live like birds and have
a very scanty intestinal flora. I have been unable to get any exact
information as to the duration of life of the true bats, that is to
say, the insectivorous bats, as all the requests that I have addressed
to specialists have proved fruitless. It appears, however, that it is
a popular belief that bats live long. There is a Flemish phrase: “as
long-lived as a bat,” and a similar phrase is common in Little Russia.

As for the fruit-eating bats, I have been able to ascertain that even
in captivity, where the conditions are unfavourable to them, the
duration of life is relatively long. I have had in my own possession a
fruit bat (_Pteropus medius_) which was bought in Marseilles 14 years
ago. It showed no signs of old age, and the teeth were in perfect
condition. It died of some acute disease accidentally contracted. I
know of another bat of the same species which lived in captivity for
more than 15 years, and I have been informed that[60] in the London
Zoological Gardens, a fruit bat has lived for 17 years. If these bats
were adult when caught, it would be necessary to add something to the
known figures.

Although I do not know the exact duration of the life of bats, it is
clearly relatively long for mammals no bigger than guinea-pigs. The
difference is remarkable if we compare it with the life of sheep, dogs
and rabbits, mammals very much larger in size, but possessed of a rich
intestinal flora.

The series of facts that I have been discussing strengthens my
conviction that the intestinal flora is an extremely important factor
in the causation of senility. It must not be supposed, however, that
all the known facts can be explained equally easily on this hypothesis.
The harm done by microbes cannot always be measured by their abundance
in the alimentary canal. In the first place, it must be remembered
that some microbes are useful; moreover, microbes, even although their
products are very dangerous, may exist in quantities in an organism,
and yet do no harm if the organism has the power of resisting bacterial
poisons. Thus, for instance, the bacillus of tetanus, which thrives
in the alimentary canal, and which can endanger life if the wall of
the gut is wounded, does not harm a crocodile or a tortoise, as these
animals are extremely resistant to the poison of tetanus. Dr. Favorsky,
by experiments at the Pasteur Institute, has shown that the poison of
botulism can be absorbed with impunity by some birds, and by tortoises,
although death follows if a very small quantity of it be introduced
into the alimentary canal of a mammal.

The bodies of man and of higher animals are possessed of a complex
mechanism which resists the harmful action of bacteria and their
poisons. The various parts of this mechanism may act differently, with
the result that there is great variation in the power of resistance.
Thus, however abundant microbes may be in the intestine, they may
bring little harm to an organism that has a high power of destruction
or neutralisation of the toxins, or when these harmful products are
unable to pass through the intestinal wall. It is in this way that I
explain some exceptions to the general rule, which are exceptions only
in appearance. Such a case is that of the nocturnal birds of prey.
Although the diurnal birds of prey (eagles, vultures, etc.) have very
short cæca, in which the food is never found, owls have very large
cæca, which may be as long as 10 cm. (Eagle-Owl, _Bubo maximus_). These
long cæca, however, contain debris of the food only in the enlarged
terminal portion, and the food masses contain a very small number of
microbes. Notwithstanding a great difference in the length of the cæca
between the owls and the eagles, these two groups of birds do not
differ greatly in longevity. But the difference in the cæca does not
imply a corresponding difference in the intestinal flora which appears
to be very scanty in both cases.

It is possible that the elephant is a more real exception to the rule.
Here is a case of a mammal with an enormous large intestine and a
capacious cæcum, and which none the less is capable of surviving for a
century. I have had no opportunity of investigating the elephant from
this point of view, and have no explanation to suggest.

Monkeys and man differ from most mammals in so far as they possess
a long duration of life, although their large intestines are very
capacious. I have been unable to get exact information as to the
longevity of monkeys, but I understand that these animals live longer
than domesticated mammals, such as the ox, sheep, dog, and cat.
Anthropoid apes are supposed to be able to reach the age of 50 years.
The only other mammal with a longevity similar to that of the elephant
is man.

DURATION OF HUMAN LIFE

Longevity of man—Theory of Ebstein on the normal
duration of human life—Instances of human
longevity—Circumstances which may explain the long
duration of human life

Man has inherited from his mammalian ancestors his organisation and
qualities. His life is notably shorter than that of many reptiles, but
longer than that of many birds and most other mammals. None the less
he has inherited a capacious large intestine in which a most abundant
intestinal flora flourishes.

Gestation and the period of growth are long in the human race, and
from the point of view of theoretical considerations, human longevity
should be longer than it generally is. Haller, a distinguished Swiss
physiologist of the 18th century, thought that man ought to live to 200
years; Buffon was of the opinion that when a man did not die from some
accident or disease he would reach 90 or 100 years.

According to Flourens, man takes 20 years to grow and ought to live 5
times 20, that is to say, 100 years.

The actual longevity is much below these figures, which are based
on theory. I have shown, moreover, that even if the rule based on
the theory of growth can be accepted as generally true, it cannot be
applied in every case, as the factors controlling duration of life are
very variable.

Statistics show that the highest human mortality occurs in the earliest
years of life. In the first year after birth alone, one quarter of the
children die. After this period of maximum mortality, the death-rate
slowly falls until the age of puberty, and then rises again slowly and
continuously. It reaches a second maximum between the ages of 60 and
75, and then slowly falls again to the extreme limit of longevity.

Bodio,[61] an Italian man of science, holds the view that the great
mortality of infants is a natural adaptation to prevent too great an
increase of the human race. This view, however, cannot be supported,
and rational hygiene readily brings about a great diminution in the
mortality of children. The cause of mortality is in most cases maladies
of the intestinal canal, produced by erroneous diet, and with the
advance of civilisation, infant mortality has been very greatly reduced.

I find it impossible to accept the view that the high mortality between
the ages of 70 and 75 indicates a natural limit of human life. As
a result of investigations into mortality in most of the European
countries, Lexis came to the conclusion that the normal duration of
human life was not more than 75 years. Dr. Ebstein[62] accepts this
statistical result and announces that “we now know the normal limit set
by nature to the life of mankind. This limit is at the age of maximum
mortality. If man dies before then, his death is premature. Everyone
does not reach the normal limit; life ends generally before it, and
only in rare cases after it.”

The fact that many men of from 70 to 75 years old are well preserved,
both physically and intellectually, makes it impossible to regard that
age as the natural limit of human life. Philosophers such as Plato,
poets such as Goethe and Victor Hugo, artists such as Michael Angelo,
Titian and Franz Hals, produced some of their most important works
when they had passed what Lexis and Ebstein regard as the limit of
life. Moreover, deaths of people at that age are rarely due to senile
debility. In Paris, for instance, in 1902, of cases of deaths between
the ages of 70 and 74, only 8·5 per cent. were due to old age.[63]
Infectious diseases, such as pneumonia, tuberculosis, diseases of the
heart and the kidneys, and cerebral hæmorrhage, caused most of the
deaths of these old people. Such cases of death, however, can often be
avoided and must be regarded as accidental rather than natural.

Confirmation of the view that the natural limit is not at 70 to 75
years is to be found in the fact that so many men reach a greater age.
Centenarians are really not rare. In France, for instance, nearly one
hundred and fifty people die every year, after having reached the age
of 100 or more. In 1836, in a population of thirty-three millions and
a half (33,540,910), there were 146 centenarians, that is to say, one
in about 220,000 inhabitants. In some other countries, particularly in
Eastern Europe, the number of centenarians is still greater. In Greece,
for instance, there is a centenarian for each set of 25,641 living
persons, that is to say, nine times as many as in France.[64]

What age can be reached by the human species? Formerly it was supposed
that individuals might live for several centuries; to say nothing
of Methuselah, whose age of 969 years, mentioned in the Bible, is
the result of a mistake in calculation, I may mention Nestor, who,
according to Homer, lived for three human ages, that is to say, 300
years, or Dando, the Illyrian, and the King of the Lacedaemon,
who were supposed to have reached ages of five or six centuries. These
ancient records are, of course, quite incorrect. Much more confidence
can be placed in some facts relating to more modern times, according to
which the extreme old age reached by man was 185 years. Kentigern, the
founder of the Cathedral of Glasgow, known by the name of St. Mungo,
died at the age of 185, on Jan. 5th, 600.[65] Another astonishing case
of longevity is related from Hungary, where an agriculturist, Pierre
Zortay, born in 1539, died in 1724. The Hungarian records of the 18th
century contain other cases of death at ages between 147 and 172 years.

The case of Drakenberg is still more authentic; he was born in Norway
in 1626 and died in 1772, at the age of 146. He was known as the Old
Man of the North. He had been captured by African pirates and was held
by them for fifteen years, and was engaged as a sailor for ninety-one
years. His romantic history attracted contemporary attention, and the
journals of the time (_Gazette de France_, 1764, _Gazette d’Utrecht_,
1767, etc.)[66] contain information regarding him. The well-known
instance of Thomas Parr appears to rest on good authority. Parr was
a poor Shropshire peasant, who did hard work until he was 130 years
old, and who died in London at the age of 152 years and 9 months. The
celebrated Harvey examined the body after death and was unable to
discover organic disease; even the cartilages of the ribs were not
ossified and were elastic as in a young man. The brain, however, was
hard and resisting to the touch, as its blood-vessels were thickened
and dry. Parr was buried in Westminster Abbey.[67]

It appears, then, that human beings may reach the age of 150, but such
cases are certainly extremely rare, and are not known from the records
of the last two centuries. I cannot accept without a good deal of
reserve the statements as to two persons who died in the beginning of
the 19th century at the ages of 142 and 145. On the other hand, cases
of duration of life from 100 to 120 years are not very rare.

Extreme longevity is not limited to the white races. According to
Prichard,[68] negroes have lived respectively to 115, 160, and 180
years. In the course of the 19th century there have been observed, in
Senegal, eight negroes ranging from 100 to 121 years old. M. Chemin[69]
saw himself in 1898 at Foundiougne an old man, whom the natives stated
to be 108 years of age; although he was in good health, he had been
blind for several years. The same author, on the authority of the _New
York Herald_ of June 13th, 1895, mentions the case of a coloured woman
in North Carolina, who was more than 140 years old, and of a man 125
years old.

Women more frequently become centenarians than men, although the
difference is not very great. For instance, in Greece, in 1885, in a
population of nearly two millions (1,947,760), there were 278 persons
aged from 95 to 110 years, of whom 133 were male and 145 female.

In the seven years, from 1833 to 1839 inclusive, according to Chemin,
there were in Paris twenty-six men over the age of 95, and forty-five
women. Such facts, and many others, support the general proposition
that male mortality is always greater than that of the other sex.

In most cases centenarians are notably healthy and of strong
constitution. There are instances, however, of abnormal people having
reached a great age. A woman, called Nicoline Marc, died in 1760, at
the age of 110. Since she was two years old, her left arm was crippled.
Her hand was bent under the arm like a hook. She was a hunch-back, and
so bent that she appeared to be no more than four feet high. A Scotch
woman, Elspeth Wilson, died at the age of 115 years. She was quite
a dwarf, being only a little over two feet high. On the other hand,
although they usually have a very short life, giants have been known to
reach the age of 100.

Haller, in the eighteenth century, remarked that centenarians often
occurred in the same family, as if longevity were a hereditary
quality. It is certainly the case that the descendants of centenarians
frequently reach extreme age. Thomas Parr, for instance, left a son
who died in 1761, at the age of 127 years, having retained his mental
faculties until death. In M. Chemin’s list of centenarians, there
are eighteen cases of extreme old age having been reached by their
relations. As all innate characters can be transmitted, the influence
of heredity and longevity must be admitted. At the same time, it
is necessary to remember the important influence of the similarity
of conditions in the case of parents and children. Many cases of
tuberculosis and leprosy, which used to be assigned to heredity, are
now known to be due to infection in the same conditions of life, and
some of the examples of the attaining of a great age by more than one
member of a family may be explained by the influence of surrounding
circumstances. Very frequently the husband and wife, although not
related by blood, both attain extremely advanced age. I found 22 cases
of this kind in M. Chemin’s list; I will give a few of them. A widow,
Anne Barak, died at the age of 123, in Moravia; her husband died at the
age of 118. In 1896, there was alive in Constantinople, M. Christaki,
a retired army doctor of the age of 110; his wife was 95 years old.
In 1886, M. et Mme. Gallot, aged respectively 105 years and 4 months,
and 105 years and one month, died within two days of each other at
Vaugirard, 54, Rue Cambronne. Lejoncourt mentions a South American of
143 years old, whose wife had lived to the age of 117.

It is worth enquiring if there be any relation between longevity and
locality. There are some countries in which very many of the natives
reach old age. It appears that Eastern Europe (Balkan States, and
Russia), although its civilisation is not high, contains many more
centenarians than Western Europe. I have already mentioned that Dr.
Ornstein had shown the existence of many extremely old people in
Greece. M. Chemin states that in Servia, Bulgaria and Roumania there
were more than 5,000 centenarians (5,545) living in 1896. “Although
these figures appear to be exaggerated,” wrote M. Chemin, “it is
undoubtedly the case that the pure and keen air of the Balkans, and
the pastoral or agricultural life of the natives, predisposes to old
age.” The same author mentions several localities in France, notable
for the numbers of very old people. In 1898 in the commune of Sournia
(Pyrénées-Orientales) the total population was 600, amongst which there
was one woman of 95 years, a man of 94, a woman of 89, two men of 85,
two of 84, and two of 83, three women of 82, and two men of 80. At St.
Blimont in the Department of the Somme, amongst the 400 inhabitants
alive in 1897, there were six men between the ages of 85 and 93 years
and one woman in her 101st year.

It cannot be accepted that it is the keen air which lengthens the life,
because Switzerland, a mountainous country, is notable for the rarity
of centenarians. It is more likely that some circumstance in the mode
of living influences longevity.

It has been noticed that most centenarians have been people who were
poor, or in humble circumstances, and whose life has been extremely
simple. There are instances of rich centenarians, such as Sir Moses
Montefiore who died at the age of 101, but such are extremely rare.
It may well be said that great riches do not bring a very long life.
Poverty generally brings with it sobriety, especially in old age, and
it has been often said that most centenarians have lived an extremely
sober life. They have not all followed the example of the celebrated
Cornaro, who brought himself to subsist on a daily diet of no more than
twelve ounces of solid food, and fourteen ounces of wine, and who,
although his constitution was weak, lived for about a century. He has
left extremely interesting Memoirs, and retained his intelligence until
his death on the 26th April, 1566 (Lejoncourt, p. 146).

In M. Chemin’s list I have counted twenty-six centenarians,
distinguished by their frugal life. Most of them did not drink wine,
and many of them limited themselves to bread, milk and vegetables.

Sobriety is certainly favourable to long life, but it is not necessary,
because quite a number of centenarians have drunk freely. Several of
those who are catalogued by Chemin, drank wine and spirits even to
excess. Catherine Reymond, for instance, who died in 1758 at the age of
107 years, drank much wine, and Politiman, a surgeon who lived from
1685 to 1825, was in the habit, from his twenty-fifth year onwards, of
getting drunk every night, after having attended to his practice all
day. Gascogne, a butcher of Trie (Hautes-Pyrénées), died in 1767 at the
age of 120, and had been accustomed to get drunk twice a week. A most
curious example is that of the Irish land-owner Brawn, who lived to the
age of 120, and who had an inscription put upon his tombstone that he
was always drunk, and when in that condition was so terrible that even
death had been afraid of him. Some districts, even, are distinguished
at once for the longevity of their inhabitants and for the large local
consumption of alcohol. In 1897, village of Chailly in the Côte-d’Or
had no less than twenty octogenarians amongst 523 inhabitants. This
village is one of the localities in France where most alcohol is
consumed, and the old people are very far from being distinguished from
their younger fellows by any special sobriety.

In some cases centenarians have been much addicted to the drinking
of coffee. The reader will recall Voltaire’s reply when his doctor
described the grave harm that comes from abuse of coffee which acts as
a real poison. “Well,” said Voltaire, “I have been poisoning myself for
nearly 80 years.” There are centenarians who have lived longer than
Voltaire, and have drunk still more coffee. Elisabeth Durieux, a native
of Savoy, reached the age of 114. Her principal food was coffee, of
which she took daily as many as forty small cups. She was jovial and a
boon table companion, and used black coffee in quantities that would
have surprised an Arab. Her coffee-pot was always on the fire, like the
tea-pot in an English cottage (Lejoncourt, p. 84; Chemin, p. 147).

It has been noticed that many centenarians do not smoke, but this like
all other traits is not universal. M. Ross, who gained a prize for
longevity in 1896 at the age of 102, was an inveterate smoker. In 1897,
a widow named Lazennec, died at La Carrière, in Kérinou, Finistère, at
the age of 104. She lived in a hovel on charity, and she had smoked a
pipe ever since she was quite young.

It is plain that any factor to which long duration of life has been
attributed disappears when many cases are examined. Naturally a sound
constitution and a simple and sober life are favourable to longevity,
but apart from these, there is something unknown which tends to long
life. The celebrated physiologist of Bonn, Pflüger,[70] came to
the conclusion that the chief condition of longevity is something
“intrinsic in the constitution,” something which cannot be defined
exactly, and which must be set down to inheritance.

In the present state of knowledge, we cannot denote the chief cause of
human longevity, but the proper course will be to seek it out as we
would seek out that of animal longevity. As human longevity is often
local in its character, and is exhibited by married people who have
nothing in common except their mode of life, we may enquire into the
intestinal flora and the mechanism by which the organism resists its
harmful effect as factors which influence the duration of life. It is
reasonable to suppose that in persons living in the same district or
under the same roof, the intestinal flora may be similar. The problem
can be settled only by a series of laborious researches which have yet
to be made. At present I can do no more than bring together a large
number of facts regarding the duration of life in man and in animals,
with the hope of suggesting the lines for future investigation.

PART III

INVESTIGATIONS ON NATURAL DEATH

NATURAL DEATH AMONG PLANTS

Theory of the immortality of unicellular
organisms—Examples of very old trees—Examples of
short-lived plants—Prolongation of the life of some
plants—Theory of the natural death of plants by
exhaustion—Death of plants from auto-intoxication

It must surprise my readers to find how little science really knows
about death. Although death has a preponderating place in religions,
systems of philosophy, literature and folk-lore, scientific works pay
little attention to it. This unfortunate fact explains, although it may
not justify, the bitter attack made on science on the grounds that it
is occupied with minutiæ and neglects the great problems of human life,
such as death. When Tolstoi was absorbed by the problem and searched
for some solution in the writings of scientific men, he found that the
explanations were trivial or inexact. In consequence he was extremely
indignant with the men who devoted themselves to the investigation of
what seemed to him useless problems (such as the insect world, or the
structure of cells and tissues) and who were yet unable to say what the
destiny of man or death might be.

I am far from claiming to solve these problems; I can do little more
than describe the actual state of the question of natural death. I hope
in this way at least to prepare for scientific investigation, and to
call attention to it as the most important problem of humanity.

By the use of the phrase “natural death” I mean to denote a phenomenon
that is intrinsic in the nature of an organism and that is not the mere
result of an external accident. Popular phraseology includes under
natural death all cases due to diseases. But as such deaths can be
avoided and are not due to qualities inherent in the organism, it is
erroneous to include them in the category “natural death.”

In nature, death comes so frequently by accident that there is
justification for asking if natural death really occurs. It used to be
thought that death was the inevitable end of life and that the living
principle contained within itself the germ of death. Accordingly,
it was a surprising discovery that many low organisms die only by
accident, and that if such accident be avoided, death does not fall on
them. Unicellular organisms (such as infusoria, many other protozoa
and low plants) multiply by simple division, the organism thus giving
rise to two new organisms; the parent so to speak loses itself in its
offspring without undergoing death. To criticisms of this mode of
presentment of the facts, Weismann, who has attracted most attention
to the view, replied as follows:—“In cultures of Infusoria, these
little animals continually multiply by division and no dead bodies are
found. The individual life is short, but it ends not in death but in
transformation to two new individuals.”

Max Verworn,[71] a physiologist of repute, objected that Weismann had
overlooked the occurrence within the organism of a process of partial
destruction, and that under certain conditions a complete organ of
the infusorian body (the nucleus) dies and is absorbed. Such death of
a part, however, is not followed by death of the whole, and as the
continuous destruction of some of the cells in our own bodies is not
regarded as our death, the criticism of the German physiologist cannot
be accepted.

It is not only the extremely short-lived microscopic organisms that
escape death. Some of the higher plants, which may attain to gigantic
size, encounter death only by accidents. There is nothing to be found
in the nature of their organisation which would seem to indicate that
death is the inevitable or even probable result of their constitutions.

The longevity of some trees has long been notorious, as these appear to
live for many centuries and to die only when they are overwhelmed by
the ravages of a storm or killed by human agency.

When the Canary Islands were discovered, in the beginning of the
fifteenth century, the early explorers were struck with the gigantic
size of a dragon tree which was venerated by the natives as their
tutelary deity. The tree stood in a Garden at Orotava in Teneriffe,
and even in these early days, its huge trunk contained a gigantic
hollow. The tree did not reward the worship of the natives, who
were annihilated by the Spaniards, and it survived them for nearly
four centuries. At the end of the eighteenth century it was seen
by Humboldt,[72] who found that the trunk was forty-five feet in
circumference, and who attributed to it a great age because dragon
trees grow extremely slowly. Early in the nineteenth century (1819) a
furious tempest swept over Orotava and with a gigantic crash nearly
a third of the crown of leaves and branches fell on the ground.
Notwithstanding this shock, the monster survived for fifty years.
Berthelot,[73] who visited it in 1839, described it as follows:—“A
dragon tree stood in front of my dwelling, grotesque in form, gigantic
in size, which a storm had smitten without overwhelming. Ten men would
have much ado to girdle its vast trunk, fifty feet in circumference at
the ground. The huge column had a deep cave within it, hollowed by the
ages; a rustic porch gave access to the interior, and the lofty dome,
although half had been destroyed by a storm, still bore an enormous
crown of branches.”

[Illustration: FIG. 15.—The Dragon-tree of the villa Orotava.]

The famous dragon-tree got more and more damaged, and was finally
overthrown by a storm in 1868. A few years after the catastrophe (in
1871) I myself saw the remains of the colossus, lying on the ground as
a huge grey mass like some antediluvian monster. No accurate estimate
of its age can be formed, but it must have lived several thousand years.

Trees have been known which were still older than the dragon-tree of
Teneriffe. One of the best known is the baobab of Cape Verd, described
by Adanson. “This remarkable tree was thirty feet in diameter when the
famous French naturalist measured and described it. Three centuries
earlier, some English sailors had cut an inscription on it, and
Adanson laid this bare by removing three hundred layers of wood. On
his observations Adanson based an estimate of 5,150 years as the age
of the tree.[74] The old cypresses of Mexico are thought to be still
older. A. de Candolle[75] concluded that the cypress of Montezuma was
2,000 years old when he saw it, and that the cypress at Oazaca was much
older than the tree described by Adanson. In California, trees of the
species _Sequoia gigantea_ are three thousand years old, and Sargent,
an American botanist, attributes to some of them an age of at least
five thousand years.

The question of the nature of individuality in the vegetable world
has been raised in connection with the longevity of trees. It has
been asked if a tree is to be regarded as a single individual or as
a colony of many plants like a branching polyp. It is a difficult
question, but only of secondary importance from the point of view of
this discussion. A. de Candolle,[76] having paid special attention to
the subject, came to the conclusion that trees do not die of old age,
that, in the real sense of the phrase, there is no natural end of their
existence. Many botanists agree with him. Naegeli[77] holds that a tree
several thousand years old dies only from external accidents.

It is plain that amongst the lower plants and the higher plants there
are cases where natural death does not exist. Theoretically, life would
have an unlimited duration, subject to the continuous replacement of
the substance of the organism in the normal metabolism. It must not be
inferred, however, that there is no such occurrence as natural death
amongst plants. There are numerous cases where death comes quite apart
from the agency of external forces. Even amongst closely related plants
there are some cases where natural death does not occur, and others
where it is normal. The lower fungi offer a good instance. Some of
these pass through a longer or shorter vegetative stage and then the
living mass breaks up into spores (_Myxomycetes_). The whole bulk of
matter is not transformed, but the remnant consists only of cuticular
secretions, not living cells. In other fungi, only some of the cells
transform to spores, the others dying naturally.

One stage of the life history of some lower plants is of short
duration. The prothalli of some cryptogams (_Marsiliaceæ_) live only a
few hours, just long enough for the appearance of the sexual organs.
When these are ripe the body of the prothallus and all its constituent
cells fall a prey to natural death. In such cases there is a “corpse,”
composed of dead cells and protoplasm. Even amongst the higher plants
there are instances of an extremely short duration of life. _Amaryllis
lutea_ passes through all the stages of its life-history in ten days,
the minimum time necessary for the sprouting of the leaves and flowers
and the production of the seeds, after which it dies naturally.[78] It
is interesting to find that in the same family there are other plants
notable for long duration of life. The Agave requires a century to
produce its flowers before death comes naturally.

Everyone is familiar with the so-called “annual” plants which live
only a few months, from the time when they sprout, until, after the
production of seed, death comes to them naturally. The life of annuals,
however, can be preserved for two or for several years. Rye is normally
an annual, but some varieties are able to live for two years and
produce two crops. The Cossacks of the Don have established this fact,
and have cultivated a biennial variety of rye for many years.[79]
Beetroot[80] is normally biennial, but has been changed to a plant
which lives for from three to five years. Such instances are by no
means unique.

Natural death can be postponed if the plant be prevented from seeding.
Professor Hugo de Vries has prolonged the life of the Oenotheras he
cultivates, by cutting the flowers before fertilisation. Under ordinary
conditions the stem dies after producing from forty to fifty flowers,
but, if cutting be practised, new flowers are produced until the winter
cold intervenes. By cutting the stem sufficiently early, the plants are
induced to develop new buds at the base, and these buds survive winter,
and resume growth in the following spring.” (Extract from a letter of
Prof. H. de Vries.)

The grass of lawns is usually mowed before it begins to flower, so as
to prevent the ripening of the seeds and the death of the plant. When
this is done, the grass remains continually green, and its life lasts
for several years.

The connection between the seeding of plants and their natural death
has been recognised for long, and is usually explained as being due to
the exhaustion of the plant.

As I am not a botanist, and was anxious to know the views of botanists
on natural death, I wrote to Prof. de Vries, as a universally accepted
authority. The distinguished botanist replied to me as follows. “Your
question is extremely difficult. I do not think that much is known as
to the exact cause of the death of annual plants, but it is customary
to attribute it to exhaustion.” All the botanists who have expressed
opinions on this matter appear to hold a similar view. Hildebrand,[81]
the author of a memoir on the duration of life in plants, stated this
view again and again. According to him “the life of annuals is usually
short because they are exhausted by their extensive production of seeds
(p. 116).” “Even amongst plants which produce seeds for several years,
there are some which are prematurely exhausted by fructification and
which die spontaneously” (p. 67). In the prothallus of many of the
higher cryptogams, the formation of a single embryo is followed by
natural death; as Goebel[82] points out, the embryo completely absorbs
the prothallus.

As plants generally obtain their food with ease, it is natural to ask
what is the cause of the exhaustion after seeding. When a plant which
cannot resist cold dies after it has produced its seeds in the end of
the summer, the event is natural enough. But how can we explain the
death of an annual plant which is growing in a rich soil, and which
seeds in the beginning of the summer, as being due to exhaustion long
before the winter cold. It frequently happens that after harvest new
shoots spring up from grains which have fallen. The soil which can
support this new vegetation cannot have been exhausted by the cereal
in question; and there has been enough warmth for the new crop. It
cannot be the external conditions which have caused the death of
the parent plant. The explanation of this apparent contradiction
has been sought in the constitution of the plant itself. Hildebrand
remarks that “certain species have a constitution which tends to early
fructification. As soon as the seeds have been set, the strength of the
plant is exhausted in the swelling of the grains, so that the plant
dies.” “Other species, on the contrary, are so constituted that they
vegetate for a long time, before fruiting, after which, however, they
also die. A third set of plants have such a constitution that “they
do not die after seeding, that they can seed often and live for many
years” (p. 113).

Being unable to indicate exactly the intrinsic mechanism of these
different “constitutions,” several botanists explain them by a kind of
teleological predestination. According to Hildebrand “the nutritive
processes of a plant have no other purpose than to make it capable of
reproduction; this final end, however, can be reached in different
modes and after different periods of time” (p. 132). Goebel sets
down similar views. “In heterosporous plants the whole course of the
development of prothalli is predetermined. The prothalli, so far as
we actually know, to use the phrase of theologians, are predestined;
their fate is determined once for all” (p. 403). M. Massart[83]
expresses the same kind of view, when he says that “sometimes cells
die because their work is finished, and they have no longer any reason
for existing.”

Such an interpretation of the facts is quite opposed to determinism,
and makes the problem of natural death in the plant world more
difficult but more interesting.

The modern scientific conception of the universe excludes the idea
of predestination. The relations between fructification and natural
death must be regulated by the law of selection, according to which no
organism survives if its reproduction is impossible. It occasionally
happens that children are born without organs which are indispensable
to life. Such monsters of different kinds being non-viable, cannot be
said to be predestined to death, as they die because of defects in
their structure. Others are born with all that is necessary for life,
and survive for that reason, not because they are predestined to life.
So also species of plants which develop incompletely and which die
before they have produced spores or seeds, cannot survive; whilst those
which die after having given birth to the next generation survive in
their descendants. However quickly death follow the production of seed,
the species will survive equally well. The cause of the natural death
of plants must be sought, therefore, not in predestination, but in the
mechanism of the organic processes.

Nothing seems more probable than that a plant should die when all its
organic forces have been exhausted. It would be interesting, however,
to ascertain the mechanism of that exhaustion, and this especially
because it is often very difficult to imagine a cause for it. Many
plants exist which produce several generations each season, in the same
soil, without exhausting it. In perennial plants, some parts, such
as the flowers, die periodically, although the plant itself is not
exhausted. Everyone has seen that in geraniums some of the flowers
wither whilst others are blooming, the process going on throughout the
season. We can scarcely attribute such a natural death of the flowers
to any exhaustion of the plant which continues to produce new flowers.

The fairly frequent prolongation of the life of plants is also
out of harmony with the theory of natural death as the result of
exhaustion. It sometimes happens that male plants produce female
flowers abnormally; cases of this kind have been observed in willows,
stinging-nettles, hops, and especially in maize.[84] Here we have
to deal with a kind of monstrosity, differing, however, from the
non-viable monsters of the human race, in the respect that the
production of female flowers on the male branches results in the
prolongation of their lives. Generally the male branches die a natural
death as soon as the pollen has been shed, and therefore some time
before the death of the female flowers. If, however, a male branch
bears a female flower which becomes fertilised, then the life of the
branch is prolonged until the seeds ripen. If the natural death of the
male flowers is the result of exhaustion due to the development of the
pollen, how can we reconcile this with the prolongation of life in a
case where the male branch has also female flowers to nourish and seeds
to mature?

It is quite clear that natural death, in such cases, is the result of a
mechanism more complex than simple exhaustion.

Prof. de Vries has already noted that the duration of life in plants
depends on their vital processes. That view implies that there are some
qualities inherent in its organisation which can prolong or shorten
the life of a plant, and it is here that we ought to find the key
to the problem of natural death in the vegetable world. However, to
gain exact knowledge of such factors, it would be necessary to have
information on many points in plant physiology which unfortunately are
very imperfectly known. In this respect, the vital conditions of the
simplest plants, such as yeasts and bacteria, have been investigated
much more fully. It is true that such low organisms reproduce freely
either by division or by budding, so that they are amongst the
organisms in which natural death is not inevitable. None the less, in
their lives phenomena occasionally present themselves which can be
interpreted as cases of natural death.

At a time when it was still unknown that all fermentation was due
to the action of microscopic plants, it had been observed that, in
certain conditions, fermentation ceased much more quickly than in
other conditions. For instance, when sugar is being transformed to
lactic acid, it is useful to add chalk, as otherwise the fermentation
stops before the greater part of the sugar has been acted upon. When,
in 1857, Pasteur made his great discovery of the lactic acid microbe,
he showed that that little organism, although it could produce lactic
acid, was interfered with by an excess of the acid. To secure complete
fermentation, it was necessary to neutralise the acid by the addition
of chalk.

When the action of lactic acid is continued too long, it not only
arrests the process of fermentation but definitely kills the microbe.
It is for that reason that it has been found difficult to preserve the
lactic acid ferment for a long time in a living condition. Amongst the
ferments which have been isolated from Egyptian ‘leben’ by MM. Rist and
Khoury[85] there is one which is extremely delicate.

When it is inoculated deep in a nutritive medium, it dies in a few
days, death, without doubt, being due to the lactic acid produced by
the microbe from the sugar and not neutralised. As this transformation
of sugar into lactic acid is a fundamental property of the microbe,
depending on its constitution, the arrest of the fermentation and the
death of the ferment in these definite conditions can be interpreted
only as natural death due to auto-intoxication, that is to say to
poisoning by a product of the physiological activity of the microbe
itself. As death takes place at a time when the medium still contains
enough sugar for the nutrition of the microbe, it is certain that
it cannot be the result of exhaustion. This case of the lactic acid
ferment is not unique. The microbe which produces butyric acid is
also interfered with by the acid it secretes. M. G. Bertrand, who has
examined carefully the microbe which produces fermentation in sorbose
(sugar extracted from fruit of the service-tree) (_Sorbus domestica_)
has informed me that this fermentation, too, ceases under the influence
of the secretions of the microbes, and that the microbes undergo
natural death at a time when the medium is far from exhausted of the
nutritive material. The yeast which produces alcohol is also interfered
with by an excess of alcohol, and as soon as a certain limit of
alcoholic strength has been reached, fermentation stops. When the yeast
is grown in media rich in nitrogen and poor in sugar, the plant takes
the nitrogenous material and produces salts of ammonia. These alkalies
damage the yeast and cause its death by auto-intoxication.[86]

In the examples that I have given, natural death was a result of
the activity of the microbes, and was in correlation with their
organisation. Such death can be avoided by changing the external
conditions, and, if the acids or alkalies produced by these bacteria
are neutralised, the bacteria survive. The facts are in harmony with
those that I described in the case of the higher plants. By preventing
the ripening of seed, the life of many annual plants may be preserved
and the plants changed to biennials or perennials. In such cases death,
although the result of the constitution of the plant, may be postponed.

We may ask then if the natural death of higher plants, usually
attributed to exhaustion, cannot be explained more simply as the
result of poisons produced in their metabolism. Many plants produce
poisons which are fatal to animals and man. May they not also produce
substances fatal to themselves? There is nothing improbable in the
supposition that some of the poisons may develop when the seeds are
ripening. By preventing the latter process, the ripening of the whole
organism may also be prevented. Such a theory would explain the many
cases of natural death which occur whilst the cell is far from having
reached exhaustion. The equally numerous cases of partial death, such
as that of flowers, whilst the same stem is still producing other
flowers (_e.g._ geraniums) would be explained by a local action of the
poisons not strong enough to kill the whole plant.

I must insist that this theory, that natural death of the higher
plants, is the result of auto-intoxication, is a mere hypothesis
which future investigations may disprove. If, however, it comes to be
confirmed, it would explain the coincidence of death and fructification
more simply than the hypothesis of predestination.

The higher plants may be subjects of auto-intoxication in the same
fashion as bacteria and yeasts. If these poisons were produced before
the ripening of the seeds, the plants would remain sterile, leaving
no descendants, so that the race would become extinct. The production
of poisons at the time of fructification would not interfere with the
succession of generations, and the race would be preserved. As the
poisoning is not necessary, it is easy to understand why many plants
survive seeding and escape natural death. The Dragon-tree, baobab, and
the cedars, which I spoke of earlier, would be examples of such escape.

Although the existence of auto-intoxication in the higher plants is
still only a hypothesis, the natural death of bacteria and yeasts by
poisons which they themselves produce is an ascertained fact.

In the plant world, therefore, there are examples of natural death
(bacteria and yeasts) due to auto-intoxication, and there are other
cases where high or low plants escape natural death.

NATURAL DEATH IN THE ANIMAL WORLD

Different origins of natural death in animals—Examples
of natural death associated with violent acts—Examples
of natural death in animals without digestive
organs—Natural death in the two sexes—Hypothesis as to
the cause of natural death in animals

The cases of natural death amongst animals differ from those found in
the vegetable world by their greater variety and complexity. As M.
Massart has shown for plants, so also natural death must have become
established independently in different groups of animals. In some
cases, the characters presented are strange and almost paradoxical.

It is usual to contrast natural death with violent death on account of
the difference between the two. None the less, natural death may occur
in the animal kingdom, that is to say death resulting directly from the
constitution, and yet in intimate association with violent acts. I will
give some examples.

Small, helmet-shaped organisms, transparent and graceful, are common on
the surface of the sea. These have been described by zoologists under
the name _Pilidium_. The organisation is simple. The body wall is a
delicate pellicle, through which, on the lower surface, a mouth leads
into a capacious stomach. Continual movements of waving cilia direct
small particles of food through the mouth to the digestive stomach.
As there are no organs of reproduction, it was assumed that these
creatures were not adults, but floating larvæ of some marine animal,
and, after a good deal of trouble, it was found that the Pilidia were
the young stages of ribbon-shaped worms of the group of Nemertines.
At a definite stage in the life-history, a fœtus begins to develop
round about the stomach of the Pilidium, and eventually completely
encloses it and detaches it by violent muscular contractions. The end
of the story is that the fœtus abandons the body of the Pilidium
carrying off with it the stomach, an organ necessary to the maintenance
of life. The remnant of the Pilidium swims about in the sea-water, but
soon dies as the result of the mortal wound caused by the removal of
the digestive organs.

The act by which the Nemertine separates from its mother is violent,
and yet the death of the Pilidium must be regarded as natural. It is
the result of agencies within the body and not, as in most cases of
accidental death, of violence from without.

The group of Nematode worms contains many common intestinal parasites
of man, such as _Ascaris_, _Trichina_, _Trichocephalus_, _Oxyuris_,
&c., but also others that live free in soil or water or in such fluids
as vinegar. They are protected by a strong cuticle, and some of them
are viviparous, that is to say, instead of laying eggs they give
birth to young worms already well grown and capable of independent
activity. Amongst the human Nematode parasites, the _Trichinæ_ give
birth to swarms of small larvæ which easily escape from the body of
the mother by the female generative aperture. In the case of some
free-living Nematodes, however, the female aperture is too small to
give passage to the rather stout larvæ. More than forty years ago, when
I was investigating the life-history[87] of one of these Nematodes
(_Diplogaster tridentatus_) I was struck by the fact that the larvæ
could leave the body of the mother only by violence and after they had
devoured most of its substance. These larvæ develop from eggs produced
within the maternal body. As the external reproductive aperture of
the female is minute, the larvæ cannot escape through it, but wander
amongst the tissues tearing and absorbing them. The mother soon dies,
and although her death is violent, it must be included in the category
of natural death.

From the teleological point of view it might be said that Pilidium
and Diplogaster cease to live because they have fulfilled their
function of giving rise to a Nemertine or young Nematodes. Their
natural death would thus be predestined. There is no ground for such
an interpretation. On the other hand, it is certain that this death,
coming after the birth of the new generation, is in no way against the
preservation of the species in which the extraordinary natural death
by violence occurs. If the female orifice of Diplogaster were slightly
larger, the larvæ would emerge without difficulty and without causing
the death of the mother which none the less would have fulfilled her
purpose.

All the cases of natural death amongst animals are not so brutal as
those of the Pilidium and the Nemertine worms. In many instances the
death is peaceful. As very frequently it is difficult to establish
definitely that the death is natural, I shall select clear cases.

Animals are occasionally found which are devoid of some organ necessary
for prolonged life. The absence of a digestive tract in an animal that
lives in an environment rich in dissolved nutritive material (as for
instance tapeworms living in the intestinal tract) is not surprising.
But when creatures of the sea or of fresh water have no digestive
tract, their life can be maintained only at the expense of nutritive
material stored within them during embryonic life. The death which
comes eventually is truly natural. The best cases, that is to say those
which can be studied most completely, of such natural death occur
amongst the Rotifera. These are minute creatures of fresh or sea water,
at one time confused with the Infusoria, but possessed of a much more
complex organisation. They have a well-developed digestive tube, organs
of excretion, nervous system, and organs of sense. The animals are
diœcious; in each species both males and females exist. Whilst the
females have the complete structure of the species, the males are much
reduced, and are devoid of a digestive canal. The cuticle is fairly
stout, and they are unable to absorb dissolved nutriment through it; as
they have no organs of digestion, their life must be short.

To study in detail the life and death of these creatures, I selected a
species sent to me by M. Haffkine. So far as I can judge, the species
in question is a hitherto unknown member of the genus _Pleurotrocha_,
and I propose for it the name _Pleurotrocha haffkini_. This rotifer is
convenient to study as it thrives in vessels containing fresh-water to
which some bread-crumb has been added (in the proportion of a gram of
bread to 500 grams of water).

The sexes of the little rotifer can be distinguished from the earliest
age, for eggs that are to become females are much larger than those
from which males develop. It is easy to isolate the male eggs and to
follow the life-history up to the moment of natural death. The whole
course of life from the laying of the egg until death lasts only about
three days, and is probably the shortest duration of life in the animal
kingdom. Although some Ephemeridæ live only a few hours in the adult
state, their total life-cycle is much longer than that of the rotifers,
as the larval stages last for months or even for years.

[Illustration: FIG. 16.—Male _Pleurotrocha haffkini_.]

The little males (Fig. 16) begin to swim soon after hatching, the
wheel-apparatus and the musculature being vigorous. They seek out
the females, as their reproductive organs are mature almost at the
moment of hatching. The transparent body, which is devoid of digestive
apparatus, swarms with mobile spermatozoa. As soon as the male has
seized a female, he discharges the contents of his body. It might be
supposed that such an evacuation would cause a violent perturbation of
the system leading to the death of the organism. There is no question
of this however. The males are able to live for twenty-four hours after
having accomplished their function, and the period represents a third
of their total duration of life. Moreover, I have isolated males from
females without any prolongation of their lives. In one experiment, I
isolated two males and placed a third in company with two females. It
was the third specimen that lived longest.

The natural death of the males is foreshadowed by a weakening of the
movements; although the muscles and cilia remain mobile, the whole
animal moves only spasmodically; sometimes the muscles of the head
contract, sometimes those of the tail, but no locomotion occurs.
Occasionally there is a violent effort of ciliary motion as if the
attempt were being made to overcome the immobility of the body. Such
a condition lasts for several hours and is followed by death. The
spermatozoa inside the body retain activity last of all.

Towards the crisis, bacteria, which abound in the medium occupied by
the rotifers, begin to attack the males. Some cluster round the head,
others round the tail, although none of them can effect entrance to
the body. The death of the males cannot be attributed to microbial
infection, but comes from some intrinsic cause.

Is it inanition that is the cause of death? I do not think so, because
up to the time of death the tissues appear to be unmodified. In the
case of the females I have sometimes seen phenomena of inanition. In
old and exhausted cultures the starved females become thin, flattened
and quite transparent, and the tissues lose their granular appearance.
No such changes are visible in the dying males, the tissues of which,
on the contrary, retain a normal aspect.

The most probable explanation is that death comes from poisoning by the
secretions of the tissues themselves. The large size of the organs of
excretion indicates that in the course of metabolism waste matter is
produced some of which is got rid of. If, after a time, the secretions
are insufficiently eliminated, the tissues must be poisoned. As death
is preceded by a spasm of uncoordinated movement, it appears as if the
fatal intoxication of the males affected the nervous system first. The
vibrating cilia and the muscles are attacked later.

There can be no doubt but that the death of these male rotifers is
natural in the fullest sense. The females, however, although they are
provided with complete digestive organs, do not escape a similar fate.
Their life is longer and more complex than that of the males, and so
is subject to many more chances. The females therefore may come to die
from starvation or from other external, accidental causes. But, if they
are kept in favourable conditions, they may live for about fifteen
days, towards the end of which they die naturally, exhibiting the
symptoms that I have described in the case of the males (Fig. 17).

[Illustration: FIG. 17.—Female _Pleurtrocha haffkini_, which has died
a natural death.]

Rotifers are not the only animals which undergo natural death in a
fashion quite unlike the violent end of Pilidium and Diplogaster. There
are other cases amongst invertebrates, but I shall limit myself to
describing one that is well ascertained.

More than fifty years ago, Dana, the American naturalist, discovered a
pelagic marine creature with characters so curious that he gave to it
the name _Monstrilla_. It is a little crustacean akin to the _Cyclops_
of lakes. But although the latter is endowed with the organs necessary
to capture and digest food, _Monstrilla_ has neither organs of
prehension nor a digestive canal. It is a highly muscular animal with
organs of sense and reproduction and a nervous system; but it is devoid
of apparatus for prolonging life by nutrition. _Monstrilla_ therefore
is a creature doomed to natural death.

[Illustration: FIG. 18.—_Monstrilla._ (After M. Malaquin.)]

The detailed observations of M. Malaquin[88] have supplied full
information regarding this strange life-history. _Monstrilla_ passes
a portion of its life as a parasite on Annelid worms. In that stage
it accumulates the necessary material for the growth of the sexual
products (ova and spermatozoa) and for free life in the sea whilst the
young are developing. It is not only the males which have no digestive
apparatus. The females also lack it, which is the more surprising as
they carry about the eggs attached to the body (as is done by many
other Crustacea, such as crayfish and lobsters) until the young are
ready to hatch (Fig. 18). M. Malaquin thinks that the Monstrillas die
of starvation.

“As they are without a digestive tube or organs of prehension or
mastication,” M. Malaquin says (p. 192), “the Monstrillas, which have
no means of nutrition, are doomed to death from inanition after a short
pelagic life. This is a logical inference from their structure.”

In support of his view, M. Malaquin states that before death the
tissues and organs show plain signs of degeneration.

“The eyes first show traces of degeneration. The pigment spreads and
disappears little by little and then the visual elements fade out.”

“Finally, individuals, usually females, show complete degeneration.
A female taken in a fine-meshed net showed no trace of organs in the
head; the eyes, the brain and the intestinal tract had disappeared
almost completely. The antennæ were reduced to stumps consisting of the
lowest joint and a portion of the second. These were clear indications
of the senility that precedes death” (p. 194).

Such evidence not only supports the hypothesis that the natural
death of Monstrilla is due to inanition, but is opposed to a similar
interpretation being applied to the case of male rotifers, in which
death is not preceded by wasting of the organs. The death of some
insects, which comes rapidly after the adult stage has been reached,
cannot readily be attributed to starvation. In the strange butterflies
known as psychids (_Solenobia_) some of the females lay eggs without
having been fertilised,[89] and their life in the adult condition lasts
only a day. On the other hand, other females of the same butterfly
are fertilised before laying their eggs and in this case survive for
more than a week although they take no food. The rapid death of the
first-mentioned set cannot be attributed to inanition.

In some Ephemeridæ, which supply good cases of natural death, the end
comes after a few hours of adult life without any sign of degeneration
of the organs. As in others (_Chloë_), life lasts for several days
without food having been taken, it is clear that inanition is not
the cause of the swift arrival of death in the first set. It is much
more probable that the natural death is due to an auto-intoxication
which takes effect at different intervals of time in different
circumstances.[90]

In the higher animals such as vertebrates the conditions are less
favourable than in the case of insects for the investigation of the
causes of natural death. Vertebrates have always well-developed organs
of digestion and so live a relatively longer time and encounter a
greater number of chances of accident, with the result that in most
cases death comes from external accidental causes. Vertebrates usually
perish from hunger or cold, or are devoured by their enemies or killed
by the attacks of parasites or diseases. There remains only the human
race amongst the more highly developed animals, in which to study
the onset of natural death. And in the human race cases which may be
designated as natural are extremely rare.

III

NATURAL DEATH AMONGST HUMAN BEINGS

Natural death in the aged—Analogy of natural death and
sleep—Theories of sleep—_Ponogenes_—The instinct
of sleep—The instinct of natural death—Replies to
critics—Agreeable sensation at the approach of death

The death of old people, which has often been described as natural
death, is in most cases due to infectious diseases, particularly
pneumonia (which is extremely dangerous) or to attacks of apoplexy.
True natural death must be very rare in the human race. Demange[91]
has described it as follows:—“Arrived at extreme old age, and still
preserving the last flickers of an expiring intelligence, the old man
feels weakness gaining on him from day to day. His limbs refuse to obey
his will, the skin becomes insensitive, dry, and cold; the extremities
lose their warmth; the face is thin; the eyes hollow and the sight
weak; speech dies out on his lips which remain open; life quits the
old man from the circumference towards the centre; breathing grows
laboured, and at last the heart stops beating. The old man passes away
quietly, seeming to fall asleep for the last time.” Such is the course
of what properly speaking is natural death.

The natural death of human beings cannot be regarded as due to
exhaustion from reproduction or from inanition, as in the case
of _Monstrilla_. It is much more likely that it is due to an
auto-intoxication of the organism. The close analogy between natural
death and sleep supports this view, as it is very probable that sleep
is due to poisoning by the products of organic activity.

It is more than fifty years since sleep was explained as the result
of auto-intoxication. Obersteiner, Binz, Preyer, and Errera are among
the competent men of science who have taken this view. The first two
attributed sleep to an accumulation in the brain of the products of
exhaustion which are carried away by the blood during repose. The
attempt has been made even to discover the nature of these narcotic
substances. Some investigators think that an acid, produced during
the activity of the organs, is stored up in quantities that cannot be
tolerated. During sleep, the organism gets rid of this excess of acid.

Preyer[92] tried to put the problem upon a more exact basis by the
theory that the activity of all the organs gives rise to substances
which he called _ponogenes_ and which he regarded as producing the
sensation of fatigue. According to him these substances accumulate
during the waking hours, and are destroyed by oxidation during sleep.
Preyer thinks that lactic acid is the most important of the ponogenes,
and lays stress on its narcotic effect. If his theory were correct,
there would be a remarkable analogy between the auto-intoxication by
lactic acid in the cases of man and animals, and the case of bacteria
which produce the same acid and the fermenting activity of which is
arrested as the acid accumulates. Just as sleep may be transformed
to natural death, so also the arrest of lactic fermentation may be
followed by the death of the bacteria which form the acid.

So far, however, there has been no confirmation of Preyer’s theory.
Errera[93] has brought forward against it another theory according
to which the cause of sleep is not acid products, but certain
alkaline substances described by M. Armand Gautier under the name of
_leucomaines_. Gautier laid down that these substances act on the
nervous centres and produce fatigue and sleepiness. According to Errera
they might very well be the cause of sleep, as that comes on at a
time when there is the greatest accumulation of these leucomaines in
the body. He thinks that their action in producing sleep is a direct
intoxication of the nerve centres. During sleep they are removed, and
the disturbance which was produced in the organism is arrested.

If it were possible to accept Errera’s theory, a kind of analogy could
be established between sleep and natural death on the one hand, and
the arrest of development and death of yeast grown in nitrogenous
media on the other hand, because in the latter case the poisoning is
produced by an alkaline salt of ammonia. It must be confessed, however,
that the actual state of our knowledge does not allow of a definite
view of the real mechanism of the sleep-producing intoxication. Our
ideas regarding leucomaines in general are still incomplete, and,
recently, one of them, _adrenaline_, the product of the supra-renal
capsules, has been investigated. Adrenaline is an alkaloid[94] which is
produced in the supra-renal bodies and is discharged into the blood.
It has the power of contracting arteries strongly, and has been used
to control blood-pressure. When it is given in large quantities or
in frequent doses, it acts as a true poison, whilst, in small doses,
it produces anæmia of the organs and has a special influence on the
nervous centres. Dr. Zeigan[95] has shown that a milligramme of
adrenaline, mixed with five grammes of normal salt solution injected
into the brain of cats, produces a soporific action. “About a minute
after the injection, the animal appears to be plunged into deep sleep
which lasts from 30 to 50 minutes. During this time, the sensitiveness
of the animal has completely ceased throughout the body, and for some
time after that it is much decreased. When they awake the animals
seem to have been drunk with sleep for some time.” Sleep is generally
associated with anæmia of the brain, and as adrenaline can actually
produce such anæmia, it might be supposed that this narcotic substance
is the most important of the organic products which give rise to sleep.
Against this hypothesis, however, some weight must be given to recent
investigations on fatigue and its causes.

Each stage in the advance of knowledge has had its influence on
the study of the interesting and complex problem of sleep. When it
was thought that alkaloids (ptomaines) were of great importance in
infectious diseases, it was attempted to explain sleep as due to the
action of similar bodies. Now, when we believe that in such diseases
the chief part is played by poisons of extremely complex chemical
composition, the attempt is made to explain fatigue and sleep by
similar bodies.

Weichardt[96] has recently made the best known investigations in this
direction. This young man maintains with ardour the view that during
the activity of organs there is an accumulation of special materials
which are neither organic acids nor leucomaines, but which are much
more like the toxic products of pathogenic bacteria.

Weichardt made animals in his laboratory go through fatiguing
movements for hours and then killed them. The extract from muscles of
such animals had a powerful toxic effect when it was injected into
normal animals, producing lassitude and sometimes death within 20 to
40 hours. As all attempts to determine the exact chemical nature of
this fatigue-producing substance were baffled, it is impossible to get
an exact account of it. Amongst its properties there is one of great
interest. When it has passed into the circulation of normal animals in
quantities insufficient to produce death, it excites the formation of
an anti-toxin in the same way as a poison of diphtheria stimulates the
production of a diphtheria anti-toxin.

When Weichardt injected into animals a mixture of the poison which
produces fatigue with small doses of the serum antidote, no results
followed. The neutralising effect of the antidote was apparent
even when it was introduced by the mouth. Towards the end of his
investigations, Weichardt supposed that it would be possible to obtain
a material that would prevent fatigue.

Although it is still impossible to specify exactly the nature of the
substances which accumulate during the activity of organs and which
produce fatigue and sleep, it is becoming more and more probable that
such substances exist, and that sleep is really an auto-intoxication
of the organism. So far, such a theory has not been shaken by any
argument. Recently M. E. Claparède,[97] a psychologist of Geneva,
has argued against the current theory of sleep. He thinks that it
is contradicted by the fact that new-born infants sleep a great
deal, whilst very old people sleep very little. This fact, however,
can readily be explained by the greater sensibility of the nerve
centres of infants, as shown with regard to many harmful agencies. The
other objections of Claparède, such as the fact that sleepiness is
induced by exercise in the open air, or that excess of sleep itself
produces sleepiness, are not really incompatible with the theory of
auto-intoxication. They are facts of secondary importance probably
depending on some complication which the present state of our knowledge
makes it difficult to indicate exactly. The insomnia of neurasthenia,
which Claparède brings forward as another objection, can readily be
explained as due to hyperæsthesia of the nervous tissues which lose
part of their sensitiveness to poisons.

On the other hand, there are many well established facts in agreement
with the theory of auto-intoxication. Leaving out of the question
sleep induced by narcotics, I may mention in this connection the
so-called “sleeping sickness.” It has been proved that this disease
is caused by a microscopic parasite, the _Trypanosoma gambiense_ of
Dutton, which develops in the blood and spreads to the liquid of the
membranes surrounding the central nervous system. One of the most
typical symptoms of the advanced stages of this disease is continual
drowsiness. “The drowsiness increases progressively, and the habitual
attitude becomes characteristic; the head is bent on the breast; the
eyelids are closed; in earlier stages the invalid can be aroused
easily, but, after a time, incurable attacks of sleep overcome the
patient in all circumstances, but especially after meals. These
fits of sleepiness become longer and deeper, until they reach a
comatose condition from which it is almost impossible to arouse the
patient.”[98] The total result of medical knowledge of this disease
is that it is impossible to doubt that the sleepiness is due to
intoxication produced by the poison of the trypanosome.

Claparède has opposed what he calls an “instinctive” theory to
the toxic theory of sleep. According to this theory, sleep is the
manifestation of an instinct “the object of which is to arrest
activity; we do not sleep because we are intoxicated or exhausted, but
to prevent ourselves from falling into such a condition.” However, in
order to bring this narcotic instinct into play, certain conditions
are necessary, one of which certainly would be the intoxication of
the nerve centres. M. Claparède supposes that sleep is an active
phenomenon, induced when waste matter begins to accumulate in the
organism. “To bring about sleep, the nerve centres must be influenced
by waste matter, and this influence can readily be regarded as a kind
of intoxication.”

Hunger is an instinctive sensation as much as sleepiness, but it does
not appear until our tissues are in a condition of exhaustion, the
exact nature of which cannot as yet be indicated. There is no real
contradiction between the toxic and instinctive theories of sleep. The
two theories represent different sides of a special condition of the
organism.

The analogy between sleep and natural death is in favour of the
supposition that the latter, also, is due to an intoxication much more
profound and serious than that which results in sleep. Therefore, as
natural death in human beings has been studied only very superficially,
it is impossible to do more than frame theories regarding it.

It would be natural if, just as in sleep there is an instinctive
desire for rest, so also the natural death of man were preceded by an
instinctive wish for it. As I have already discussed this subject in
the “Nature of Man” (chap. xi) I need not deal with it at length here.
I should like, however, to add some information which I have recently
obtained.

The most striking fact in favour of the existence of the instinct for
natural death in man appears to me to have been related by Tokarsky
in regard to an old woman. While Tokarsky was alive I asked one of
his friends to obtain for me further details of this very interesting
case. Unfortunately Tokarsky could add nothing to what he had already
published in his article. I think that I have discovered the source of
his information. In his famous book on the _Physiology of Taste_[99]
Brillat-Savarin relates as follows:—“A great-aunt of mine died at
the age of 93. Although she had been confined to bed for some time
her faculties were still well preserved, and the only evidence of her
condition was the decrease in appetite and weakening of her voice.
She had always been very friendly to me, and once when I was at her
bedside, ready to tend her affectionately, although that did not
hinder me from seeing her with the philosophical eye that I always
turned on everything about me, ‘Is it you, my nephew?’ she said in
her feeble voice. ‘Yes, Aunt, I am here at your service, and I think
you will do very well to take a drop of this good old wine.’ ‘Give it
me, my dear; I can always take a little wine.’ I made ready at once,
and gently supporting her, gave her half a glass of my best wine. She
brightened up at once, and turning on me her eyes which used to be so
beautiful, said: ‘Thank you very much for this last kindness; if you
ever reach my age you will find that one wants to die just as one wants
to sleep.’ These were her last words, and in half an hour she fell into
her last sleep.” The details make it certain that this was a case of
the instinct of natural death. The instinct showed itself at an age
not very great in the case of a woman who had preserved her mental
faculties. Generally, however, it seems not to appear till much later,
for old men usually exhibit a keen wish to live.

It is a well-known saying that the longer a man has lived the more
he wishes to live. Charles Renouvier,[100] a French philosopher who
died a few years ago, has left a definite proof of the truth of the
saying. When he was eighty-eight years old, and knew that he was
dying, he recorded his impressions in his last days. Let me quote from
what he wrote four days before his death. “I have no illusions about
my condition; I know quite well that I am going to die, perhaps in a
week, perhaps in a fortnight. And I have still so much to say on my
subject.” “At my age I have no longer the right to hope: my days are
numbered, and perhaps my hours. I must resign myself.” “I do not die
without regrets. I regret that I cannot foresee in any way the fate
of my views.” “And I am leaving the world before I have said my last
word. A man always dies before he has finished his work, and that
is the saddest of the sorrows of life.” “But that is not the whole
trouble, when a man is old, very old, and accustomed to life, it is
very difficult to die. I think that young men accept the idea of dying
more easily, perhaps more willingly than old men. When one is more
than eighty years old, one is cowardly and shrinks from death. And
when one knows and can no longer doubt that death is coming near, deep
bitterness falls on the soul.” “I have faced the question from all
sides in the last few days; I turn the one idea over in my mind; I
_know_ that I am going to die, but I cannot _persuade_ myself that I
am going to die. It is not the philosopher in me that protests. The
philosopher does not fear death; it is the _old man_. The old man has
not the courage to submit, and yet I have to submit to the inevitable.”

I know a lady, a hundred and two years old, who is so oppressed by
the idea of death, that those about her have to conceal from her the
death of any of her acquaintances. Mde. Robineau, however, when between
one hundred and four and one hundred and five years old, became quite
indifferent to the close approach of her own death. She often expressed
a wish for it, thinking herself useless in the world.

M. Yves Delage[101] in an analysis of my “Nature of Man” doubted the
existence of an instinct for death. “Animals,” said he, “cannot have
the instinct for death, because they do not know of death. In their
case, we must consider that what happens is an apathy tending to the
abolition of the sense of self-preservation. In man, the knowledge
of death implies that the indifference to its approach cannot be an
instinct.” “There may be developed, at the end of life, a special state
of mind which accepts death with indifference or with pleasure, but
such a state cannot be designated as an instinct.” M. Delage, however,
does not suggest what the state of mind in question is to be called.
As the aunt of Brillat-Savarin compared her sensations just before
death with the desire to sleep, and as this desire is an instinctive
manifestation, I think that the cheerful acquiescence in death,
exhibited by extremely old people, is also a kind of instinct. However,
the important matter is that the sentiment exists, and not what we are
to call it. M. Delage is far from denying its existence.

Dr. Cancalon,[102] another of my critics, cannot admit the existence
of an instinct of death, “because of the theory of evolution. Of what
good would it have been, as M. Metchnikoff tells us that natural death
is very rare; how could it have been transmitted, as it comes into
existence long after the age of reproduction, and how could it have
aided the survival of the species? If its existence were proved as
the result of biological evolution, it would be a contradiction of
adaptation and an argument in favour of final causes.” I cannot agree
in any way with these opinions. In the first place, it is well known
that men and animals have many harmful instincts that do not tend
to the survival of the species. I need recall only the disharmonic
instincts which I described in the “Nature of Man,” such as the
anomalies of the sexual instinct, the instinct which drives parents to
devour their young or which attracts insects to flames. The instinct
of natural death is far from being harmful, and may even have many
advantages. If men were convinced that the end of life were natural
death accompanied by a special instinct like that of the need for
sleep, one of the greatest sources of pessimism would disappear. Now
pessimism is the cause of the voluntary death of a certain number of
people and of many others refraining from reproduction. The instinct
of natural death would contribute to the maintenance of the life of
the individual and of the species. On the other hand, there is no
difficulty in admitting the existence of instincts hostile to the
preservation of the species, especially in the case of man, in whom
individualism has reached its highest development. As man is the only
animal with a definite notion of death, there is nothing extraordinary
if it is in man that the instinctive wish for death develops. M.
Cancalon denies the possibility that death can be pleasant, as it is
the arrest of the physiological functions; but as sleep and syncope
are often preceded by very pleasant sensations, why may not this also
happen in natural death? Several facts prove it beyond dispute. It is
even probable that the approach of natural death is one of the most
pleasant sensations that can exist.

It is indubitable that in a large number of cases of death, the
cessation of life is associated with very painful sensations. One has
only to see the horror shown in the faces o£ many dying people to be
convinced of this, but there are diseases and serious accidents in
which the approach of death does not arouse sorrowful sensations. I
myself, in a crisis of intermittent fever, in which the temperature
descended in a very short time from about 106° Fahr. to below normal,
experienced a feeling of extraordinary weakness, certainly like that
at the approach of death. This sensation was much more pleasant than
painful. In two cases of serious morphia poisoning, my sensations were
more agreeable; I felt a pleasant weakness, associated with a sensation
of lightness of the body, as if I were floating in the air.

Those who have noted the sensations of persons rescued from death have
related similar facts. Prof. Heim, of Zurich, has described a fall
in the mountains which nearly killed him, as well as several similar
accidents to Alpine tourists. In all these cases he states that there
was a sensation of pleasure.[103] Dr. Sollier has told of a young woman
addicted to morphia, who had been convinced that she was at the point
of death. On recovering from a most serious attack of syncope, from
which she was restored only by giving another dose of morphia, she
cried: “I seem to come from far away; how happy I was!” Another of
Dr. Sollier’s patients, a lady who had an attack of peritonitis from
which she expected to die, felt herself “suffused with a feeling of
well-being, or rather the absence of all pain.” In a third Case of Dr.
Sollier, a young woman suffering from puerperal fever, feeling herself
at the point of death, had a similar sensation “of physical well-being
and of detachment from everything.”[104]

As a sensation of happiness occurs even in cases of pathological death,
it is much more likely to occur in natural death. If natural death be
preceded by the loss of the instinct of life and by the acquisition of
a new instinct, it would be the best possible end compatible with the
real organisation of human nature.

I do not pretend to give the reader a finished study on natural death.
This chapter of Thanatology, the science of death, only opens the
subject; but it is already apparent that study of the circumstances of
natural death in plants, in the animal world, and in human beings, may
give facts of the highest interest to science and humanity.

PART IV

SHOULD WE TRY TO PROLONG HUMAN LIFE?

THE BENEFIT TO HUMANITY

Complaints of the shortness of our life—Theory of
“medical selection” as a cause of degeneration of the
race—Utility of prolonging human life

Although the duration of the life of man is one of the longest amongst
mammals, men find it too short. From the remotest times the shortness
of life has been complained of, and there have been many attempts to
prolong it. Man has not been satisfied with a duration of life notably
greater than that of his nearest relatives, and has wished to live at
least as long as reptiles.

In antiquity, Hippocrates and Aristotle thought that human life was too
short, and Theophrastus, although he died at an advanced age (he lived
probably seventy-five years) lamented when he was dying “that nature
had given to deer and to crows a life so long and so useless, and to
man only one that was often very short.”[105]

Seneca (_De brevitate vitæ_) and later, in the 18th century, Haller,
strove in vain against such complaints, which have lasted until our own
days. Whilst animals have no more than an instinctive fear of danger,
and cling to life without knowing what death is, men have acquired an
exact idea of death, and their knowledge increases their desire to live.

Ought we to listen to the cry of humanity that life is too short and
that it would be well to prolong it? Would it really be for the good
of the human race to extend the duration of the life of man beyond its
present limits? Already it is complained that the burden of supporting
old people is too heavy, and statesmen are perturbed by the enormous
expense which will be entailed by State support of the aged. In
France, in a population of about 38 millions, there are two millions
(1,912,153) who have reached the age of 70, that is to say, about five
per cent. of the total. The support of these old people absorbs a
sum of nearly £6,000,000 per annum.[106] However generous may be the
views of the members of the French Parliament, many of them hesitate
at the idea of so great a burden. Without doubt, men say, the cost of
maintaining the aged will become still heavier if the duration of life
is to be prolonged. If old people are to live longer, the resources of
the young will be reduced.

If the question were merely one of prolonging the life of old people
without modifying old age itself, such considerations would be
justified. It must be understood, however, that the prolongation of
life would be associated with the preservation of intelligence and
of the power to work. In the earlier parts of this book I have given
many examples which show the possibility of useful work being done
by persons of advanced years. When we have reduced or abolished such
causes of precocious senility as intemperance and disease, it will no
longer be necessary to give pensions at the age of sixty or seventy
years. The cost of supporting the old, instead of increasing, will
diminish progressively.

If attainment of the normal duration of life, which is much greater
than the average life to-day, were to overpopulate the earth, a very
remote possibility, this could be remedied by lowering the birth-rate.
Even at the present time, while the earth is far from being too quickly
peopled, artificial limitation of the birth-rate takes place perhaps to
an unnecessary extent.

It has long been a charge against medicine and hygiene that they tend
to weaken the human race. By scientific means unhealthy people, or
those with inherited blemishes, have been preserved so that they can
give birth to weak offspring. If natural selection were allowed free
play, such individuals would perish and make room for others, stronger
and better able to live. Haeckel has given the name “medical selection”
to this process under which humanity degenerates because of the
influence of medical science.

It is clear that a valuable existence of great service to humanity is
compatible with a feeble constitution and precarious health. Amongst
tuberculous people, those with inherited or acquired syphilis, and
those with a constitution unbalanced in other ways, that is to say,
amongst so-called degenerates, there have been individuals who have had
a large share in the advance of the human race. I need only instance
the names of Fresnel, Leopardi, Weber, Schumann and Chopin. It does
not follow that we ought to cherish diseases and leave to natural
selection the duty of preserving the individuals which can resist them.
On the other hand, it is indispensable to try to blot out the diseases
themselves, and, in particular, the evils of old age, by the methods
of hygiene and therapeutics. The theory of medical selection must be
given up as contrary to the good of the human race. We must use all
our endeavours to allow men to complete their normal course of life,
and to make it possible for old men to play their parts as advisers and
judges, endowed with their long experience of life.

To the question propounded at the beginning of this section of my book,
I can make only one answer: Yes, it is useful to prolong human life.

SUGGESTIONS FOR THE PROLONGATION OF LIFE

Ancient methods of prolonging human life—Gerokomy—The
“immortality draught” of the Taoists—Brown-Séquard’s
method—The spermine of Poehl—Dr. Weber’s
precepts—Increased duration of life in historical
times—Hygienic maxims—Decrease in cutaneous cancer

Men of all times have attempted all manner of devices to bring about an
increase of years, although they have not considered the problem in its
general bearing.

In Biblical times it was believed that contact with young girls would
rejuvenate and prolong the life of feeble old men. In the first Book of
Kings it is related as follows:—

“Now King David was old and stricken in years; and they covered him
with clothes, but he gat no heat.

“Wherefore his servants said unto him, Let there be sought for my Lord
the king a young virgin; let her stand before the king and let her
cherish him, and let her lie in thy bosom, that my lord the king may
get heat” (Kings I., chap. i.).

This device, afterwards called _gerokomy_, was employed by the Greeks
and Romans, and has had followers in modern times. Boerhave, the
famous Dutch physician (1668-1738), “recommended an old burgomaster of
Amsterdam to lie between two young girls, assuring him that he would
thus recover strength and spirits.” After quoting this, Hufeland, the
well-known author of “Macrobiotique” in the eighteenth century, made
the following reflection:—“If it be remembered how the exhalations
from newly opened animals stimulate paralysed limbs, and how the
application of living animals soothes a violent pain, we cannot refuse
our approval to the method.”[107]

Cohausen, a doctor of the eighteenth century, published a treatise on
a Roman, Hermippus, who had died aged a hundred and fifteen years. He
had been a master in a school for young girls, and his life, passed in
their midst, was greatly prolonged. “Accordingly,” commented Hufeland
(p. 6), “he gives the excellent advice to breathe the air of young
girls night and morning, and gives his assurance that by so doing the
vital forces will be strengthened and preserved, as adepts know well
that the breath of young girls contains the vital principle in all its
purity.”

In the Eastern half of the world equal ingenuity was exercised in
the attempt to rejuvenate the body and renew the forces of man. The
successors of Lao-Tsé searched for a beverage that would confer
immortality and have recounted extraordinary matters concerning it.

The Emperor of China, Chi-Hoang-Ti (221-209 B.C.), displayed extreme
friendliness to the Taoists, believing that these had the secret of
long life and immortality. In his reign, Su-Chi, a Taoist magician,
persuaded him that eastwards of China there lay fortunate islands
inhabited by genii whose pleasure it was to give their guests to
drink of a beverage conferring immortality. Chi-Hoang-Ti was so
delighted with the news that he equipped an expedition to discover the
islands.[108]

Later on, in the dynasty of the Tchengs (618-907), when Taoism
had again become a religion in favour at court, efforts were made
to obtain imperial patronage for the draught of immortality, and
magicians were in high favour. The Taoist writers called this drink
_Tan_ or _Kin-Tan_, the “golden elixir.” According to Mayers, the
chief ingredients of this marvellous compound were “cinnabar, the
red sulphate of mercury, and a red salt of arsenic, potassium and
mother-of-pearl. The preparation of it required nine months, and it
passed through nine changes. One who had drunk of it was changed to a
crane, and in this form could ascend to the dwellings of the genii,
there to abide with them.”[109]

The Taoists represent their saints, in the shade of willows, seeking
the elixir of life, and in Chinese Buddhist temples there are placed
votive cakes shaped like the tortoise, a sacred animal and the symbol
of long life. Worshippers let stones of divination fall on these cakes
and so ascertained if their lives were to be prolonged, promising for
each subsequent year as many cakes as the divinity might demand.

The mysticism of the East reached Europe in the Middle Ages, and then,
and even in modern times, drugs were used to prolong life. Cagliostro,
the celebrated quack of the eighteenth century, boasted that he had
discovered an elixir of life by the use of which he had survived for
many thousand years.

There still exists, in some modern pharmacopœias, an “elixir ad
longam vitam” compounded of aloes and other purgatives. Analogous
preparations are known, such as the “vital essence of Augsburg” which
is a mixture of purgatives and resins.

Serious physicians have rejected such preparations of the quacks.
They have abandoned the search for a specific, and, in their efforts
to prolong human life, have relied on common rules of hygiene, such
as cleanliness, exercise, fresh air, and general sobriety. In our own
days, Brown-Séquard is an isolated instance of a seeker for a specific
against senescence. This distinguished physiologist, setting out from
the view that the weakness of old men is due partly to diminution of
the secretions of the testes, hoped to find a remedy in the employment
of subcutaneous injections of emulsions of the testes of animals
(dogs and guinea-pigs). Brown-Séquard,[110] then aged 72 years, gave
himself several such injections, and declared that he found himself
reinforced and rejuvenated. Since then, numbers of persons have
undergone the treatment which for a time was in vogue. The observations
of physicians, made on old men and sick persons, have not justified the
hopes which were entertained of the mode of treatment. Fürbringer,[111]
in particular, working in Germany, has discredited the injections of
Brown-Séquard. However, instead of following exactly the original
prescription, Fürbringer employed a testicular emulsion which had
been previously raised to the boiling-point. Brown-Séquard’s method
has not resisted scientific investigation, and although it is still
occasionally employed in France, it has been given up in many countries.

Brown-Séquard laid stress on the efficacy of emulsions of testis
as opposed to chemical substances prepared from the gland. Other
scientific men, on the other hand, have attached value to such
substances and in particular to an organic alkali the salt of which is
known as spermine. That salt, made by Poehl of St. Petersburg, has been
largely used. Several observers declare that its employment, injected
in solution or even absorbed directly as a powder, has been followed by
a strengthening of bodily power enfeebled by age or labour.

As I have no personal experience of spermine, I shall quote from
Professor Poehl[112] some indications of its efficacy. Several
physicians (Drs. Maximovitch, Bukojemsky, Krieger and Postoeff) have
given injections of spermine to enfeebled old men who had lost appetite
and sleep, and have noted improvement lasting for months. From the
instances given, I have selected that of an old lady of ninety-five
years, afflicted with severe sclerosis of the arteries, with no
appetite, a bad digestion and constipation. This patient had complained
for several years of sacral pains, and moreover was nearly quite deaf
and suffered from periodic attacks of malarial fever. The injections of
spermine, given for a period of fifteen months, restored the old lady
to such an extent that she recovered her power of hearing and felt the
sacral pains only slightly and after a long walk. Her general condition
was highly satisfactory.

Spermine, as it has been used medically, is prepared not only from the
testes of animals but from the prostate gland, ovary, pancreas, thyroid
gland and spleen. The substance is not specially associated with
spermatozoa but has a wide distribution in the mammalian body.

In the medical treatment of the evils of old age, testicular emulsions
or spermine have not been so favoured as general hygienic measures. Dr.
Weber,[113] a London medical man, has recently summarised more general
measures, and his evidence is the more important as he has been able
to test the efficacy of his precepts in his own case. Dr. Weber is 83
years old, and in his practice has cared for many other old men.

The following are the precepts which Dr. Weber formulated: All the
organs must be preserved in a condition of vigour. It is necessary to
recognise and subdue any morbid tendencies whether these be hereditary
or have been acquired during life. It is necessary to be moderate in
food and drink, and in all other physical pleasures. The air should
be pure in the dwelling and in the vicinity. It is necessary to take
exercise daily, whatever be the weather. In many cases the respiratory
movements must be specially exercised, and exercise on level ground and
up-hill should be taken. The persons should go to bed early and rise
early, and not sleep for more than six or seven hours. A bath should
be taken daily and the skin should be well rubbed, the water used
being hot or cold, according to taste. Sometimes it is advantageous
to use hot and cold water. Regular work and mental occupation are
indispensable. It is useful to stimulate the enjoyment of life so
that the mind may be tranquil and full of hope. On the other hand,
the passions must be controlled and the nervous sensations of grief
avoided. Finally, there must be a resolute intention to preserve the
health, to avoid alcohol and other stimulants as well as narcotics and
soothing drugs.

By following his own precepts, Dr. Weber has enjoyed a vigorous and
happy old age. A Mde. Nausenne, who died on March 12th, 1756, at the
age of 125 years, in the Dinay Infirmary (Côtes-du-Nord) explained the
secret of her still greater longevity as follows: “Extreme sobriety, no
worry, body and mind quite calm” (Chemin, _op. cit._, p. 101).

Hygienic measures have been the most successful in prolonging life and
in lessening the ills of old age.

Although until quite recently hygiene has rested upon a very small
number of scientifically established facts, and although its precepts
have not been followed rigidly, none the less it has already succeeded
in increasing the duration of human life. This becomes evident if we
compare the mortality tables of the present day with those of the past.

There is reason to state definitely that the mortality in civilised
countries has decreased on the whole in the last one or two centuries.
I have taken some facts regarding this from the valuable monograph
of M. Westergaard.[114] That author came to the conclusion that the
mortality rate in the 19th century in civilised countries was “much
lower than in most earlier centuries.” This diminution has been chiefly
in infantile mortality. According to Mallet, the mortality rate of
infants in the first year of their life was, in Geneva, 26 per cent.
in the 16th century, and fell gradually to 16-1/2 per cent. at the
beginning of the 19th century. A similar change has been reported from
Berlin, Holland, Denmark and other places. However, it is not only very
young infants that have shown a diminution in the death-rate. The life
of old people has been prolonged to an extent equally remarkable. The
following are some of the facts which support this statement. Whilst
the old Protestant clergymen of Denmark at ages varying from 74-1/2 to
89-1/2 years had a mortality rate of 22 per cent. in the second half
of the 18th century, the rate had sunk to 16·4 per cent. by the middle
of the 19th century. This is not an isolated fact. The old clergymen
of England (65 to 95 years) have also come to live longer, because
in the 18th century the mortality rate was 11·5 per cent. and in the
19th century (1800-1860) only 10·8 per cent. There has been a similar
decrease in the mortality rate in the members of both sexes of the
Royal Houses of Europe (Westergaard, p. 284).

From 1841 to 1850, in England and Wales 162·81 individuals out of every
thousand of both sexes died annually, but the corresponding figure for
the period 1881 to 1890 was decreased to 153·67 per thousand.

Westergaard (p. 296) has displayed in a most useful table the mortality
in the chief countries of Europe and in the State of Massachusetts, in
two periods of time. In the case of old persons from 70 to 75 years,
there has been a constant decrease in the death-rate, without any
exceptions. The exact statistics collected by Pension Bureaus and Life
Assurance Companies exhibit the same general tendency.

It cannot be disputed then that there has been a general increase
in the duration of life, and that old people live longer at the
present time than in former ages. This fact, however, cannot be taken
absolutely, and it is still possible that in particular cases there may
have been more centenarians hitherto than at present.

The prolongation of life which has come to pass in recent centuries
must certainly be attributed to the advance of hygiene. The general
measures for the preservation of health, although they were not
specially directed to old people, have had an effect of increasing
their longevity. As in the 18th century and for the greater part of
the 19th, the science of hygiene was in a very rudimentary condition,
we may well believe that improvement in cleanliness and in the general
conditions have contributed largely to the prolongation of life. It is
now a long time since Liebig said that the amount of soap used could
be taken as a measure of the degree of civilisation of a people. As
a matter of fact, cleanliness of the body brought about in the most
simple way, by washing with soap, has had a most important effect
in lessening disease and mortality from disease. In this connection,
the fact recently published by Prof. Czerny,[115] a well-known German
surgeon, has a special interest. Although cancer, the special scourge
of old age, has increased in recent times, one form of the disease,
cancer of the skin, has diminished notably. “Cancers of the skin,”
Prof. Czerny says, “are met with almost exclusively on uncovered
regions of the body, or on parts accessible to the hands. They develop
especially where the susceptibility is increased by ulcers or scars
which are easily soiled. And so it happens that in the classes where
care is taken as to cleanliness cancer of the skin is very rare and
certainly much more rare than it used to be.”

M. Westergaard thinks that vaccination against small-pox has been of
considerable importance in lowering the death-rate in the 19th century.
This, however, can have had little effect on the duration of life in
old people, as deaths due to small-pox in the old are excessively
rare. For instance, in the second half of the 18th century, that is
to say before the introduction of Jenner’s method, the mortality from
small-pox at Berlin was 9·8 per cent. of all the deaths, but of these
only 0·6 per cent. were cases of persons more than fifteen years old.
The rest, that is to say, 99·3 per cent. fell on children under that
age. It may be supposed that most of the old people at that time were
already protected by previous attacks of small-pox, contracted when
they were young.

If hygiene were able to prolong life when it was little developed, as
was the case until recently, we may well believe that, with our greater
knowledge of to-day, a much better result will be obtained.

III

DISEASES THAT SHORTEN LIFE

Measures against infectious diseases as aiding in the
prolongation of life—Prevention of syphilis—Attempts to
prepare serums which could strengthen the higher elements
of the organism

Attacks of infectious diseases incurred during life frequently shorten
its duration and it has been observed that most centenarians have
enjoyed good health throughout their lives. Syphilis is the most
important of these diseases. It is not really a cause of death itself,
but it predisposes the organism to the attacks of other diseases,
amongst the latter being some particularly fatal to old people,
such as diseases of the heart and blood-vessels (angina pectoris
and aneurism of the aorta) and some malignant tumours, especially
cancer of the tongue and of the mouth. To lengthen human life, it
is a fundamental necessity to avoid infection by syphilis. To reach
this result everything must be done to spread medical knowledge about
such diseases. It is absolutely necessary to overcome the deeply
rooted prejudice in favour of concealing everything relating to
sexual matters. Complete information should be widely spread as to
the means of protecting humanity against this awful scourge. It has
now been possible to apply experimental methods to the investigation
of this disease, and science has obtained a series of results of the
highest practical utility. Prof. Neisser of Breslau, one of the most
distinguished of modern venereal physicians, has summed up the present
state of knowledge of these matters in the following lines.[116] “It is
our duty as medical men,” he says, “to recommend strongly as a means of
disinfection in all possible cases of contagion the calomel ointment
which Metchnikoff and Roux have advised.” It is to be hoped that future
generations, by following this advice, will see an enormous diminution
in the number of cases of syphilis.

Syphilis, however, although a very important factor, is not alone
in shortening the life of man. A very large number of persons die
prematurely although they have not contracted that disease. We do not
know the duration of human life before the arrival of syphilis in
Europe, but there is no reason to think that it was very different
from what it is to-day. We must, therefore, try to prevent as many
infectious diseases as possible, and recent advances in medicine
have made this task much less difficult. Pneumonia, it is true, the
most common infectious disease amongst the old, cannot yet be easily
avoided. All the anti-pneumonic serums which have hitherto been
prepared have turned out to have little efficacy; but there is no
reason to give up the hope that this problem will yet be solved.

Diseases of the heart, which are common in extreme old age, are
particularly difficult to avoid, because in most cases we do not know
sufficiently well their primary causes. In so far as they depend upon
intemperance or infectious diseases such as syphilis, they can be
avoided by the employment of suitable measures.

As the higher elements of the body in old people become weaker and are
devoured by the macrophags, it seems probable that the destruction or
deterioration of these voracious cells would tend to the prolongation
of life. However, as the macrophags are indispensable in the struggle
against the microbes of infectious diseases, and particularly of
chronic disease, such as tuberculosis, it is necessary to preserve
them. We must turn rather to the idea of a remedy which could
strengthen the higher elements and make them a less ready prey to the
macrophags.

In the “Nature of Man” (Chap. III.) in discussing the simian origin
of mankind, I touched on the existence of animal serums that have the
power of dissolving the blood corpuscles of other species of animals.
There is now, in biological science, a new chapter upon such serums,
which have been called cytotoxic serums because they are able to poison
the cells of organs.

The blood and blood serum of some animals act as poisons when they
are introduced into an organism. Eels and snakes, even non-poisonous
snakes, are cases in point. A small quantity of the blood of a snake,
an adder for instance, injected into a mammal (rabbit, guinea-pig, or
mouse) soon brings about death. The blood of some mammals is poisonous
to other mammals, although in a lesser degree than that of snakes. The
dog is specially notable from the fact that its blood is poisonous to
other mammals, whilst, on the other hand, the blood and blood serum
of the sheep, goat, and horse have generally little effect on other
animals and on man. It is for this reason that these animals, and
particularly the horse, are used in the preparation of the serums
employed in medicine.

Now, these harmless serums become poisonous when they have been taken
from animals which have been first treated with the blood or the
organs of other species of animals. For instance, the blood serum of
a sheep which has been treated with the blood of a rabbit becomes
poisonous because it has acquired the power of dissolving the red blood
corpuscles of the rabbit. It is a poison in the case of the rabbit,
but is harmless to most other animals. The injection of the rabbit’s
blood into the sheep has conferred on the sheep a new property which
comes into operation only with regard to the red blood corpuscles
of the rabbit. We have here to do with something analogous to what
has been observed in the cases of serums used to arrest infectious
disease. When the bacilli of diphtheria, or their products, have been
injected into horses, there is produced an anti-diphtheric serum,
capable of curing diphtheria, but powerless against tetanus or plague.
After M. J. M. Bordet of the Pasteur Institute had made his discovery
of serums that had acquired the power of dissolving the red blood
corpuscles of other animals, the attempt was made to prepare similar
serums directed against all the other elements of the body, such as
white blood corpuscles, renal and nervous cells. In the course of
these investigations it was proved to be necessary to employ a certain
dose of the serum in order to obtain the poisonous result. If smaller
quantities of the poisonous dose were used, the reverse effect was
produced. Thus a serum, strong doses of which dissolved the red blood
corpuscles and so made them less numerous in the blood, increased the
number of these when given in very small doses.

M. Cantacuzène was the first to establish this fact in the case of
the rabbit, whilst M. Besredka and I myself did it in the case of
man.[117] Since then M. Bélonovsky of Cronstadt has confirmed the
result on anæmic patients, treating them with small quantities of
serum. He has been able to produce in them an increase in the number
of the red blood corpuscles, and in the quantity of the red colouring
matter (hæmoglobin) in the blood. Later on M. André[118] devoted much
attention to this matter at Lyons. He prepared a serum by injecting
human blood into animals and made use of it in the case of several
persons who suffered from anæmia from different causes. In the case
of patients, the anæmic condition of which had hitherto remained
stationary, Dr. André found a sudden increase in the number of red
corpuscles after injecting small doses of the serum. M. Besredka,
in the case of laboratory animals, increased the number of white
corpuscles by injecting them with a small quantity of a serum, strong
doses of which destroyed these cells.

These facts are only a special case of the general rule that small
doses of poisons increase the activity of the elements that are killed
by large doses. In order to increase the activity of the heart, medical
men give successfully small doses of cardiac poisons such as digitalis.
As a commercial process, the activity of yeasts is increased by
submitting them to weak doses of substances (fluoride of sodium) which,
given in larger quantities, would kill them.

My general conclusion from these facts is that it is logical to lay
down the principle that the higher elements of our body could be
strengthened by subjecting them to the action of small doses of the
appropriate cytotoxic serums. There is, however, much difficulty in
putting this into practice. It is quite easy to obtain human blood
to inject into animals with the object of preparing a serum which
can increase the number of red corpuscles. On the other hand, it is
extremely difficult to get human bodies sufficiently fresh to use them
for a practical purpose. According to law, _post mortem_ examinations
can be made only after an interval of time in course of which the
tissues have changed; besides, the organs obtained in this way are
frequently affected by injuries or diseases militating against their
use. Even in Paris, with its three million inhabitants, it is extremely
rare that there is a good opportunity for the preparation of human
cytotoxic serums. In two or three years, during which Dr. Weinberg has
collected the organs from human bodies fairly fresh, he has been unable
to obtain sufficiently active serums.

The best results have been obtained from new-born infants which have
been killed by some accident in the process of child-birth, as in them
the organs are in a normal state. However, owing to the advance in
the practice of obstetrics, such accidents, already infrequent, are
becoming extremely rare. In such conditions we may have to wait long
before getting a positive result, unless the future will find some
method of obtaining the necessary materials for this difficult and
interesting purpose.

As it is so difficult to prepare a remedy which can strengthen the
weakened higher elements of the body, it may be easier to find a means
of preventing the weakening which interferes so much with our desire to
live long. As the products of microbes are the most active agents in
deteriorating our tissues, we must look towards them for the solution
of the problem.

INTESTINAL PUTREFACTION SHORTENS LIFE

Uselessness of the large intestine in man—Case of
a woman whose large intestine was inactive for six
months—Another case where the greater part of the
large intestine was completely shut off—Attempts to
disinfect the contents of the large intestine—Prolonged
mastication as a means of preventing intestinal
putrefaction

The general measures of hygiene directed against infectious diseases
play a part in prolonging the lives of old people, but, in addition to
the microbes which invade the body from outside, there is a rich source
of harm in the microbes which inhabit the body. The most important of
these belong to the intestinal flora, which is abundant and varied.

The intestinal microbes are most numerous in the large intestine. This
organ, which is useful to mammals the food of which consists of rough
bulky vegetable matter, and which require a large reservoir for the
waste of the process of digestion, is certainly useless in the case
of man.[119] In the “Nature of Man” I have dealt with this question
at length, as it was an important example of what I regard as the
disharmonies of the human constitution. A case upon which I have always
laid great stress is that of a woman who lived for thirty-seven years,
although her large intestine was atrophied and inactive, as this seems
to be a remarkable proof of the uselessness of the organ in the human
body. The small size or complete absence of the large intestine in
many vertebrates confirms my conclusion. None the less, some of my
critics think that my argument is incomplete. To strengthen it, I may
call their attention to a medical observation which is as valuable as
if it had been an experiment. It relates to a woman, sixty-two years
old, a patient of Prof. Kocher at Berne. She had been suffering from a
strangulated hernia associated with gangrene of part of the intestine,
and had to be operated upon suddenly.

The gangrenous portion of the ileum having been removed, the healthy
part was implanted in the skin so as to form an artificial aperture
through which waste matter from the food passed to the exterior
without traversing the large intestine. Although the patient was old
and seriously ill, the operation, performed by M. Tavel, was quite
successful. Six months later, in a new operation, the small intestine
was rejoined to the large intestine so that the fæces were again able
to pass to the exterior by the natural channel. In this case, then, the
large intestine was thrown out of use for half a year, not only without
injury to the general health, but with the result that the patient was
completely cured and gained in weight. MM. Macfadyen, Nencki, and Mde.
Sieber[120] studied the digestive processes in the small intestine
and the nutritive metabolism, and determined that these were active
and healthy, the absence of intestinal putrefaction, that evil of the
constitution, being specially favourable.

[Illustration: FIG. 19.—Diagram of the lower bowel in a female patient.

_A.C.N._, Artificial anus: _A.S._, Insertion of the ileum to the colon.

(After M. Mauclaire.)]

[Illustration: FIG. 20.—Diagram of the lower bowel, after a third
operation, on the case in Fig. 19.

(After M. Mauclaire.)]

In six months of non-action, the part played by an organ can be
satisfactorily estimated. M. Mauclaire,[121] however, has put on record
a case the history of which was longer. In 1902 he operated on a young
woman and produced an artificial anus, there being no escape of fæcal
matter by the ordinary channel. Ten months later M. Mauclaire operated
a second time and shut off a portion of the intestine. He left the
artificial anus, but cut across the lower end of the small intestine
and inserted it near the iliac end of the descending colon (Fig. 19).
For several days after the operation the fæces were passed by the
normal aperture, as the small intestine now communicated directly with
the large intestine, near the rectum. This condition, however, did not
persist, for the fæcal matter began to flow back through the excluded
portion of the large intestine, so reaching the artificial anus, and
causing inconvenience. Giving up the hope that this would cease, M.
Mauclaire performed a third operation twenty months later. He cut
across the large intestine near the point where the small intestine
had been artificially led into it (Fig. 20), so dividing the digestive
tube into two parts, one of which remained in communication with the
natural anus, whilst the other, consisting of nearly the whole of
the large intestine, communicated with the exterior by the artificial
anus. In the new state of affairs, the food refuse passed directly
into the terminal portion of the large intestine, and thence, by way
of the rectum, to the exterior through the normal anus without being
able to pass up the large intestine towards the artificial anus. In
this last operation about a yard of the small intestine and the greater
part of the large intestine, the cæcum, and ascending, transverse and
descending colons were removed from activity.

By the kindness of M. Mauclaire, I have been able to watch his patient
during the last four years. I satisfied myself that after the supposed
exclusion of the large intestine, food dejecta ascended the colon and
emerged by the artificial anus. There was such an accumulation of
waste in the large intestine that fragments did not emerge until three
weeks after the meal of which they had formed part. It was only after
the final operation, that in which the large intestine was separated,
that the dejecta escaped only by the natural anus, whilst a little
mucus containing microbes was passed through the artificial aperture.
Even three years after the operation, mucus continued to escape by the
latter aperture, it being shown thus that after the large intestine had
ceased to be a channel for the fæces, its walls continued to secrete
although otherwise it had lost its function completely. Nevertheless
the condition of this patient improved and she lived perfectly well
without a functional large intestine. She takes food well but has to go
to stool three or four times a day and has a tendency to diarrhœa.
The excreta are smooth and often nearly liquid, especially after fruit
has been eaten.

The case I have been describing, and which I am still keeping under
observation, demonstrates once more the uselessness of the human large
intestine; it should convert the most sceptical critic. But it also
shows that the suppression of nearly the entire large intestine for
several years does not completely get rid of the intestinal flora. Even
without this evidence, however, I do not suggest that removal of the
large intestine can be thought of as a means to prevent the pernicious
effect of the intestinal flora.

Is it possible, without operative interference, to take direct action
against the intestinal flora by the use of antiseptics? Consideration
of this is already ancient history. When the theory that the intestine
was a source of auto-intoxication was propounded, M. Bouchard[122] made
the attempt to cure such cases by disinfecting the digestive tube with
[Greek: b]-naphthol. He found, however, that that antiseptic, like
many others, not only did not completely disinfect the intestine but
sometimes had a harmful effect on the body.

M. Stern[123] has shown, in an elaborate memoir, that such antiseptics
as calomel, salol, [Greek: b]-naphthol, naphthaline, and camphor, when
administered in quantities compatible with health, do not disinfect
the digestive tube at all. More recently M. Strasburger[124] has shown
that when naphthaline has been given in quantities sufficient to impart
its odour to the fæces, the intestinal microbes, so far from being
diminished, are even increased in numbers. On the other hand, after
meals consisting of milk to which there has been added an antiseptic
in the proportion of a quarter of a gram to the litre, the intestinal
microbes are really reduced in number. Strasburger obtained his best
results with tanocol. Two persons who used, according to this method,
three to six grams of tanacol per day, displayed a notable reduction in
quantity of the intestinal flora.

Strasburger’s conclusion was that “the attempt to destroy the
intestinal microbes by the use of chemical agents has little chance of
success.” It cannot be denied that under special circumstances it is
possible to decrease the number of microbes, especially in the small
intestine. But this result is small and may be followed by the contrary
effect, for the natural means of defence of the intestine against
microbes are weakened, and the intestine itself may be harmed more than
the microbes.

Strasburger, moreover, is no convinced advocate of the use of
purgatives. The diminution of the sulpho-conjugate ethers in the
urine, which certainly may follow the use of purgatives, does not
necessarily indicate reduced putrefaction in the intestine, but may
point only to a lessened absorption of the bacterial products. Such an
interpretation is supported by an observed fact; in the case of a dog
belonging to Strasburger, which had a fistula of the small intestine,
the diarrhœa induced by calomel was accompanied by an indubitable
increase in the total quantity of intestinal microbes.

Strasburger thinks that the most favourable results can be obtained
by aiding the intestine in the discharge of its normal function. If
it can be brought to digest the food more completely, there is the
less pabulum left for the microbes. A similar result can be reached by
lowering the amount of food taken, and to this course the beneficial
effects of starvation in acute diseases of the intestine may be
attributed.

The general conclusion, reached after many experiments on the
disinfection of the intestine, is unfavourable. Very little is to be
expected from the method. None the less I cannot regard the matter
as definitely settled. Cohendy has investigated the effect on the
intestinal flora of thymol which was administered in several cases with
the object of destroying parasites. From nine to twelve grammes of
thymol were administered to each patient in the space of three days,
and there was a notable antiseptic effect, Cohendy believing that the
quantity of microbes had been reduced to a thirteenth.

Such facts prove only that the antiseptic treatment is available
up to a certain point. To attain the results, however, such large
quantities must be used that the treatment can be applied only in
special cases and at long intervals. More use can be made of simple
purgatives which do not kill the microbes but eliminate them by the
normal channel. It has been urged repeatedly that calomel, which is
often used as a purgative, acts also as an intestinal antiseptic;
but it is probable that its influence in reducing the intestinal
flora is merely mechanical. It has been shown that calomel, like
some other purgatives, lessens intestinal putrefaction, the evidence
being the decrease in the sulpho-conjugate ethers in the urine. But
although the diarrhœa induced by purgatives generally has such a
result, spontaneous diarrhœas such as those of typhoid fever and of
intestinal tuberculosis are associated with increased putrefaction.[125]

It is clear, however these matters may be settled, that regular
activity of the bowels, increased by the occasional use of purgatives,
must diminish the formation of intestinal poisons, and therefore also
the damage done by these to the higher elements of the body.

When I asked the relatives of Mde. Robineau if they could tell me of
any special circumstance which in their opinion had contributed to
the extreme duration of the life of this old lady, they replied as
follows:—“We are convinced that a slight bodily derangement, present
for the last fifty years, has tended to prolong the life of the old
lady. It cannot be said that she has suffered from diarrhœa, but
she has been often subject to frequent calls of nature.” It was most
remarkable that the old lady showed no traces of sclerosis of the
arteries. I may mention the strongly contrasting case of one of my
old colleagues to whom a natural desire to empty the bowels came only
once a week. A more frequent call was a sign of illness in his case.
Now sclerosis of the arteries appeared in so marked a form that he
died from it before he had reached the age of fifty years. This may be
added to the list of facts which point to a close association between
sclerosis of the arteries and the functions of the digestive tube.

Recently, at the suggestion of Mr. Fletcher,[126] the advantage of
eating extremely slowly has been recognised, the object being to
prepare for the utilisation of the food materials, and to prevent
intestinal putrefaction. Certainly the habit of eating quickly favours
the multiplication of microbes round about the lumps of food which have
been swallowed without sufficient mastication. It is quite harmful,
however, to chew the food too long, and to swallow it only after it
has been kept in the mouth for a considerable time. Too complete a
use of the food material causes want of tone in the intestinal wall,
from which as much harm may come as from imperfect mastication. In
America, where Fletcher’s theory took its origin, there has already
been described under the name of “Bradyfagy” a disease arising from the
habit of eating too slowly. Dr. Einhorn,[127] a well-known specialist
in the diseases of the digestive system, has found that several cases
of this disease were rapidly cured when the patients made up their
minds to eat more quickly again. Comparative physiology supplies us
with arguments against too prolonged mastication. Ruminants, which
carry out to the fullest extent Mr. Fletcher’s plan, are notable for
extreme intestinal putrefaction and for the short duration of their
lives. On the other hand, birds and reptiles, which have a very poor
mechanism for breaking up food, enjoy much longer lives.

Prolonged mastication, then, cannot be recommended as a preventative
of intestinal putrefaction any more than the surgical removal of the
large intestine or the disinfection of the digestive tube. The field
lies open for other means which may probably solve the problem more
completely and more practically.

LACTIC ACID AS INHIBITING INTESTINAL PUTREFACTION

The development of the intestinal flora in
man—Harmlessness of sterilised food—Means of
preventing the putrefaction of food—Lactic fermentation
and its anti-putrescent action—Experiments on
man and mice—Longevity in races which use soured
milk—Comparative study of different soured
milks—Properties of the Bulgarian _Bacillus_—Means
of preventing intestinal putrefaction with the help of
microbes

At birth the human intestine is full, but contains no microbes.
Microbes very soon appear in it, because the meconium, the contents
of the intestines of new-born children, composed of bile and cast-off
intestinal mucus cells, is an excellent culture medium for them. In the
first hours after birth, microbes begin to reach the intestine. In the
first day, before the child has taken any food whatever, there is to
be found in the meconium a varied flora, composed of several species
of microbes. Under the influence of the mother’s milk this flora is
reduced and comes to be composed almost entirely of a special microbe
described by M. Tissier and called by him _Bacillus bifidus_.

The food, therefore, has an influence on the microbes of the intestine.
If the child be fed with cow’s milk, the flora is richer in species
than in the case of a child suckled by its mother. Later on, also,
the flora varies with the food, as has been proved by MM. Macfadyen,
Nencki, and Mde. Sieber in the case of a woman with an intestinal
fistula. The dependence of the intestinal microbes on the food makes
it possible to adopt measures to modify the flora in our bodies and
to replace the harmful microbes by useful microbes. Unfortunately,
our actual knowledge of the intestinal flora is still very imperfect
because of the impossibility of finding artificial media in which it
could be grown. Notwithstanding this difficulty, however, a rational
solution of the problem must be sought.

Man, even in the savage condition, prepares his food before eating it.
He submits much of it to the action of fire, thus notably lessening the
number of microbes. Microbes enter the digestive tube in vast numbers
with raw food, and in order to lessen the number of species in the
intestines, it is important to eat only cooked food and to drink only
liquids that have been previously boiled. In that way, although we
cannot destroy all the microbes in the food, because some of them can
withstand the temperature of the boiling point of water, we can kill
the great majority of them.

It has sometimes been supposed that cooked or completely sterilised
food (that is to say food that has been subjected to a temperature of
from 248°-284° Fahr.) is harmful to the organism and that much of it
is not well digested. From this point of view protests have been made
against the feeding of infants with sterilised milk or even with boiled
milk. Although in certain cases sterilised milk is not well supported
by infants, it cannot be doubted but that boiled milk and cooked
food are generally successful. The large number of children brought
up successfully on boiled cow’s milk and the health of travellers in
arctic regions are ample proof of this. I have been told by M. Charcot
that in his voyage to the antarctic regions, he and his companions
lived entirely on sterilised food, or on cooked food such as the flesh
of seals and penguins. As they had no green food nor fresh fruit, the
only raw food that they ate was a little cheese. Living under these
conditions, all the members of the expedition enjoyed good health,
and there was no case of digestive disturbance in the whole period of
sixteen months.

It is obvious that abstaining from raw food, and so reducing largely
the entrance of new microbes, by no means causes the disappearance
of the intestinal flora already existing. We must reckon with that
and with the evil that it does by weakening the higher cells of the
tissues. As the part of the flora that does most damage consists of
microbes which cause putrefaction of the contents of the intestine and
harmful fermentations, particularly butyric fermentation, it is against
these that our efforts must be directed.

Long before the science of bacteriology was in existence, men had
turned their attention to methods of preventing putrefaction. Food,
especially if it be kept in a warm place or in a moist atmosphere, soon
begins to putrefy and to become unpleasant to the taste and dangerous
to the health. Everyone has known cases of poisoning from putrid flesh
or other food material. Foà,[128] the explorer of Central Africa, has
related that once, when they were starving, he and his men came on the
putrefying body of an elephant. The negroes rushed to lay hold of the
carrion, but Foà tried to dissuade them, explaining that to eat flesh
in such a state was as bad as taking poison. All did not listen to him,
and three negroes, who had taken pieces of the body, swallowed them
before they had been properly cooked. All three died in a few days,
with the neck and throat swollen, the tongue almost paralysed, and the
abdomen inflated.

In another case, sausages made of putrid horse flesh caused an epidemic
at Rohrsdorf, in Prussia, in 1885.[129] About forty people fell ill
after having eaten the sausages, which, according to witnesses, were
green in colour, smelt badly, and had a revolting appearance. One
person died, whilst the others recovered after cholera-like symptoms.
It is true that all putrefying food does not produce the same effect.
MM. Tissier and Martelly[130] found no digestive trouble after having
eaten food that was quite putrid. Everyone knows that the Chinese
prepare a dish particularly pleasant to gourmets by allowing eggs
to putrefy. Some decaying cheeses are harmful to the health, but
others can be eaten with impunity. The reason of this is that whilst
putrefying food may contain microbes and dangerous toxins, it does
not contain them in all cases. On the other hand, we must take into
account the different susceptibilities of people to the harmful action
of microbes and their products. Some can swallow without any evil
result a quantity of microbes which in the case of other individuals
would produce a fatal attack of cholera. Everything depends upon the
resistance offered to the microbes by the invaded organism.

Experiments on animals fed on putrefying food have also given varied
results. Some animals eat it without any harm resulting, others have
attacks of vomiting and show such a repugnance that it is impossible to
continue the experiment.

Not only flesh and other animal substances, but vegetables can undergo
putrefaction and fermentation (butyric) which make it dangerous
to eat them. Many accidents have occurred in man as the result of
deteriorated preserved fruit. Vegetables, preserved in silos to feed
cattle, sometimes go wrong. “If, for instance, rainy days come after
sunny days, so that the uncovered fodder is wetted again, the resulting
ensilage is poor and has an extremely unpleasant butyric odour, so that
the animals turn from it.” Sometimes the fodder grows black in the
silo, and acquires a special smell. “The animals will take it only in
the absence of other food; their excreta become black, and if they are
kept on such a diet for a time they waste in a marked manner.”[131]

In popular practice, the value of acids for preserving animal
and vegetable food and for preventing putrefaction has long been
recognised. Meats of all kinds, fish and vegetables have been
“marinated” with vinegar, as the acetic acid in that substance, the
product of bacteria, wards off putrefaction. If the materials which
it is desired to preserve give off acids themselves, the addition of
vinegar may be unnecessary. For this reason some animal products such
as milk, or vegetables rich in sugar become acid spontaneously and so
can be preserved. Soured milk can be made into many kinds of cheese,
and these last for longer or shorter times. Many vegetables can undergo
a natural process of souring, when they “keep” without difficulty.
Thus cabbage becomes “sauerkraut” and beetroot and cucumbers pass
into an acid state. In many countries, as for instance in Russia, the
use of acidified vegetables is of great importance in the food-supply
of the populace. Fresh fruit and vegetables cannot be obtained in the
long winters, during which the people consume large quantities of
cucumbers, melons, apples, and other fruits which have undergone an
acid fermentation in which lactic acid is the chief product. During
summer, milk, which acidifies readily, is the chief source of acid
materials for consumption. The chief beverage is “kwass,” of which
black bread is the main ingredient, and this passes through not only an
alcoholic fermentation, but an acidifying change in which lactic acid
is the most important product.

Rye bread, the chief food of the populace, is also a product of
fermentations amongst which the lactic acid fermentation is most
important, but in other kinds of bread also there is a fermentation in
which some of the sugar is transformed to lactic acid.

Soured milk, because of the lactic acid in it, can impede the
putrefaction of meat. In certain countries, accordingly, meat is
preserved in acid skimmed milk with the result that putrefaction
is prevented. Lactic acid fermentation is equally important in the
food supply of cattle. It is the chief agent that, in the process of
preserving vegetation in silos, hinders putrefaction. Finally, the same
fermentation serves in distilleries to preserve the must from which
alcohol is prepared.

This short review is in itself enough to show the great importance of
lactic fermentation as a means of stopping putrefaction and butyric
fermentation, both of which hinder the preservation of organic
substances and are capable of exciting disturbances in the organism.

As lactic fermentation serves so well to arrest putrefaction in
general, why should it not be used for the same purpose within the
digestive tube?

It is a matter of common knowledge that putrefaction and butyric
fermentation are arrested in the presence of sugar. Whereas meat
preserved without special care soon putrefies, milk in exactly the
same conditions does not putrefy, but becomes sour, the reason being
that meat is poor in sugar whereas milk contains a good deal of it.
However, the scientific explanation of this fundamental fact is
difficult. It has been shown conclusively that sugar itself cannot
prevent putrefaction. Milk, for instance, however rich in sugar it
may be, readily putrefies in certain conditions. Sugar preserves
organic matter from putrefaction only because it can readily undergo
lactic fermentation, and this fermentation is the work of the microbes
described fifty years ago by Pasteur. That great discovery proved the
part played by microbes in fermentation and founded bacteriology, a
science equally rich in theory and in practice.

I need not pause to develop the theme that the anti-putrescent action
of the lactic fermentation depends on the production of lactic acid by
microbes, because I have explained the matter at length in the tenth
chapter of the “Nature of Man.” If the lactic acid be neutralised,
the organic matter soon putrefies, notwithstanding the presence of
the lactic microbes. The most important point is as to whether lactic
fermentation really arrests intestinal putrefaction. Several sets of
observations have been made upon this matter. Dr. Herter,[132] of
New York, injected directly into the small intestine of a number of
dogs quantities of different microbes. To test the action of these on
intestinal putrefaction, he investigated the sulpho-conjugate ethers
in the urine, as he believed, in accordance with current and well
justified opinion, that these substances are the best proofs of the
existence of putrefaction. He found that whilst the introduction of
quantities of _Bacillus coli_ or _Bacillus proteus_ increased the
intestinal putrefaction, lactic bacilli notably lessened it. Herter
found a notable diminution of sulpho-conjugate ethers in the urine of
dogs which had been treated with the lactic microbes.

The experiments which Dr. M. Cohendy[133] performed upon himself during
a period of nearly six months are still more interesting.

When Dr. Cohendy had proved that much intestinal putrefaction occurred
during a period of 25 days, in which he lived on an ordinary mixed
diet, he began to take pure cultures of lactic bacillus, taken from
yahourth. In a period of 74 days, he took quantities varying from 280
to 350 grams of the culture.

Analysis of the urine during the progress of the experiment showed
that intestinal putrefaction had notably decreased whilst the lactic
bacilli were being taken, and that the diminution persisted seven weeks
after the taking of the bacilli ceased. Dr. Cohendy gives it as the
direct result of his experiment that the introduction of lactic ferment
into the intestine definitely arrests putrefaction. He obtained this
result on a diet consisting of 400 grams of soup, 150 of meat, 700 of
grain-food, 400 of green vegetables, 300 of fruits and dessert and a
litre of water. He came to the conclusion that the elimination of meat
from the diet was unnecessary, as the particular kind of lactic ferment
he employed was extremely active in inhibiting the proteolytic ferments.

Later experiments made by Dr. Cohendy showed that the lactic bacillus
became so acclimatised in the human intestine that it was to be found
there several weeks after it had been swallowed.

Dr. Pochon, assistant to Professor Combe[134] at Lausanne, has repeated
on himself the experiments of Cohendy. He took for several weeks
milk curdled with pure cultures of lactic acid microbes and obtained
“results that were quite definite as to intestinal putrefaction.”
Analysis of his urine showed that there was a marked diminution of
indol and phenol, substances which are certain indexes of intestinal
putrefaction.

In addition to such observations on lactic bacilli there is a good deal
of knowledge as to the effect of lactic acid taken in bulk. The result
of the various observations[135] shows that the acid lessens intestinal
putrefaction and lowers the quantity of sulpho-conjugate ethers in the
urine. This fact explains why favourable results follow the use of
lactic acid in many intestinal diseases such as infantile diarrhœa,
tuberculous enteritis and even Asiatic cholera. The addition of this
remedy to practical therapeutics is due chiefly to Professor Hayem.
It is employed not only in the treatment of diseases of the digestive
system (dyspepsia, enteritis and colitis), but is indicated also in
diabetes and is used locally in tuberculous ulcerations of the larynx.
As quantities up to twelve grams can be given by the mouth daily, it is
plain that the system is tolerant of this acid. It is either oxidised
in the tissues or excreted with the urine. In the case of a diabetic
woman who had taken 80 grams of lactic acid in four days, Nencki and
Sieber[136] found no traces of it in the urine. On the other hand,
Stadelmann[137] found a notable quantity of the acid in another
diabetic patient who had been taking over four grams daily.

The general interpretation of the benefits gained from the use of
lactic acid ferments is that they depend solely on the action of the
lactic acid which they produce in preventing the multiplication of
the microbes which cause putrefaction. Recent investigations made by
Dr. Bélonowsky, at the Pasteur Institute, show that a lactic ferment
isolated from yahourth and described as the Bulgarian bacillus owes
its antiseptic powers not only to lactic acid but to another substance
which it secretes. Dr. Bélonowsky has studied the effects of this
bacillus upon mice, by adding to their previously sterilised food
quantities of this lactic microbe. As control experiments he fed
other mice on food to which lactic acid had been added in quantities
corresponding to the quantity produced by the Bulgarian bacillus, or
which had been mixed with other kinds of bacilli. Another set of mice
were given normal food without the addition of either microbes or
lactic acid.

Out of these groups of mice, those which had been given the Bulgarian
bacillus thrived best and had most progeny. Their droppings showed
fewest microbes, particularly microbes of putrefaction.

The next stage in Dr. Bélonowsky’s experiments was to feed mice not
with living quantities of the Bulgarian bacillus, but with cultures
which had been sterilised by heat (120°-140° Fahr.). These mice lived
as well as those to which living cultures had been supplied, and
notably better than those supplied with pure lactic acid. It is evident
therefore that there is some other product of this bacillus which
favours life by preventing intestinal putrefaction.

Dr. Bélonowsky showed, moreover, that the Bulgarian bacillus cures a
special intestinal disease known as mouse typhus.

The experiments which I have described show that intestinal
putrefaction is to be combated not by lactic acid itself, but by the
introduction into the organism of cultures of the lactic bacilli.
The latter become acclimatised in the human digestive tube as they
find there the sugary material required for their subsistence, and by
producing disinfecting bodies benefit the organism which supports them.

From time immemorial human beings have absorbed quantities of lactic
microbes by consuming in the uncooked condition substances such as
soured milk, kephir, sauerkraut, or salted cucumbers which have
undergone lactic fermentation. By these means they have unknowingly
lessened the evil consequences of intestinal putrefaction. In the Bible
soured milk is frequently spoken of. When Abraham entertained the three
angels he set before them soured milk and sweet milk and the calf which
he had dressed (Genesis xviii. 8). In his fifth book, Moses enumerates
amongst the food which Jehovah had given his people to eat “Soured milk
of kine and goat’s milk, with fat of lambs and rams of the breed of
Bashan, and goats with the fat of kidneys” (Deut. xxxii. 14).[138]

A food known as “Leben raib,” which is a soured milk, prepared from
the milk of buffaloes, kine or goats, has been used in Egypt from
the remotest antiquity. A similar preparation known as “yahourth” is
familiar to the populations of the Balkan Peninsula. The natives of
Algiers make a kind of “leben” not identical with the Egyptian form.

Soured milk is consumed in great quantities in Russia in two forms,
“prostokwacha,” which is raw milk spontaneously coagulated and soured,
and “varenetz,” which is boiled milk soured with a yeast.

The chief food of many natives of tropical Africa consists of soured
milk. The staple diet of the Mpeseni is “a curdled milk, almost
solidified.” “Meat is eaten only on ceremonial occasions.” According
to Foà, a tribe of the Nyassa-Tanganyika plateau, like the Zulus, take
milk only in the form of a raw cheese mixed with salt and pepper.

Dr. Lima of Mossamedes, in West Africa, has told me that the natives
of many regions south of Angola live almost entirely on milk. They
employ the cream as an ointment for the skin, whilst the milk, soured
and curdled, is their staple food. M. Nogueira reported the same
circumstances nearly fifty years ago after his journey in the province
of Angola.

Just as cheeses vary in different countries, so curdled milk varies
slightly according to the nature of the flora of microbes. Taking all
the soured milks that are produced by natural processes, it may be said
that the greater number of them contain not only microbes that produce
lactic acid, but also yeasts that cause alcoholic fermentations.
Kephir, which is prepared from the milk of kine, and koumiss, which
is a product of mares’ milk, are notably alcoholic. Koumiss is the
well-known national beverage of the Kirghises, Tartars and Kulmucks,
nomads of Asiatic Russia who are famous horse breeders, whilst kephir
is the native drink of the mountaineers of the Caucasus, the Ossetes,
and some other tribes.

It has been supposed that the chief merit of kephir was that it was
more easy to digest than milk, as some of its casein is dissolved in
the process of fermentation. Kephir, in fact, was supposed to be partly
digested milk. This view has not been confirmed. Professor Hayem thinks
that the good effects of kephir are due to the presence of lactic acid
which replaces the acid of the stomach and has an antiseptic effect.
The experiments of M. Rovighi, which I spoke of in _The Nature of Man_,
have confirmed the latter fact, which now may be taken as certain. The
action of kephir in preventing intestinal putrefaction depends on the
lactic acid bacilli which it contains.

Kephir, although in some cases certainly beneficial, cannot be
recommended for the prolonged use necessary if intestinal putrefaction
is to be overcome. It is produced by combined lactic and alcoholic
fermentations, and as it contains up to one per cent. of alcohol, its
use as a food for years would involve the absorption of considerable
quantities of alcohol. The yeasts which produce it can be acclimatised
in the human digestive tract, in which, however, they are harmful, as
they are favourable to the germs of infectious diseases such as the
bacillus of typhoid fever, and the vibrio of Asiatic cholera.

Kephir has also the disadvantage that its flora varies considerably and
is not well known. There has been little success in producing it by
pure cultures as would be necessary were it to be brought into general
use. When it is prepared from a dried remnant there is the risk of
stray microbes being included, and these may bring about pernicious
fermentations. Professor Hayem prohibits its use in the case of
persons in whom food is retained for long in the stomach. “When it
is retained in the stomach, kephir goes on fermenting, and there are
developed in the contents butyric and acetic acids which aggravate the
digestive disturbances.”[139]

As it is the lactic and not the alcoholic fermentation on which the
valuable properties of kephir depend, it is correct to replace it by
soured milk that contains either no alcohol or merely the smallest
traces of it.

The fact that so many races make soured milk and use it copiously is
an excellent testimony to its usefulness. M. Nogueira has written
to me to say how much he was astonished, on revisiting after a long
period of absence the district of Mossamedes, to find the natives so
well preserved and displaying so few traces of senility. Dr. Lima has
stated that amongst the natives of the region south of Angola “many
individuals of extraordinary longevity are to be found.” Although they
are thin and withered, these old people are very active and can make
long journeys.

Mr. Wales, a lawyer at Binghampton, U.S.A., has been so good as to
make me acquainted with some extremely interesting facts taken from a
work by James Riley which is now a bibliographical rarity.[140] In the
narrative of a shipwreck of the vessel on which he made a voyage in
1815, James Riley states that the wandering Arabs of the desert live
almost wholly on the milk of camels, fresh or soured.

On this diet they enjoy excellent health, display great vigour and
reach advanced ages. Riley estimated that some of the old men must have
lived for two to three hundred years. No doubt these figures are much
too high, but it is probable that the Arabs Riley encountered lived
really unusually long.

Mr. Wales has examined Riley’s work critically, and is of the opinion
that that author was a well-informed, sagacious and conscientious
observer.

M. Grigoroff, a Bulgarian student at Geneva, has been surprised by
the number of centenarians to be found in Bulgaria, a region in which
yahourth, a soured milk, is the stable food. Some of the centenarians,
described by M. Chemin in his memoir, lived chiefly on a milk diet.
Marie Priou, for example, who died in the Haute-Garonne in 1838 at the
age of 158 years, had lived for the last ten years of her life entirely
on cheese and goat’s milk (_op. cit._ p. 100). Ambroise Jantet, a
labourer of Verdun, who died in 1751 at the age of 111 years, “ate
nothing but unleavened bread and drank nothing but skimmed milk” (p.
133). Nicole Marc, who died aged 110 years, at the chateau of Colemberg
(Pas-de-Calais), a hunch-back and cripple, “lived only on bread and
milk-food. It was only towards the end of her life and after much
persuasion that she took a little wine” (Chemin, p. 139).

I owe to the kindness of M. Simine, an engineer in the Caucasus, the
following communication, taken from the newspaper _Tiflissky Listok_,
Oct. 8th, 1904. “In the village of Sba, in the district of Gori, there
is an old Ossete woman, Thense Abalva, whose age is supposed to be
about 180 years (?). This woman is still quite capable and looks after
her household duties and sews. Although she is bent, she walks firmly
enough. Thense has never taken alcoholic liquors. She rises early in
the morning, and her chief food is barley bread and butter milk, taken
after the churning of the cream. Butter milk is a liquid containing
very many lactic microbes.

Mrs. Jenny Read, an American, has written to me that her father,
eighty-four years old, “owes his health to the curdled milk which he
has taken for the last 40 years.”

Curdled milk and the other products of milk to which I have referred
are the work of the lactic microbes which produce lactic acid at the
expense of milk sugar. As many different kinds of soured milk have been
consumed on a vast scale and have proved to be useful, it might be
supposed that any of them is suitable for regular consumption with the
object of preventing intestinal putrefaction.

From the point of view of flavour I find that soured milk, prepared
from raw milk, is much the more agreeable. However, when a food is to
be selected for consumption during a long period of time, we must keep
hygiene strictly in view. It is certain, therefore, that the Russian
“prostokwacha,” as well as any other soured raw milk, must be rejected.
Raw milk contains a large assortment of microbes, and frequently some
of these are harmful. The bacillus of bovine tuberculosis, as well
as other pernicious microbes, may be found in it. According to the
investigations of Heim[141] the vibrios of Asiatic cholera, when placed
in raw milk, survive even when the milk has become quite soured. In
similar conditions the bacillus of typhoid fever remains alive for 35
days and dies only after it has been kept for 48 days in completely
soured milk.

As raw milk nearly always contains traces of fæcal matter from the
cow, it sometimes happens that pernicious microbes are introduced from
that source, and remain alive notwithstanding the acid coagulation of
the milk. The lactic microbes certainly prevent the multiplication
of other microbes, as, for instance, those of putrefaction, but are
incapable of destroying them. Moreover, raw milk often contains fungi
(yeasts, torulas, and oïdia) the presence of which is favourable to the
development of such pernicious microbes as the cholera vibrio and the
bacillus of typhoid fever.

Prolonged consumption of raw milk increases the risk of introducing
dangerous microbes into the organism, and this possibility drives me to
recommend soured milk prepared after heating. Theoretically, it would
be best to sterilise the milk completely so that all the contained
microbes would be destroyed. This, however, requires heating the milk
to a temperature of from 226° to 248° Fahr., by which it acquires an
unpleasant flavour. On the other hand, the pasteurising of milk at a
temperature of about 140° Fahr. is not sufficient to get rid entirely
of the bacilli of tuberculosis and the spores of the butyric bacilli.
We have, therefore, to fall back on a middle course, and be content
with boiling the milk for several minutes. By so doing we certainly
kill the tubercle bacilli and the spores of some of the butyric
bacilli,[142] there being left only some butyric spores and the spores
of _Bacillus subtilis_, to destroy which a much higher temperature is
necessary.

As some kinds of soured milk, such as “varenetz,” “yahourth,” “leben,”
etc., are prepared from boiled milk, it might be supposed that
they fulfil the conditions necessary for prolonged use. A closer
examination, however, makes us reject them.

Boiled milk, to make it undergo the lactic fermentation properly,
must have added to it a prepared ferment. What is necessary is not
merely rennet, as was formerly supposed, but a number of organised
ferments, that is to say, microbes. In the preparation of these soured
milks, a leaven is employed, one of the names of which is “Maya,”
and which contains not only lactic microbes, but several others. MM.
Rist and Khoury[143] have come to the conclusion that the Egyptian
“leben” contained a flora composed of five species, three of which
are bacteria and two yeasts. The bacteria produce lactic acid and the
yeasts alcohol. Although the result is that “leben” is a nearly solid
substance, whilst kephir is a liquid, the two are closely similar.
In both cases we have to do with coincident lactic and alcoholic
fermentations, and my remarks regarding kephir apply equally well to
the Egyptian “leben.”

Through the agency of Prof. Massol of Geneva, I have obtained a
specimen of the Bulgarian “yahourth.” Working with his pupil, M.
Grigoroff, M. Massol[144] has isolated several microbes from this milk,
amongst these being a very active lactic bacillus. The same soured
milk has been studied in my laboratory by Drs. M. Cohendy[145] and
Michelson. They found in it a very powerful lactic ferment, which has
been named the Bulgarian bacillus. This was the microbe employed in the
experiments of M. Bélonowsky, to which I have already referred. More
recently, it has been carefully investigated from the chemical point of
view by MM. G. Bertrand and Weisweiler[146] at the Pasteur Institute.
It proved to be an extremely active producer of lactic acid, supplying
25 grammes per litre of milk. The other acids which this bacillus
produces, such as succinic and acetic acids, are formed only in very
small quantities (about 50 centigrams a litre). Formic acid is produced
only in traces. On the other hand, the Bulgarian bacillus forms neither
alcohol nor acetone, two frequent products of bacterial fermentation.
The bacillus also differs from other lactic ferments inasmuch as it
has no action on albuminoids (casein, etc.), nor on fats. All these
qualities make the Bulgarian bacillus much the most useful of the
microbes which can be acclimatised in the digestive tube for the
purpose of arresting putrefactions and pernicious fermentations, such
as the butyric fermentation.

As in all the known soured milks (yahourth, leben, prostokwacha,
kephir, and koumiss) the lactic bacilli are associated with a rich
flora in which pernicious microbes may be met (such as the red torula,
a microbe which predisposes to cholera and typhoid fever, which I found
in the leaven of yahourth, bought in Paris), it is necessary to work
out a method by which good curdled milk can be produced with the aid of
pure cultures of the lactic microbes.

It was the obvious course to begin with the Bulgarian bacillus, as
that is known to be the best producer of lactic acid. It coagulates
milk rapidly, giving it a strongly acid flavour, but it often also
gives a disagreeable taste of tallow. It is true that after it has been
kept for a long time in the laboratory in the form of pure cultures
in sterilised milk, the bacillus loses to a large extent its power
of saponifying fats, the taste of the curdled milk being then more
agreeable. If necessary, therefore, soured milk prepared exclusively
with the Bulgarian bacillus can be used. In practice, however, it
is useful to associate with it another lactic microbe, known as the
paralactic bacillus, as the latter, although producing less lactic acid
than the Bulgarian bacillus, does not break up the fats and gives the
curdled milk a very pleasant flavour.

As it is undesirable to absorb too much fatty matter, it is necessary
to prepare curdled milk for regular use from skimmed milk. After the
milk has been boiled and rapidly cooled, pure cultures of the lactic
microbes are sown in it, in sufficient quantities to prevent the
germination of spores already in the milk and not destroyed in the
process of boiling. The fermentation lasts a number of hours, varying
according to the temperature, and finally produces a sour curdled milk,
pleasant to the taste and active in preventing intestinal putrefaction.
This milk, taken daily in quantities of from 300 to 500 cubic
centimetres, controls the action of the intestine, and stimulates the
kidneys favourably.[147] It can therefore be recommended in many cases
of disorder of the digestive apparatus, of the kidneys, and in several
skin diseases.

The Bulgarian bacillus taken from yahourth or from soured milk,
prepared from pure cultures of lactic microbes, can live in warm
temperatures, and, as has been shown by Dr. Cohendy, is able to take
its place in the intestinal flora of man.

Soured milk, prepared according to the receipt which I have given, has
been analysed by M. Fouard, an assistant at the Pasteur Institute.
When it was ready to be taken, M. Fouard found in it about 10 grammes
of lactic acid per litre. Moreover, a large proportion (nearly
38 per cent.) of the casein had been rendered soluble during the
fermentation, which shows that its albuminous matter is prepared for
digestion much as in kephir. Of the phosphate of lime (which is the
chief mineral substance of milk) 68 per cent. was rendered soluble
during the fermentation. These facts all confirm the utility of the
soured milk prepared from pure cultures of lactic bacteria.

Those persons who, from some reason or other, cannot take milk, may
swallow the bacilli in a pure culture without milk. However, as the
microbes need sugar to produce lactic acid, it is necessary to take
with them a certain quantity of sweet food (jam, sweet-meats, and
especially beetroot).

The Bulgarian bacillus produces lactic acid not only from milk sugar,
but also from many other sugars, for instance, cane sugar, maltose,
levulose and especially glucose.

Cultures of the bacillus can be made not only in milk, but in vegetable
broths, or broths of animal peptone to which sugar has been added. The
cultures can be taken in a dry form (powders or tabloids), or in the
liquid in which the bacilli had themselves been developed.

A reader who has little knowledge of such matters may be surprised
by my recommendation to absorb large quantities of microbes, as the
general belief is that microbes are all harmful. This belief, however,
is erroneous. There are many useful microbes, amongst which the lactic
bacilli have an honourable place. Moreover, the attempt has already
been made to cure certain diseases by the administration of cultures
of bacteria. M. Brudzinsky[148] has used cultures of lactic microbes
in certain intestinal diseases of infants, whilst Dr. Tissier[149] has
used them in similar affections of infants and adults.

From the general point of view of this book, the course recommended
consists of the absorption either of soured milk prepared by a group of
lactic bacteria, or of pure cultures of the Bulgarian bacillus, but in
each case taking at the same time a certain quantity of milk sugar or
saccharose.

For more than eight years I took, as a regular part of my diet, soured
milk at first prepared from boiled milk, inoculated with a lactic
leaven. Since then, I have changed the method of preparation and have
adopted finally the pure cultures which I have been describing. I am
very well pleased with the result, and I think that my experiment
has gone on long enough to justify my view. Several of my friends,
some of whom suffered from maladies of the intestine or kidneys, have
followed my example, and have been well satisfied. I think, therefore,
that lactic bacteria can render a great service in the fight against
intestinal putrefaction.

If it be true that our precocious and unhappy old age is due to
poisoning of the tissues (the greater part of the poison coming from
the large intestine inhabited by numberless microbes), it is clear
that agents which arrest intestinal putrefaction must at the same time
postpone and ameliorate old age. This theoretical view is confirmed by
the collection of facts regarding races which live chiefly on soured
milk, and amongst which great ages are common. However, in a question
so important, the theory must be tested by direct observations. For
this purpose the numerous infirmaries for old people should be taken
advantage of, and systematic investigations should be made on the
relation of intestinal microbes to precocious old age, and on the
influence of diets which prevent intestinal putrefaction in prolonging
life and maintaining the forces of the body. It can only be in the
future, near or remote, that we shall obtain exact information upon
what is one of the chief problems of humanity.

In the meantime, those who wish to preserve their intelligence as
long as possible and to make their cycle of life as complete and as
normal as is possible under present conditions, must depend on general
sobriety and on habits conforming to the rules of rational hygiene.

PART V

PSYCHICAL RUDIMENTS IN MAN

RUDIMENTARY ORGANS IN MAN

Reply to critics who deny the simian origin of
man—Actual existence of rudimentary organs—Reductions
in the structure of the organs of sense in man—Atrophy
of Jacobson’s organ and of the Harderian gland in the
human race

Several critics of _The Nature of Man_ have protested against my
theory of the simian origin of man. Some of these found my arguments
unsatisfactory and unconvincing. Others have attacked generally my
suggestion that some anthropoid had been suddenly transformed to a
primitive human being.

It is true that so long as we have little palæontological evidence as
to the actual descent of man, we cannot discuss the subject without
the aid of hypotheses. I think, however, that recent additions to
knowledge confirm the theory of the descent of man in a way that ought
to influence the most resolute opponents. I have in mind chiefly
the arguments supplied by the embryology of anthropoid apes, and by
the investigation of their blood. None the less, there are still
many authors who maintain their opposition. One of my critics, Dr.
Jousset,[150] enumerates certain differences in the structure of the
skeleton in man and apes, and concludes that these radically separate
man from apes.

No one has ever doubted that man was not identical in structure with
the anthropoid apes, or that he differs from them in several characters
of the skeleton and of many other organs. The differences, however,
do not justify any radical separation of the two. The unusual length
of arm, upon which my opponents throw so much weight, is in harmony
with the mode of life of apes, as these climb on trees and walk on all
four limbs. The difference between apes and Europeans in length of arm
is certainly considerable, but is much less in the case of some lower
races, such as the Veddahs. In the Akkas of Central Africa, the arms
are so long that the hands nearly reach the knees. The fœtus of
Europeans also shows an unusual length of arm, probably an ancestral
feature. It is only after birth that the arms become relatively shorter.

All the other characters different in man and the apes, are equally
secondary. On the other hand, just as apes differ amongst themselves,
so also, the different races show differences often strongly marked.
M. Michaelis,[151] in a comparative study of the muscular systems
of monkeys, has made known many details of the musculature in the
orang-outan and the chimpanzee, and it appears from his investigations
that, although there are some differences between these two apes, they
are both closely similar to man.

There are many variations in the muscular structure of man, and these
find parallels in the muscles of apes. This is also the case with other
abnormalities of structure, some of which resemble the condition in
mammals much lower than apes. An example of this is the presence of
additional pairs of nipples, arranged symmetrically on the sides of the
chest and occasionally found in human beings. A similar abnormality
has been found in some monkeys, and the best explanation of such an
occurrence is that monkeys, like man, are descended from mammals which
possessed several pairs of mammary glands.

The large number of abnormalities and rudimentary organs which may
be found in man affords important evidence in favour of the descent
of man from lower animals. Some authors, however, have tried to
dispute this view and even deny the existence of rudimentary organs.
M. Brettes,[152] amongst my opponents, has brought together most
facts upon this matter, with the object of proving that such organs
fulfil some function indispensable to the body and bear witness to the
existence of a general plan of organisation. My opponent, however,
confines himself to general propositions, laying much stress on a law
of “the subordination of organs” without proving that rudimentary
organs have an actual function. In _The Nature of Man_ I remarked on
the uselessness of the wisdom teeth, which are not cut until long
after childhood and which are useless in mastication. In many human
beings these teeth never cut through the gum, and their absence is
no disadvantage. This is a typical case of a rudimentary organ. To
maintain the contrary it would be necessary to prove that the wisdom
teeth fulfil an indispensable function and that their absence was in
some way harmful to the organism. No one has been able to show this.

The mammary glands in males are another case of rudimentary organs. The
function of these, of course, is well known in females, but it is only
in the rarest cases that they are active in males.

The organs of sense supply many cases of rudimentary structures.
Animals which live in caves, in the dark, do not discern objects by
sight, and in these cases the eyes are rudimentary. It is quite
impossible to deny the existence of rudimentary organs. They are
extremely important guides to us in our investigation of the past
history of the human race. The comparative study of the organs which
are rudimentary in man and more or less well developed in lower animals
is of fundamental importance in the problem of our origin.

The higher apes, or anthropoids, display reduction in some parts of
the organs of sense. The organ of smell, for instance, is much less
developed in them than in many other animals. Man has inherited the
imperfect condition of this organ, and his sense of smell is much
less developed than that of mammals which are lower in the scale of
life. Man, however, because of his intelligence, has been able to tame
domestic animals, such as dogs, ferrets, and pigs, and to make use
of their acute sense of smell for tracking game or obtaining edible
plants. The imperfect condition of the sense of smell in man in other
cases is well replaced by his mental powers. He no longer recognises
the approach of an enemy by the sense of smell, in order that he may
take flight, because he has better means of defence than those of
animals. It is not surprising, therefore, that the olfactory apparatus
of man is much reduced as compared with that of lower mammals. In apes
and man the nasal region of the head is much smaller than in their
mammalian ancestors, and in the deep-lying parts of the system there
are corresponding differences. Most mammals, for instance, and the dog
in particular, have four turbinal bones, the purpose of which is to
increase the surface of the mucous membrane of the nose, whilst in man
there are only three, one of which is rudimentary.

The olfactory apparatus in most mammals contains a well-developed
portion known as the organ of Jacobson, the probable function of
which is to appreciate the flavour of food in the mouth. In man, this
organ is in a rudimentary condition and cannot fulfil its function,
as it is devoid of its proper nerve. This remnant, now useless, gives
us information as to the evolution of the organ of smell in man. In
the human fœtus, Jacobson’s organ is not only better developed than
in adult man, but it is also provided with a stout nerve trunk, which
disappears towards the end of embryonic life. The organ, however,
cannot perform any olfactory function. The human fœtus, moreover,
possesses five turbinals which later on become reduced to three, and of
these only two develop completely.

The history of the evolution of the organ of smell, as it has been made
out by comparative anatomy and embryology, links this apparatus in
man with the corresponding organs of other mammals by means of these
useless rudiments, which, however, are important evidence in scientific
theory.

The auditory apparatus also has become reduced in man. Many animals,
in the struggle for existence, require a very acute sense of hearing,
more so than man or some of the most intelligent mammals. We have all
seen how horses raise their ears to hear better when there is the
slightest sound near them. Monkeys and man have lost this power, and
man sometimes tries to supply the defect by artificial means. When a
lecturer, for instance, is not speaking sufficiently loud some of the
audience put their hands to their ears, making a kind of trumpet which
serves to catch the sound. The human external ear is supplied with
muscles, but in most cases these are too feeble to move it. In very
rare cases persons can move their ears, the muscles inserted to the
shell in most of us being mere rudiments of those that existed in our
ancestors.

In the organ of sight, the little fold in the inner angle of the eye,
known as the semilunar fold, is of special interest. This membrane
is a useless vestige of a structure much better developed in lower
mammals. In the dog it is present as a small third eyelid, supported
by a special cartilage provided with a secreting gland, known as the
Harderian gland. In birds, reptiles and frogs, the corresponding
structures are much better developed. Everyone has seen the delicate
membrane which, in the case of a bird, may shoot out from the inner
angle of the eye and cover the whole of the exposed part of the eyeball
(nictitating membrane). In these animals, the eye is protected by this
third lid, which has its own muscles. As in the dog, this third eyelid
of birds and lower vertebrates is generally provided with a large
Harderian gland, which produces a liquid secretion like tears.

In most monkeys, this apparatus is much reduced. Many of them have
still a small Harderian gland and a weak third eyelid. In man, as I
have already said, there are only vestiges of these organs, the gland
being almost atrophied and the third eyelid represented only by an
insignificant crescentic fold. In the lower races the fold sometimes
contains a small cartilage. Giacomini found it twelve times in sixteen
negroes, whilst in 548 white people it was found only in three cases.

The interpretation of these facts is not doubtful. This little fold is
the last vestige in use of an organ which was useful only in our remote
ancestors.

The organs of reproduction in the human race also show a number of
rudiments. There remain even traces of a hermaphrodite condition,
a very low degree of organisation, going back to extremely
remote ancestors. The evidence given by the very large number of
abnormalities that are found in these organs makes it clear that, in
the long period of the evolution of the human race, they have been
subjected to a series of modifications. Thus, for instance, there is
occasionally present in women a form of uterus resembling that of the
lower mammals, or even the double uterus of marsupials.

The evolution of man has been dominated by the great development of
the brain and of the intelligence, and man, accordingly, has lost many
organs and functions which were of use in his more or less remote
ancestors.

HUMAN TRAITS OF CHARACTER INHERITED FROM APES

The mental character of anthropoid apes—Their muscular
strength—Their expression of fear—The awakening of
latent instincts of man under the influence of fear

The facts of which I have given a résumé serve to show that evolution
always leaves definite traces indicating its successive stages in
the form of rudiments. It is probable, therefore, that the pre-human
mental functions or psycho-physiological qualities, which have so long
a history behind them, have also left more or less appreciable traces.
These, however, must be more difficult to find than rudimentary organs
which can be made visible by dissection.

If we turn first to the animals most nearly related to man, we find
that the living anthropoid apes show in the clearest way their close
relationship with the human race, and suggest that their kinship with
our remoter ancestors must be even greater.

The anthropoid apes alive to-day are animals inhabiting chiefly virgin
forests, and feeding on fruits and shoots, although they do not despise
eggs or even little birds. To satisfy their wants, they climb with the
greatest ease. Orang-outans and chimpanzees climb slowly and carefully,
whilst gibbons show a greater agility and more perfect acrobatic power.
They may be seen throwing themselves from branch to branch across
spaces of forty feet with the greatest precision. They play at the top
of very tall trees, hardly grasping the branches through which they
pass, making leaps of from twelve to eighteen feet for hours together
with little apparent exertion.

To give an idea of the dexterity and swiftness of gibbons, Martin
took the case of a female which he observed in captivity. One time
she hurled herself from a perch across a space at least twelve feet
wide, against a window which one would have thought would have been
immediately broken. To the great surprise of the spectators it was not
broken. The gibbon seized with her hands the narrow board between the
panes, and then in an instant twisted herself round and jumped back to
the cage she had left, performing this manœuvre with great strength
and the most marvellous precision.

The muscular force implied in the above narrative is possessed by all
the anthropoid apes. Battel, an English sailor who gave the first
description of the gorilla in the beginning of the 17th century, stated
that the strength of that animal was so great that ten men could hardly
master an adult specimen. The other anthropoids, although not so strong
as the gorilla, nevertheless display surprising force.

Edouard, the young male chimpanzee which I used in my experiments
on syphilis, struggled so much at the least touch that it took four
men to master him. I had to give up allowing him to leave his cage
because there was no way of getting him back to it. Even quite young
chimpanzees, females not yet two years old, cannot be handled easily.
Although they are very friendly, my specimens used to resist with all
their strength when it was necessary to put them back in their cages
for the night. Two men had much ado to shut them up.

Notwithstanding this great muscular force, the anthropoid apes are
cowardly. They have no idea of their strength, but fly from the
approach of the slightest imagined danger. My young chimpanzees,
although their teeth and muscles were already formidable weapons,
showed the greatest fear when I put with them animals even so weak and
harmless as guinea-pigs, pigeons and rabbits. Mice frightened them
very much at first, and it took them a considerable time before they
got over their fear of so insignificant an enemy. When living in a
state of nature the anthropoid apes scarcely ever assume the offensive.
“Though possessed of immense strength,” wrote Huxley,[153] “it is rare
for the Orang to attempt to defend itself, especially when attacked
with fire-arms. On such occasions he endeavours to hide himself, or
to escape along the topmost branches of the trees, breaking off and
throwing down the boughs as he goes.” Savage[154] wrote of chimpanzees
that “they do not appear ever to act on the offensive, and seldom,
if ever really, on the defensive.” When a female was surprised on a
tree with her young ones “her first impulse was to descend with great
rapidity and make off into the thicket.”[155]

The gorilla, the strongest and most ferocious of the apes, has
sometimes been observed to take the offensive. Savage, quoted by
Huxley, said that “they are exceedingly ferocious, and always offensive
in their habits, never running from man, as does the chimpanzee.
The females and young, at the first cry, quickly disappear. He (the
male) then approaches the enemy in great fury, pouring out his horrid
cries in quick succession.”[156] Only males take the offensive,
nor can this be of frequent occurrence, as one of the most recent
observers, Koppenfels,[157] states that “the gorilla never attacks man
spontaneously; he tries to avoid him, and, as a rule, takes to flight
as soon as he sees a man, uttering peculiar guttural cries.”

Which of these characters are preserved in the human race? Man is
naturally feebler and less of a gymnast than the great apes, but his
disposition is cowardly. One of the earliest signs of mental activity
in an infant is the fear of surrounding circumstances. The smallest
change in its balance or its being put in a bath cause it to show
signs of real terror. Later on, it is alarmed when it sees any kind of
animal, exactly in the fashion of a young chimpanzee. The most harmless
spider is enough to frighten it.

Although mental culture subdues fear to a large extent, fear reveals
itself more or less strongly from time to time, and it is on such
occasions that we may find in the human being psychological relics of
his ancestors. An analysis of fear is of special interest.

The first result of the emotion of fear is flight. Consciousness of
danger sets our limbs in motion, and our instinctive desire to escape
displays itself even when flight is more dangerous than what we wish
to avoid. At the first alarm of fire in a public building, people rush
towards the exits and in so doing often perish from their wish to
escape. Even in the extreme of terror, the desire of flight is one of
the earliest impulses. Mosso, a well-known Italian physiologist, in a
monograph on fear, relates that when a Calabrian brigand was sentenced
to death “he uttered a sharp cry, heart-rending and terrible, looked
around him as if he were eagerly seeking for something, and then
stepped backwards as if to fly, and threw himself against the wall of
the court, writhing, with arms outstretched, scratching at the wall as
if he were trying to break through it.”

Although in such a case it was futile and often is harmful, the
instinct of flight from danger is inherited from ancestors from a
time when it served to save life. Attempts to escape are not the
only signs of fear. There is often a trembling fit which would make
flight impossible. In Mosso’s case of the Calabrian brigand, “after
his struggles, cries and contortions, he fell on the ground in a
motionless heap, like a wet rag; he became pale and trembled more than
I have seen any other person tremble; his muscles seemed changed into
a soft and quivering jelly.” This condition of trembling inertia is
another legacy from animals. Quivering of the muscles often manifests
itself in terrified animals. Darwin[158] wrote of it, “trembling is of
no service, often of much disservice, and cannot at first have been
acquired through the will, and then rendered habitual in association
with any emotion.” The phenomenon seemed to him obscure and difficult
to explain, a view shared by Mosso. The trembling of the musculature of
the body is a generalised and exaggerated form of the movements of the
cutaneous muscles in the condition known popularly as “goose-skin.” The
latter, however, is a relic of an adaptation useful to some animals.
The hedgehog rarely takes to flight at the approach of danger, but
stands still, and using strongly developed muscles, rolls itself into a
ball. In birds and many mammals, the muscles of the skin cause erection
of the feathers or hairs. These movements often are performed during
fright, and according to Darwin, serve not only to warm the skin,
but sometimes to make the animal appear larger and more terrifying to
enemies.

Fear and cold alike cause contraction of the superficial blood-vessels,
and, in man, excite the contraction of the minute rudimentary muscles
inserted to the roots of the hairs. “Goose-skin” is caused by the
contraction of these muscles, the condition being a functional
rudiment, no longer serving to warm the skin nor to make the body
appear larger. In a few exceptional cases, “goose-skin” can be produced
voluntarily. In the normal condition, the rudimentary cutaneous muscles
of man are immobile, and it requires some special stimulation to set
them in action.

Fear, which is occasionally able to excite the contraction of the
involuntary muscles, also stimulates other muscles against the will.
Under the influence of emotions that powerfully affect the nervous
system, and particularly under that of fear, contractions of the
bladder and intestines may be so violent that it is impossible to
prevent the voiding of their contents. Accidents of this kind are not
infrequent in the case of youthful candidates at examinations. Mosso
relates of a friend, a volunteer in the war of 1866, that he was seized
with terror during a battle and that the utmost efforts of his will
failed to make his body endure the terrible spectacle.

The involuntary action of the bladder and intestines during fear is
a legacy from animals. The phenomenon is common in dogs and monkeys.
Chimpanzees, when laid hold of, discharge their urine and fæces. At
Madeira I had an unusually cowardly _Cercopithecus_ monkey which when
at all alarmed discharged the contents of the rectum. Quite possibly
such a mechanism was useful for the preservation of the individual. The
emission of various kinds of excretions is of use in the struggle for
existence. In that way the fox drives the badger from its earth and
takes possession of it, whilst polecats and skunks defend themselves
against more powerful carnivorous animals by discharging on them
fœtid secretions.

Instinctive fear is therefore a very powerful stimulant, awakening
functions which are rudimentary and almost completely extinct.
Sometimes it sets in operation mechanisms which have long been
paralysed. Pausanias gives an example of a dumb young man who recovered
his speech when he was terrified by seeing a lion. Herodotus relates
that the son of Crœsus, who was dumb, on seeing a Persian about to
kill his father, cried out: “You must not kill Crœsus,” and from
that time onwards was able to talk. These ancient narratives have been
confirmed by many modern observations. A woman, for instance, who had
been dumb for several years, on seeing a fire, was terrified and cried
out suddenly “Fire!” after which her speech was restored. Such are
cases of the awakening of a function which has been arrested only for
several years. But fear can bring into activity other mechanisms which
have been inactive from time immemorial.

Many different kinds of animals can swim instinctively. This is true
in the case of most birds and mammals. There are some species which
show a repugnance to water, but none the less swim well enough if they
are thrown into it. Cats shun water as much as possible, but, none
the less, can swim quite easily. Historians relate that Hannibal had
great difficulty in getting his elephants to cross the Rhone. Some
females were ferried across first, upon which the other elephants threw
themselves into the water to pursue them and swam across the river
without any difficulty (Lenthéric, _Le Rhône_, 1892, p. 81).

The lower monkeys can swim without being taught, but the anthropoid
apes have lost this power, and man also is without it. M. Volz[159]
states that the different species of gibbons which live in Sumatra are
separated by rivers. Their inability to swim makes these a complete
barrier. It is probable that the lower races, in this respect, are
better endowed than we are. It is said that in the case of negroes,
children run to the sea or to rivers almost as soon as they leave the
cradle, and learn to swim almost as quickly as to walk.[160] In the
case of white people, many find it very difficult to learn to swim,
and it is at least certain that swimming is not instinctive as in the
case of our animal ancestors. Christmann,[161] the author of a treatise
on swimming, states that the reason of man is a worse guide than the
infallible instinct of the animal. Fear is able to stifle reason and
to allow the instinct to come into play. It is known that children or
adults may be taught to swim by throwing them into the water. Under the
influence of fear, the instinctive mechanism inherited from animals
awakens, and man soon becomes a swimmer. There are some teachers of
swimming who use this method successfully. I have myself known an
individual who learnt the art in that way, and M. Troubat, librarian at
the International Library, has informed me that one of his friends, a
journalist who died at Noyon several years ago, bathed in the Seine one
evening at Neuilly when he could not swim. Unexpectedly finding himself
beyond his depth, a sudden movement of fear saved him. Since then, he
said, he knew how to swim.

Just as there are cases in which terror provokes flight, and others in
which it causes an arrest of motion, so also fear may do a disservice
to a swimmer. Those who employ fear as a means of teaching to swim,
know that they must intervene if there is real danger. It is true, none
the less, that up to a certain point fear can awaken functions which
have been atrophied for numberless generations, and that we can learn
from it something as to the evolution of the human race.

III

SOMNAMBULISM AND HYSTERIA AS MENTAL RELICS

Fear as the primary cause of hysteria—Natural
somnambulism—Doubling of personality—Some examples of
somnambulists—Analogy between somnambulism and the life
of anthropoid apes—The psychology of crowds—Importance
of the investigation of hysteria for the problem of the
origin of man

The study of fear is interesting in other respects than those with
which I have been dealing. It is also a primary cause of the obscure
and complicated phenomena of hysteria.

Thus, for instance, amongst twenty-two hysterical women observed by
Georget[162] the primary causes were: terror, 13 cases; extreme grief,
7 cases; extreme annoyance, one case. A patient of M. Pitres, of
Bordeaux, first exhibited hysteria after being extremely terrified. A
man with a tame bear had come to the village. The patient went to see
the performance and elbowed her way through the crowd until she got
to the front row. The bear, whilst dancing, passed so close that its
cold muzzle touched the cheek of the young girl. Marie—for that was
the patient’s name—was terrified. She ran quickly home, and almost
on her arrival fell on her bed in an attack of convulsion and extreme
delirium. Since then the attacks have been repeated many times, and the
delirium associated with them always turns upon the terror caused by
the bear touching her.

A hysterical woman at the Salpétrière is haunted by terrifying dreams.
She thinks someone is trying to murder her, or to cut her throat, or
that she is falling into water, and she keeps crying for help.[163]

Some of the most curious phases of hysteria are the paradoxical and
extraordinary cases of so-called natural somnambulism, in which the
patients, whilst asleep, perform all sorts of acts of which they
remember nothing in their waking hours. Cases of duplication of
personality are also known, in which the patients live in two different
states without, in one of these, having the slightest remembrance of
what takes place in the other. One of the most curious observations was
that of the somnambulist who became _enceinte_ whilst in her second
state. In her first, or normal condition, she was ignorant of the
reason of her physical changes, although in the second state she knew
about it quite well and spoke freely of it (Pitres, _op. cit._ II, 215).

In the state of natural somnambulism the patients generally reproduce
the normal acts of their daily life which they have acquired the habit
of performing unconsciously. Artisans devote themselves to their manual
work, sempstresses begin to sew, maid servants brush shoes or clothes,
lay the table and so forth. Educated persons devote themselves to
intellectual work to which they are accustomed. Clergymen have been
known to compose their sermons in the somnambulistic condition, and to
read them over to correct mistakes in style or in spelling.

However, besides somnambulists who during slumber simply repeat the
usual acts of their life, there are others who do special things to
which they are unaccustomed.

It is these cases which are most interesting from my point of view.
I shall take one case which has been specially well reported. A
hysterical patient, a girl of 24 years of age, was admitted as an
in-patient to the hospital Laënnec. One Sunday, she got up about one
o’clock in the morning. The night watchman, who was alarmed, went for
the night doctor, who witnessed the following scene. “The patient went
to the staircase leading to the nurses’ quarters, then suddenly turned
round and walked towards the wash-house. The door of that being closed,
she then groped for a time and turned towards the women’s dormitory
in which she had formerly slept. She went up to the top of the house
where this dormitory was, and when she got on the landing, opened a
window leading to the roof, went out of the window, walked along the
gutter, under the horrified eyes of the nurse who followed her and who
did not dare to speak to her, went in again by another window and went
down the stairs.” “It was at this moment that I saw her,” said the
night doctor; “she was walking noiselessly, her gait was automatic, her
arms hanging by her sides, a little bent, the head erect and fixed,
her hair disordered, her eyes wide open; she seemed like some strange
apparition.”[164] This is obviously the case of a hysterical subject,
who in a normal condition was not accustomed to climb upon roofs and
walk along the gutters.

Another observation, reported by Charcot, related to a young man,
seventeen years old, the son of a large manufacturer, and of good
address. Tired out by working for his final examination, he had gone
to bed early. Some time later he rose from the bed in his college
dormitory, went out by a window, and without accident climbed on the
roof and took a long and dangerous walk along the gutters. He was
awakened before any accident occurred (Feinkind, p. 70).

A case observed by Dr. Mesnet and M. Mottet was still more interesting.
A lady thirty years old and extremely hysterical got out of bed in the
night, “dressed herself, completed her toilet without help, removed the
furniture in her way without stumbling against it. She was indifferent
and idle by day, but strenuous at night in performing the most varied
acts. I have seen her walking about in her rooms, opening doors, going
down to the garden, leaping on seats with the utmost agility, running
about, in fact doing all these things much better than in her waking
hours, in which she got about only slowly and with aid” (Feinkind, p.
84).

Horst has related an extraordinary incident which took place in the
sixteenth century. “A soldier walked in his sleep to a window, and with
the help of a rope climbed a high tower, secured a jackdaw’s nest with
its young birds, and regained his bed, where he remained asleep until
the morning.”[165] Unfortunately there are not sufficiently detailed
facts regarding this incident, and for fully described cases we must
return to modern times. Dr. Guinon has related one case in ample
detail. A man thirty-four years of age, by occupation an interpreter,
was taken into hospital for hysterical attacks. “One night soon after
he came under the care of the physicians, this patient, towards one
o’clock in the morning, suddenly arose from bed, threw open a window
and jumped across the sill into the courtyard of the hospital. The
attendants on duty ran after him, and saw him hurrying away, undressed
and carrying a pillow in his arms. He traversed a series of gardens
and walks, with the topography of which he was unacquainted, climbed a
ladder and got on the roof of the hydrotherapeutic establishment, up
and down which he proceeded to run with the greatest agility. Sometimes
he stopped in his flight and rocked the pillow he was carrying, kissing
and soothing it as if it were a child. Then he retraced the route he
had taken.” On being questioned next morning, he had not the faintest
remembrance of his nocturnal exploit. “A similar fit came on him five
or six times” (Feinkind, p. 108).

The same patient, “after having turned over in bed several times,
seized a pillow and held it to his breast. He then got out of bed,
and, in his nightgown, ran through the dormitory to a door leading to
the lavatories. He opened the door, readily but with violence, and
entered one of the closets. Then, still holding the pillow against his
chest with one arm, by a gymnastic feat both difficult and dangerous,
yet which he performed with the utmost precision, using his feet and
the free arm, he got hold of the edge of the frame of an open window,
through which he swung himself to the sill, alighting on both feet,
after which, preserving the pillow carefully from contact or shocks,
he jumped to the ground (the infirmary ward was on the ground floor).
He then ran quickly to the opposite corner of the courtyard, passing
the whole length of the great building at full speed, holding the
pillow carefully. By a path which led round the building, he reached a
corner where there was a tower supporting a great water-tank. A kind of
metallic ladder, placed almost vertically and with rounded steps, led
up the side of the tower to a sort of observation-landing which at one
point was adjacent to the edge of the roof of the bath-house.

“The patient set himself to climb this ladder without any hesitation,
holding on by his free hand and placing his naked feet on the rounded
steps with extreme precision. When he reached the nearest point to
the roof of the bath-house he leapt upon that, and at a running pace
climbed the zinc roof to the crest, looking round him from time to time
to see if his imaginary pursuers were near. He ran along the crest
which was so narrow that his feet had to be placed alternately on
either side on the slopes of the steep-pitched roof, a performance so
dangerous that none of the officials would follow him, and which none
the less he performed with complete assurance and without a single slip.

“When he reached the middle of the building he sat down on the crest
of the roof, leaning against a ventilating chimney. He then took the
pillow which he had been carrying carefully, placed it on his knees
with a corner against his shoulder, and began to rock it as if it
were a child, crooning to it, stroking it with his hand or with his
cheek that he pressed gently against the corner. From time to time his
eyebrows contracted and his looks hardened, and he gazed around him as
if he were being pursued or watched, then gave a growl of rage, and
took to flight again, carrying the pillow on his dangerous path. All
the time he kept speaking, but we could not hear what he said. He saw
nothing that was not in his dream; he did not understand when his name
was called aloud; but he could hear, for at the slightest sound near
him he rushed off again as if his pursuers were upon him. This episode
lasted about two hours, during which he had climbed over all the roofs
in the vicinity, defying our pursuit of him” (Feinkind, pp. 106-112).

I could give other similar cases, but I think that I have shown
sufficiently that man, when in the condition of natural somnambulism,
exhibits qualities that he does not possess in the normal state,
becoming strong, adroit, and a good gymnast, like his anthropoid
ancestors. The close resemblance between the manœuvres of Martin’s
gibbon, which I described earlier in this chapter, and the dangerous
exploits of some sleep walkers is most striking.

The impulses to climb on roofs and poles, to run along in rain gutters,
to climb a tower to take a bird’s nest, are characteristic examples of
the instinctive actions of climbing animals, like the anthropoid apes.
Dr. Barth[166] defines somnambulism as “a dream with exaltation of the
memory and automatic action of the nervous centres, without voluntary
and conscious control.” “The striking exaltation of the memory is the
dominating condition. The extreme exactness of the memory of places
displayed by the somnambulist makes us understand how he performs
his nocturnal wanderings, doing almost without the aid of his senses
numberless deeds of which he would be practically incapable in a
waking condition.” However, as such a patient performs new acts which
he has never accomplished before in his own individual life, we must
suppose that the exaltation of memory includes extremely ancient facts,
dating perhaps from the pre-human period. Man has inherited from his
ancestors a number of mechanisms of the brain, the activity of which
is inhibited by restraints which have been developed later. Just as
man possesses mammary glands which under ordinary conditions cannot
secrete milk, so also, in his brain, there are contained groups of
cells which are inactive in the normal condition, but, also, just as in
some exceptional cases man and the males of several species of mammals
are able to give milk, so also in abnormal conditions the atrophied
mechanisms of other nervous centres begin to act.

The secretion of milk by males is a return to an extremely ancient
condition in which both sexes were able to nourish the young; so, also,
the gymnastic feats and the extraordinary strength of somnambulists are
a return to a normal condition much less remote from us than lactation
in males.

It is curious to find that, in some cases, natural somnambulism
is associated with power to move the shell of the ear. I know two
brothers, who, when they were young, used to walk in their sleep in
the most typical way. One of them, a chemist, used to climb on a high
cupboard, or simply walk about in the room. The other brother, a
sailor, in a fit of somnambulism, climbed to the top mast of a sailing
ship. These brothers, who were somnambulists, had the cutaneous muscles
extremely well developed and were able to move their ears voluntarily.

In this case the abnormality was hereditary in the family, and the
two daughters of one of the brothers were also somnambulistic and had
control over the muscles of the ears. Here, then, is a case of the
simultaneous recurrence of two characters of our ancestors: mobility
of the ear and agility in gymnastic feats. M. Barth characterises the
somnambulist as “a living automaton in whom conscious will is for the
time being destroyed.” According to him, the somnambulist “acts at
the suggestion of circumstances, and what seem most extraordinary in
what he does are in reality instinctive reactions.” This description
agrees well with my view that in natural somnambulism the instincts
of our pre-human ancestors are awakened, instincts which under normal
conditions are latent and rudimentary.

Sometimes, under the stimulus of fear, the instinctive mechanism of
swimming is awakened in man. It would be extremely interesting to know
if a similar occurrence took place in somnambulists. I have been unable
to find in literature any sufficient facts upon this subject. I can
quote only one case, and that with all reserve, which was published
in the article “Somnambulism” in the _Dictionnaire des Sciences
Médicales_. “It is related that a somnambulist who took to swimming
during one of his fits was called by his name several times, and became
so frightened when he awoke that he was drowned.” It would be extremely
interesting to collect more numerous facts on the instincts shown by
somnambulists.

I have given a good deal of attention to natural somnambulism with
the idea that I should find in it traits recalling those of the life
of anthropoid apes. I think that the extremely varied phenomena of
hysteria could supply us with other facts, useful in investigating
the psycho-physiological history of man. Perhaps some of the facts of
so-called “lucidity” which are well established could be explained
as the awakening of special sensations atrophied in the human race,
but present in animals. It is known that in vertebrate anatomy organs
are found which have the structures of organs of sense, but which are
absent or quite rudimentary in the human body. On the other hand,
it is known that animals perceive some phenomena of the surrounding
world, for the perception of which man has no organs of sense. Fish,
for instance, appreciate gradations in the depth of water, birds and
mammals have a sense of orientation and can anticipate changes in the
weather more exactly than our meteorological science. When under the
influence of hysteria, man may possibly be able to recover these senses
of our remote ancestors, and to know things of which he is ignorant in
the normal condition.

Hysteria is common to man and animals. Amongst the numerous chimpanzees
which I have owned, several have shown signs of hysteria. Some,
when they were in the slightest degree annoyed, lay on the ground,
screaming terribly, and rolling about like children in a fit of
passion. One young chimpanzee used to pull out its hair when it was in
a fit of temper. The view that hysteria is a relapse to the condition
of our animal ancestors is supported by the conception of hysterical
phenomena, suggested by Dr. Babinsky.[167] This well-known neurologist
thinks that “the phenomena of hysteria have two special characters,
the one being that they can be reproduced by suggestion in some cases
with the most complete fidelity, and the other that they can disappear
under the sole influence of persuasion.” M. Babinsky thinks that “the
hysteric patient is neither unconscious nor completely conscious, but
is in a state of special consciousness.” In my opinion the latter
condition corresponds to the state of mind of our more or less remote
ancestors.

Occasionally a man, under some sudden impulse, falls into a condition
of extreme violence, and, being unable to control himself, commits
acts of which he repents immediately afterwards. It is the custom to
say that at such times the brute has awakened in the man. This is
more than a metaphor. (Probably some nervous mechanism from a remote
ancestor has come into action, at the call of some stimulation.) As our
anthropoid ancestors and primitive man lived in tribes, it is natural
that when men are grouped together, certain savage instincts should
awaken. In this connection it is interesting to study the psychology
of crowds. When man is surrounded by a great many of his fellows,
he becomes particularly responsive to suggestion. This condition is
characterised as follows by M. G. Le Bon,[168] the author of a study
on the psychology of crowds: “The most careful observations seem to
prove that an individual immerged for some length of time in a crowd
in action soon finds himself—either in consequence of the magnetic
influence given out by the crowd, or from some other cause of which we
are ignorant—in a special state, which much resembles the state of
fascination in which the hypnotised individual finds himself in the
hands of the hypnotiser. The activity of the brain being paralysed
in the case of the hypnotised subject, the latter becomes the slave
of all the unconscious activities of his spinal cord, which the
hypnotiser directs at will. The conscious personality has entirely
vanished; will and discernment are lost. All feelings and thoughts
are bent in the direction determined by the hypnotiser” (p. 11). Man,
under the influence of the crowd, gets into a condition like that of
a hysterical patient and displays a state of mind identical with that
of our ancestors. “Moreover, by the mere fact that he forms part of
an organised crowd, a man descends several rungs in the ladder of
civilisation. Isolated, he may be a cultivated individual; in a crowd,
he is a barbarian—that is, a creature acting by instinct” (p. 13).

It is quite natural to find relics of our prehistoric past in all kinds
of hysterical phenomena. We could reach extremely interesting facts
regarding the tribal and sexual life of apes, if we tried to compare
with them the phenomena of human hysteria. The passionate gestures
which are characteristic of some hysterical cases could probably be
explained in this way quite simply, and the wild cries uttered by
patients in acute hysteria would be similarly explicable.

I think that just as anatomists seek for points of comparison between
man and animals, as palæontologists make excavations to discover the
buried remains of creatures intermediate between man and apes, so
also, psychologists and doctors should investigate the rudimentary
psycho-physical functions with the object of building up the history of
the evolution of our psychical life. It cannot be doubted that in this
branch of science new arguments would be found to support the already
well founded theory of the simian origin of the human race.

PART VI

SOME POINTS IN THE HISTORY OF SOCIAL ANIMALS

THE INDIVIDUAL AND THE RACE

Problem of the species in the human race—Loss
of individuality in the associations of lower
animals—Myxomycetes and Siphonophora—Individuality in
Ascidians—Progress in the development of the individual
living in a society

In the following pages I shall try to reply to the criticism on _The
Nature of Man_ that in that book I only considered the individual
without thinking of the interests of society or of the race. I have
been reproached for having lost sight of the truth that in the general
course of evolution the interests of the individual must yield to the
higher interests of the community. It was asserted, in fact, that by
advising orthobiosis, that is to say, the most complete cycle of human
life, ending in extreme old age, I was suggesting something to the
detriment of humanity as a whole.

This objection rests on a misunderstanding which it will be interesting
to clear up. I think that the complete development of the individual
not only would not injure the community but would be of great advantage
to it. Moreover, we must not lose sight of the fact that the individual
has rights which must not be ignored.

In the attack on my theory many facts were brought forward which show
that in the animal and vegetable kingdoms the individual is always
sacrificed to the advantage of the race. There is no doubt as to this,
and in the course of this book I have given exact facts bearing on it.
I instanced plants such as the Agave and some Cryptogams which die as
soon as they have reproduced; I have also spoken of the small female
round worms (_Nematoda_) which are brutally torn in pieces and devoured
by their progeny. It would be difficult to find better cases of the
sacrifice of the individual to the species. The rule, however, does not
apply to man, who, in this respect, stands in a special position.

Since the arrival of man, several species of animals have disappeared
from the earth. Man has played a large part in the destruction of the
Moa (_Aepyornis_) of Madagascar, the largest member of the class of
birds. He destroyed the Dodo of the Island of Mauritius and Steller’s
sea cow (_Rhytina stelleri_), a harmless relative of the Manatee, from
the shores of the Aleutian Archipelago. Man is about to cause the
extinction of several species of harmful carnivorous animals, such
as the wolf and the bear, and possibly it will not be long before
automobiles have replaced the horse, which would then become extremely
rare. However, although he has destroyed so many other species, man has
taken good care of himself. The progress already made by civilisation
has considerably reduced our mortality. Every year, a large number
of young infants are kept alive by the aid of hygiene and medicine.
The decrease of war and of assassination has also played a part in
maintaining the race. The position which man has acquired in the world
makes it more likely that what we have to fear is too great an increase
of population, and although the theory of Malthus has not been
verified in all its details, it is still true that man could multiply
on the face of the earth too abundantly. It is already clear that
almost in the proportion that humanity stops the effusion of its blood
in war, it tends to limit the propagation of the race.

As the future of the species seems to be safe, it is natural to
consider in the first place that of the individual. In this respect the
facts of general biology are of special interest.

Man is not the only social animal on the earth. Long before his
appearance other living beings existed in organised societies.
The splendid colonies of Siphonophora float on the surface of the
seas, whilst in the ocean depths there are societies of corals of
extraordinary variability, whilst again, on land, many kinds of insects
live in highly organised societies.

This social life has been developed without external assistance, and
without any code to regulate the conduct of the individuals united for
a common purpose.

It will be interesting to give a slight survey of the fundamental
principles of such societies; I intend to draw special attention to
one of the essential points in the societies of animals, hoping to
elucidate the relations between the individuals and society.

In the organisation of human society the most difficult points are
the extent to which the society may encroach on the individual and
the degree to which the individual may preserve his rights and his
independence. Disputes on these have been interminable, and I do not
propose to discuss the theories according to which an individual must
be sacrificed for the good of the community to which he belongs.
I shall limit myself to reviewing the fate of the individuals in
societies of beings much inferior to man.

There are examples of societies composed of many individuals, even
amongst living things on the borderland between the animal and
vegetable kingdoms.

[Illustration: FIG. 21.—Isolated individuals of a Myxomycete.

(After Zopff.)

_a_, spore; _b-f_, escape of the zoospores.]

[Illustration: FIG. 22.—Myxomycete individuals united to form a
plasmodium.

(After Zopff.)]

There may be found in woods, on dead leaves or on decaying timber,
minute plants resembling tiny mushrooms. These are Myxomycetes, and
the visible portions are minute sacs filled with microscopical rounded
bodies, known as spores. When one of the spores is moistened, there
emerges a minute organism with a mobile appendage by which it can be
impelled through water. A drop of water on a leaf or on a fragment of
timber may be filled with numbers of these tiny swimming bodies (Fig.
21). Their free life as individuals, however, is of brief duration.
When they come into contact, their bodies fuse, forming a gelatinous
mass which may be quite large (Fig. 22). This mass is called a
plasmodium, and is composed of a living substance which can move slowly
over leaves and which exhibits streaming movements in the interior, so
that the whole resembles in some respects the lava from a volcano.

The plasmodia may be regarded as societies in the constitution of which
the individuality of the members has been completely sacrificed. The
ideal of those philosophers who have urged that man should renounce
his individuality and merge himself in the community has been realised
in the fullest way at the lower end of the scale of life, at an epoch
inconceivably remote from the appearance of the human race.

Amongst animals, even the most lowly, there are no societies in which
the members are sacrificed so completely to the whole. Individuality
is always preserved to a greater or lesser extent. Consider the
polyps, colonies of which form reefs in the sea and may even become
islands. These creatures live in aggregations, the members of which
are incapable of living an independent life. They are united by living
substance and resemble double monsters, such as Doodica and Radica, who
were so much talked of some years ago when M. Doyen operated upon them.
The peritoneal cavities of these twins were in free communication,
and the blood-vessels were united so that the blood of the one passed
freely into the body of the other. In another double monster, the two
Tscheck girls, Rosa and Josepha, the intestinal tracts communicate,
both leading to a common rectum. In these, who are still alive, the
peritoneum is joined and there is a single urethra.

In the case of the coral polyps, the fusion of the individuals of the
colony is nearly always much more complete. Each individual has its
own mouth and stomach, whilst the other organs cannot be assigned to
individuals but must be regarded as common to the whole.

In the swimming polyps or Siphonophora, the loss of individuality
is still more remarkable. These graceful and transparent creatures,
sometimes large in size, live in the sea and may appear on its
surface in great numbers. They possess many whip-like filaments
provided with tentacles, swimming bells and stomachs. There can be
no doubt as to their colonial nature (Fig. 23), but it is difficult
to decide as to whether each piece of the colony, each swimming
bell, stomach and so forth, is to be regarded as an individual or
an organ, different zoologists having taken different views on the
question. One interpretation is that colonial life has brought with
it such modifications that of each individual there remains only a
single organ. Some individuals have been reduced to simple stomachs,
attached to the central stem, whilst others have lost all organs
except that of locomotion which has become one of the swimming bells
of the colony. Other zoologists, and I myself amongst them, think
that the Siphonophora are colonies of organs in which there has been
as yet practically no development of individuality. A living chain of
Siphonophora is simply a number of organs such as stomachs, tentacles,
swimming bells and so forth, united on a common stem. I need not
discuss the disputed point further, for the only matter pertinent to
my argument is that in the Siphonophora the loss of individuality,
the sacrifice of the parts to the whole, is not so great as in the
Myxomycetes.

[Illustration: FIG. 23.—One of the Siphonophora.

(After Chun.)

_pn_, pneumatic chamber; _clh_, swimming bells; _stl_, stolon.]

In support of my view, I must recall the small forms of Siphonophora
known as _Eudoxia_. These are detached pieces of the common trunk
which swim freely in the sea and have a remarkable structure (Fig.
24). Their mobility is due to a bell provided with strong muscular
fibres. The bell is a portion of an individual which possesses organs
of reproduction but which is devoid of the means to capture or digest
food. These two functions are performed by a second individual which
is closely united with the first. The nutrient individual has a long
tentacle by which the prey is captured, and a capacious stomach in
which it is digested. The products of digestion pass by channels into
the reproductive individual, carrying as it were a ready-made blood.
_Eudoxia_ in fact is a double being composed of an individual incapable
of locomotion or of reproduction, but adapted for prehension and
digestion, and of a second individual which can reproduce and which is
mobile. _Eudoxia_ is an association resembling that of the blind man
and the paralytic, in Florian’s fable.

[Illustration: FIG. 24.—_Eudoxia._

(After Chun.)]

[Illustration: FIG. 25.—_Botryllus_ colonies.

_o_, mouth ; _A_, common cloaca.]

Advance in the organisation of social animals is plainly incompatible
with complete loss of individuality, and this becomes the more apparent
the higher we reach in the scale of life. In the social Ascidians,
each member retains all the organs necessary to life. Animals of the
genus _Botryllus_ (Fig. 25), perhaps the most interesting of these
Ascidians, occur in the form of circular colonies. The individuals
which compose the colony are grouped radially around a common centre
which is occupied by the cloaca. Each individual has its own mouth
and digestive tube, but the latter opens into a cloaca, common to all
the individuals, by which the excreta are voided. There is, in fact,
a single anus, as in the case of Rosa and Josepha which I have just
mentioned.

INSECT SOCIETIES

Social life of insects—Development and preservation of
individuality in colonies of insects—Division of labour
and sacrifice of individuality in some insects

Hitherto I have dealt with associations of animals the members of
which are linked by an actual material bond. In the insect world there
are many cases of highly developed colonies. But the organisation of
insects is high, and is incompatible with the existence of actual
physical connection between the members of the society.

In early stages of the development of the social instinct in bees,
fully formed and similar individuals join together with the object
of securing the safety of their individual lives. Sometimes they act
together to drive away a common enemy, sometimes, as in winter, they
cling in a mass to maintain their temperature. In such primitive
societies, the young are not reared in common. It is only in much more
highly developed colonies, such as those of some bees and wasps, and of
ants and termites, that the chief object of the common action is care
of the progeny. Such an extreme development of the colony is attained
only by sacrificing the individuality of the members. There is a
far-reaching division of labour, so that the queens, for instance, are
mere machines for laying eggs. In hive-bees the queen can no longer
judge of what is good for the colony, her intellectual functions being
degenerate. She is enclosed in her cell and supported by the workers,
who see in her the future of the race. In times of want the worker-bees
sacrifice their own lives and give the queen the last remnants of
the food-supply so that she survives them. The males are incomplete
individuals and are tolerated only so long as they are required, after
which the workers kill them remorselessly.

The workers, which take such pains for the well-being of the hive,
are incomplete individuals. Their brains are well developed and they
are well equipped with organs for making wax and collecting food, but
their reproductive organs are reduced to mere vestiges incapable of
fulfilling their functions.

Here then is a case of loss of individual characters increasing with
the perfection of the colony. Amongst ants and termites, the social
life of which arose quite independently of that of bees, the same
course of events has been repeated. High intelligence and skill
are confined to the workers, in which the reproductive organs are
atrophied. The soldiers have powerful jaws used in defence of the camp,
but they, too, are sexually incomplete. The females and males, in which
the reproductive organs have attained huge proportions so that the
bodies are little more than sacs containing the sexual elements, have
no intelligence and very little skill.

An extremely curious specialisation, consisting in the formation of
honey-bearing workers, occurs in some Mexican ants. Some of the workers
of these races absorb so much honey that their bodies become swollen
honey-bags. The limbs can no longer support the expanded body, and the
insects, reduced to immobility, do not quit the burrows. Normal life
has become impossible for these individuals, who soon die for the good
of the community. When the normal workers or the sexual individuals
are hungry, they approach the honey-bearers and take honey from their
mouths. The honey-bearers have become no more than animated cupboards
(Fig. 26).

[Illustration: FIG. 26.—A Honey-ant.

(After Brehm.)]

The termites belong to quite another class of the group Insecta, but
in their case a similar sacrifice of the individual to the state
is practised. The females become transformed to shapeless bags of
eggs. They cannot move, but remain secluded in the recesses of the
“ant”-hill, where they lay as many as 80,000 eggs a day. The soldiers
have become provided with jaws so enormous that these unsexed insects
can perform no function other than defence of the colony.

The partial reduction of individuality in social insects never goes
so far as in the cases of the lower animals I have described. It
may be stated as a general rule that increase in the perfection of
organisation brings with it a more or less complete preservation of
individuality in the members of a community.

I shall now examine to what extent this law can be applied in the case
of man.

III

SOCIETY AND THE INDIVIDUAL IN THE HUMAN RACE

Human societies—Differentiation in the human
race—Learned women—Habits of a bee, _Halictus
quadricinctus_—Collectivist theories—Criticisms by
Herbert Spencer and Nietzsche—Progress of individuality
in the societies of higher beings

Social life is for the most part little developed amongst vertebrate
animals. The birds and fishes which live in communities present no
organisation of society even comparable with that found amongst
insects. There is little advance in this respect in the case of
mammals, and it is not until we come to man that highly organised
societies are to be found. Man is the first vertebrate to develop an
organised social life. But, whilst in the insect world, instincts are
of supreme importance in the regulation of the community, there is
little instinctive action in human communities. The consciousness of
individuality, or egoism, is very powerful in human beings, and perhaps
for that reason our ancestors made little progress in the development
of social relations.

Anthropoid apes adhere in little groups or in families without any true
social organisation. Love of the neighbour, or altruism, appears to be
a recent and feeble human acquisition.

Although the organisation of human society is far advanced and
division of labour very complete, there is no differentiation of the
individuals comparable with what is found amongst insects. Although in
animals so different as Siphonophora, bees, wasps, and termites the
development of the community, proceeding along different lines, has
brought into existence non-sexual individuals, there is no trace of
this specialisation amongst human beings.

Certain abnormalities in the condition of the sexual organs are
occasionally found in men and women, but these cannot be compared with
the production of sexless individuals that has taken place amongst
other social creatures. I cannot accept the view that we are to see
something analogous to the case of worker bees in the prohibition of
sexual relations imposed by some religious systems on a certain number
of individuals. But in any event there is little importance in this
occurrence, which is rapidly becoming rarer.

In recent times, both in Europe and the United States of America, there
has been an active development of a femininist movement impelling women
towards higher education. Women, no longer content with the avocations
of mother and housewife, have pressed into professions such as law and
medicine. There is a steady increase in the number of women who study
at the Universities, and countries like Germany, which have tried to
exclude women from higher studies, will soon have to yield before an
irresistible pressure.

Can we regard the results of this movement as analogous to the
production of sexless workers which has taken place amongst social
insects? I think not. It is undoubtedly true that a certain number
of young women, who, for some reason or other are unlikely to marry,
devote themselves to scientific study. In these cases, however,
celibacy is the cause, not the result of the increased intellectual
activity. On the other hand, it must be remembered that many women
students of science eventually marry. In St. Petersburg, for instance,
there were 1,091 women in the Medical School; of these 80 were already
married and 19 were widows. Of the remaining 992, 436 or 44 per cent.
married during the course of their studies.

Observation of the femininist movement, which has lasted for more than
forty years, shows that in most cases there is no tendency towards the
formation of individuals resembling the infertile worker insects. Most
lady doctors and learned women would like nothing better than to be the
founders of a family. Even the women who have been most distinguished
in the scientific world are no exception to the rule. In this relation
it is very interesting to follow the details of the life of Sophie
Kowalevsky, one of the most notable of learned women. In her youth,
when she began to study mathematics, she would not admit that feelings
of love had any importance. Later on, however, when she felt herself
growing old, these sentiments awoke in her to such an extent that on
the day when the prize of the Academy of Sciences was bestowed on her,
she wrote to one of her friends, “I am getting innumerable letters of
congratulation, but by the strange irony of fate, I have never felt so
unhappy.”

The cause of this discontent reveals itself in the words which she
addressed to her most intimate woman friend. “Why is it,” she said,
“that no one loves me? I could give more than most women, and while the
most ordinary women are loved, as for me, I am not loved.”[169]

It is, in fact, impossible to regard the celibacy of persons devoted
to religion or to scientific studies as the beginning of a special
organisation analogous to that of worker bees.

However, it is still probable that in the human race a special
differentiation has been established for the accomplishment of
different and essential functions.

The organisation of human societies has certainly not followed the path
by which social insects attained the formation of sexless individuals.
It much more closely resembles what has taken place in some isolated
animal types. A solitary bee, named _Halictus quadricinctus_ (Fig. 27),
is characterised by the fact that the female does not die when she has
laid her last eggs, as generally happens amongst insects, but remains
alive to cherish her offspring. This final portion of her life does not
last long, and the bee cannot play the prominent part of governess in a
society of insects organised by this specialisation of elderly females.
In the human race the individual life lasts longer and a division of
labour takes place in the fashion suggested by _Halictus quadricinctus_.

[Illustration: FIG. 27.—_Halictus quadricinctus._

(After Buffon.)]

An ordinary woman ceases to be fertile at between forty and fifty years
old, that is to say, at a time when, according to statistics, she has
still on the average twenty years to live. During this long period,
she can perform an extremely useful function in society, a function
resembling that of the old mothers of _Halictus quadricinctus_, and
consisting chiefly in the bringing up and education of the children.
Who does not know the extraordinary devotion of grandmothers, and, as
a general rule, of old women, who are extremely useful in bringing up
children. And none the less, it must not be forgotten that, actually,
old age begins too soon, that it is not what it ought to be under
normal conditions, and that human life itself does not last nearly so
long as it ought to do in ideal conditions. We may predict that when
science occupies the preponderating place in human society that it
ought to have, and when knowledge of hygiene is more advanced, human
life will become much longer and the part of old people will become
much more important than it is to-day.

The members of human society are not divided into sexual and neuter
individuals as amongst insects, but the active life of every individual
can be divided into two periods, the first one of productive activity,
and the second of sterility but none the less devoted to work useful
to the community. The essential difference between the two cases may
be reduced to the contrast that whilst the individuals of which animal
societies are composed are structurally incomplete, in human societies
the individual preserves his integrity.

We come, then, to the result that the more highly organised a social
being may be, so also the more highly developed is his individuality.
It follows that amongst the theories which seek to control social
life, those are the best which leave a field sufficiently wide and
free for the development of individual initiative. The ideal which
has been so often advocated and according to which the individual
is to be sacrificed as completely as possible to society, cannot be
regarded as in harmony with the general law of organic associations.
Special conditions exist in social life in which great sacrifices are
inevitable, but such an arrangement cannot be considered as general
and permanent. We may predict that the more human beings succeed in
advancing communal life, the fewer cases there will be in which the
individual has to be sacrificed.

In the hope of subduing the egoism rooted in human nature, moralists
have preached renunciation of individual happiness and the need of
subordinating it to the good of the community. Very often such
doctrine has borne little fruit, but there are cases where it has been
embraced with such ardour that men and, still more, young women have
been led to sacrifice their well-being for what they have taken to be
the common good. However it may involve self-abnegation, there has been
continued insistence on the duty of sacrificing the individual to the
community.

The existing great inequalities in the distribution of wealth have
revived doctrines the object of which is to redress such injustice.
For more than a century, different forms of socialism have claimed
to formulate rules for the amelioration of mankind. They agree in
a verdict against existing conditions, but follow different paths
in their proposals for the reformation of society. The varieties of
socialism are so numerous that it is difficult even to define the
word. Although collectivist theories have lost much of their early
thoroughness, they are still far from admitting the just claims of
the individuals constituting the society. At socialist assemblies and
congresses the resolutions adopted frequently proclaim aggressively the
sacrifice of the rights of the individual. The members of one socialist
party have been seen refusing the collaboration of newspapers which are
not the official organs of the party, or declining any co-operation
with a government they have proscribed. In strikes organised by
socialists, work is forbidden to men who ardently desire it. Recently
printers have refused to set up newspapers the opinions of which they
did not share, and even doctors have been known to decline to treat
those belonging to another political party.

It is no new charge against collectivists that they would encroach
too much on individual liberty. They reply that “in social-democratic
society of the future, tyranny and oppression will be impossible. The
secret of the bond will reside in a discipline totally different from
the inanimate obedience of the soldier, a discipline depending on a
willing submission of the individual to the group because of the common
object.”[170] But such discipline and submission may go so far that the
conscience of the individual is seriously offended. And so amongst the
socialists themselves there has arisen a small group which declines to
accept this submergence of the individual in the whole. This group is
composed of anarchists, who, in the name of liberty and the individual,
attack the property and sometimes the lives of their opponents.

It appears that there has been a notable evolution of collectivist
theories in the century or more in which the abolition of human misery
has been an accepted problem. Whilst there was formerly advocated
the total abolition of private property and the establishment of
phalansteries for communal life, at the present time the demand is
limited to the nationalisation of the means of production, leaving
housing and food to be provided by individual property.[171]

Through a publication, of M. Kautsky, one of their best known
representatives, the social democrats have announced that “the
nationalisation of the land does not necessarily bring with it the
abolition of private dwellings. The customary attachment of the
dwelling to agricultural employment will cease, but there is no reason
why the peasants’ houses should become collective property.” “Modern
socialism does not exclude individual property in food. One of the
most important, perhaps the most important factor, in making human
life happy and adding to its pleasures is the possible attainment of
a private house. Collective ownership of the land does not exclude
this.” It is very difficult to separate house and garden, especially
from the point of view of considering the pleasures of life. A
garden furnishes the opportunity for endless improvements, many of
which cannot be separated from the idea of individual property. The
concessions which collectivists have been compelled to make show
conclusively the importance of private property.

Notwithstanding such modifications, many voices have been raised
against the prospect of the socialisation of the means of production
and the concomitant limitations of individual enterprise. The great
English philosopher, Herbert Spencer,[172] against whom narrowness
of view or conservatism could be urged, energetically attacked
collectivist doctrines as tending to reduce human individuality to
a dead level. By a series of cogent instances, he showed the evil
results of the best intentioned efforts to equalise opportunities
and to abolish poverty. He foretold that slavery would be the real
outcome if the State interfered too much in spheres that ought to be
left to individual enterprise. He believed that the institution of a
collectivist State would bring great dangers.

Nietzsche has attacked socialism with his customary exaggeration.
“Socialism,”[173] he wrote, “is the fanatical younger brother of dying
despotism, whose goods he wishes to inherit; his efforts are, in the
deepest sense of the word, reactionary. He wishes a wealth of power in
the State greater than despotism ever enjoyed, but he goes beyond all
the past inasmuch as he strives absolutely to stifle the individual;
for him the individual is a useless efflorescence of nature to be
tamed into a useful organ of the community.” Further, “Socialism at
least teaches brutally and convincingly the danger of concentrating
power in the State, for it is a covert attack on the State itself.
When its harsh voice raises the war-cry ‘Let the State control as much
as possible,’ the cry will at first become louder; but soon another
phrase will grow equally clamant, ‘Let the State control as little as
possible.’”

It is most probable that no shade of socialism will be able to
solve the problem of social life with a sufficient respect for the
maintenance of individual liberty. None the less the progress of human
knowledge will inevitably bring about a great levelling of human
fortunes. Intellectual culture will lead men to give up many things
that are superfluous or even harmful, and that are still thought
indispensable by most people. The conceptions that the greatest good
fortune consists in the complete evolution of the normal cycle of human
life and that this goal can be reached most easily by plain and sober
habits will convince men of the folly of much of the luxury that now
shortens human existence. Whilst the rich will choose a simpler mode of
life and the poor will be able to live better, none the less, private
property, acquired or inherited, may be maintained. Evolution must
be gradual and much effort and new knowledge is required. Sociology,
a new-born science, must learn of biology, her older sister. Biology
teaches us that in proportion that the organisation becomes more
complex, the consciousness of individuality develops, until a point is
reached at which individuality cannot be sacrificed to the community.
Amongst low creatures such as _Myxomycetes_ and _Siphonophora_, the
individuals disappear wholly or almost wholly in the community;
but the sacrifice is small, as in these creatures the consciousness
of individuality has not appeared. Social insects are in a stage
intermediate between that of the lower animals and man. It is only in
man that the individual has definitely acquired consciousness, and for
that reason a satisfactory social organisation cannot sacrifice it on
pretext of the common good. To this conclusion the study of the social
evolution of living beings leads me.

It is plain that the study of human individuality is a necessary step
in the organisation of the social life of human beings.

PART VII

PESSIMISM AND OPTIMISM

PREVALENCE OF PESSIMISM

Oriental origin of pessimism—Pessimistic
poets—Byron—Leopardi—Poushkin—Lermontoff—Pessimism
and suicide

In the attempt to formulate a pessimistic theory of human nature, we
are naturally led to ask why it is that so many famous men have come to
a purely pessimistic conception of human life.

Pessimism, although it has been most prominent in modern times, is
extremely old. Everyone knows the pessimistic wail of Ecclesiastes,
written nearly ten centuries before our era: “Vanity of Vanities, all
is vanity.” Solomon, the supposed author, states that he “hated life,
because the work that is wrought under the sun is grievous unto me, for
all is vanity and vexation of spirit” (Eccl. ii., 17).

Buddha raised pessimism to the rank of a doctrine. All life seemed to
him sorrow. “Birth is sorrow, old age is sorrow, disease is sorrow,
union with one whom we do not love is sorrow, separation from one whom
we love is sorrow, not to gratify desire is sorrow, in short, our five
bonds with the things of the earth are sorrow.”[174] This Buddhistic
pessimism has been the source of most of the modern pessimistic
theories.

Pessimism arose in the East and was much in vogue in India even apart
from Buddhism. In the poems known under the name of Bhartrihari, and
dating from the beginning of the Christian era, human life has been
commiserated in the following fashion. “One hundred years are the
limit of the life of man; night takes half of them, half of the other
half is childhood and old age, the rest is filled with diseases, with
separations and the misfortunes that come from them, with working for
others and with wasting one’s time. Where can happiness be found in an
existence most like to the bubbles in broken water?” “Man’s health is
destroyed by every kind of care and disease. When fortune comes to him,
evil follows as if by an open door. Death takes all human beings, one
after the other, and they can offer no resistance to their fate. What
is there assured amongst all that the mighty Brahma has created?”[175]

Pessimistic theories spread from the Asiatic East to Egypt and Europe.
Three centuries before the Christian era, there arose the philosophy of
Hegesias, which maintained that experience was generally deceptive and
that enjoyment was quickly followed by satiety and disgust. According
to him, the sum of pain surpassed the sum of pleasure in life, so that
happiness was unattainable, and in reality never existed. It was vain
to seek pleasure and happiness, as these could not be realised. It was
better to try to be indifferent, dulling feeling and desire. In fact,
life was no better than death, and it was often preferable to end it
by suicide. Hegesias was called _Pisithanatos_, the adviser of death.
“Listeners thronged around him, his doctrine spread rapidly, and his
disciples, persuaded by his voice, gave themselves to death. Ptolemy
was perturbed by it, and fearing that the dislike of life would become
contagious, closed the school of Hegesias and exiled its master.”[176]

The pessimistic tendency sometimes appears in the writings of many
Greek and Latin philosophers and poets. Seneca wrote: “The spectacle of
human life is lamentable. New misfortunes overwhelm you before you have
freed yourself from the old ones.”[177]

It is in modern days, however, that there has been the greatest spread
of pessimism.

Besides the philosophical theories of the last century, those
of Schopenhauer, von Hartmann and Mailaender, which I discussed
sufficiently in _The Nature of Man_, poets have formulated a
pessimistic view of life. Even Voltaire was a pessimist in the
following lines:

Alas! what are the course and the goal of life?
Only follies and then the darkness.
Oh Jupiter! in creating us you made
A heartless jest.

In _The Nature of Man_ I described Byron’s expression of his conception
of the evils of human life. Soon after the death of the great English
poet, a celebrated Italian poet, Giacomo Leopardi, sounded a note of
abandoned pessimism.

Here are words which he addressed to his own heart[178]: “Be quiet for
ever, you have beaten enough, nothing is worthy of your beating and the
earth is not worthy of your sighs. Life is nothing but bitterness and
weariness, there is nothing else in it. The world is nothing but mire.
Repose from now onwards. Be in despair for ever. Destiny has given us
nothing but death. Despise henceforth yourself and nature, and the
shameful concealed power which decrees the ruin of all and the infinite
variety of all.”

Leopardi makes his readers witnesses of his distraction and his grief:
“I shall study the blind truth”—he wrote in a poem dedicated to
Charles Pépoli—“I shall study the blind fates of things mortal and
immortal. Why humanity came into existence, and was burdened with pain
and sorrow, to what final end destiny and nature are driving it, for
whose pleasure or advantage is our great pain, what order, what laws
rule this mysterious universe which wise men cover with praise, and I
am content to wonder at” (_ibid._, p. 15).

Quite a school of poets has been developed, singing the pain of the
world, the “Weltschmerz” of German authors, amongst whom Heine and
Nicolas Lenau are specially distinguished.

Russian poetry was born under the influence of Byronism, and its best
exponents, Poushkin and Lermontoff, often laboured over the problem of
the object of human existence, finding only sad answers. Poushkin, who
is justly regarded as the father of lyric poetry in Russia, stated his
pessimistic conception in the following lines:—

Useless gift, gift of chance,
Life, why wert thou given me?
And why from the beginning art thou doomed
Irrevocably to death?

What unfriendly power
Has drawn me from the darkness,
Has filled my soul with passion,
And breathed doubt into my soul?

There is no goal for me,
My heart and my soul are empty;
And the dull emotion of life
Has filled me with black care.

Recently, Mde. Ackermann, in a series of short poems, has given voice
to the grief caused to her by the world and life as they are, although
she does not state exactly the reason of her bitter complaints.

Whilst pessimistic philosophers and poets reflect the thoughts and
feelings of their contemporaries, it is certain that they also
seriously influence their readers. And so there has come into existence
a deeply rooted conviction that the miseries of human life are far
from being countervailed by its happiness. Probably such ideas have
influenced the number of suicides. We do not know with any certainty
the real motives of most cases of self-destruction, but it cannot be
denied that the trend of modern thought has played an important part.
According to statistics, the chief causes of suicide are “hypochondria,
melancholia, weariness of life, and unbalancing of the mind.” Thus from
the Danish statistics it appears (and Denmark is the country in which
suicide is most prevalent) that of 1,000 cases of suicides of males,
between 1866 and 1895, 224, or one-quarter, were referred to the causes
I have just mentioned. In the case of women, the corresponding figures
are higher, amounting to nearly one-half (403 out of 1,000). The second
most common cause of male suicides is alcoholism (164 in 1,000).[179]
It is very probable that pessimism was the determining condition in
most of the suicides referred to these two categories of causes.
Leaving out of the question the true cases of mental alienation,
amongst the victims of melancholia, hypochondria and weariness of life,
in whom the mental condition was not pathological in the strict sense
of the word, there must have been many who killed themselves because
their view of life was pessimistic. And amongst the victims of drink,
there are many who take to alcohol because they are convinced that
life is not worth preserving.

The progressive increase in the numbers of suicides in modern times
is an index of the great influence of pessimism. There have been even
societies for the promotion of suicide. In such a society, founded in
Paris in the beginning of last century, members placed their names
in an urn, to be drawn by chance. He whose name was drawn had to
kill himself in the presence of the other members. According to its
rules, this society admitted only persons of honour who must have had
experience of “the injustice of man, the ingratitude of a friend, the
infidelity of a wife or mistress, and who, moreover, for many years
had had a void in their souls and a distaste of what this world can
offer.”[180]

Although such societies no longer exist, individuals continue to put
their lives to an end, in greater numbers every year.

ANALYSIS OF PESSIMISM

Attempts to assign reasons for the pessimistic conception
of life—Views of E. von Hartmann—Analysis of
Kowalevsky’s work on the Psychology of Pessimism

In view of the facts I brought together in my last chapter, there
is occasion to inquire if it be possible to discover the intimate
mechanism by which men arrive at a conception of life as an evil to be
got rid of as quickly as possible. Why do so many think that man is
less happy than the beasts, and that cultured and intelligent men are
more unhappy than those who are ignorant or feeble-minded ?

I have related how in a society of friends of suicide, injustice and
unfaithfulness were regarded as prime factors in arousing a distaste
for life. Shakspeare made Hamlet exclaim that if it were possible to
put an end to our days no one would continue to live:—

For who would bear the whips and scorns of time,
The oppressor’s wrong, the proud man’s contumely?

For Byron, besides diseases, death and slavery, the evils that we see,
there are others:—

And worse, the woes we see not—which throb through
The immedicable soul, with heart-aches ever new.

In many of his works he insists on the feeling of satiety which was
almost continually upon him. Every sensation of pleasure that came to
him was rapidly succeeded by a still stronger feeling of disgust.

Heine thought that existence was evil and saw

... across the hard surfaces of the rocks
The homes of men and the hearts of men—
In the one as in the others, lies, imposture and misery.

As I urged in _The Nature of Man_, consciousness of the shortness of
human life has been an important factor in exciting pessimism, and we
find this theme recurring in pessimistic writers. Leopardi returns to
it again and again in his poems. “Falling in peril of death from some
mysterious disease,” he said in his _Souvenirs_, “I lamented over my
sweet youth and the flower of my poor days which was to fall so soon,
and often in the midnight hours wove from my sorrows, by the pale light
of my lamp, a sad poem, and in the silence of the night wept over my
fleeting life, and half fainting, sang to myself my funeral song”
(_loc. cit._, p. 28). The bas-relief on an ancient tomb, representing
the departure of a young girl who took farewell of her friends,
suggested to Leopardi the following thoughts: “Mother, who from their
birth makes her family of living beings tremble and weep, Nature,
monster unworthy of our praise, who brings into the world and nurtures
only to kill, if the premature death of a mortal be evil, why do you
bring it on so many innocent heads? If it be a good, why do you make it
sad for those who go and for those left behind? Why is it the hardest
grief to console? The only relief from our woes is death, death, the
inevitable end, the immutable law which you have established for human
beings. Why, alas, after the sad voyage of life, do you not make the
arrival joyful? This certain end, this end which is in our souls all
our lives, which alone can soothe our troubles, why do you drape it in
black and surround it with mournful shades? Why do you make the harbour
more terrible than the open seas?” (_loc. cit._, p. 55).

The three chief grievances—injustice, disease, and death—often come
together. From the anthropomorphic point of view fate is represented as
a sort of wicked being who commits injustice by visiting all kinds of
evils on mankind.

A pessimistic conception of life is arrived at by a complex
psychological process in which both feelings and reflection are
involved, and hence it is difficult to analyse it satisfactorily.
Formerly, therefore, writers were content with general and very vague
estimates of the process by which we may become pessimists. Ed. von
Hartmann has tried to deal more exactly with this inner process of
the human mind. In the first place, he lays stress on the fact that
pleasures always bring less satisfaction than pains bring grief.
False notes in music, for instance, are more painful than the best
music is delightful. The pain of toothache is much more violent
than the pleasure when relief comes. So also with all diseases. In
love, according to Hartmann, the pleasure is always very greatly
over-balanced by the pain. Muscular work brings pleasure only in a very
small degree, and devotion to science and art and intellectual work in
general brings more pain than pleasure to the votaries. As the result
of an analysis, Hartmann is convinced that there is much more pain than
pleasure in the world. Pessimism is founded upon the essential nature
of human feelings.

M. Kowalevsky,[181] a German philosopher at Koenigsberg, adopting the
modern habit of measuring mental processes as exactly as possible, has
recently published an attempt to analyse pessimism psychologically.
Although this has not solved the problem, it is extremely interesting
as an instance of the application of the methods now being adopted in
modern psychology.

M. Kowalevsky took advantage of all the known methods of estimating the
relative values of our emotions; he tried to make use of the notes of
Munsterberg, another living psychologist who kept a journal in which
he set down daily his psychical and psycho-physical impressions. The
object of the work had no relation to the question of pessimism, and
for that reason Kowalevsky thought that it was specially important in
his investigations.

Munsterberg was not content with the existing classification of
emotions as agreeable or painful. He subdivided them much further. He
recognised, for instance, emotions of tranquillity and excitement,
serious and pleasant impressions. Having completed the reckoning,
Kowalevsky came to the conclusion that his colleague, who was by
no means a pessimist, but a psychologist of well-balanced mind,
experienced many more painful emotions (about 60 per cent. as compared
with 40 per cent.) than agreeable emotions. “Such a result is in favour
of pessimism,” concluded Kowalevsky.

However, he went beyond the foregoing enquiry. By several other
methods, he tried to gain an exact idea of the value of our emotions.
He visited elementary schools in order to investigate the pleasures
and pains of the scholars. In the case of 104 boys, of eleven to
thirteen years of age, he found that pain was much more deeply felt
than corresponding pleasure. Thus, while in 88 cases illness was set
down as an evil, only in 21 was health reckoned as a good. One-third of
the pupils noted down war amongst evils, whilst only one noted peace
amongst the good things. Poverty was written down thirteen times as an
evil, against twice in which riches were put down as a good. In another
series of investigations, Kowalevsky took notes on the pleasures and
pains felt by pupils of the two sexes attending the same school. The
result was that the greatest evil, according to them, was illness,
noted 43 times, then death 42 times, after which came fire 37 times,
hunger 23 times, floods 20 times. Amongst the good things, the first
place was given, as might have been expected, to games (30) and the
second to presents.

As Kowalevsky did not find that such investigations could solve the
problem, he tried to discover a more exact method. With this object,
he turned to different sensations, such as those of smell, hearing and
taste, to which he applied methods of exact measurement. In the case of
taste, for instance, he determined the minimum quantity of different
substances which could excite definitely pleasant or unpleasant
sensations. In his experiments, Kowalevsky found that doses which
gave bad tastes were not balanced by those which gave good tastes.
For instance, to neutralise the unpleasant taste of quinine, it was
necessary to employ a much larger quantity of sugar. He was specially
pleased with one experiment. Four persons were given definite mixtures
of sugar and quinine in order to discover the proportion of the two
substances necessary to obtain a neutral sensation. He found that to
take away the bad taste of quinine, it was necessary to double the
quantity of sugar given. Similarly with smells, he found that those
which were unpleasant were appreciated much more strongly than those
which were pleasant. Here, then, was a series of scientific results
supporting the view of the pessimists. Must we really conclude from
them that the world is very badly arranged? The analysis of good and
bad temper made by Kowalevsky is in favour of such an interpretation.
In order to estimate these conditions of mind, he measured the gait,
that is to say, the number of steps taken in a minute. This method
depended upon the following idea. It is an accepted view that the
condition of mind is shown by the rapidity of the human walk; we
have only to compare the slow pace of a man in deep grief with the
rapid steps of a man in a state of joy. Pain, as a general rule,
depresses, while joy stimulates voluntary movements. The result of
the measurements taken according to this method give a new argument
in favour of pessimism. However, it is useless to attempt to analyse
these figures on which Kowalevsky had to employ the integral calculus,
because the principle of his method cannot be supported. As a matter of
fact, the rapidity of walking is an index of the degree of excitation,
and not of the happy or unhappy condition of the mind. When a person
suddenly undergoes a strong impression, either pleasant or unpleasant,
he takes to walking actively about in his room, and may even want to
go out of doors to walk more quickly. A letter which has been received
and which gives some unexpected news, as for instance of the infidelity
of a person one loves, or of an inheritance which one did not expect,
produces a condition of excitement shown chiefly by rapid walking. Many
orators and professors have to make gestures and to walk about in the
course of their lectures. A man of science to whom some new idea comes
and who wishes to think it out, rises from his chair and begins to
walk. But not only on such pleasant occasions, but when one has to face
an insult or an act of defiance which makes one very angry, the need to
walk actively is felt. It is therefore impossible to utilise records of
movements in the study of the pessimistic state of mind.

M. Kowalevsky employed still another mode of attacking the problem.
He examined the recollection of painful or pleasant impressions. He
asked the children of both sexes, whom he was investigating, questions
which gave him indications as to whether pleasures or pains made
the more lasting impression on the memory, and he registered the
answers. The result, which agreed with what had already been obtained
by Mr. Colegrove, an American psychologist, was unfavourable to the
pessimistic view. He found, in fact, that in the majority of cases (70
per cent.) recollection of pleasant impressions predominated. However,
in such investigations there is a facile source of error arising from
the condition of mind of those who are being questioned. It is probable
that Kowalevsky made his enquiry in school during recreation time, when
most of the pupils were free from the boredom of the actual class. When
we are happy the tendency exists in us to recall pleasant impressions
of the past. If the enquiry had been made during a difficult or
wearying lesson, or on children shut up in a hospital, or undergoing
punishment, it is probable that the result would have been reversed.

It is evident that all such attempts to solve a problem so complex as
that of pessimism, even by the so-called exact methods of physiological
psychology, cannot lead to any convincing result. Thus Kowalevsky’s
different investigations led to contradictory conclusions. Whilst some
of his series of facts supported the pessimistic conception, others
were opposed to it, and he obtained no definite general conclusion.
How can one expect to apply a method of measurement to sensations and
emotions so different, not only from the qualitative point of view,
but also in relation to their intensity? Take, for instance, the case
of an individual who has experienced in one day nine sensations which
were painful and one which was agreeable. According to the valuation
of experimental psychologists, he ought to have reason to become a
pessimist. However, this may be far from the case, if the nine painful
impressions were much weaker than the single happy impression. The
first were provoked by small wounds to his pride, fleeting pains of no
importance, and small losses of money, whilst the happy emotion came
from receiving a love letter. The sum of the ten impressions would be a
happy one, and might well put him in an optimistic frame of mind. The
learned attempts of experimental psychologists must be abandoned, as
incapable of illuminating the problem. If, however, the human spirit
still seeks some means of explaining the psychology of pessimism, there
remains only the less subtle method given by the biographical study of
human beings.

III

PESSIMISM IN ITS RELATION TO HEALTH AND AGE

Relation between pessimism and the state of the
health—History of a man of science who was pessimistic
when young, and who became an optimist in old
age—Optimism of Schopenhauer when old—Development of
the sense of life—Development of the senses in blind
people—The sense of obstacles

Animals and children in good health are generally cheerful and of
optimistic temperament. As soon as they fall ill they become sad
and melancholy until their recovery. We may infer from this that an
optimistic view is correlated with normal health, whilst pessimism
arises from some physical or mental disease. And so in the case of
the prophets of pessimism, we may seek for the origin of their views
in some affliction. The pessimism of Byron has been attributed to his
club-foot, and that of Leopardi to tuberculosis, these two nineteenth
century exponents of pessimism having died whilst young. Buddha and
Schopenhauer, on the other hand, reached old age, whilst Hartmann died
when sixty-four years old. Their diseases at the time when they formed
their theories could not have been very dangerous, and none the less
they took a most gloomy view of human existence. The recent historical
investigations of Dr. Iwan Bloch[182] make it very probable that
Schopenhauer, in his youth, contracted syphilis. There has been found
a note-book of the great philosopher in which he wrote down the details
of the severe mercurial treatment which he had to undergo. The disease,
however, was not contracted until several years after the appearance of
his great pessimistic work.

Although we must attach due weight to the connection between disease
and pessimism, we can assure ourselves that the problem is more complex
than it appears at first sight. It is well known that blind people
often enjoy a constant good humour, and, amongst the apostles of
optimism, there has been the philosopher Duering,[183] who lost his
sight during his youth.

Moreover, it has been noticed that persons affected with chronic
diseases frequently have a very optimistic conception of life, whilst
young people in full strength may become sad, melancholic, and
abandoned to the most extreme pessimism. Such a contrast has been
well described by Émile Zola in his novel _La Joie de Vivre_, where a
rheumatic old man, tried by severe attacks of gout, maintained his good
humour, whilst his young son, although vigorous and in good health,
professed extreme pessimism.

I have a cousin who lost his sight in early youth. When he grew up he
formed a most enviable judgment of life. He lived in his imagination
and everything in life seemed to him good and beautiful; he married,
and pictured his wife to himself as the most beautiful woman in the
world, and thus he feared nothing more than the recovery of his sight.
He had adapted himself to live without sight, and was convinced that
the reality was much lower than his imagination. He feared that if he
were able to see his wife she would appear to him less beautiful.

I know a girl twenty-six years old, blind from her birth, the subject
of infantile paralysis and liable to fits of epilepsy. She is nearly an
idiot, lives in a carriage, and sees life from its best side. She is
certainly the most happy member of all her family.

The good humour and megalomania of those affected with general
paralysis of the insane also is well known. All such examples show that
pessimism cannot be explained as depending on bad health.

Examination of the state of mind of a pessimist may throw some light on
the subject. There has been within my own circle a typical case of a
person who went through a phase of life in which everything seemed as
gloomy as possible. My intimate knowledge of him makes it possible to
apply my observations to the matter under discussion.

The subject was born of parents of good health and in comfortable
circumstances, so that, from the beginning of his life, he was
surrounded by a favourite environment. He lived in the country and
escaped the diseases of childhood, so that he reached maturity in good
health, and passed well through college and the university. Science
attracted him, and he had the ambition to become a distinguished
investigator. He threw himself into a scientific career with zeal and
ability. His ardent disposition, although certainly favourable to work,
was the cause of many troubles. He wished to succeed too quickly, and
the obstacles he encountered embittered him. As he thought himself
naturally talented, he conceived it to be the duty of his seniors to
aid his development. And so, when he met with natural and very common
indifference from those who had already become successful, the young
man thought that there was a plot against him, to bring to nothing his
scientific talents. From this view, many quarrels and difficulties
arose, and as he could not overcome these sufficiently quickly, he
fell into a mood of pessimism. In this life, he said to himself, the
main thing is to adapt oneself to external conditions. According to
Darwin’s law of natural selection, the individuals who do not succeed
in adapting themselves go to the wall. The survivors are not the
best but only the most cunning. In the history of the earth it has
been seen that many lower animals have long survived creatures much
higher in organisation and general evolution. Whilst so many of the
higher mammals, the nearest relatives of man, have been crushed out of
existence, simpler animals, such as evil-smelling cockroaches, have
survived from the remotest times, and multiply in the neighbourhood of
man in despite of his efforts to exterminate them. The animal series
and human evolution itself show that delicacy of the nervous system,
with its concomitant extreme development of the sensibilities, hinders
the power of adaptation and brings with it insuperable evils. The
least blow to his pride, or a slighting word from a comrade, threw
this pessimist into a most painful condition. No, he would cry, it
would be better to be without friends, if one is to be wounded so
deeply by them. It would be best to seclude oneself in some remote
spot and be engrossed in one’s work. He was very impressionable and a
lover of music, and from his visits to the opera, he retained in his
mind an air from the “Flûte enchantée.” “Were I as small as a snail,
I would hide myself in my shell.” His moral hypersensibility was
associated with physical hyperæsthesia. Noises of all kinds, such as
the whistling of railway-trains, the cries of street-vendors, or the
barking of dogs, excited extremely painful sensations. The least trace
of light prevented him from sleeping at night. The unpleasant flavour
of most drugs made it impossible for him to take medicine. He agreed
thoroughly with the pessimistic philosophers who declare that the ills
of life far surpass the good things. He required no experiments on the
sense of taste to convince him. He believed that the organisation of
his body prevented him from becoming adapted to external conditions and
that he would have to disappear like the mammoth and the anthropoid
apes.

The course of his life confirmed the convictions of our pessimist.
He had no private fortune and married a woman who became affected
with tuberculosis, and so was confronted with the greatest evils of
existence. A young lady, hitherto in good health, contracted influenza
in some northern town. It was a mere nothing, said the doctors;
influenza is everywhere and no one escapes it; after a little patience
and rest, she will be well again. However the “influenza” persisted
and brought with it feebleness and wasting. The doctors then found
that there was a little dullness in the apex of the left lung, but as
there was no bad family history, there was nothing to fear. I need not
describe the familiar course of events. The trifling influenza was
replaced by degeneration of the left lung, and brought death after four
years of great suffering. Towards the end, when there was no hope, the
patient found her only solace in morphine. Under the influence of that
drug, she passed hours free from pain and in relative calm, but her
excited imagination passed almost into hallucination.

It is not surprising that the death of his wife was a severe shock
to the husband. His pessimism became complete. He was a widower at
the age of twenty-eight years, and, in his condition of mental and
physical exhaustion, took to morphine like his wife. He knew that
it was a poison which would complete the ruin of his constitution
and make his work impossible. But what was the value of his life?
As his organisation was too nervous for him to adapt himself to
external conditions, was it not as well to come to the aid of natural
selection and so make room for others? As it happened, a large dose of
morphia did not solve the problem. It produced in him a condition of
extraordinary happiness combined with extreme physical weakness. Little
by little the instinct of life awoke in him, and he resumed his work.
Pessimism, however, remained the fundamental quality in his character.
Life was not worth the pains necessary to protect it. It would be
a true crime to bring into the world other living beings doomed to
elimination by natural selection. Moral and physical sensibility, as
they continued to develop, brought with them so much evil that there
could be no good end. The “injustice” of those who were unwilling to
“understand” him made life painful to the man himself and to those
about him. The closest absorption and hard work made his existence more
tolerable, but his pessimistic conception was not in the least altered.
Thus, he was easily driven to morphia for consolation, when he suffered
from some act of “injustice” or vexation. A severe fit of poisoning,
however, stopped this excess.

Years passed. When he discussed with his friends the problem of
the goal of human life and similar topics, he was always ardent in
supporting the point of view of pessimism. However, he occasionally
wondered if his pleading for this were really sincere. As his nature
was honest and frank, this question which he put to his conscience
appeared most curious to him. Analysis of what passed in his mind
revealed to him a change. It was not that his conceptions had changed
in the course of years, but rather his feelings and sensations. As
he was now in full maturity, between forty-five and fifty years old,
he found that there was a great change in the intensity of these
last. Disagreeable sounds did not trouble him to the same extent as
formerly, and he was undisturbed by the caterwauling of cats or by
harsh street cries. As his hypersensibility diminished his character
became more tolerant. Even the injustices or wounds to his pride which
formerly drove him to morphia, no longer provoked in him any painful
reaction. He could easily conceal the bad effect of these upon him,
and no longer felt them with the same intensity. Thus his character
had become much more supportable to those with him, and much better
balanced.

“It is old age which is come upon me,” he cried; “I feel painful
impressions much less acutely and pleasant impressions have less
effect on me. The relative proportions of the two remain as before,
that is to say, unpleasant things still impress me much more strongly
than pleasant things.” By analysing and comparing his emotions, he
discovered something new, in fact that some impressions were, so to
speak, neutral. As he was less sensitive to unharmonious sounds, and
at the same time less affected by music itself, he found himself in
a more tranquil condition. Awakening in the middle of the night, he
experienced a kind of happiness which reminded him of that formerly
produced by morphine, and which was characterised by his hearing no
sound, either pleasant or unpleasant. He became less disgusted by
drugs, but at the same time indifferent to the pleasures of the table
which he had appreciated in his youth. He also delighted in consuming
more and more simple food. A piece of black bread and a glass of water
became real treats to him. Insipid dishes, which he formerly despised,
were now specially agreeable to him.

Just as in the evolution of art, violent coloration has yielded to the
low tones of Puvis de Chavannes, as views of fields and meadows are
preferred to those of mountains and lakes; just as in literature,
tragic and romantic studies have been successfully replaced by scenes
of daily life, so the psychical development of my friend displayed
a similar change. Instead of taking his pleasure in mountains or in
places famed for their picturesqueness, he was content to watch the
budding of the leaves of the trees of his garden, or a snail overcoming
its fears and putting out its horns. The simplest occurrences, such
as the lisping or the smile of a baby or the first words of a child,
became sources of real delight to this elderly man of science. What
was the meaning of these changes which took so many years to be
accomplished? It was the growth of his sense of life. The instinct of
life is little developed in youth. Just as a young woman gets more
pain than pleasure from the earlier part of her married life, just as
a new-born baby cries, so the impressions from life, especially when
they are very keenly felt, bring more pain than pleasure during a long
period of human life. The sensations and feelings are not stable; they
undergo evolution, and when that takes place more or less normally, it
brings about a state of psychical equilibrium.

And thus my friend, formerly so entrenched in pessimism, came to share
my optimistic view of life. The discussions that we had had for so many
years ended in complete agreement. “However,” said he, “to understand
the value of life, one must have lived long; otherwise one is in the
position of a man blind from his birth to whom are recounted the
beauties of colours.” In a word, my friend towards the end of his life
changed from abject pessimism to complete optimism.

Such a transformation or evolution cannot be regarded as unusual.
In _The Nature of Man_, I showed that most of the great pessimistic
writers had been young men. Such were Buddha, Byron, Leopardi,
Schopenhauer, Hartmann, and Mailaender, and there might be added many
other names of less well known men.

The question has often been asked why Schopenhauer, who was certainly
sincere in his philosophy and who extolled Nirvana as the perfect
state, came to have a strong attachment to life, instead of putting
it to a premature end as was done later on by Mailaender. The reason
was that the philosopher of Frankfort lived long enough to acquire a
strong instinct of life. M. Moebius,[184] a well-known authority on
madness, has made a close investigation of Schopenhauer’s biography,
and has established the fact that towards the end of his life his views
were tinged with optimistic colours. On his seventieth anniversary, he
took pleasure in the consoling idea of the Hindoo Oupanischad and of
Flourens that the span of man’s life might reach a century. As Moebius
put it, “Schopenhauer as an old man enjoyed life and was no longer a
pessimist” (p. 94). Not long before his death he still hoped to survive
yet another twenty years. It is true that Schopenhauer never recanted
his early pessimistic writings, but that was probably because he did
not fully realise his own mental evolution.

In looking through the work of modern psychologists, I cannot
find recognition of the cycle of evolution of the human mind. In
Kowalevsky’s able and conscientious study of pessimism, I was specially
struck by one phrase. “Evils such as hunger, disease, and death are
equally terrible at all stages of life and in every rank of society”
(p. 95) said that author. I notice here a failure to recognise the
modification of the emotions in the course of life which, none the
less, is one of the great facts of human nature. Fear of death is by
no means equally great at all stages of life. A child is ignorant of
death and has no conscious aversion from it. The youth and the young
man know that death is a terrible thing, but they have not the horror
of it that comes to a mature man in whom the instinct of life has
become fully developed. And we see that young men are careless of the
laws of hygiene, whilst old men devote to them sedulous attention.
This difference is probably a notable cause of pessimism in young men.
In his studies of the mind, Moebius[185] has stated his view that
pessimism is a phase of youth which is succeeded by a serener spirit.
“One may remain a pessimist in theory,” he says, “but actually to be
one, it is necessary to be young. As years increase, a man clings more
firmly to life.” “When an old man is free from melancholia, he is not
a pessimist at heart.” “We cannot yet explain clearly the psychology
of the pessimism of the young, but at least we can lay down the
proposition that it is a disease of youth” (p. 182).

The cases of Schopenhauer and of the man of science whose psychical
history I have sketched fully confirm the view of the alienist of
Leipzig.

The conception that there is an evolution of the instinct of life in
the course of the development of a human being is the true foundation
of optimistic philosophy. It is so important that it should be examined
with the minutest care. Our senses are capable of great cultivation.
Artists develop the sense of colour far beyond the point attained
by ordinary men, and distinguish shades that others do not notice.
Hearing, taste, and smell also can be educated. Wine tasters have an
appreciation of wine much more acute than that of other men. A friend
of mine, who does not drink wine, can distinguish burgundy from claret
only by the shapes of the bottles, but is devoted to tea and has a very
fine palate for different blends. I do not know if a good palate is a
natural gift, but however this may be, it is certain that the palate
can be brought to a high condition of perfection.

The development of the senses is specially notable in the case of the
blind in whom other powers become extremely acute. As I thought that
investigation of the educability of other senses in blind persons very
important from the point of view of the development of the sense of
life, I have tried to obtain the best available information on the
question. The perfection of touch in the blind is accepted so generally
as a truth that one would have expected to find convincing facts in its
favour. However, it is not true. Griesbach,[186] using a well-known
method for estimating tactile discrimination, found that the sense of
touch is not more acute in the blind than in normal persons. Blind
persons distinguished the points of a pair of compasses as separate,
only when they were at least as far apart as in case of normal persons.
Dr. Javal,[187] a well-known oculist who himself became blind, stated
his surprise at finding that “tactile discrimination is quite notably
less acute in the case of the blind than in the case of those with
unimpaired vision. For instance, the index finger of a blind man who
was a great reader got separate sensations from the points of a pair
of compasses only when these were three millimetres apart, whilst a
man with normal sight had the double sensation at a distance of two
millimetres” (p. 123). Griesbach goes still farther, stating that
neither hearing nor smell is better developed in the blind than
amongst normal people. Although these senses may come to replace to a
certain extent the sense of sight, this occurs merely because the blind
person uses impressions which the clear-sighted person hardly notices.
As we see what is going on around us, we do not concentrate our
attention on the different sounds and smells or other such phenomena.
The blind person, on the other hand, not being absorbed by impressions
of sight, gives attention to the others. Such and such a sound tells
him that the garden gate of his neighbour has been opened to let out a
carriage which he must avoid. A particular smell lets him recognise the
place where he is, as stable or kitchen.

From the present point of view, it is not exactly the acuteness of the
senses which is most important. The acuteness might be equal in a blind
person and in a normal person. It might even be greater in the latter,
and yet it is only the blind person who can decipher without difficulty
raised points so as to understand their meaning as well as when a
normal person reads a printed book. This power of the blind person is
developed only after a long period of learning, and depends on the
appreciation of very delicate tactile impressions. I must point out,
moreover, that the method of deciding by means of a pair of compasses
gives information only with regard to one side of the tactile sense.

However, although we admit that blind people do not really gain
anything in the four remaining senses, there is developed in them a
special kind of sensibility, which is spoken of in their case as a
sixth sense, the “sense of obstacles.” Blind people, especially those
who have lost their sight in youth, acquire a surprising habit of
avoiding obstacles and of recognising at a distance objects round
about them. Blind children, for instance, can play in a garden, without
knocking themselves against the trees.

Dr. Javal[188] states that some blind people, when passing in front
of a house, can count the ground floor windows. A professor, who had
been blind from the age of four years, could walk in the garden without
striking against a tree or post. He appreciated a wall at a distance
of two metres from it. One day, going for the first time into a large
apartment, he recognised the presence of a big piece of furniture in
the middle, which he took to be a billiard table.

Another blind man, walking in the street, could distinguish houses from
shops and could count the number of doors and windows. The existence
of this sense of obstacles rests upon so many exact facts that it is
indubitable. The opinions as to the mechanism by which it operates,
however, are very varied. Dr. Zell[189] thinks that it is not a sense
peculiar to blind people and “that those of normal sight could equally
well acquire it by practice, because it exists in nearly everyone
without being noticed.” None the less, there are some blind people who,
even in the course of years, do not acquire it. M. Javal, for instance,
learnt to read with his fingers extremely well, but was never able to
distinguish obstacles at a distance.

The most probable hypothesis refers this sixth sense to the action of
the tympanic membrane and the auditory apparatus. It is known that
loud noise makes it more difficult to perceive obstacles, and snow,
by dulling the sound of steps, has a precisely similar effect. Blind
tuners, in whom the sense of hearing is well developed, have the sixth
sense very marked.

The examples I have given show that the human body possesses senses
which come into operation only in special conditions, and which
require a special education. The “sense of life” to a certain
extent comes within this category. In some persons it develops very
imperfectly, generally revealing itself only late in life, but
sometimes a disease or the danger of losing life stimulates its earlier
development. Occasionally in persons who have tried to commit suicide,
a strong instinct of life wakens suddenly, and impels them to make
frantic efforts to escape.

It happens, therefore, that the sense of life develops sometimes in
healthy people, sometimes in those who suffer from acute or chronic
disease. These variations are parallel with the development of the
sexual instinct, which in some women is completely absent and in others
develops only very late. In certain cases, it is awakened only by
special conditions, such as child-birth, or even some defect of health.

As the sense of life can be developed, special pains ought to be taken
with it, just as with the making perfect of the other senses in the
blind. Young people who are inclined to pessimism ought to be informed
that their condition of mind is only temporary, and that according to
the laws of human nature it will later on be replaced by optimism.

PART VIII

GOETHE AND FAUST

GOETHE’S YOUTH

Goethe’s youth—Pessimism of youth—Werther—Tendency to
suicide—Work and love—Goethe’s conception of life in
his maturity

There can be drawn from analysis of the lives of great men information
that is very important in the study of the constitution of man. I have
chosen Goethe for several reasons. He was a man of genius distinguished
by the comprehensive character of his ability. He was a poet and
dramatist of the highest rank, his mind was stored with the most
varied knowledge, and he contributed to the advancement of natural
science. As minister of state and as the director of a theatre, he was
occupied with practical affairs. He reached the age of eighty-three
years, and he passed through the phases of life in relatively normal
circumstances; in his many writings there are most valuable facts which
throw a keen light on his life and nature. The Goethe cult in Germany
has brought about the existence of fuller biographical details than
exist regarding any other great man. He aspired to lead “the higher
life,” and, throughout his existence, he occupied himself with the most
serious problems of humanity.

It is not surprising that Goethe became a subject of investigation for
me, but as the main facts as to his history are widely known I need not
elaborate them here.

Goethe was reared in circumstances that were favourable in every
respect, and from his earliest years showed remarkable traits. As his
memory was good and his imagination vast, the study of ancient and
modern languages and the routine curriculum of a classical education
were little more than an amusement to him. The rich library of his
father placed all sorts of books at his disposal, and whilst he was
still young he devoted himself to reading with the enthusiasm and
passion that were the chief qualities of his character. When he was
fifteen years old he began to write verses, although he was still
unconscious of his destiny as a poet. He intended to be a learned man,
and looked forward to the career of a professor.

At the age of sixteen, he entered the University of Leipzig with the
intention of studying natural science seriously. Law and philosophy
interested him but little; he turned to natural science and medicine,
although his actual study was rather superficial. His disposition was
lively and restless; he made many friends, frequented the theatre
and plunged into all kinds of gaiety. Extracts from letters he wrote
during this period show the kind of life he led. When he was a student,
eighteen years old, he wrote to a friend, “And so good-night; I am
drunk as a hog.” A month later, to the same friend, he summed up his
life as a “delirium in the arms of Jetty.”

He graduated in law at Strassburg, and became a barrister, but
realising that such a career was unsuitable, he became a man of
letters, encouraged by the success of his first literary efforts.

From the point of view of a writer, he sought all kinds of experiences.
He devoted himself to literature and science, including even the
occult sciences, and frequented the theatre and society. He was
specially attracted by the imaginative side and gave little thought to
the problems of science. “I must have movement,” he wrote in one of his
note-books.

When he was young, his temper was violent and he fell into fits of
passionate rage. His contemporaries have related that when he was in
such a condition he would destroy the illustrations and tear up the
books on his work-table. These experiences have been vividly described
in his famous romance, _The Sorrows of Werther_. I shall give a few
extracts to show the exact state of mind of the young pessimist. “It is
the fate of some men not to be understood.” “Human life is a dream; I
am not the first to say that, but the idea haunts me. When I reflect on
the narrow limits which circumscribe the powers of man, his activities
and intelligence; when I see how we exhaust our forces in satisfying
our wants and that these wants are for no more than the prolongation
of a miserable existence; that our acquiescence in so much is merely
resignation engendered by dreams, like that of a prisoner who has
covered the walls of his cell with pictures and new landscapes; such
things, my friend, plunge me into silence.” “Our learned teachers
all agree that children do not know why they have desires; but that
grown men should move on the earth like children, and, like these, be
ignorant whence they have come and whither they go, like these strive
little for real things, but be ruled by cakes and sweets and rods; no
one will believe such things, though their truth is patent. I admit
readily (for I know what you will say) that they are the happiest men
who live from day to day like children, who play with their dolls,
dress them and undress them, who reverence the cupboard where mamma
keeps the gingerbread, and who, when they have got what they wish,
cry, with their mouths full, ‘How happy we are!’”

Werther proclaimed his pessimism before his romance with Charlotte, and
it was his view of life that made his love-affair turn out unhappily.
But the fame of Goethe’s _Werther_ was due, not to the tragic fate
of the young lover, but to the general views which were in harmony
with the conception of the world held by the best minds of the time.
Byronism was born before Byron.

_Werther_ affords a good illustration of the disharmonies in the
development of man’s psychical nature. Inclination and desires develop
extremely strongly and before will. Just as in the development of
the reproductive functions, as I showed in _The Nature of Man_, the
different factors develop unequally and unharmoniously, so there is
inequality and disharmony in the order of the appearance of the higher
psychical faculties. Sexual appreciation and a vague attraction to
the other sex appear at a time when there can be no possibility of
the normal physical side of sex, with the result that many evils come
about in the long period of youth. The precocious development of
sensibility brings about a kind of diffused hyperæsthesia which may
lead to trouble. The infant wishes to lay hold of everything he sees
before him; he stretches out his arms to grasp the moon and suffers
from his inability to gratify his desires. In youth there is still
well-marked disharmony. Young people cannot realise the true relations
of things, and formulate their desires before they understand that
their will-power is not strong enough to gratify them, as will is the
latest of the human powers to develop.

Werther fell in love with a kindred spirit and gave way to his passion
without consideration of the difficulties, Charlotte being already
betrothed to another. This is the plot of the tragedy of the young
man, who committed suicide, having given way to pessimism. He had not
the will-power to conquer his sentiments and so fell into a state of
lassitude, until, weary of life, he could see no other end than to blow
out his brains.

I need not linger over the last phase of the story of Werther, for it
is the character of Goethe himself that is of interest. Goethe was
able to subdue his passion for Lotte, and, after many amorous woes,
consoled himself with another woman. Notwithstanding this difference,
it is certain that in _Werther_, Goethe was telling part of the story
of his own youth. Goethe himself is a witness to this, for in a letter
to Kestner he wrote that “he was at work on the artistic reproduction
of his own case.” The letter was written in July, 1773, whilst Goethe,
then a writer twenty-four years old, was relating the sorrows of young
Werther.

The general tendency of _Werther_ has been described excellently
by Carlyle.[190] “_Werther_,” he wrote, “is but the cry of that
dim, rooted pain, under which all thoughtful men of a certain age
were languishing; it paints the misery, it passionately utters the
complaint; and heart and voice, all over Europe, loudly and at once
responded to it.” Werther was “the first thrilling peal of that
impassioned dirge which, in country after country, men’s ears have
listened to, till they were deaf to all else.”

In the pessimistic period of his life, Goethe often cherished the idea
of suicide. In his biography he relates that at this time he used to
have, by his bedside, a poisoned dagger, and that he had repeatedly
tried to plunge it in his bosom. Of these times he wrote to his friend
Zelter[191]—“I know what it has cost me in effort to resist the waves
of death.” The suicide which was the subject of the end of his romance
made a deep impression upon him. Although he overcame his passion
for Charlotte, his view of life remained tinged with pessimism for
many years; in a note-book of 1773, for instance, he wrote “I am not
made for this world.”[192] These words are the more striking as they
date from a period when exact ideas regarding the adaptation of the
organism and the character to the environment did not exist. Goethe,
with his too delicate sensibility, felt himself out of harmony with his
environment.

It is very interesting to trace Goethe’s subsequent development and
the transformation of a youthful pessimist into a convinced optimist.
Goethe found a remedy for his crises of grief in work, poetical
creation and love. He declared that the mere describing his woes on
paper brought assuagement. The tears that they shed console women and
children; and the poetry in which he expresses his suffering consoles
the poet. Goethe’s romance with Charlotte was not quite at an end when
he found himself ready to love her sister Helen. He wrote to Kestner in
December, 1772:—“I was about to ask you if Helen had arrived, when I
got the letter telling me of her return.” “To judge from her portrait
she must be charming, even more charming than Charlotte. Well, I am
free and I am thirsting for love.” “I am here at Frankfort again with
new plans and new dreams, and all will be well if I find someone to
love.” Soon afterwards, in another letter to Kestner, he wrote:—“Tell
Charlotte that I have found here a girl whom I love with all my heart;
if I wanted to marry, I should choose her before anyone else.”

As he had not yet realised his true vocation, Goethe became a court
minister at Weimar. He devoted himself to his duties with an
enthusiasm that carried him far beyond the usual affairs of state.
He wished to deepen his knowledge of such administrative problems as
the construction of roads and the management of mines, and he studied
geology and mineralogy with a real zest. Forest administration and
agriculture led him seriously into botany, and as he had the direction
of a school of design, he thought it necessary to learn anatomy.
Such varied work gave him a real taste for science. It was no longer
the superficial interest that characterised his work at Leipzig and
Strassburg but a true devotion which led him to important discoveries,
some of which have become classic.

Even such varied occupations did not absorb his prodigious genius. In
his leisure he wrote poetry and prose. Engrossed in so much work, he
was happy. His discovery of the human intermaxillary bone suffused him
with joy. His intense activity was strengthened by his love for Madame
von Stein, a love that he declared was “a life-belt supporting him in
the sea.” A few hours with her in the evenings set free his soul.

The powerful influence of love on the life of Goethe was specially
prominent in this period when he was passing from pessimistic youth to
optimistic maturity. Being forced to separate from Madame von Stein,
he gave way to grief that plunged him again in the worst hours of his
life. At the age of thirty-seven he fell back into a crisis like that
of the days of _Werther_. “I have discovered,” he said in 1786, “that
the author of _Werther_ would have done well to blow out his brains
when he had finished his work.” Soon afterwards he wrote that “death
would have been better than the last years of his life.”

This relapse into pessimism was shorter and less acute than his first
experience. He began to find that frequently his delight in existence
and sense of life were proved by his fear of death. When he was little
more than thirty years old, he began to take precautions against the
chance of his death. He wrote to Lavater:—“I have no time to lose; I
am already getting on in years, and it may be that fate will destroy
me in the midst of my life.” On all sides his wish to live and his
shrinking from death reveal themselves. It was at this time, a few
days after his thirty-first birthday, that he wrote those famous
lines, counted amongst the finest of his poetry, on the summit of
the Gickelhahn, on the wall of a small room, and which end with the
presentiment of his own death, “Before long, you also will be at rest.”

The crisis through which he passed at the age of thirty-seven, as the
immediate result of his separation from Madame von Stein, but perhaps
also partly due to brain fatigue, brought about his sudden departure
from Weimar and his long sojourn in Italy. There he came to life again,
and everything interested him, archæology, art and nature. The joy of
life came back to him, and he soon consoled himself for the lost love
of the blue-stocking Baroness in the arms of a pretty, blue-eyed girl
of Milan. This girl, whose name was Maddalena Riggi, like Charlotte,
was already betrothed, a circumstance, however, that had a different
result. Even after she had given up the man to whom she had been
engaged, Goethe avoided any permanent bond and soon abandoned her
definitely. He chose to associate with Faustine, another Italian girl,
with whom he lived during the last period of his stay at Rome. This
affair, which was less ideal and much simpler than his love for Madame
von Stein, he has described in his _Roman Elegies_, which throw a vivid
light on his temperament. I shall give some characteristic extracts.

“A sacred enthusiasm inspires me on this classic soil; the old world
and the world around me raise their voices and draw me to them.
Here I follow the ideas and turn over the pages of the ancient
writers, giving myself no rest whilst day lasts and ever reaching new
delights. By night love calls me to other cares; and if I am only half
a philosopher, I am twice happy. But may I not say that I am also
learning when my eye follows the contours of a loving breast, when with
my hand I trace the lines of her form? It is then that I understand
marble, I think and compare, I see with an eye that touches and touch
with a hand that sees.” “Often I have made verses in her arms; often
my playful finger has softly beaten out my hexameters on her back. As
she breathes in her sweet sleep, her breath burns me to my innermost
soul.”[193]

His stay in Italy brought Goethe definitely to maturity. On this
important stage in his life let us hear his biographer, Bielschowsky.
“The voyage to Italy made a new man of him. His sickliness and
nervousness disappeared. The melancholy which led him to think of early
death and made him regard death as better than the former conditions
of his life was replaced by a sublime serenity and joy in living. The
taciturn and preoccupied man who in no society abandoned his grave
thoughts had become happy as a child” (vol. i, p. 412). “From this
time on, in calm and enviable security, he passed through the cycle of
life which seemed so mysterious to others. Goethe became the serene
Olympian, the wonder of posterity, whilst many of his contemporaries no
longer saw in him the passionate pilgrim” (_ibid._, p. 417).

It was after reaching the age of forty years that Goethe entered on the
optimistic phase of his life.

GOETHE AND OPTIMISM

Goethe’s optimistic period—His mode of life
in that period—Influence of love in artistic
production—Inclinations towards the arts must be
regarded as secondary sexual characters—Senile love of
Goethe—Relation between genius and the sexual activities

The moral equilibrium of the great writer was not established once
for all. In the course of his life, Goethe had several relapses into
pessimism which, however, were ephemeral, and after which he became a
man as complete and harmonious as was possible in the circumstances of
his life. He reached a serene old age, and his activity did not relax
until after his eightieth year, when he died.

As I have already said, Goethe realised the value of life in good
time. Having become an optimist, he experienced the joy of existence
and coveted as much of it as possible. When he was an old man, he
declared that life, like the Sibylline books, became more valuable
the fewer of them were left. There appeared in him a normal phase of
human nature. The conditions under which he lived, however, were far
from ideal. His health was indifferent. In his youth he suffered from
severe hæmorrhage, probably tuberculous, and throughout his life he was
subject to various more or less serious maladies, such as gout, colic,
nephritis, and intestinal troubles. His habits were unwholesome. He
was brought up in a region of vineyards, and in his youth he acquired
the habit of drinking wine in quantities certainly harmful. This he
himself realised, and when he was thirty-one years old, after he had
acquired the instinct of life, he gave it serious attention. “I wish I
could abstain from wine,” he wrote in his note-book. Some weeks later
he wrote, “I now drink almost no wine.”[194]

But he had not the strength of character to remain temperate, and soon
after his decision, he had fits of bleeding at the nose, which he
attributed to “having taken some glasses of wine.”[195] To his last
day, he took wine regularly, and sometimes to excess. J. H. Wolff,
who dined with him at Weimar, when he was in his eightieth year, was
surprised by his appetite and by the quantity of wine he drank. “In
addition to other food, he ate an enormous portion of roast goose, and
drank a bottle of red wine.”[196] In Eckermann’s interesting narrative
of the last ten years of Goethe’s life (1822-1832) there is repeated
mention of wine. Goethe seized every occasion to drink it. Sometimes
it was the visit of a stranger, sometimes a present of some famous
vintage. It was said that he drank from one to two bottles of wine
daily (Moebius). None the less, he was convinced that wine was not good
for intellectual work. He had remarked that when his friend Schiller
had drunk more than usual, to increase his strength and stimulate his
literary activity, the result was deplorable. He said to Eckermann
(March 11, 1828), “He will ruin his health and will spoil his work.
That is why he has made the faults the critics have pointed out.” In
another conversation (March 11, 1828) he stated that what was written
under the influence of wine was abnormal and forced, and ought to be
deleted.

Love was the great stimulus of Goethe’s genius. The love affairs,
the histories of which fill his biography, are well known. Many have
been shocked by them; others have tried to justify them. It has been
suggested that his disposition made it necessary for him to impart his
ideas and obtain sympathy for them, and that his love for women was the
expression of a purely artistic feeling and had nothing in common with
the ordinary passion.

The truth is that artistic genius and perhaps all kinds of genius are
closely associated with sexual activity. I agree with the proposition
formulated by Dr. Moebius[197] that “artistic proclivities are probably
to be regarded as secondary sexual characters.” Just as the beard
and some other male characters are developed as means of attracting
the female sex, so also bodily strength, strong voice and many of
the talents must be regarded as due to the need to fulfil the sexual
relations. In primitive conditions woman worked more than man; man’s
superior force served him principally in fighting with other males, the
object of the combats usually being possession of a woman. Just as a
victorious combatant covets the presence of a woman as witness of his
prowess, so an orator speaks better in the presence of a woman to whom
he is devoted. Singers and poets are stimulated in their arts by the
love they awaken. Poetic genius is intimately associated with sexual
power and castration inhibits it. Just as castrated animals retain
their physical strength, but become changed in character, losing in
particular their combative nature, so a man of genius loses much of
his quality with the sexual function. Amongst the eunuchs on record,
Abelard is the only poet, but Abelard was forty years old when he
ceased to be a man, and at the same time he ceased to be a poet. Many
singers have been eunuchs, but they have been merely executants, and
have taken no part in musical creation. Some musical composers have
been eunuchs, but these were of mediocre ability and their names have
been forgotten. When castration has taken place at an early age, it
has a much more powerful influence in modifying the secondary sexual
characters.

From the point of view of a naturalist, I cannot agree with the
moralists who have blamed Goethe for his sexuality, nor do I share the
views of those defenders of him who have wished to deny the facts or to
explain them away by the suggestion that they did not relate to sexual
love.

Extracts from the _Roman Elegies_ show quite clearly what was the
nature of Goethe’s love affairs. His feelings towards the Baroness von
Stein have been taken as revealing merely idealistic love. But some of
his letters to her are clear evidence that their relations were erotic
(Moebius, _Goethe_, vol. ii, p. 89). The love which he bore for Minna
Herzlieb, the girl who inspired him to write _Elective Affinities_
(_Wahlverwandschaften_), has been described by Goethe himself in a poem
so crudely erotic that it has been impossible to publish it (Lewes,
vol. ii, p. 314).

A fact to which I specially desire to call attention is that Goethe’s
amorous temperament survived until the end of his life, and all the
world has been astonished by the vigour of his poetic genius in extreme
old age.

Goethe has been the subject of derision because at the age of
seventy-four years he fell deeply in love with Ulrique de Lewetzow, who
was quite a young girl. This incident, however, merits close attention
as it is a typical case of senile love in a man of genius.

Whilst he was at Carlsbad, Goethe became acquainted with a pretty girl
seventeen years old, with beautiful blue eyes, brown hair, and of an
ardent, good-humoured and happy disposition. In the first two seasons
nothing in particular happened. But in the third summer, at Marienbad,
Goethe became passionately enamoured of Ulrique, who was then nineteen
years old and in the full bloom of her young womanhood. His love made
him young again; he passed long hours with her and took to dancing with
her. “I am quite certain,” he wrote to his son, “that it is many years
since I have enjoyed such health of body and mind” (Aug. 30, 1823). His
passion became so serious that the Grand Duke of Saxe-Weimar, on behalf
of his friend, made a formal proposal of marriage for Mademoiselle de
Lewetzow. The mother gave an evasive answer, and the matter rested
in suspense for long, and ended in a refusal. Goethe withdrew to his
family, but encountered there strong opposition to his project of
marriage.

This misadventure troubled the old poet so seriously that he fell ill.
He suffered from pain in the region of the heart and from profound
mental disturbance. He complained to Eckermann “that he could do
nothing, that he could get to work on nothing, and that his mind had
lost its power.” “I can no longer work,” he said. “I cannot even read,
and it is only in rare and fortunate moments that I can think, feeling
myself partially soothed” (Eckermann, Nov. 16, 1823). Eckermann makes
the following reflection on the state of mind of the great old man.
“His trouble seems to be not merely physical. The passionate desire
which he acquired for a young lady at Marienbad this summer, and
against which he is still struggling, must be regarded as the chief
cause of his illness” (Nov. 17, 1823).

As in all earlier crises, Goethe sought consolation in poetry and
love. He left Marienbad in a carriage and began to set down verses
astonishingly vigorous for so old a man. His Marienbad elegy is held to
be one of the best of his poetical achievements. The following extracts
will give an idea of his state of mind at that period.

“I am lost in unconquerable desire; there is nothing left but
everlasting tears. Let them flow, let them flow unceasingly. But they
can never extinguish the fire that burns me. My heart rages; it is
torn in pieces, this heart where life and death meet in a horrible
combat.” “I have lost the universe, I have lost myself, I who until now
have been the favourite of the gods; they have put me to the question,
they offered me Pandora, rich in treasure and still richer in perilous
seductions; they made me drunken with the kisses of her mouth, which
gave me its sweets; they have torn me from her arms, and have struck me
with death.”

Goethe concealed his elegy for some time, guarding it as something
sacred, but eventually handed it over to Eckermann. Poetic creation
soothed his mind only for a time. His nature demanded some more
efficacious consolation. A few weeks after the separation he began to
complain bitterly of the absence of the Countess Julie von Egloffstein,
whom he wanted very much. “She cannot know what she is keeping from me
and what she makes me lose, nor can she know how I love her and how
she engrosses my mind.” He derived a little comfort from the visits of
Madame Szymanowska, whom he admired “not only as a great artist, but
as a pretty woman” (Eckermann, Nov. 3, 1823). “I am deeply grateful
to this charming woman,” he said to the chancellor, “for her beauty,
her sweetness, and her art have soothed my passionate heart” (Bode, p.
151). He also renewed his relations with Marianne Jung, the retired
actress and dancer. “When Goethe had to turn his thoughts from Ulrique,
the image of the pretty owner of Gerbermühle again occupied his mind. A
visit to her, and intimate correspondence with her, restored peace to
his heart so greedy of love” (Bielschowsky, vol. ii, p. 487).

His devotion to Ulrique was Goethe’s last acute attack of love; but
until the end of his days he felt the need of being surrounded by
pretty women. As director of the theatre, he came in contact with many
young women who wished engagements. He confessed to Eckermann that he
required much strength of mind to resist feminine charms which tempted
him to be unjustly favourable to the prettiest of those who sought
employment. “If I allowed myself to fall into an intrigue of gallantry,
I would become like a demagnetised needle as soon as the girl found a
real lover” (Eckermann, March 22, 1825).

His daughter-in-law’s sister has related that Goethe liked to have
young girls in his study whilst he was at work. They had to sit
quietly, neither working nor talking, often a difficult task for them
(Bode, p. 155).

Even on the last day of his life, whilst in delirium, he cried out,
“What a pretty woman’s head with black curls on a black ground” (Lewes,
vol. ii, p. 372). After uttering several other more or less incoherent
phrases, he drew his last breath.

The facts which I described in the chapter of this book dealing with
old age have made clear how long sexuality persists in men. As the
testes resist atrophy better than other organs, and even in extreme old
age still form active spermatozoa, it is natural that their condition
should be reflected on the organism generally, and that feelings of
love should still be excited. If by some accident Goethe had become
a eunuch early in life, he would have been a different being. The
moralists who have been shocked by his amorous intrigues would have
been satisfied, but the world would have lost a great poet. Moreover,
Goethe is no exceptional case amongst writers. The temperament of
Victor Hugo and his devotion to women up to the end of his days are
well known. More recently, after the death of Ibsen, a profound
sensation was made by the revelation of his love for Mademoiselle
Bardach, who inspired his genius during the last period of his life.

Not only poetic creation but other forms of genius are intimately
associated with the sexual function. The philosopher Schopenhauer, who
was no ascetic, wrote as follows, at the age of twenty-five, when he
was in full creative activity, “In the days and at the hours when the
voluptuous instinct is strongest, when it is a burning covetousness,
it is then that the greatest forces of the mind and the greatest
stores of knowledge are ready for the most intense activity.” “At
such moments life is truly at its strongest and most active, for its
two poles are then operating most actively; and this is plain in the
man of the highest intelligence. In these hours one sees more than in
years of passivity” (quoted in Moebius’ _Schopenhauer_, p. 55). “This
means that in Schopenhauer intellectual creation was linked with erotic
excitement” (_ibid._, p. 57).

It was facts of such a nature that led Brown-Séquard to his idea of
strengthening cerebral activity by injections of the substance of
testes. To obtain the same effect, he prescribed another means, the
value of which was proved in the case of two individuals aged from
forty-five to fifty years, the observations being continued over
several years. “By my advice,” he said, “when these had to perform
any great physical or intellectual work, they got themselves into a
condition of sexual excitement.” “The testes being in this way thrown
into functional activity, there was soon produced the desired increase
in the power of the nerve centres.”[198]

Although I insist on the existence of a close relation between
intellectual activity and the sexual function, I do not mean to assert
that there have not existed exceptions to the rule.

Now that I have described certain important factors in the genius of
Goethe, I shall pass on to a study of his state of mind in the last
period of his life, the splendour and harmony of which have been so
often admired.

III

GOETHE’S OLD AGE

Old age of Goethe—Physical and intellectual vigour of
the old man—Optimistic conception of life—Happiness in
life in his last period

Drinkers of wine may take the case of Goethe as an argument against
temperance. Although he was not healthy in his youth, his large
consumption of wine did not prevent him from enjoying an old age full
of force and intellectual work. Eckermann, who was his intimate and
constant companion in the last ten years of his life, was never weary
of expressing his surprise and delight at the physical and moral vigour
of the distinguished old man. He found Goethe on his return to Jena,
at the age of seventy-four, in a condition “very pleasant to see; he
was in good health and robust, so that he could walk for hours” (Sept.
15, 1823). His eyes were “brilliant and clear and his whole expression
was that of joy, vigour and youth” (Oct. 29). In walks with Eckermann,
Goethe forced the pace and showed strength which filled his companion
with delight (March, 1824). His voice was full of character and of
force (March 30, 1824), and every word showed his vitality (July 9,
1827).

In a conversation that Eckermann had with Goethe when the latter was
seventy-nine years old “the sound of his voice and the fire in his eyes
were of such strength as would have been normal in the full flush
of youth” (Mar. 11, 1828). Such characters were preserved until the
end of the life of the great man, and a few months before his death
Eckermann jotted in his book that he saw him every day in full vigour
and freshness, looking as if his health might be prolonged indefinitely
(Dec. 21, 1831). In the beginning of the following spring, Goethe
caught a feverish cold, possibly pneumonic, and died, probably from
weakness of the heart. His illness lasted a week. If he had not been a
drinker of wine he would have been able to withstand this attack and to
live still longer.

The intellectual vigour of Goethe was even greater and more remarkable
than his physical strength. His interests were extremely wide, and his
thirst for knowledge was never appeased. Once, when he was absorbed
by the interest of hearing d’Alton describe in detail the skeleton of
rodents, Eckermann states his surprise that a man not far short of
eighty years old “did not give up seeking for and gaining knowledge.”
But in these matters he never lost his interest. He wished always to go
further and further, always to learn, so showing himself to be a man
of eternal and undying youth (April 16, 1825). Goethe’s aptitude for
understanding and his memory were most unusual. When he was more than
eighty, he surprised those who heard him “by the incessant flow of his
ideas and by his extraordinary fertility in invention” (Oct. 7, 1828).

“The old age of Goethe is the most striking proof of the extreme force
of his constitution,” said his medical biographer, Dr. Moebius. Works
which were written in his last years are for the most part beyond
praise, both because of their finished form, and by their wisdom and
feeling. What other man of eighty has written anything of the same
character? From the physiological point of view I am more surprised
at his works when he was old than at those of his youthful activity”
(Moebius, _Goethe_, i, 200, 201).

Although Goethe’s character, which was fiery and intense in his youth,
became much more calm with age, there still came to him moments when
he was carried away. He had certain eccentricities of an old man, and
in particular was often very despotic, and this trait has been the
occasion of many stories. His temper, however, became much more certain
in his old age, and his general conceptions much more optimistic.
Apart from certain short crises, he was happy in his life. In 1828, he
settled down at Dornburg and there passed a tranquil existence. “I stay
out of doors nearly all day and engage in private conversations with
the tendrils of the vine which communicate their excellent ideas to
me, ideas about which I shall have marvellous things to tell you”—he
wrote to Eckermann on June 15, 1828—“I am composing verses which are
quite good, and I hope that it will be given to me to live long in
this condition. I am quite contented,” he said to his collaborator,
“at the beginning of spring, when I see the first green leaves, I am
pleased to watch how, from week to week, one leaf after another appears
on the stem. I am delighted in May, when I see a flower-bud; I feel
really happy, when in June the rose offers to me its splendour and its
perfume” (Eckermann, April 27, 1825). His delight in life at this epoch
is also revealed in many letters. “I wish to whisper this in your ear,”
he wrote to Zelter on April 29, 1830. “I am delighted to find that even
at my great age, ideas come to me the pursuit and development of which
would require a second life.”

His conception of life had changed enormously since the epoch of
_Werther_. Goethe himself said: “When one is old, one thinks many
things about this world quite different from when one was young”
(Eckermann, Dec., 1829). The youthful sensitiveness which had brought
him so much suffering was notably dulled. Eckermann was astonished
at the way he accepted wounds to his pride. It happened that his
design for the new theatre at Weimar was abandoned while it was being
constructed, and replaced by another not his own work. Eckermann
was much disturbed by this, and went to see Goethe in a state of
apprehension. “I was afraid,” he said, “that so unexpected a step
would profoundly wound Goethe. Well, there was nothing of the sort;
I found him in the best of tempers, quite calm, absolutely above all
feelings in the matter.” When he had reached his eighty-fourth year,
Goethe had no weariness of life. In his last illness, he showed not
the smallest desire to die. He expected to get better, and thought
that the approach of summer would restore his strength. The desire to
live was strong in him. None the less, he recognised that his cycle of
life was finished, and although he had no weariness of life, he felt
a kind of satisfaction that life was over. “When, like me, a man has
lived eighty years,” he said, “he has hardly the right to live, but
ought to be ready every day to die, and to think of putting his house
in order” (Eckermann, May 15, 1831). None the less, he continued his
work, in particular revising the last two chapters of the second part
of _Faust_. When he had finished them, Goethe was extremely pleased. “I
can consider,” he said, “any days which come to me yet as a real gift,
as it is a matter of no moment if I write anything more or what such
work should be” (Eckermann, June 1, 1831).

Goethe gave Faust one hundred years of life, and it is probable that he
thought of that period as his own span. Although he did not reach it,
he approached it, after having lived a most active life, full of most
valuable lessons for posterity.

GOETHE AND “FAUST”

_Faust_ the biography of Goethe—The three monologues
in the first Part—Faust’s pessimism—The brain-fatigue
which finds a remedy in love—The romance with Marguerite
and its unhappy ending

“Goethe was Faust, Faust Goethe,” said the biographer of the great
poet (Bielschowsky, vol. ii, p. 645). Most people admit that in
_Faust_ Goethe gave his autobiography on a more detailed scale than
in _Werther_. Why then should I follow my analysis of Goethe himself,
which was based on exact facts, with an analysis of Faust? I do so
because in addition to the biographical details in _Faust_, there are
many ideas which illuminate the poet’s conception of life. Goethe’s
life explains _Faust_, and _Faust_ explains the soul of its author.
And I am convinced that an accurate study of so great a man is of high
importance in the investigation of human nature.

The two Parts of _Faust_ correspond with two distinct periods in
Goethe’s life. In the first Part, Faust was pessimistic, in the second
optimistic. Although many of the high problems that occupy humanity are
raised and discussed in _Faust_, love is the centre on which the drama
turns.

In the first Part, conceived and for the most part written during
his youth, the chief theme is the love of a young man for a pretty
and attractive girl towards whom the hero acts in a fashion opposed
to conventional morality. As in most of his principal works, Goethe
has made an episode in his own life the basis of _Faust_. It is the
well-known story of Frederique, the daughter of a clergyman, for
whom the brilliant young author conceived a violent passion and who
returned his affection with a deeper and more enduring feeling. Goethe
was alarmed at the possibility of definitely settling his future, and
deserted the poor victim of love in an unfortunate state. Later on, he
confessed to the Baroness von Stein that he had abandoned Frederique
at a time when his desertion was likely to cause the death of the poor
girl. “I had wounded to the quick,” he wrote (Bielschowsky, vol. i, p.
135), “the best heart in the world, and I had to repent of it long and
almost unendurably.” As an atonement, he made Frederique the heroine
of “Goetz” and of “Clavigo,” but not thinking these worthy of her, he
immortalised her as the Marguerite of _Faust_.

A learned doctor, skilled in all human knowledge, but who had found
no satisfaction in his studies, found consolation in the beauty and
charm of a young girl with whom he fell passionately in love. It will
be interesting to trace the psychological process which induced him to
leave the scene of his scientific studies for the streets and resorts
where he found Marguerite.

Although Faust was represented as an old man, who had had time enough
to absorb all human learning, his image bears the stamp of green youth.
“Discontented with all his knowledge, he wished to know the secret
entrails of the world, to be a witness of the centre of all activity,
to unveil the principle of life.”[199] These are the demands of a young
man seeking to resolve the most intricate problems at one stroke. The
speech in question dates from the period of _Werther_, when Goethe
was twenty-five years old, and for that reason leaves no very serious
impression.[200] The second monologue, which ends with the attempt to
take poison, is later, and is absent in the edition of 1790 (Fragment).
It was revised when Goethe had reached his fiftieth year, and displays
a riper maturity. Although lacking exactness, it depicts in an
interesting fashion the miseries of life.

Some alien substance more and more is cleaving
To all the mind conceives of grand and fair;
When this world’s Good is won by our achieving,
The Better, then, is named a cheat and snare.
The fine emotions, whence our lives we mould,
Lie in the earthly tumult dumb and cold.
If hopeful Fancy once, in daring flight,
Her longings to the Infinite expanded,
Yet now a narrow space contents her quite,
Since Time’s wild wave so many a fortune stranded.
Care at the bottom of the heart is lurking;
Her secret pangs in silence working,
She, restless, rocks herself, disturbing joy and rest;
In newer masks her face is ever drest,
By turns as house and land, as wife and child, presented,—
As water, fire, as poison, steel;
We dread the blows we never feel,
And what we never lose is yet by us lamented.[201]

Fear of the evils which lie in wait for us and against which we can
make no provision render life insupportable. Faust’s frame of mind as
described in these lines recalls Schopenhauer, who was always afraid of
something; fear, sometimes of thieves, sometimes of diseases, tormented
him. He would never go to a barber’s to be shaved, and always carried
his own drinking cup with him.

“Is it not better to end such a life, and to kill oneself, even if it
mean annihilation?” asked Faust. He took up the poisoned goblet and
put it to his lips, but, arrested by singing and the sound of bells
outside, he refrained, and life laid hold of him. Not religious faith,
however, but memories of childhood, “the happy sports of youth and the
gay festivals of spring” were the agencies that recalled Faust to the
earth. He went out of doors, mingled with the crowd, tried to amuse
himself amongst men, and savoured the beauty of the new-born spring,
but all these could not make him forget the evil of life. He met his
pupil, talked with him, and again displayed his pessimism.

O happy he, who still renews
The hope, from Error’s deeps to rise for ever!
That which one does not know, one needs to use;
And what one knows, one uses never.[202]

Then follows the celebrated monologue of Faust over which so many
commentators have lost their heads and wasted oceans of ink.

Two souls, alas! reside within my breast,
And each withdraws from, and repels, its brother.
One with tenacious organs holds in love
And clinging lust the world in its embraces;
The other strongly sweeps, this dust above,
Into the high ancestral spaces.[203]

On this passage has been built up a whole theory of “double natures”
with which has been incorporated the dualism of Manicheism, the two
natures of Christ and what not besides.[204]

There exists in literature no better expression of human disharmony
than this monologue “of the two souls.” It portrays the unbalanced
condition so frequent in youth and is a valuable indication of the real
youth of Faust.

On his return to his study, Faust again revealed his pessimism.

But ah! I feel, though will thereto be stronger,
Contentment flows from out my breast no longer.
Why must the stream so soon run dry and fail us,
And burning thirst again assail us?
Therein I’ve borne so much probation![205]

It is at this point that Faust addresses the Spirit “that denies” and
that is called “sin” and “evil.” This spirit invokes before his eyes
“the fairest images of dreams,” that is to say, a woman’s body in its
beautiful nudity. Faust declares himself

Too old to play with passion,
Too young to be without desire.[206]

Pursued by desire

... when night descends, how anxiously
Upon my couch of sleep I lay me.
There, also, comes no rest to me;
But some wild dream is sent to fray me.[207]

So that

Death is desired, and Life a thing unblest.
O fortunate, for whom, when victory glances,
The bloody laurels on the brow he bindeth!
Whom, after rapid, maddening dances,
In clasping maiden-arms he findeth![208]

Faust thus reached the ecstasy of passion. Soon afterwards in the
Witches’ kitchen, he saw in a mirror a “heavenly form” and cried:—

O lend me, Love, the swiftest of thy pinions,
And bear me to her beauteous field.

A woman’s form, in beauty shining!
Can woman, then, so lovely be?
And must I find her body, there reclining;
Of all the heavens, the bright epitome?
Can Earth with such a thing be mated?[209]

Discontent with life, sense of the insufficiency of human knowledge
and the most gloomy pessimism lead to the passion of love which,
eventually, after many devious paths, throws Faust into the arms of
Marguerite. The story is one of the world’s great romances and everyone
knows it. Faust all unconsciously was following the prescription of
Brown-Séquard. Brain-fatigue had made the continuation of the study
which caused it impossible. The condition is plainly stated in the
following lines:—

The thread of Thought at last is broken,
And knowledge brings disgust unspoken.
Let us the sensual deeps explore.[210]

The brain has refused to work, and blind instinct, in the guise of
dreams, whispers that there is in the organism something that can
restore the intellectual forces. This something, however, is what is
called sin, and much courage is needed to plunge into it. Without this
evil, life cannot last. Faust has to choose between love and death, and
chooses love.

The end of the romance of Goethe and Frederique was bad, and that of
Faust and Marguerite was still worse. The poet painted it in the most
sombre colours. Marguerite killed her child, poisoned her mother,
became crazy, and was beheaded. Faust’s cup of misery was filled to the
brim; he blamed his evil genius, he made desperate efforts to save the
poor woman, and cried “O that I had never been born.”

To sum up: in the first Part, Faust is a young, learned man who
expects too much from science and life, and whose genius requires
extra-conjugal love as a stimulant; he is unbalanced and inevitably
pessimistic. It is not surprising that his life goes badly, and that
his conduct leaves him much to repent of. But although, at first,
a vague general discontent nearly drives him to suicide, later on
the terrible evil which he had wrought on a poor creature he loved
passionately did no more than plunge him into misery that was bitter
but far from mortal. His mind had developed far in the direction of
optimism. The crisis through which he passed, serious as it was, ended
by his return to a life of great activity and enterprise.

THE OLD AGE OF FAUST

The second Part of _Faust_ is in the main a description
of senile love—Amorous passion of the old man—Humble
attitude of the old Faust—Platonic love for Helena—The
old Faust’s conception of life—His optimism—The general
idea of the play

The first Part of _Faust_ was acclaimed by the world almost as soon as
it appeared, but the second Part met a very cold reception. Everyone
knows and reads the first Part; the second Part has few readers, and
these chiefly poets and dramatists. No doubt it has more effect on the
stage than when it is read, but this is due to subsidiary features in
which it resembles a fine ballet. There is general agreement that the
real meaning of the second Part is obscure, complex and difficult to
interpret. Many literary critics have racked their brains in the effort
to discover the author’s central idea. When Eckermann, who persuaded
Goethe to revise and finish the second Part, asked what was the meaning
of some of the scenes in it, Goethe evaded the question and played the
sphinx. Thus, with regard to the famous “mothers” Goethe answered,
with a mysterious air:—“You have the manuscript; study it, and see
what you can make of it” (January 10, 1830). G. H. Lewes, although
one of Goethe’s most resolute admirers, admitted the impossibility
of grasping the sense of the second Part. The Wanderjahre and the
second Part of _Faust_ were arsenals of symbols, and it pleased the
old poet to see acute critics labouring to interpret them whilst he
was silent and refused to help them. Lewes thought that Goethe, so far
from showing the smallest wish to clear up their difficulties, took
a pleasure in giving them new problems to puzzle over. Lewes himself
thought that the second Part was poor in idea and execution, and
admitted that he had failed after repeatedly trying to get a conception
of it that would reveal its beauties. In writing about it, he contented
himself with giving a summary of it. Now this second Part, although its
general lines had been laid down for long, was actually written during
several years in the last period of the poet’s life. The fact that it
was composed out of the regular sequence of the Acts and Scenes gives
us an important clue. The third Act and then the second Part of the
fifth Act were put on paper first. Next followed the first Act and part
of the second; the classical Walpurgis night was written in 1830, the
fourth Act in 1831, and last of all the beginning of the fifth Act.

As the second Part of _Faust_ is a crowded motley, containing many
subjects, obviously of minor importance, such as the volcanic theory
of the earth and the disquisition on paper-money, the key-note may be
found in the portions which were first composed. Now Act III. contains
the story of Helena, and the second part of Act V. Faust’s activity for
the general welfare.

Setting out from the conception that the works of Goethe reflect the
acts and incidents of his own life, I shall try to explain on that
basis the meaning of the most obscure of his writings.

I have already stated that love was the stimulus of Goethe’s activity
in youth and age; it is the scarlet thread running through his
history. There was no difficulty in his using his love for Frederique
as material for a play; that a young man should love a young girl
was natural enough. The story of an old man enamoured of a young
beauty was quite another matter. It was said that one of the reasons
that prevented his marriage with Ulrique de Lewetzow was the fear of
ridicule (Lewes, _op. cit._, ii, p. 345), a fear that plays a large
part in human affairs. It is easy to understand that the old poet was
in a difficulty when he came to write of senile love. Faust’s love for
Helena was not that of a supposed old man who became young by doffing
his beard and changing his cloak, but of a real old man whom no mystery
nor magic was to make young again. And yet old Faust’s love was a true
passion, and Goethe has written no finer lines than those describing it.

When the second Part begins, Faust has passed through the terrible
crisis of the first Part. Wearied and restless, he seeks a new mode of
life.

Life’s pulses now with fresher force awaken
To greet the mild ethereal twilight o’er me;
This night, thou, Earth! hast also stood unshaken,
And now thou breathest, new-refreshed before me,
And now beginnest, all thy gladness granting,
A vigorous resolution to restore me,
To seek that higher life for which I’m panting.[211]

The invoked image of the most beautiful woman in the history of the
world transforms Faust’s desire of love into an overwhelming passion.

Have I still eyes? Deep in my being springs
The fount of Beauty, in a torrent pouring!
A heavenly gain my path of terror brings.
The world was void, and shut to my exploring,—
And, since my priesthood, how hath it been graced!
Enduring 'tis, desirable, firm-based.
And let my breath of being blow to waste,
If I for thee unlearn my sacred duty!
The form, that long erewhile my fancy captured,
That from the magic mirror so enraptured,
Was but a frothy phantom of such beauty!
'Tis Thou, to whom the stir of all my forces,
The essence of my passion's courses,—
Love, fancy, worship, madness,—here I render.[212]

In the throes of this passion, Faust is tortured by jealousy when he
sees the lovely woman clinging to and kissing a young man. He desires
her at all costs.

Am I nothing here? To stead me,
Is not this key still shining in my hand?
Through realms of terror, wastes and waves it led me,
Through solitudes, to where I firmly stand,
Here foothold is! Realities here centre!
The strife with spirits here the mind may venture,
And on its grand, its double lordship enter!
How far she was, and nearer, how divine!
I’ll rescue her and make her doubly mine.
Ye Mothers! Mothers! Crown this wild endeavour!
Who knows her once must hold her, and for ever.[213]

The disappearance of the beautiful woman so moved Faust that he fainted
and fell into a prolonged sleep. As soon as he recovered consciousness
he asked: “Where is she?” and set out to seek for her. When he learned
that Chiron had already carried off Helena on his back Faust cried
out:—

Her didst thou bear?

_Chiron_: This back she pressed.

_Faust_: Was I not wild enough, before;
And now such seat, to make me blest!
O, I scarcely dare
To trust my senses!—tell me more!
She is my only Aspiration!
Whence didst thou bear her—to what shore?[214]

Thou saw’st her once; _to-day_ I saw her beam,
The dream of Beauty, beautiful as Dream!
My soul, my being, now is bound and chained;
I cannot live, unless she be attained.[215]

Chiron found this attitude of passionate emotion so strange that he
advised Faust to take care of his health.

After many wanderings and difficulties Faust again met the woman he
coveted and spoke to her as follows:—

What else remains, but that I give to thee
Myself, and all I vainly fancied mine?
Let me, before thy feet, in fealty true,
Thee now acknowledge, Lady, whose approach
Won thee at once possession and the throne![216]

This language, so very different from what the same man had formerly
addressed to Marguerite, is much more like that of an old lover to a
young beauty whom he admires. When Helena invited Faust to sit on the
throne beside her, he replied:—

First, kneeling, let the dedication be
Accepted, lofty Lady! Let me kiss
The gracious hand that lifts me to thy side.
Confirm me as co-regent of thy realm,
Whose borders are unknown, and win for thee
Guard, slave and worshipper, and all in one![217]

The old man in the throes of a passion so great that he was wholly
absorbed by it did not dare to address the beloved woman except in the
most humble terms.

Helena made no declaration of love, but was complacent to him, and when
Faust suggested: “Now let our throne become a bower unblighted,” Helena
agreed to follow him to a secluded and green bower. There they remained
alone for some time, cared for by an old servant.

The result of this union was not a child like that to which Marguerite
gave birth and afterwards killed. It was a strange and peculiar being;
a boy who immediately after his birth began to leap about and to alarm
his parents by the activity of his movements.

Although Goethe preserved an obstinate silence when he was asked to
explain many of the scenes in the second Part, he had no hesitation in
explaining the significance of this astonishing child. “The child was
not a human being but an allegory, in which was personified poetry,
which is not bound to any time, to any place, or to any person”
(Eckermann, December 20, 1829). Struck by the tragic fate of Byron,
Goethe made the son of Faust and Helena a symbol of the English poet.

Literary critics, setting out from the categorical explanation of
Goethe himself, have declared that the union of Faust and Helena
was meant to denote the alliance of romanticism and classicism, a
marriage from which was born modern poetry, personified in its highest
representative, Byron. This, however, cannot be the idea of Goethe, who
himself was far from an enthusiast about classicism and romanticism.
“What,” he said, “is all this noise about the classic and the romantic?
The essential thing is that a piece of work should be wholly good and
serious; then it will also be classic” (Eckermann, October 17, 1828).
It is much more probable that Goethe intended poetry to spring from the
relations between the old Faust and his adorable companion, relations
of a kind to be included in so-called platonic love. Such love inspires
the creation of perfect work even in an old poet, when he is stimulated
by a beautiful woman.

When Faust and Helena emerged from the grotto with their son, Helena
said:—

_Helena_: Love, in human wise to bless us,
In a noble pair must be;

But divinely to possess us,
It must form a precious Three.

_Faust_: All we seek has therefore found us;
I am thine and thou art mine!
So we stand as love hath bound us;
Other fortune we resign.[218]

After the death of her son, Helena abandoned Faust, leaving him her
garments:—

_Helena_: Also in me, alas! an old word proves its truth,
That Bliss and Beauty ne’er enduringly unite.
Torn is the link of Life, no less than that of Love;
So, both lamenting, painfully I say: Farewell!
And cast myself again,—once only,—in thine arms.[219]

After this crisis the old Faust sought to console himself in the bosom
of nature, just as after the terrible catastrophe with Marguerite the
contemplation of nature had given him the strength to live. On this
occasion he reached the summit of a high mountain from which he watched
the changing vapours of a cloud which seemed to him to assume the form
of female beauty. But Faust was old, and now saw only memories of love.
He cried out:—

Yes! mine eyes not err!—
On sun-illumined pillows beauteously reclined,
Colossal, truly, but a godlike woman-form,
I see! The like of Juno, Leda, Helena,
Majestically lovely, floats before my sight!
Ah! now ’tis broken! Towering broad and formlessly,
It rests along the east like distant icy hills,
And shapes the grand significance of fleeting days.
Yet still there clings a light and delicate band of mist
Around my breast and brow, caressing, cheering me.
Now light, delaying, it soars and higher soars,
And folds together.—Cheats me an ecstatic form,
As early-youthful, long-foregone and highest bliss?
The first glad treasures of my deepest heart break forth;
Aurora’s love, so light of pinion, is its type,
The swiftly-felt, the first, scarce-comprehended glance,
Outshining every treasure, when retained and held.

Like Spiritual Beauty mounts the gracious Form,
Dissolving not, but lifts itself through ether far,
And from my inner being bears the best away.[220]

This state of mind resembles Goethe’s condition after the rupture with
Ulrique.

Love and poetry alike were over for him. None the less his craving for
the higher life was not yet weakened. The desire to live was still
very strong in the old Faust. But now he no longer as in the days
of his youth dreamed of an ideal which could not be attained. When
Mephistopheles asked him ironically:—

Then might one guess whereunto thou hast striven?
Boldly-sublime it was, I’m sure.
Since nearer to the moon thy flight was driven,
Would now thy mania that realm secure?

_Faust_: Not so! This sphere of earthly soil
Still gives us room for lofty doing.
Astounding plans e’en now are brewing:
I feel new strength for bolder toil.[221]

Such optimistic language, extraordinarily different from Faust’s
lamentations in the first Part, becomes still more marked. When he was
approaching his centenary he made the following profession of faith:—

I only through the world have flown:
Each appetite I seized as by the hair;
What not sufficed me, forth I let it fare,
And what escaped me, I let go.
I’ve only craved, accomplished my delight,
Then wished a second time, and thus with might
Stormed through my life: at first ’twas grand, completely,
But now it moves most wisely and discreetly.
The sphere of Earth is known enough to me;
The view beyond is barred immutably:
A fool, who there his blinking eyes directeth,
And o’er his clouds of peers a place expecteth!
Firm let him stand, and look around him well!
This World means something to the Capable.
Why needs he through Eternity to wend?
He here acquires what he can apprehend.[222]

When he had reached the maturity of his wisdom, Faust organised
drainage works, the object of which was to increase the area of land
that could be utilised:—

To many millions let me furnish soil,
Though not secure, yet free to active toil;
Green, fertile fields.
A land like Paradise here, round about.
Yes! to this thought I hold with firm persistence;
The last result of wisdom stamps it true:
He only earns his freedom and existence,
Who daily conquers them anew.
Thus here, by dangers girt, shall glide away
Of childhood, manhood, age, the vigorous day:
And such a throng I fain would see,
Stand on free soil among a people free!
Then dared I hail the Moment fleeing:
“_Ah, still delay—thou art so fair!_”
The traces cannot, of mine earthly being,
In æons perish,—they are there!—
In proud fore-feeling of such lofty bliss,
I now enjoy the highest Moment,—this![223]

These were the last words of the wise centenarian. It has been said
that they contain the quintessence of Goethe’s moral philosophy, and
that they preach the sacrifice of the individual for the benefit of
society. Lewes, for instance, takes this view, holding that Faust was
the exposition of a man who had conquered the vanity of individual
aspirations and joys, and had come to the knowledge of the great truth
that man must live for man, and can find lasting happiness only in
work for the benefit of humanity. For my own part, it seems to me that
according to Goethe’s _Faust_ man must dedicate a large part of his
life to the complete development of his own individuality, and that
it is only in the second half of his life, when he has grown wise by
experience and feels satisfied as an individual, that he should use
his activity for the good of mankind. It was no part either of the
ideas of Goethe or of the nature of his work to preach the sacrifice of
individuality.

Goethe was thus absorbed in _Faust_ by the problem of the conflict
between certain actions and guiding principles. The misdeeds of the
hero in the first Part of his life had to be redeemed. He said to
Eckermann that “the key to the salvation of Faust was to be found in
the Angels’ Chorus”:—

The noble spirit now is free,
And saved from evil scheming:
Whoe’er aspires unweariedly
Is not beyond redeeming.[224]

However, that of which he did not speak, and which none the less was
most important in Faust and in Goethe himself, is the action of love as
a stimulant to artistic creation, and it was probably to this that he
referred at the end of his tragedy. The mystical chorus sent up prayers
in a religious and erotic ecstasy, and their mysterious song is:—

The Indescribable,
Here it is done;
The Woman-Soul leadeth us
Upward and on![225]

Although these verses have been interpreted as love which sacrifices or
even love which leads to the grace of God (Bode, p. 149), it is much
more probable that it is love for feminine beauty, a love which makes
possible the execution of wonderful things. Such an interpretation
agrees with the fact that the verses are spoken by a _mystic_ choir
which speaks of the _indescribable_ (_das Unbeschreibliche_) in
which we must see the amorous passion of the old man. In such an
interpretation the whole of _Faust_ (and especially the second Part) is
an eloquent pleading for the importance of love in the higher activity
of man, in accordance with the law of human nature, which is a much
better justification of Goethe’s conduct than all the arguments of his
interpreters and admirers.

I do not agree with the common idea that the two Parts of _Faust_ are
two distinct works, but regard them as complementary. In the first Part
we see the young pessimist, full of ardour and of desires, ready to
make an end of his days and stopping at nothing to satisfy his thirst
for love. In the second Part we have a mature old man still loving
women, but in a different way, a man who is wise and optimistic, and
who, having satiated the wants of his individual life, dedicates the
rest of his days to mankind, and who, having reached a century, dies
extremely happy, in fact almost exhibiting the instinct of natural
death.

PART IX

SCIENCE AND MORALITY

UTILITARIAN AND INTUITIVE MORALITY

Difficulty of the problem of morality—Vivisection
and anti-vivisection—Enquiry into the possibility of
rational morality—Utilitarian and intuitive theories of
morality—Insufficiency of these

In the course of this book I have from time to time approached
subjects closely related with the problem of morality. For instance,
in considering the prolongation of human life, it was necessary to
show that extension of longevity far beyond the reproductive period of
man in no way is opposed to the principles of the highest morality,
although there exist races who find the sacrifice of old people in
harmony with their conception of morality.

Experimental biology, which lies at the root of most of the doctrines
exposed in this work, depends on vivisection of animals. There are,
however, very many persons who regard it as immoral to operate on
living animals when it is not for the direct benefit of these. The
attempts which have been made in France and Germany to prevent or to
limit vivisection in laboratories have not succeeded, but in England
there is a severe law controlling operations on animals and submitting
them to oppressive regulations to which many of the scientific men in
the country are opposed.

The question of experiments upon human beings is still more delicate.
Just as formerly the examination of a human corpse could be made only
in secret, so at the present time, if the slightest experiment is to be
made upon a human being, it can be only by devious ways. People who are
hardly shocked at all at the numberless accidents caused by automobiles
and other means of transit, or in field sports, make the strongest
protest against any proposal to try some new method of treatment upon a
human being.

A large number of people, amongst them even men of science, regard
as immoral any attempt to prevent the spread of venereal diseases.
Recently, in connection with the investigations into the action of
mercurial ointment as a means of preventing syphilis, the members of
the Faculty of Medicine in France made a public protest, declaring
that it would be “immoral to let people think that they could indulge
in sexual vice without danger,” and that it was “wrong to give to the
public a means of protection in debauch.”[226] None the less, other men
of science, equally serious, were convinced that they were performing
an absolutely moral work in attempting to find a prophylactic against
syphilis which would preserve many people, including children and other
innocent persons who, if no preventive measures existed, would suffer
from the terrible disease.

Such examples show the reader what confusion exists in the problem of
morality. Although at every moment, in every act of human conduct, the
precepts of morality must be reckoned with, even the most authoritative
persons are far from agreeing as to what rules to follow. About a
year ago in a Parisian journal[227] an enquiry into the subject of
rational morality was directed to distinguished authors. The object
was to discover if, at the present time, moral conduct could be based
not on religious dogma, which binds only those who believe in it, but
on rational principles. The answers were most contradictory. Some
denied the possibility of rational morality, others admitted it, but
in very different fashions. Whilst one philosopher, M. Boutroux,
held that “morality must be founded on reason and could have no
other foundation,” a poet, M. Sully-Prudhomme, turned to feeling and
conscience as the basis of morality. According to him, “in the teaching
of morality, it is the heart and not the mind which is at once master
and pupil.” In the contradictions which I mentioned in the beginning
of this chapter, these two views appear. When antivivisectionists
are protesting against experiments on animals, they are inspired by
sympathy for poor creatures which cannot defend themselves. Guided by
conscience, they think immoral any suffering inflicted upon a living
being for the benefit of another being, whether human or animal. I
know distinguished physiologists who have determined to limit their
experiments to animals with little sensibility, such as frogs. The
great majority of scientific men, however, would have no scruple in
opening bodies and subjecting their victims to severe suffering in the
hope of clearing up some scientific problem which sooner or later would
increase the happiness of human beings and animals. If vivisection
had not been performed, or if it had been restricted, the great laws
of infectious diseases would not have been discovered, nor would
the discovery of many valuable remedies have been made. To justify
investigation, men of science set out from the utilitarian theory of
morality, which approves everything that is useful to the human race.
The antivivisectionists, on the other hand, rely on the intuitive
theory, according to which conduct is controlled by the spontaneous
activity of our conscience.

In the case which I have selected the problem is easy to solve. It is
plain that vivisection is inevitable in the experimental investigation
of vital processes, as it is the only means by which serious progress
can be made. None the less, very many people cannot accept this
necessity, because of the intensity of their love for animals.

In the question of the prevention of syphilis, the moral problem is
still more easy to settle. Whilst in the case of vivisection a real
suffering may be inflicted upon animals, in preventive measures against
syphilis, the evil is more or less intricate and very problematic.
The certainty of safety from this disease might render extra-conjugal
relations more frequent, but if we compare the evil which might come
from that with the immense benefit gained in preventing so many
innocent persons from becoming diseased, it is easy to see to which
side the scale dips. The indignation of those who protest against the
discovery of preventive measures can never either arrest the zeal of
the investigators or hinder the use of the measures. This example
again shows that reasoning is necessary in the solution of most moral
questions.

However, the problems which arise in actual life are often very much
more complicated than the two cases I have taken as an introduction.
It is easy to prove the high utility of the work of vivisectors and
of those who are seeking means of preventing syphilis, whilst their
adversaries have nothing to invoke but their feelings. The situation is
quite different in many questions which border on morality. The sexual
life abounds in extremely difficult problems, in which it is almost
impossible to determine what is right. Let me recall the vagaries
in the life of Goethe, whose great genius was so often in conflict
with the morality of his time. Was he wrong in giving up Frederique
and Lili from the fear that a permanent bond would damage his poetic
productivity? Then there is the moral question of the marriage of
men affected with syphilis, or other diseases which might influence
the offspring. The problems of the continence of young people before
marriage, of prostitution and of means of preventing conception are
without doubt questions of great importance, the solution of which is
extremely difficult from the point of view of morality. Differences of
opinion are revealed in nearly everything relating to punishment. The
question of the death penalty is much in dispute and requires numerous
investigations of different kinds. Statistics have been collected to
give information as to the utility or inutility of the death penalty.
According to some results, capital punishment does not diminish the
number of crimes, whilst according to others it has a real preventive
effect. Punishments less violent than death, and particularly the
punishments of children, are equally troublesome, and schoolmasters
have difficulty in finding a solution.

The utilitarian theory of morality often finds it impossible to prove
the advantage of the conduct it prescribes, and this the more because
in many cases we do not exactly know who is to profit by it. Is the
utility of any particular act to be considered so far as it affects
relatives, members of the same religion, of the same country, or of the
same race, or all humanity?

In face of these difficulties, many moral philosophers have given up
the utilitarian theory and declared for an intuitive theory. The basis
of morality is to be found in a feeling innate in every man, a sort of
social instinct urging him to do good to his neighbour, and which, by
the voice of his own conscience, dictates how he ought to act much more
precisely than could be done by any comprehension of the utility of his
conduct.

It is certainly true that man is an animal living in society because
of his need for association with other human beings. But whilst in
the animal world the members of societies are actuated by an instinct
which is blind and generally very precise, in man we find nothing of
the kind. The social instinct appears in him in endless variety. In
some of us love of neighbours is extremely highly developed, so that
some persons are only happy when sacrificing themselves for the public
good. They give all that they have to the poor, and often die for some
ideal which is necessarily altruistic. Such examples are rare. Many
men, however, profess an affection for some of their kind, devote
themselves to their relations, their friends, or their compatriots,
and remain practically indifferent to all others. Other individuals,
again, have an even narrower sphere of affection, and take advantage
of their fellows, either in their own interest or in that of their own
family. Still more rare are the really wicked persons who have no love
for anyone but themselves and who take pleasure in doing harm to those
about them. Notwithstanding this diversity in the development of the
social instinct, all men have to live together.

If it were possible to know the inner motives of men, these might be
used as a basis for classifying conduct. Those acts might be described
as moral which were inspired by neighbourly love, and those as immoral
the motive of which was egoism. But it is seldom that the real motives
are discovered; they lie deep down in the individual mind, sometimes
unknown even to the man himself. We can nearly always harmonise our
acts with the dictates of our consciences and find reasons for the
harm we inflict upon others. It is only rare natures that possess a
conscience so delicate as to be always tormented lest they are not
doing good to their neighbours.

In the course of life, men are disposed to attribute bad motives to
their opponents. Such an attitude makes criticism easier and panders
to the common wish to speak evil of one’s neighbours. Notwithstanding
the numerous precedents for such an attitude amongst politicians and
journalists, it must be discarded from any serious study of morality.

The motives and the conscience are elusive elements of little use
in any attempt to value human conduct. We have to fall back on the
consequences of action. Now it is easy to show that the social instinct
often leads to action which is not good. It frequently happens that
men, acting with the highest and best intentions, do much harm.
Schopenhauer long ago pointed out that morality based on sentiment is a
mere caricature of real morality. Impelled by the altruistic wish to do
good, men often lavish unreflecting charity and do harm to others and
to themselves. In _Timon of Athens_ Shakespeare depicted

A most incomparable man; breathed, as it were,
To an untirable and continuate goodness,

and who gave away to the right and the left, creating around him a
cloud of parasites. He finally ruined himself and became a hopeless
misanthrope. Shakespeare put his verdict in the mouth of Flavius:—

Undone by goodness. Strange, unusual blood,
When man’s worst sin is, he does too much good.

Morality, founded purely on sentiment, has inspired the attacks on
vivisectors which in all confidence spread evil amongst men.

It is a surprising result of the great complexity of human affairs,
that society is sometimes better served by wicked acts than by acts
inspired by the most generous feelings. Thus extremely rigorous
measures of repression are often more successful than the half-measures
employed by humane and charitable administrators.

The intuitive theory of morality has had no greater success than
utilitarianism. Even if the sentiment of society were a true basis of
moral conduct, it fails in actual practice. On the other hand, although
utility is the object of all morality, it is in most cases so difficult
to determine what is really useful, that utilitarianism breaks down as
the foundation of morality.

We must look elsewhere for principles which can guide us towards right
conduct.

MORALITY AND HUMAN NATURE

Attempts to found morality on the laws of human
nature—Kant’s theory of moral obligation—Some
criticisms of the Kantian theory—Moral conduct must be
guided by reason

Even in antiquity, there were efforts to find a basis for morality
other than the precepts of religion based on revelation, but the
failure of such attempts has long been admitted. In the first chapter
of _The Nature of Man_, I described such efforts to find a basis
for morality in human nature itself. The Epicureans and the Stoics,
although their doctrines were opposed, each claimed to set out from
human nature. The principle is too vague for practical use, as human
nature can be interpreted in very different fashions.

When several attempts to find a rational basis for morality had failed,
Kant’s theory appeared and was hailed by many as a real advance. None
the less, it has not met with general approval and may be taken as a
supreme instance of the failure to solve the great problem of morality
by reason. I do not wish to deal with it at length, but a review of its
main outlines is pertinent to my argument.

According to Kant, morality cannot be founded on the feeling of
sympathy, nor can it have as its object the happiness of men. Nature
would have been an unskilful workman were her object the happiness of
human beings, for many lower animals have much more happiness. An inner
law is the force compelling us to morality, and without that we should
have to seek our guide in happiness.

Kant’s doctrine is an intuitive theory of morality. It is based neither
on sympathy nor on any inherent charity, which would make us covet
happiness for our fellows, but solely on the consciousness of duty.
Kant thought that the action of a man who wished to do good to his
fellows was devoid of merit. Conduct was moral only in so far as it was
obedience to the inner sense of duty. Schiller’s epigram has thrown
into relief this part of the great philosopher’s theory, “When I take
pleasure in doing good to my neighbour, I am uneasy, as I fear that I
have been lacking in virtue.”

In his criticism of Kant’s system, Herbert Spencer drew a picture of
a world inhabited by men who had no sympathy for their fellows and
who did good to them against their natural instincts and only from
a pure sense of duty. Spencer thought that such a world would be
uninhabitable. Clearly, moral conduct, on the Kantian basis, could
be followed only by exceptional persons, for most men follow their
inclinations rather than any sense of duty. People of lower culture
would accept kindnesses from others without caring whether the motive
were kindness or a sense of duty, but highly civilised people would not
endure service from those whom they knew to be acting against their
instincts in obedience to a sense of duty. And so men would be driven
to hide the real motives of their conduct, lest they should offend the
sensibility of those towards whom their moral conduct was directed.
Such cases, where the real motive is concealed, show how impossible
it is to judge of conduct from the motives which may be supposed to
have inspired it. As it is generally impossible to know whether some
altruistic conduct has been inspired by kindness or has been performed
as a duty, it is better to give up any attempt to appraise the springs
of moral conduct.

Kant himself realised the need of some other standard for appraising
human conduct. With such a purpose he arrived at his well-known
maxim:—“Let your conduct be such that your motive might serve as a
standard of universal application.” To explain the maxim he gave a
number of examples. A man who is without money and cannot pay a debt
is in doubt as to whether he should promise to repay his creditor.
According to Kant, he ought to ask himself what would be the result
if such a promise were to be made under similar circumstances by
everyone. It is plain that if such false promises became universal,
they would cease to be believed and so would be impracticable in
actual life. Kant’s formula, therefore, would supply a rational basis
for the discrimination of immoral conduct. In the case of theft it
would operate as follows: if it became the custom for everyone to take
whatever he wanted, private property and theft would simultaneously
cease to exist. So also suicide is immoral, since if it became general
the human race would cease to exist.

Kant, however, was looking at only one side of the problem. Moral
conduct is frequently limited to an individual, and cannot be
generalised for all humanity. Thus, for instance, if one about to
sacrifice his life for the good of his fellows were to estimate his
action according to Kant’s formula, he would reach a conclusion similar
to that in the case of suicide; if everyone were to sacrifice his life
for others, no one would remain alive, and so, according to Kant, the
sacrifice of one’s life for the good of others would be an immoral act.

It is plain that in his search for a rational basis of morality, Kant
found only a hollow form, void of any substantial body of morality.
It is not enough that a moral man should take his consciousness of
duty as a guide. He must know what would be the result of his acts.
If it is immoral to make a false promise, it is because people would
lose confidence in such promises, and confidence is necessary to our
well-being. When the formula of Kant condemns theft, it is because, if
theft became general, there could be no private property, and property
is regarded as necessary to the well-being of men. Suicide is immoral,
according to Kant, because it would lead to the disappearance of the
human race, and human life is of course a good.

Kant tried to found his theory of morality on a rational basis which
excluded the idea of the general good, but it was impossible for him to
avoid it. His “practical reason,” when it raised the consciousness of
duty to a principle, should have pointed the goal towards which moral
acts were to be directed. In this matter, I find that Kant’s ideas are
very vague, although extremely interesting.

The innate feeling of duty implies the _will_ to pursue moral conduct.
This will is independent of the circum-ambient conditions. Kant in his
nebulous language explains this consideration as follows:—“Our reason
informs us of a law to which all our maxims are subject, as if our will
had created its own natural order of things. This law, then, is in
the sphere of a nature which we do not know empirically but which the
freedom of the will makes possible, a nature which is supra-sensible,
but which from the practical point of view we make objective, because
it is created by our will in virtue of our existence as rational
beings. The difference between the laws of a nature to which the will
is subject and a nature subject to the will subsists in this, that
in the first the objects must be the causes which determine the will,
whilst in the second, the will itself causes the objects so that the
causality of the will resides exclusively in pure reason, pure reason
being thus practical reason” (_Critique of Practical Reason_).

So far as I can follow the argument of Kant, it seems to me to imply
that rational morality cannot be bound by human nature as it exists. I
may perhaps interpret Kant’s thought as if he had the intuition that
the moral will was capable of modifying nature by subjecting it to its
own laws.

On the other hand, several critics of Kant have attempted to improve
his theory of morality by reconciling it with human nature as it
actually exists. Vacherot,[228] for instance, has taken such an
attitude in the most definite fashion. He insists that Kant “did not
appreciate the capital importance of the object of the moral law. The
problem which under the designation _summum bonum_ absorbed the schools
of antiquity plays a minor part in the Kantian theory. Kant should have
recognised that human destiny is not limited to duty but must include
happiness” (p. 316).

But what is this “happiness” which is to be the standard of human
actions? To answer this Vacherot places himself in the position of
those ancient philosophers whom I discussed in _The Nature of Man_. He
makes his point absolutely clear. “What is the ‘good’ for any being?
The attaining of its purpose. What is the purpose of a being? The
simple development of its nature. Apply this to man and morality. When
human nature is known by observation and analysis, the deduction can be
made as to what is the purpose, and the good, and therefore the law of
man. For the conception of the good necessarily involves the idea of
duty and of law to be imposed on the will. We have to fall back, then,
on knowledge of man, but it must be complete knowledge, a recognition
of the faculties, feelings, and inclinations that are peculiar to him
and that distinguish him from animals” (p. 319). Here is a summary
of this doctrine:—“Develop all our natural powers, subordinating
those which are subsidiary to those which form the peculiar quality
of human beings; this is the true economy of the little world we call
human life; this is its purpose and this its law. The formula states
in the most scientific and least doubtful form a very old truth, the
foundation of all morality and the test of all its applications. If we
seek to know what are justice, duty and virtue, we must look in the
world itself, and not above or below it” (Op. 301).

Professor Paulsen, a more recent critic of Kant, comes to a similar
conclusion.[229] He thinks that Kant should have modified his formula
in some such way as follows:—“The laws of morality are rules which
might serve for a natural legislation for human life; in other words,
rules that, when they guided conduct according to natural law, would
result in the preservation and supreme development of human life.”

From whatever side we examine the problem of morality, we come to
submit conduct to the laws of human nature. Sutherland, a modern author
who discusses morality by the scientific method, defines morality
as “conduct guided by rational sympathy.” Such sympathy would not
subordinate the chief good of others to an advantage less important but
more immediate. Thus a mother may sympathise with her child when it has
to take some unpleasant medicine; but if her sympathy be rational she
will not let it interfere with the health of the child.

In the foregoing case, sympathy has to be controlled by medical
knowledge. In moral conduct generally, reason must be the determining
factor, whatever be the inspiring motive of the conduct, whether it
come from sympathy or from the sense of duty. And thus morality in the
last resort must be based on scientific knowledge.

III

INDIVIDUALISM

Individual morality—History of two brothers brought
up in same circumstances, but whose conduct was
quite different—Late development of the sense of
life—Evolution of sympathy—The sphere of egoism in
moral conduct—Christian morality—Morality of Herbert
Spencer—Danger of exalted altruism

Although moral conduct refers specially to the relations between men,
there exists a morality of the individual. As this latter is simpler, I
shall consider it first in my investigation of rational morality.

When a man, seeking his individual happiness, gives way to his
inclinations without restraint, he often comes to behave in a way that
is generally regarded as immoral. Following his inclination, he may
become idle and drunken. Idleness may depend on some irregularity of
the brain, and may thus be as natural as is the wish to take drink
in the case of a man to whom alcohol brings a feeling of well-being
and gaiety. Why is it that idleness and alcoholism are immoral? Is
it because they prevent the living of life in its completest and
widest sense, according to the theory of Herbert Spencer? But it is
precisely in this way that the adherents of the theory justify all
kinds of excess without which fullness and width of life seem to them
impossible.

Whilst vices such as idleness and drunkenness arise directly from
qualities of the human constitution, they must be regarded as immoral
because they prevent the completion of the ideal cycle of human
life. I knew two brothers, almost the same age, subject to the same
influences, and brought up in the same environment. None the less,
their tastes and conduct were very different. The older brother,
although very intelligent, during his college career devoted himself
eagerly to bodily exercises and indulged in every way his inclination
for pleasure. “As the chief end of life is happiness,” he said, “one
must try to get as much of it as possible,” and so he got into the
habit of visiting places where there was most amusement. Cards, good
living, and women furnished for him the means of pleasure. As his
ability was unusual, he passed his examinations almost without having
worked. The example of his younger brother, always a devoted student,
did not attract him. “It is all very well for you,” he said, “as you
find your happiness in work; as for me, I detest books, and I am happy
only when I am giving myself up to pleasure. Everyone must take his
own road to the goal of life.” As a result, the health of the older
brother was seriously affected by his mode of life. He acquired some
disease of the circulatory system, had to face the end, and died at
the age of fifty-six. The last years of his life were very unhappy,
as the instinct of life developed in him extremely strongly. He was a
victim of his own ignorance because when he was young he did not know
that the sense of life would develop later on, and would become much
stronger than in his youth. His brother was equally unaware of this
fact, but, absorbed in scientific study, he kept himself apart from the
indulgences of youth and lived a sober life. In this way he found that
his strength and activity were fully preserved at a time of life when
his older brother was already a physical wreck.

I have quoted this example, not to repeat the banal idea that a sober
life is followed by a healthier old age than an intemperate life, but
because I wish to insist on the importance of the development of the
instinct of life in the course of each individual life. I see that
this idea is very little known. I was present at the last moments of
my older brother (he was called Ivan Ilyitch, and he was the subject
of the famous story of Tolstoi: _The Death of Ivan Ilyitch_). Knowing
that he was going to die from pyemia, at the age of forty-five, my
brother preserved his great intelligence in all its clearness. As I
sat by his bedside he told me his reflections in the most objective
fashion possible. The idea of his death was for long very terrible to
him, but “as we all die” he came to “resign himself, saying that after
all there was only a quantitative difference between death at the age
of forty-five and later on.” This reflection, which relieved the moral
sufferings of my brother, is none the less untrue. The sense of life is
very different at different ages, and a man who lives beyond the age of
forty-five experiences many sensations which he did not know before.
There is a great evolution of the mind during the advance of age.

Even if we do not accept the existence of an instinct of natural
death as the crown of normal life, we cannot deny that youth is only
a preparatory stage and that the mind does not acquire its final
development until later on. This conception should be the fundamental
principle of the science of life and the guide for education and
practical philosophy.

Individual morality consists of conduct permitting the accomplishment
of the normal cycle of life and ending in a feeling of satisfaction as
complete as possible and which can be reached only in advanced age. And
so, when we see a man wasting his health and strength and youth, and
thus making himself incapable of feeling the most complete pleasure in
life, we call him immoral.

A man entirely isolated does not exist in nature. We are born weak
and incapable of satisfying our needs and at once come into relations
with the human being who feeds us and protects us. The child, although
egoistic, becomes attached to his protector, and in this way the
feeling of sympathy is born. Guided by this feeling as well as by the
sense of his own interest, the child soon begins to employ his will
in restraining some of his instincts, which, none the less, are quite
natural. Thus, the fear of being deprived of food makes him obedient
to his protectors. The child cannot complete his normal cycle without
pursuing a certain moral conduct.

When he becomes adult, man experiences the instinctive need of
relations with someone of the other sex. This need lays certain duties
on him, and although the love of a young man is less egoistical
than that of the child, it is far from presenting the characters of
self-abnegation and sacrifice.

A young woman, after having passed through the usual cycle of life
with her mother and with a man, becomes herself a mother. Maternal
instinct furnishes her with certain rules of conduct, but this natural
instinct is not enough to fulfil its object, that is to say, to rear
the child until an age when it can live independently. Directed by a
feeling of sympathy for her child, the young mother learns from women
with more experience to ward off dangers from her child. In the first
years, moral conduct on the part of the mother consists almost entirely
in bringing up the child in a healthy way. For this purpose she must
acquire much knowledge. If she remains ignorant, her conduct must be
regarded as immoral.

So far as concerns the bringing up of a child, the moral problem is
quite simple, because we are all agreed that the object is to rear
the child to maturity in the healthiest possible condition. When the
child exhibits any habits harmful to this object, although due to
natural instincts, the mother applies her knowledge to restrain them
without paying attention to the theory that happiness consists in the
fulfilment of everything that is natural. When a child has passed
through the perilous first period of its life, the mother has to ask
what general object she is to follow in its education. She wishes her
child to be as happy as possible. Here the conception of orthobiosis
will serve her, and it will teach her that the greatest happiness
consists in the normal evolution of the sense of life, leading to
serene old age, and finally reaching the fulness of satiety of life.
Man, who has passed his apprenticeship to life from his birth, with his
protectors, and, later on, with persons of the other sex, inevitably
acquires certain elements necessary for social life. Persuaded that
in order to succeed in his individual life he must have help from his
fellows, he learns to subdue his anti-social tendencies, at first
in his own interests. Let me take an example of this. When a man
has reached a certain stage of civilisation, it generally becomes
impossible to him to supply his bodily wants without the help of
persons less cultured than himself. He takes into his house one or more
servants, with whom he enters into definite relations. He wishes for
himself and those about him a normal life, such as I have described
in _The Nature of Man_. To attain this it is indispensable in his own
interest and in that of his family, that his domestic servants should
be well treated. The health of the family very often depends on the
conduct of the servants, who will follow conscientiously the hygienic
rules only if they themselves are living in good conditions. The custom
according to which the masters live in luxuriously furnished rooms,
while their servants have mean quarters in the attics, is immoral from
the point of view of the well-being of the masters themselves. The
crowded servants’ quarters are a nest of all sorts of infection, which
may spread in the families of the masters. Very often people who think
that they are following the rules of exact hygiene contract diseases
without knowing that the infection has come from their servants.

Anger gives us another example. It is certainly harmful to the health,
and so should be controlled in the interest of the bad-tempered
person himself. Fits of rage are frequently followed by ruptures of
blood-vessels, and by diabetes, and even cataracts have developed after
some violent passion.

Luxurious habits are also well known to be harmful to the health. Heavy
meals, evenings passed in the theatre and in society may seriously
affect activity of the organs. Moreover, the luxury of some people
is often the cause of misery to others. The knowledge that luxurious
habits shorten life and prevent man from reaching the greatest
happiness may warn people against luxury better than the appeal to the
feeling of sympathy.

As it is a fact that most men guide their lives generally from egoistic
motives, any theory of morality which is to be put into practice must
reckon seriously with this factor. All other systems have recognised
it. In the Sermon on the Mount, which is a summary of Christian
morality, each moral act is recognised on the ground that it will
bring some reward or obviate some punishment. “Rejoice,” said Jesus,
“and be exceeding glad; for great is your reward in heaven” (Matt. v.,
12). “Take heed that ye do not your alms before men, to be seen of
them; otherwise ye have no reward of your Father which is in heaven”
(Matt. vi., 1). “That thine alms may be in secret; and thy Father
which seeth in secret himself shall reward thee openly” (Matt. vi.,
4). “Judge not, that ye be not judged” (Matt. vii., 1). “But if ye
forgive not men their trespasses, neither will your Father forgive your
trespasses” (Matt. vi., 15). Jesus had no high opinion of the influence
of altruism on human conduct.

Herbert Spencer in his treatise on morality (_The Data of Ethics_)
also insists that laws of conduct, to be of general application, must
not require men to make too great sacrifices, as otherwise the best
teaching would remain a dead letter. He imagines, however, that in the
future the human race will be so much improved that moral conduct will
become instinctive, needing no compulsion. The English philosopher
presents a view of the future of the human race totally at variance
with the Kantian conception. Instead of human beings becoming filled
with a sense of duty opposed to their natural instincts, the world will
be peopled with men acting morally from inclination, so making the
world delightful.

The ideal is so far removed from existing conditions that the
possibility of its attainment is hardly worth considering. It is
probable that a world whose inhabitants had the feeling of sympathy
very highly developed would not be so delightful. For sympathy is
generally a reaction against evil. When evil disappears, sympathy would
be not merely useless, but annoying and harmful.

George Eliot in _Middlemarch_ describes a young woman enthusiastically
anxious to do good to her fellows. When she came to live in a village,
she made great plans to succour its poor. Her disillusion and annoyance
were great when she found that the villagers were quite comfortably
off, and had no need of her charity.

John Stuart Mill in his _Autobiography_ relates that when he was young
he dreamed of reforming society and making everyone happy. But when he
asked himself if the accomplishment of his beautiful ideas would make
him happy, he was compelled to answer “No!” and this discovery plunged
the young philosopher into a lamentable condition. He described himself
as quite overcome, all that supported him in life crumbling away. His
happiness could lie only in the constant pursuit of his object, and
the charm seemed broken, because if attainment were not to please him,
how could the means be of any interest to him? It seemed to him that
nothing was left to which he could dedicate his life.

As it is highly probable that with the advance of civilisation
the greatest evils of humanity will become lessened, and may even
disappear, the sacrifices to be made will also become less. Now that
there is a serum which protects against plague, there is no room for
the heroism of the doctors who used to incur the greatest danger in
fighting epidemics. Until lately doctors used to risk their life in
treating the throats of diphtheric patients. A young doctor who was
a friend of mine, of high ability and promise, died from diphtheria
contracted under these conditions. He met his death, in isolation from
his friends in case of infecting them, with the utmost heroism. Now
that the anti-diphtheric serum has been discovered, such heroism would
be unnecessary. The advance of science has removed the occasion of such
sacrifices.

It is now very long since there has been opportunity for the heroism
which steeled the hand of Abraham to sacrifice his only son to his
religion. Human sacrifice, based on the highest morality, has become
more and more rare, and will finally disappear. Rational morality,
although it may admire such conduct, has no use for it. So also, it
may foresee a time when men will be so highly developed that instead
of being delighted to take advantage of the sympathy of their fellows,
they will refuse it absolutely. Neither the Kantian idea of virtue,
doing good as a pure duty, nor that of Herbert Spencer, according to
which men have an instinctive need to help their fellows, will be
realised in the future. The ideal will rather be that of men who will
be self-sufficient and who will no longer permit others to do them
good.

ORTHOBIOSIS

Human nature must be modified according to an
ideal—Comparison with the modification of the
constitution of plants and of animals—Schlanstedt
rye—Burbank’s plants—The ideal of orthobiosis—The
immorality of ignorance—The place of hygiene in the
social life—The place of altruism in moral conduct—The
freedom of the theory of orthobiosis from metaphysics

As I have shown in _The Nature of Man_, the human constitution as it
exists to-day, being the result of a long evolution and containing a
large animal element, cannot furnish the basis of rational morality.
The conception which has come down from antiquity to modern times, of
a harmonious activity of all the organs, is no longer appropriate to
mankind. Organs which are in course of atrophy must not be reawakened,
and many natural characters which perhaps were useful in the case of
animals must be made to disappear in men.

Human nature, which, like the constitutions of other organisms, is
subject to evolution, must be modified according to a definite ideal.
Just as a gardener or stock raiser is not content with the existing
nature of the plants and animals with which he is occupied, but
modifies them to suit his purposes, so also the scientific philosopher
must not think of existing human nature as immutable, but must try to
modify it for the advantage of mankind.

As bread is the chief article in human food, attempts to improve
cereals have been made for a very long time. Rimpau made one of the
greatest steps in this direction when he introduced into cultivation a
variety of rye known as Schlanstedt rye, now fairly abundant in France
and Germany. Rimpau set himself the task of producing a variety with
the longest ears and containing many and heavy grains. Having conceived
his ideal, he began to seek out what was nearest to it in a very large
number of examples of rye. After patient and continued labour, using
careful selection and cross-fertilisation, Rimpau succeeded in making
the new variety, and so did a great service to mankind.

Burbank,[230] an American horticulturist, has recently gained a wide
reputation because of his improvements of useful plants. He has
produced a new kind of potato which has raised the value of potato
crops in the United States by about £3,500,000 per annum. Burbank
cultivated great numbers of fruit trees, flowers, and all kinds of
plants, with the object of increasing their utility. One of his objects
was to produce varieties which could resist dry conditions, which
reproduced rapidly and so forth. He has modified the nature of plants
to such an extent that he has cactus plants and brambles without
thorns. The succulent leaves of the former provide an excellent food
for cattle, whilst the absence of thorns in the latter makes their
pleasant fruit more suitable for gardens. Burbank has enormously
improved the production of stoneless plums, and has very much reduced
the price of many bulbs and lilies by increasing their productivity.

To obtain such results much knowledge and a long period of time
were necessary. To modify the nature of plants it was necessary to
understand them well. To frame the new ideal of the plant it was
necessary not only to have an exact conception of what was wanted, but
to find out if the qualities of the plants in question furnished any
hope of realising it.

The methods which have been successful in the case of plants and
animals must be much modified for application to the human race. In
the case of human beings the selection and cross-breeding which were
imposed upon rye and plum trees are not possible, but, at the same
time, the ideal of human nature, towards which mankind ought to press,
may be formed. In our opinion this ideal is orthobiosis, that is to
say, the development of the human life so that it passes through a long
period of old age in active and vigorous health, leading to the final
period in which there shall be present a sense of satiety of life,
and a wish for death. I do not think that the ideal should be that of
Herbert Spencer, a simple prolongation of human life. When the instinct
of death comes at a not very late period of life, there would be no
inconvenience in shortening the life, if death did not come soon after
the appearance of the instinct. Probably this would be the only case
where suicide was justified in the conception of orthobiosis.

The foregoing is the case of an action in conformity with the
ideal, but quite contrary to human nature as it is at present. A
similar contradiction appears in reproduction. Man came from animals
amongst which unlimited reproduction was an important factor in the
preservation of the species, as it allowed the species to survive under
all sorts of bad conditions, such as diseases, combats, attacks of
enemies, and changes of climate. Although man, according to the laws of
human nature, is capable of reproducing extremely rapidly, the ideal
of his happiness makes a restriction of this power necessary. Thus
orthobiosis, based upon knowledge of human nature, would set limits to
a function which is perhaps the most natural of all. The restriction
which is already partially adopted will come more and more into
operation as the struggle against diseases, the prolongation of human
life, and the suppression of war make progress. It will be one of the
chief means of diminishing the most brutal forms of the struggle for
existence, and of increasing moral conduct amongst mankind.

Just as Rimpau began to study the nature of plants before trying to
realise his ideal, so also varied and profound knowledge is the first
requisite for the ideal of moral conduct. It is necessary not only to
know the structure and function of the human organism, but to have
exact ideas on human life as it is in society. Scientific knowledge
is so indispensable for moral conduct that ignorance must be placed
among the most immoral acts. A mother who rears her child in defiance
of good hygiene, from want of knowledge, is acting immorally towards
her offspring, notwithstanding her feeling of sympathy. And this also
is true of a Government which remains in ignorance of the laws which
regulate human life and human society.

It must be well understood that I am not here thinking of written
knowledge, set down in treatises and volumes. Rimpau and Burbank went
outside manuals of botany to obtain their knowledge. Besides books,
wide ideas on the practice of life are required to direct aright the
conduct of men. A doctor who has just finished his studies at the
hospital, notwithstanding all his knowledge, is not yet sufficiently
trained to be a good practitioner. He must acquire the habit of
treating patients, and for this years are required. So also is it with
regard to the practical applications of the principles of morality.
The regulation of conduct requires profound knowledge both theoretical
and practical, and men selected to frame or to apply laws of morality
must have this double qualification. If the human race come to adopt
the principles of orthobiosis, a considerable change in the qualities
of men of different ages will follow. Old age will be postponed so
much that men of from sixty to seventy years of age will retain their
vigour, and will not require to ask assistance in the fashion now
necessary. On the other hand, young men of twenty-one years of age will
no longer be thought mature or ready to fulfil functions so difficult
as taking a share in public affairs. The view which I set forth in
_The Nature of Man_ regarding the danger which comes from the present
interference of young men in political affairs has since then been
confirmed in the most striking fashion.

It is easily intelligible that in the new conditions such modern idols
as universal suffrage, public opinion, and the _referendum_, in which
the ignorant masses are called on to decide questions which demand
varied and profound knowledge, will last no longer than the old idols.
The progress of human knowledge will bring about the replacement
of such institutions by others, in which applied morality will be
controlled by the really competent persons. I permit myself to suppose
that in these times, scientific training will be much more general than
it is just now, and that it will occupy the place which it deserves in
education and in life.

It is equally clear that if a mother is to act morally with regard to
her child, she must teach herself properly. In place of mythology and
literature, she must learn hygiene and all that relates to the rational
rearing of children. So, also, in the education of men, the study of
the exact sciences must occupy by far the most important place. Then
only will moral conduct and scientific knowledge begin to unite. An
ignorant mother will bring up a child very badly notwithstanding all
her good will and her affection. A doctor, however imbued with strong
sympathy for his patients, could do them much harm if he had not the
appropriate knowledge. Are not politicians open to the reproach from
the point of view of morality that very often through ignorance they
do the very worst evil in public administration? With the progress of
knowledge, moral conduct and useful conduct will become more and more
closely identified.

I have been reproached because in my system the health of the body
occupies too large a place. It cannot be otherwise, because health
certainly plays the chief part in existence. Notwithstanding his
pessimism, Schopenhauer was convinced that health was the greatest
treasure, a treasure before which everything else yielded. In many
religions care of the health is laid down amongst the chief duties.
Although many scientific men do not hold the opinion that circumcision
was ordained for hygienic reasons, it is certain that hygiene was
extremely important in the Jewish religion. It is only in Christianity,
which despises the human body, that hygiene is excluded from the
religious code, as in the words of Jesus:-

“Take no thought for your life, what ye shall eat, or what ye shall
drink; nor yet for your body, what ye shall put on. Is not the life
more than meat, and the body than raiment?” (Matt. vi., 25). As for
long ages hygiene was very imperfectly known, it is not surprising
that it played a small part in human affairs. Probably the objection
to the importance that I assign to it in orthobiosis is a relic from
the old order of things. Now, however, the situation is different.
Bacteriology has placed hygiene on a scientific foundation, so that the
latter is now one of the exact sciences. It has now become necessary
to give it the chief place in applied morality as it is the branch of
knowledge that teaches how men ought to live.

It has been objected that I have left no place for altruism in my
system.[231] Certainly I have tried to find an egoistic basis for
moral conduct, as I have shown above. I think, however, that the wish
to live according to the ideal of orthobiosis and to make others live
a normal life would be a powerful agency in improving social life, in
preventing mutual damage, and promoting mutual help. Such a motive,
within the reach of persons whose altruistic feelings are not specially
strong, must largely extend moral conduct amongst human beings, and
even although in future such manifestations of high morality as the
sacrifice of life and health will become wholly or nearly wholly
useless, I think that for the present there is still room for altruism.
The practical application of scientific knowledge already gained admits
much self-denial and good feeling. Struggle against prejudices of
all kinds and the development and diffusion of sound ideas require a
conduct very highly altruistic.

The fears of my opponents are still less justified when we reflect that
the feelings of sympathy and of cohesion must play a large part in the
business of helping the evolution of man towards the goal of normal
life.

Although our actual knowledge already provides a basis of rational
morality, it may be admitted that in the future, if science continues
its forward march, the rules of moral conduct will become still more
improved. There will be no ground for reproaching me for a blind faith
in the all-powerfulness of science. Much more trust can be given to
one who has faithfully carried out his promises, than to one who has
promised much and fulfilled nothing. Science has already justified the
hopes which have been placed in it. It has saved people from the most
terrible diseases, and has made life much easier. On the other hand,
religions, which demand an uncritical faith as the means of curing the
ills which afflict humanity, have not fulfilled their promises.

The reproach that I preach blind faith in the progress of science,
destined to replace religious faith, is unjust, because my faith
depends on a confidence that science has already deserved. Equally
unjust is the reproach that I have built my system on a partly
metaphysical principle. According to M. Parodi,[232] the hypothesis of
physiological old age and of natural death seem to “involve the idea
of a natural duration of human life, which, however, from accidental
reasons man does not complete at present. M. Metchnikoff repeatedly
uses the expression ‘normal cycle.’ Now do we not see here the
surreptitious repetition of the old teleological conception of nature,
although at first he so energetically disavowed it? It is the belief
that the species is a necessary reality, corresponding to a definite
type of its own, in fact a special design of nature; that nature,
to guide herself, had an ideal which circumstances could mistake or
degrade, but which had to be restored to its perfect form? Otherwise,
why does he insist that there must be a condition of perfect and stable
equilibrium between individual and environment? that there is a normal
cycle and that it must be possible to harmonise the disharmonies?”

I can show easily that all these objections rest upon a simple
misunderstanding. I have never conceived of the existence of any ideal
of nature or of the inevitable necessity of transforming disharmonies
to harmonies. I have no knowledge of the “designs” and “motives” of
nature; I have never taken my stand on metaphysical ground. I have not
the remotest idea if nature has any ideal and if the appearance of
man on the earth were a part of such an ideal. What I have spoken of
is the ideal of man corresponding to the need to ward off the great
evils of old age as it is now, and of death as we see it around us.
I have said, moreover, that human nature, that collection of complex
features of multiple origin, contains certain elements which may be
used to modify it according to our human ideal. I have done nothing
but what the horticulturist does when he finds in the nature of plants
elements which suggest to him to try and make new and improved races.
Just as the constitution of some plum trees contains elements which
make it possible to produce plums without stones which are pleasanter
to eat, so also in our own nature there exist characters which make
it possible to transform our disharmonious nature into a harmonious
one, in accordance with our ideal, and able to bring us happiness. I
have not the smallest idea what ideal nature may have on the subject
of plums, but I know very well that man has such designs and such
an ideal as form a point of departure for the transformation of the
nature of plums. Substitute man for the plum tree and you are at my
point of view. When I have spoken of the normal cycle of life or of
physiological old age, I have used the words normal and physiological
only in relation to our ideal of the human constitution. I might just
as well have said that a cactus without thorns is the normal cactus in
the conditions where it was desired to obtain a succulent plant useful
as food for cattle. The words “normal” and “physiological” seemed to
me more convenient than such a phrase as “in correspondence with human
ideals.”

I am so little convinced of the existence of any disposition of nature
to transform our ills into goods, and our disharmonies into harmonies,
that it would not surprise me if such an ideal were never reached. Even
in unmetaphysical circles it is said that nature has the intention of
preserving the species at the expense of the individual. The ground
of this is that the species survives the individual. On the other
hand, very many species have completely disappeared. Amongst these
species were animals very highly organised, such as some anthropoid
apes (_Dryopithecus_, etc.). As nature has not spared these, how can
we be certain that she is not ready to deal with the human race in the
same way. It is impossible for us to know the unknown, its plans and
motives. We must leave nature on one side and concern ourselves with
what is more congruous with our intelligence.

Our intelligence informs us that man is capable of much, and for
this reason we hope that he may be able to modify his own nature and
transform his disharmonies into harmonies. It is only human will that
can attain this ideal.

FOOTNOTES:

[1] Westergaard, _Mortalitaet u. Morbilitaet_, 2nd. Edit., 1901, pp.
653-655.

[2] The volume of the urine excreted in 24 hours (in January 1905)
was 500 c.c., with a density of 1019. There was no albumen or sugar.
The quantity, per litre, of urea was 11·50 gr., of chlorides 9 gr.,
of phosphates 1·15 gr. The sediment contained crystals of uric acid,
some pavement epithelium cells, a very few cells from the tubules, some
hyaline platelets and isolated white corpuscles.

[3] _Extinct Animals_, London, 1905, pp. 28, 29.

[4] _Rendiconti d. Accad. d. Lincei_, 1906, vol. xiv. pp. 351, 390.

[5] _Ueb. d. physiologische Degeneration bei Actinosphærium
eichhornii._ Jena, 1904.

[6] “Senescence and Rejuvenation,” _Journal of Physiology_, 1891, t.
xii.

[7] _Biologisches Centralblatt_, 1904, pp. 65, 81, 113.

[8] _Comptes rendus de l’Académie des sciences_, 23 April, 1900.

[9] _Revue générale des sciences_, 30 Dec., 1904, p. 1116.

[10] _Le Bulletin médical_, 1906, p. 721; _Le Cerveau sénile_, Lille,
1906, pp. 64-69.

[11] _Mémoires couronnés publiés par l’Académie royale de Belgique_,
Bruxelles, 1906.

[12] _Revue de Médecine_, Nov., 1906, p. 870.

[13] _Annales de l’Institut Pasteur_, Oct. 1906, p. 859.

[14] _Annales de l’Institut Pasteur_, 1900, vol. xiv. p. 113.

[15] _Eléments d’histologie humaine_, French translation, 1856, p. 222.

[16] _Leçons sur la physiologie du système nerveux_, 1866.

[17] _De la dégenérescence graisseuse des muscles chez des vieillards._
Paris, 1867.

[18] Demange, _Étude sur la vieillesse_, 1886, p. 118.

[19] _C. R. de la Société de Biologie_, 14 November, 1903.

[20] _Clinica medica_, 1905, _n._ 6.

[21] _Bulletins de la Société royale des sciences-medicales de
Bruxelles_, 1905, _n._ 4, p. 105.

[22] Sarbach, _Mittheilungen a. d. Grenzgeb. d. Med. u. Chir._, vol.
xv. 1906.

[23] _Verhandlungen d. Kongr. f. innere Medicin._ Wiesbaden, 1906, pp.
59, 98.

[24] _Archives de Neurologie_, 1886.

[25] Die Function d. Schilddrüse, _Virchow’s Festschrift_, vol. i.
1891, p. 369.

[26] Fuss, Der Greisenbogen, in _Virchow’s Archiv_, 1905, vol. clxxxii.
p. 407; S. Toufesco, _Sur le cristallin_, Paris, 1906.

[27] Edmond Fournier, _Stigmates dystrophiques de l’hérédosyphilis_,
Paris, 1898, p. 4.

[28] _Histoire naturelle générale et particulière_, vol. ii. Paris,
1749.

[29] _De la longévité humaine et de la quantité de vie sur le globe_,
Paris, 1855.

[30] _Ueber die Dauer des Lebens_, Jena, 1882, p. 4.

[31] Brehm, _La vie des animaux, Mammifères_, vol. ii. p. 623.

[32] _Leçons sur la physiologie et l’anatomie comparée_, vol. ix. 1870,
p. 446.

[33] _Archiv f. die gesammte Physiologie_, Bonn, 1903, vol. xcv. p. 606.

[34] _La Nature_, May 12, 1900, p. 378.

[35] Ashworth and Annandale, _Proceedings of the R. Society of
Edinburgh_, vol. xxv. part iv. 1904.

[36] _Bronn’s Klassen u. Ordnungen des Thierreichs_, vol. iii. p. 466.

[37] Weismann, _The Duration of Life_, in “Essays on Heredity” (English
translation), Oxford, 1889.

[38] Oustalet, “_La Longévité chez les Animaux vertébrés_,” _La
Nature_, May 12, 1900, p. 378.

[39] “_On the Comparative Ages to which Birds live_,” _The Ibis_, Jan.,
1899, vol. v. p. 19.

[40] J. Maumus, “Les cæcums des oiseaux,” _Annales des sciences
naturelles_, 902. See also P. Chalmers Mitchell, “On the Intestinal
Tract of Birds,” _Trans. Linnæan Soc. of London_, vol. viii. part 7,
1901.

[41] Weidersheim, _Elements of the Comparative Anatomy of Vertebrates_,
translated by W. Newton Parker, p. 236, 1886.

[42] _Elements of Comparative Anatomy_, English translation by F.
Jeffrey Bell, B.A., London, 1878, p. 562.

[43] _Virchow’s Archiv_, 1869, vol. xlviii. p. 151.

[44] P. Chalmers Mitchell, “On the Intestinal Tract of Mammals,”
_Trans. Zool. Soc. of London_, vol. xvii. part 5, 1905.

[45] _Travaux de la Société des médecins russes à Saint-Pétersbourg._
September-October, 1905, p. 18 (in Russian).

[46] _Virchow’s Archiv_, 1874, vol. lix, p. 161.

[47] _Zeitschrift f. klinische. Medicin_, 1887, vol. xii.

[48] _Mittheilungen a. d. Grenzgebieten d. Medicin u. Chirurgie_, 1905,
vol. xiv.

[49] Aldor, _Centralblatt f. innere Medicin_, 1898, p. 161.

[50] _L’année biologique_, 7th year, 1902. Paris, 1903, p. 590.

[51] _Gazette des Hôpitaux_, 1904, p. 715.

[52] _Accidents dus à la Constipation pendant la Grossesse,
l’Accouchement et les Suites des Couches._ Thèse, Paris, 1902, p. 32.

[53] _Comptes rendus de l’Académie des Sciences_, Paris, 1905, 10 July,
p. 136.

[54] _Archiv. f. klinische Chirurgie_, 1901, vol. lxiii, p. 773.

[55] Kolle u. Wassermann, _Handb. d. pathogenen Mikro-organismen_, vol.
ii, 1903, p. 678.

[56] Ficker, in the _Archiv. für Hygiene_, vol. lii, p. 179, has
recently published the results of an investigation into this.

[57] Quoted by Frédericq et Nuel, _Eléments de physiologie humaine_,
4th edition, 1899, p. 256.

[58] Quoted by Frédericq et Nuel, _op. cit._

[59] _L’aviculture_ (a fortnightly Russian journal), Oct. 1st, 1904,
No. 19, p. 3.

[60] _Country Life_, 1905.

[61] Quoted by Ebstein, _Die Kunst d. mensch. Leben zu verlängern_,
1891.

[62] _Op. cit._, p. 12.

[63] _Annuaire statistique de la ville de Paris_, 23rd year, 1904, p.
164-171.

[64] Ornstein, Virchow’s _Archiv._, 1891, vol. cxxv, p. 408.

[65] Ebstein, _op. cit._, p. 70.

[66] Lejoncourt, _Galerie des centenaires_, Paris, 1842, p. 96-98.

[67] Lejoncourt, _op. cit._, p. 101.

[68] _Researches into the Physical History of Mankind_, 1836, vol. i,
p. 1157.

[69] I owe to the kindness of M. Chemin a memoir in which he has
brought together the ancient and new records on the centenarians of all
countries up to the end of the nineteenth century. M. Chemin was unable
to find a publisher, but has given me his manuscript, extending to 182
pages.

[70] _Ueber die Kunst d. Verlängerung d. mensch. Lebens_, Bonn, 1890,
p. 23.

[71] _Physiologie générale_, 1900, p. 381.

[72] _Tableaux de la nature_ (French translation), 1808, vol. ii, p.
109.

[73] Webb and Berthelot, _Histoire naturelle des îles Canaries_, 1839,
vol. i, part 2, pp. 97-98.

[74] _Bibliothèque universelle de Genève_, 1839, vol. xlvi, p. 387.

[75] _Ibid._, p. 392.

[76] _Bibliothèque universelle de Genève_, vol. xlvii, p. 49.

[77] _Entstehung u. Begriff d. naturhistorischen Art_, 2nd edit.,
Munich, 1865, p. 37.

[78] Griesebach, _Die Vegetation der Erde_.

[79] Batalin, _Acta Horti Petropolitani_, vol. xi, no. 6, 1890, p. 289.

[80] I am indebted to Prof. Hugo de Vries for this and other instances
of the prolongation of life in plants.

[81] Engler’s _Botanische Jahrbücher_, Leipzig, 1882, vol. ii, p. 51.

[82] _Organographie der Pflanzen_, Iéna, 1898-1901.

[83] _Bulletin du jardin botanique de Bruxelles_, vol. i, no. 6, 1905.

[84] Hugo de Vries, _Jahrbücher für wissensch. Botanik_, 1890, vol.
xxii, p. 52.

[85] _Annales de l’Institut Pasteur_, 1902, p. 71.

[86] Duclaux, _Microbiologie_, vol. iii, 1900, p. 460.

[87] _Archiv. für Anatomie und Physiologie_, 1864.

[88] _Archives de Zoologie expérimentale_, 1901, vol. ix, p. 81.

[89] Observations of Dr. Speyer, quoted by Weismann.

[90] See _The Nature of Man_.

[91] _Étude clinique sur la vieillesse_, Paris, 1886, p. 145.

[92] _Revue scientifique_, 1877, p. 1173.

[93] _Revue scientifique_, 1887, 2nd part, p. 105.

[94] Gabriel Bertrand, _Annales de l’Institut Pasteur_, 1904, p. 672.

[95] _Therapeutische Monatshefte_, 1904, p. 193.

[96] _Münchener medicinische Wochenschrift_, 1904, No. 1;
_Verhandlungen der physiologischen Gesellschaft zu Berlin_, Dec. 5th,
1904.

[97] _Archives des sciences physiques et naturelles_, Geneva, March,
1905, vol. xvii; _Archives de physiologie_, vol. iv, p. 245.

[98] Laveran and Mesnil, _Trypanosomes et Trypanosomiases_, Paris,
1904, p. 328.

[99] Paris, 1834, 4th edition, vol. ii, p. 118.

[100] _Revue de métaphysique et de morale_, March, 1904.

[101] _Année biologique_, vol. vii, p. 595.

[102] _Revue occidentale_, July 1st, 1904, vol. xxx, p. 87.

[103] Egger, “_Le moi des mourants_,” Revue philosophique, 1896, i, p.
27.

[104] _Ibid._, pp. 303-307; v. also _Bulletin de l’Institut général
phycholog._, 1903, p. 29.

[105] Cicero, _Tusculanes_, chap, xxviii.

[106] Rapport de M. Bienvenu-Martin à la Chambre des députés, Paris,
1903.

[107] _L’Art de prolonger la vie humaine_ (French translation),
Lausanne, 1809, p. 5.

[108] A. Réville, _Histoire des religions_, vol. iii, Paris, 1889, p.
428.

[109] A. Réville, _loc. cit._, p. 455.

[110] _Comptes rendus de la Societé de Biologie_, 1899, p. 415.

[111] _Deutsche medicin. Wochenschrift_, 1891, p. 1027.

[112] _Die physiologisch-chemisch. Grundlagen d. Spermintheorie_,
Berlin, 1898.

[113] _British Medical Journal_, 1904; _Deutsche Mediz. Wochenschr._,
1904, Nos. 18-21.

[114] _Die Lehre von d. Mortalitaet u. Morbilitaet_, 2nd edition, Jena,
1901.

[115] _Medizinische Klinik_, 1905, No. 22.

[116] _Die experimentelle Syphilisforschung_, Berlin, 1906, p. 82.

[117] _Annales de l’Institut Pasteur_, 1900, pp. 369-413.

[118] _Les sérums hemolytiques_, Lyon, 1903.

[119] According to a recent publication of M. Ellenberger (_Archiv. f.
Anatomie u. Physiologie, Physiologische Abtheilung_, 1906, p. 139),
the cæca of the horse, pig and rabbit, play an active part in the
digestion of vegetable matter, which is rich in cellulose. At the end
of his treatise, Ellenberger insists that the vermiform appendix of the
cæcum is not a rudimentary organ. The reason why the appendix can be
removed in the case of man without disturbance to the functions of the
body, is that this work can be performed by the Peyer’s patches of the
intestine. The existence of the appendix is not necessary to the normal
processes of the body, and is a real danger to health and sometimes to
life. Comparative study of the cæca in birds shows that these organs
are in process of degeneration.

[120] _Archiv. für experimentelle Pathologie_, vol. xxviii, p. 311.

[121] _Sixième Congrès de Chirurgie_, Paris, 1903, p. 86.

[122] _Leçons sur les auto-intoxications_, Paris, 1886.

[123] _Zeitschrift für Hygiene_, 1892, vol. xii, p. 88.

[124] _Zeitschrift für klinische Medicin_, 1903, vol. xlviii, p. 491.

[125] There is a summary of this question in Gerhardt’s work on
intestinal putrefaction, in _Ergebnisse der Physiologie_, 3rd year,
section 1, Wiesbaden, 1904, pp. 107-154.

[126] _The A B C of our Nutrition_, New York, 1903; Dr. Regnault, Nov.
1, “L’art de manger,” _La Revue_, 1906, p. 92.

[127] _Zeitschr. f. diatetische u. physikal. Therapie_, t. viii, 1904,
1905.

[128] _Du Cap au lac Nyassa_, Paris, 1897, pp. 291-294.

[129] Gaffky and Paak, in _Arbeiten d. k. Gesundheitsamtes_, vol. vi,
1890.

[130] _Annales de l’Institut Pasteur_, 1903.

[131] Cormouls-Houlès, _Vingt-sept années d’agriculture pratique_,
Paris, 1899, pp. 57-58.

[132] _British Medical Journal_, 1897, Dec. 25th, p. 1898.

[133] _Comptes rendus de la Soc. de Biologie_, 1906, March 17th.

[134] Dr. Combe, _L’auto intoxication intestinale_, Paris, 1906. This
valuable work contains much useful information on the subject.

[135] Grundzach, _Zeitschrift für klinische Medezin_, 1893, p. 70;
Schmitz, _Zeitschrift für physiologische Chemie_, 1894, vol. xix, p.
401; Singer, _Therapeutische Monatshefte_, 1901, p. 441.

[136] _Journal für praktische Chemie_, 1882, vol. xxvi, p. 43.

[137] _Archiv. für experimentelle Pathologie_, 1883, vol. xvii, p. 442.

[138] In the English authorised version as in the translation of
Osterwald the word “butter” is used in place of “soured milk.”
Professor Metchnikoff follows the translation given by Ebstein in his
work on the Medicine of the Old Testament.

[139] _Presse médicale_, 1904, p. 619.

[140] “An authentic narrative of the loss of the American brig
_Commerce_ wrecked on the western coast of Africa in the month of
August, 1815, with an account of the sufferings of the surviving
officers and crew, who were enslaved by the wandering Arabs on the
African desert or Zaharah; and observations historical, geographical,
etc.” by James Riley. Hartford, S. Andrus and Son, 1854.

[141] _Arbeiten a. d. k. Gesundheitsamte_, 1889, vol. v, pp. 297-304.

[142] See Grasberger and Schattenfroh, _Archiv. für Hygiene_, 1902,
vol. xlii, p. 246.

[143] _Annales de l’Institut Pasteur_, 1902, p. 65.

[144] _Revue médicale de la Suisse romande_, 1905, p. 716.

[145] _Comptes rendus de la Soc. Biologique_, March 17th, 1906.

[146] _Annales de l’Institut Pasteur_, 1906, p. 977.

[147] Soured milk can be taken at any time of the day, with or in
between meals.

[148] _Jahrbuch für Kinderheilkunde, N. F. 12 Ergænsungsheft_, 1900.

[149] _Annales de l’Institut Pasteur_, 1905, p. 295; _Tribune
médicale_, Feb. 24th, 1906.

[150] _La nature humaine et la philosophie optimiste_, Paris, 1904.

[151] _Archiv. f. Anat. u. Physiol., Anatom. Abtheil_, 1903, p. 205.

[152] _L’univers et la vie_, p. 592.

[153] Huxley, _Man’s Place in Nature_. Collected Essays, vol. vii, p.
54.

[154] _Ibid._, p. 60.

[155] _Ibid._, p. 62.

[156] _Ibid._, p. 67.

[157] Ménégaux, _Les Mammifères_, p. 24.

[158] Darwin, _Expression of the Emotions in Man and Animals_, 1873, p.
67.

[159] _Biologisches Centralblatt_, 1904, p. 475.

[160] J. de Fontenelle, _Nouveau manuel complet des nageurs_, Paris,
1837, p. 2.

[161] _La natation et les bains_, Paris, 1887.

[162] Quoted by M. Pitres in _Leçons cliniques sur l’hystérie_, 1891,
vol. i.

[163] Bourneville et Regnard, _Iconographie photographique de la
Salpétrière_, 1879-1880, vol. iii, p. 50.

[164] Stéphanie Feinkind, _Du somnambulisme dit naturel_, Paris, 1893,
p. 55.

[165] _Dictionnaire des sciences médicales_, 1821, vol. lii, p. 119.

[166] _Du Sommeil non naturel_, Paris, 1886.

[167] _Conférence faite à la Société de l’Internat_, June 28th, 1906.

[168] _The Crowd: a Study of the Popular Mind._ English translation,
London, 1896.

[169] _Souvenirs d’enfance de S. Kowalevsky_, 1895, pp. 301-311.

[170] W. Herzberg, _Sozialdemokratie und Anarchismus_, 1906, p. 17.

[171] _Le problème agraire_, 1905, p. 147.

[172] “The Coming Slavery” in _Man versus the State_, 1888, p. 18.

[173] _Human, too Human._ French translation, 1899, pp. 405-407. A
German critic has reproached me for my ignorance of Nietzsche’s works.
I have read several of them, but the mixture of genius and madness in
them makes them difficult to use. In this connection Moebius’ volume,
_Ueber das Pathologische bei Nietzsche_ (Wiesbaden, 1902), is of
interest.

[174] Quoted by Oldenberg, _Le Bouddha_, French translation, Paris,
1894, p. 214.

[175] P. Régnaud, “Le pessimisme brahmanique,” in _Annales du Musée
Guimet_, 1880, vol. i, pp. 110-111.

[176] Guyau, _La Morale d’Epicure_, 4th edition, 1904, p. 116.

[177] _Ad Marciam_, chap. x.

[178] _Poésies et œuvres morales_, by Leopardi. Translated into
French 1880, p. 49.

[179] These facts are taken from Westergaard, 2nd edit., 1901, p. 649.

[180] Dieudonné, _Archiv für Kulturgeschichte_, 1903, vol. i, p. 357.

[181] Kowalevsky, _Studien zur Psychologie des Pessimismus_, Wiesbaden,
1904.

[182] _Medicinische Klinik_, 1906, n. 25 and 26.

[183] _Der Werth des Lebens._

[184] _Ueber Schopenhauer_, Leipzig, 1899.

[185] Moebius, _Goethe_, vol. i, Leipzig, 1903.

[186] V. Kunz, “Zur Blindenphysiologie,” _Wiener medicin.
Wochenschrift_, 1902, No. 21.

[187] _Physiologie de la Lecture et de l’Écriture_, Paris, 1905.

[188] _Entre aveugles_, Paris, 1903.

[189] _Der Blindenfreund_, Feb. 15th, 1906.

[190] _Critical and Miscellaneous Essays_, vol. i, pp. 164-5, in the
Essay on _Goethe_.

[191] _Briefwechsel zwischen Goethe und Zelter._ Letter of Dec. 3, 1812.

[192] Quoted in Moebius’ _Goethe_, vol. ii, p. 80.

[193] _The Fifth Roman Elegy_, Blaze’s French translation, 1873 p. 186.
Some of Goethe’s biographers, and amongst them G. H. Lewes, maintain
that these lines relate to Christine, Goethe’s wife. This is erroneous;
they refer to Faustine (see Bielschowsky, i, p. 517).

[194] Moebius’ _Goethe_, vol. ii, pp. 84-87.

[195] Moebius’ _Goethe_, vol. ii, pp. 84-87.

[196] Quoted by Bode _in Goethe’s Lebenskunst_, Berlin, 1905, p. 59.

[197] _Ueber die Wirkungen d. Castration_, Halle, 1903, p. 82.

[198] _Comptes rendus de la Société de Biologie_, 1889, p. 420.

[199] The word _Samen_ of the original is the expression of the
alchemists for the “principle of life.”

[200] Erich Schmidt, Goethe’s _Faust in ursprünglicher Gestalt_, 6th
edit., Weimar, 1905, p. 1.

[201] _Faust_, Bayard Taylor’s translation. London: Warne & Co., pp.
20-21.

[202] _Op. cit._, p. 32.

[203] _Op. cit._, pp. 33, 34.

[204] Details of this will be found in Kuno Fischer’s _Goethe’s Faust_,
pp. 328-330.

[205] _Op. cit._, pg. 36.

[206] _Op. cit._, pg. 45.

[207] _Op. cit._, p. 46.

[208] _Op. cit._, p. 46.

[209] _Op. cit._, p. 71.

[210] _Op. cit._, p. 51.

[211] _Op. cit._, p. 151.

[212] _Op. cit._, p. 203.

[213] _Op. cit._, p. 205.

[214] _Op. cit._, p. 230.

[215] _Op. cit._, p. 231.

[216] _Op. cit._, p. 284.

[217] _Op. cit._, p. 287.

[218] _Op. cit._, p 298.

[219] _Op. cit._, p. 305.

[220] _Op. cit._, p. 309.

[221] _Op. cit._, p. 313.

[222] _Op. cit._, p. 351.

[223] _Op. cit._, pp. 354-355.

[224] _Op. cit._, p. 365.

[225] _Op. cit._, p. 370.

[226] _V. Tribune médicale_, 1906, p. 449.

[227] _La Revue_, Nov. 15th and Dec. 1st.

[228] _Essais de Philosophie critique_, Paris, 1864.

[229] _System der Ethik_, 7th and 8th editions, vol. i, p. 199. Berlin
1906.

[230] De Vries, in _Biologisches Centralblatt_, 1906, Sept. 1st, p. 609.

[231] Dr. Grasset, “La fin de la vie” in the _Revue de philosophie_,
Aug. 1st, 1903.

[232] “Morale et biologie,” _Revue philosophique_, 1904, vol. lviii, p.
125.

INDEX

Abelard, 273

Abraham, use of soured milk, 171

Ackermann, Mde., 237

_Actinosphærium_, degeneration in, 14

Adanson, on age of Baobab-tree, 98

Adrenaline, effect of, 121

Agave, duration of life of, 100

Aged, treatment of in uncivilised countries, 1, 2

Alcohol and longevity, 91, 92

Algeria, ostriches at, 76, 78, 79

Altruism, 331

Ambard, Dr., on Mde. Robineau, 7

Anæmia, of brain, and sleep, 122
use of serums in, 149

André, M., use of serums in anæmia, 149

Anger, 321

Annandale, Nelson, on age of anemones, 48

Annuals, change to biennials or perennials, 100
death of, 102

Antelopes, excreta of, 66

Anthropoids, mental characters of, 191 _et seq._

Antiseptics, use of, in intestinal putrefaction, 156

Ants, 220, 221

Apes, anthropoid, mental characters of, 191 _et seq._
relationship to man, 184, 185

Arabs, use of milk by, 174

Aristotle, 132

Arteries, sclerosis of, in the aged, 31

Ascidians, social, 219

Ashworth, Mr., on age of anemones, 48

Atheroma, in the aged, 30

Atrophy, of cells, 26
of muscles, 28

Auditory apparatus, rudimentary organism, 188

Augsburg, elixir of life, 138

Auto-intoxication, from intestinal putrefaction, 69
in plants, 107
sleep, due to, 120

Babinsky, Dr., hysteria a relic from apes, 209

Balkan States, centenarians frequent in, 90

Baobab-tree, age of, 98

Barth, Dr., definition of somnambulism, 206

Batrachia, longevity of, 50

Bats, intestinal flora of, 80, 81

Bees, 49, 220, 226

Beetroot, perennial variety of, 100

Belgium, old age pensions, 4

Bélonovsky, M., on serums in anæmia, 148

Bélonowsky, Dr., on Bulgarian bacillus, 170

Berthelot, on dragon-tree of Orotava, 96

Bertrand, M. G., on sorbose fermentation, 106

Bertrand and Weisweiler, on _Bacillus bulgaris_, 179

Besredka, M., on blood serums, 148, 149

Bielschowsky, biographer of Goethe, 269

Blanchard, E., on age of carp, 50

Birds, intestinal flora of, 76, 79
longevity of, 52

Blindness, 248, 257

Bloch, Dr. I., on Schopenhauer, 247

Blood-vessels, hardening of, in the old, 31

Bodio, on infant mortality, 85

Boerhave, on gerokomy, 136

Bones, degeneration of, 29, 30

Bordet, M. J. M., on serums, 148

Botulism, poison of, 70, 82

Bouchard, M., on disinfection of intestines, 156

Bouchet, M., on constipation after parturition, 68

Bourneville, M., on effects of extirpation of thyroid, 34

Boveri, M., produced atherana by nicotine, 32

Bone, marrow, in old age, 37

_Botryllus_, 219

Boutroux, definition of morality, 303

Bradyfagy, 159

Brain, anæmia of, as cause of sleep, 122

Brehm, on age of cattle, 55

Brettes, criticism of “rudimentary organs,” 186

Bricon, M., on effects of extirpation of thyroid, 34

Brigand, Calabrian, fear of death, 194, 195

Brillat-Savarin, quotation from, 126

Brown-Séquard, specific for long life, 139, 277

Brudzinsky, M., on use of lactic microbes, 181

Buddha, on pessimism, 233, 247

Buehler, Dr., on cause of old age, 16

Buffon, on duration of life, 40, 50

Bulgarian bacillus, 178, 179, 180, 181, 182

Bunge, on relation between growth and longevity, 42

Burbank, American horticulturist, 326, 328

Butterflies, longevity of, 57

Bütschli, O., on life of cells, 15

Byron, 239, 247, 295

Cachexia, after extirpation of thyroid gland, 34

Caeca, of vertebrates, 60 _et seq._

Cagliostro, elixir of life, 138

Calomel, as an intestinal antiseptic, 158
and syphilis, 146

Camphor, as an intestinal antiseptic, 156

Canary Islands, 96

Cancalon, Dr., on instinct of death, 128, 129

Cancer, and cleanliness, 144

Candolle, A. de, on cypresses of Mexico, 98
on age of trees, 99

Cantacuzène, M., on blood serums, 148

Capital punishment, 305

Carlyle, on “Werther,” 265

Castration, effects of, 272

Cats, longevity of, 56

Cattle, longevity of, 55

Celibacy, and education of women, 224

Cell reproduction, rate of, 16

Centenarians, 4, 5, 86, 88, 89, 175, 176

Charcot, on sterilised food, 162, 163
on hysteria, 202

Charron, M., on putrefactive poisons, 69

Chemin, M., on centenarians, 88, 89

Chimpanzee, 185, 192, 193

China, Emperor Chi-Hoang-Ti and immortality, 137

Chopin, a degenerate, 134

Christian morality, 321, 330

Chromophags, action of, 25

Claparède, E., on theory of sleep, 123, 124, 125

Cleanliness, and increase of life, 144

Clergymen, increasing duration of life of, 142

Coffee and longevity, 92

Cohausen, on gerokomy, 137

Cohendy, Dr. M., on Bulgarian bacillus, 178
on intestinal flora, 78, 79
on intestinal putrefaction, 168
on thymol as a disinfectant, 157

Collectivism, 228

Colon, absorption in, 64

Constipation, evil results of, 67, 68, 69

Cooking, effect of, on microbes in food, 162

Copenhagen, suicide in, 3

Coral polyps, 216

Cornaro, 91

Cossacks, and biennial rye, 100

Cretinism, compared with senility, 32

Crœsus, 197

Cryptogams, life of, 99

Cursorial birds, intestinal flora of, 76

Cypress, age of, 98

Czerny, M., on absorption in colon, 64
on cancer, 144

D’Alton, and Goethe, 280

Dalyell, old anemone of, 48

Dana, on _monstrilla_, 115

Darwin, on fear, 195

David, King, 136

Death, instinct of, 128, 129
natural, 94, 109, 119
sensations at approach of, 126, 127, 130

Debreuil, Ch., on defecation in rheas, 76
on excreta of antelopes, 66

Degenerates, famous, 134

Delage, Yves, criticism of instinct of death, 128
on function of large intestines, 65, 66

Demange, M., on old age, 119

Denmark, suicide in, 3, 237

Descent of man, 184

Despotism, and socialism, 230

de Vries, H., on duration of life of plants, 104
on prolongation of life of plants, 100
on natural death in plants, 101

Diet and longevity, 46

Digestive system and senility, 59

_Diplogaster_, mother killed by larvæ, 111

Diphtheria, 323

Disease, and shortening of life, 145 _et seq._

Doctors, lady, 225

Dodo, 213

Dogs, longevity of, 55

Dostoiewsky, quotation from, 2

Doyen, M., operation on double monsters, 216

Dragon-tree, of Orotava, 96, 97, 98

Drakenberg, age of, 87

Drunkenness, and morality, 317

_Dryopithecus_, 334

Ducks, old, 11

Duering, on pessimism, 248

Durand-Fardel, M., on atheroma, 30

Duration of life, in animals, 39 _et seq._, 133

Eagles, intestinal flora of, 82

Ecclesiastes, quotation from, 233

Eckermann, narrative of Goethe’s last years, 271, 274, 279

Egoism, 227, 306, 331

Egyptian milk, 105

Eimer, Th., on intestines of bats &c., 62, 63

Einhorn, Dr., on bradyfagy, 159

_Elective Affinities_, Goethe’s, 273

Elephants, 9, 54, 83, 197

Eliot, George, 322

_Elixir vitæ_, 138

Ellenberger, on digestion in horse, 78

Enriquez, on infusoria, 13

Ephemeridæ, duration of life of, 113, 118

Epicureans, 309

Epiphyses of bones, as giving period of growth, 40

Ermenghem, van, on botulism, 70

Errera, Dr., on cause of sleep, 121

_Eudoxia_, 218

Ewald, on absorption in colon, 64

Exhaustion, as cause of plant death, 104, 107

Extinction of animals, 213

Eye, in old age, 36

Fatigue, Weichardt on cause of, 123

“_Faust_” and Goethe, 283 _et seq._

Favorsky, Dr., on botulism, 82

Fear, analysis of, 194

Fecundity and duration of life, 43, 44, 45, 57, 58

Feinkind, case of somnambulism quoted from, 204

Femininist movement, 224

Fermentation, cause of, 105

Fertility and longevity, 44, 45

Fish, longevity of, 50

Flamans, M., 5

Fletcher, on chewing, 159

Flora, of intestines, poisonous effect of, 70, 73 _et seq._, 151
_et seq._

Flourens, on duration of life, 40, 84

Foà, on use of soured milk in Africa, 172

Food, evil effects of putrefaction in, 163

Fouard, M., on soured milk, 180

Fürbbinger, on Brown-Séquard’s emulsions, 139

Gautier, A., on leucomaines, 121

Gegenbaur, on intestinal tract, 60, 61

Genius and sexual power, 272

Gerokomy, 136

Gessner, on age of pike, 50

Gestation and longevity, 42

Giacomini, on Harderian gland, 189

Gibbons, 192, 198

Goebel, on duration of life of prothalli, 101, 102

Goethe, 260-300, 305

“Goose-skin,” 196

Gorilla, strength of, 192

Griesbach, on sense of touch in blind, 257

Grigoroff, on Bulgarian yahourth, 175, 178

Grindon, on age of sheep, 55

Guinon, Dr., on a case of hysteria, 203

Gurney, J. H., on longevity of birds, 51, 79

Haeckel, on medical selection, 134

Haffkine, M., 112

Hair, 17, 18

_Halictus_, a solitary bee, 226

Haller, on human longevity, 84, 132

_Hamlet_, quotation from, 239

Hannibal, his elephants swim the Rhone, 197

Harderian gland, 189

Hartmann, 235, 241

Harvey, on Parr, 87

Hayem, Prof., on use of lactic acid, 169, 173

Heart, diseases of, and syphilis, 145, 146

Hegesias, and suicide, 234

Heile, on absorption in colon, 64

Heim, on microbes in milk, 176

Heim, Prof., on Alpine accidents, 130

Heine, 236, 240

Hermippus, and gerokomy, 137

Herter, Dr., experiments on lactic acid in dogs, 167

Hertwig, R., on _Actinosphærium_, 14

Hildebrand, on duration of life of plants, 101, 102

Hippocrates, 132

Hofmeister, on digestion in horse, 74

Honey-ant, 222

Horse, cæcum, 62
digestion, 74
use of serum, 147

Horsley, Sir V., on effects of extirpation of thyroid, 34

Horst, on a somnambulistic soldier, 203

Hufeland, quotation from “Macrobiotique,” 137

Hugo, V., and sexuality, 277

Humboldt, on dragon-tree of Orotava, 96
on longevity of parrots, 52

Hunger, compared with sleep, 125

Huxley, on character of Orang, 193

Hygiene, and old age, 141, 142, 143

Hypnotism, of a crowd on individuals, 210

Hysteria, analysis of, 200 _et seq._
in monkeys, 208

Ibsen, and sexuality, 277

Idleness, 316

Immortality, Chinese beverage for, 137, 138

Incubation, duration of, compared with longevity, 41, 42

India, government of, and age of elephants, 54

Individualism, 316

Individuality, 212 _et seq._

Infusoria, death of, 95
senescence of, 13

Insects, ages of, 49
social, 220 _et seq._

Instinct, of death, 128, 129
maternal, 319, 320, 329
social, 306

Intestine, large, 59, 65, 67, 151

Intuitive theory of morality, 305

Jacobson, organ of, 187

Javal, Dr., on characters of the blind, 257, 259

Jenner, effect of vaccination on mortality rate, 144

Josué, M., artificial production of atheroma, 32

Jousset, Dr., on difference between man and apes, 184

Kant, 309, 310

Kautsky, on socialism, 229, 230

Kentigern, age of, 87

Kephir, 171, 172, 173

Khoury, M., on ferment of Egyptian milk, 105

Kocher, Dr., on effects of extirpation of thyroid gland, 33

Kocher, Prof., case of removal of large intestine, 152, 153

Kölliker, on degeneration of muscles, 27

Koppenfels, on character of gorilla, 194

Koumiss, 172

Kowalevsky, Sophie, 225

Kowalevsky, analysis of pessimism, 241, 255

Kukula, experiments on intestinal poisons, 69, 70

Kwass, 166

Lactic bacilli, and putrefaction in intestine, 168

Laignel-Lavastine, M., criticism of neuronophagy, 20

Lankester, Sir E. Ray, on longevity, 12, 56

Lao-Tsé, and immortality, 137

Laud, Archbishop, old tortoise of, 51

Lautschenberger, on absorption in colon, 64

Lavater, Goethe’s letter to, 268

Laws aiding the aged, 3, 4

“Leben,” Egyptian, 105, 171, 177, 178

Le Bon, G., on hysteria in crowds, 209

Lenau, M., 236

Lenthéric, on elephants swimming, 197

Leopardi, G., pessimistic poet, 235, 236, 247

Le Play, M., on putrefactive poisons, 69

Léri, M., on senile brain, 20

Lermontoff, 236

Leucomaines, as cause of sleep, 121

Levaillant, on longevity of parrots, 52

Lewes, G. H., on Goethe, 273, 290, 292, 298

Lexis, on duration of human life, 85

Life, duration of, in animals, 39 _et seq._

Life, prolongation of human, 132, _et seq._
“sense” of, 260

Lima, Dr., on use of soured milk in Africa, 172, 174

Lloyd, M., old anemone of, 47

Loewenberg, Dr., on Mde. Robineau, 7

London Zoological Gardens, 51, 81

Longevity, in animal kingdom, 47 _et seq._
human, 84 _et seq._
rules for, 141
in sexes, 44
theories of, 39

Lorand, Dr., on ductless glands, 32

Love, Goethe and, 272

Luxury, 321

Macfadyen, Nencki and Mde. Sieber, on digestion, 153, 161

Macrophags, 25, 147

Mailaender, 235, 255

Malaquin, M., on _Monstrilla_, 116, 117

Male rotifers, death of, 114, 115

Malthus, theory of, 214

Mammals, longevity of, 53

Mammary glands, in males, 186

Man, compared with apes, 184, 185
natural death of, 119 _et seq._
longevity of, 84 _et seq._

Manouélian, M., on neuronophagy, 21, 22

Marinesco, M., on neuronophogs, 19

Marrow of the bones, in old age, 37

_Marsiliaceæ_, duration of life of prothallus, 99

Martin, on Gibbons, 192

Massart, on cause of death in plants, 102, 109

Massol, Prof., 178

Mastication, and intestinal putrefaction, 160

Matchinsky, M., on atrophy of ovary, 26

Maternal instinct, 319, 320

Mauclaire, M., operations on large intestine, 153, 154, 155

Maumus, M., on digestion in cæca, 61

Mauritius, giant tortoise from, 12

Maupas, M., on infusoria, 13

Maya, 178

Mayers, on Chinese elixir, 138

Meconium, appearance of microbes in, 161

Medical selection, 134

Mesnet and Mottet, Drs., cases of hysteria, 203

Mice, duration of life, 41, 43, 56

Michaelis, on muscles of monkeys, 185

Microbes, as cause of senility, 73
in food, 162, 163
passage through intestinal walls, 71

_Middlemarch_, G. Eliot’s, 322

Milk, importance of boiling, 177, 178
microbes of disease in, 177
putrefaction and fermentation of, 167
use of soured milk, 181, 182

Mill, J. S., 323

Milne-Edwards, H., on laws of duration of life, 42

Minot, Prof., on cause of old age, 16

Moa, 213

Moebius, on Goethe, 271
on Schopenhauer, 255

Molluscs, ages of, 48

Mongols, hair in old, 17

Monkeys, longevity of, 83

Monsters, double, 216

_Monstrilla_, life-history of, 115, 116, 117

Montefiore, Sir M., 91

Morality, Christian, 321
definitions of, 303
Kantian, 309, 310, 311, 312
science and, 301 _et seq._

Mortality rates of old persons, 142, 143

Moses, use of soured milk, 171

Mosso, on fear, 194, 196

Muscles, degeneration of, 9, 26, 27

Myxomycetes, 215

Naegeli, on age of trees, 99

Nails, growth of, in the old, 18

Naphthaline, as an intestinal antiseptic, 156

Nature, human, 325

Nausenne, Mde., cause of longevity, 141

Negroes, longevity of, 88

Neisser, Prof., on protection against syphilis, 146

Nematodes, death of, 111

_Nemertines_, life-history of _Pilidium_ of, 109 _et seq._

Nencki and Sieber, on digestion, 153, 161, 169

Neuronophags, 19, 20, 21, 22, 23, 24

Nicotine, use of in experimental production of atheroma, 32

Nietzsche, criticism of Socialism, 230

Nogueira, M., on use of soured milk in Africa, 172, 174

Obstacles, sense of, 258

Old age, Goethe and, 279 _et seq._

Olympian, Goethe as an, 269

Optimism, foundation of, 256
Goethe’s transformation to, 269, 270 _et seq._

Orang-outan, 185, 193

Orotava, dragon-tree of, 96

Orstein, Dr., on centenarians in Greece, 90

Orthobiosis, 212, 325 _et seq._

Ossetes, use of soured milk, 173

Osteoclasts, 30

Ostrich, defecation of, 76

Oustalet, M., on longevity of vertebrates, 46

Ovary, atrophy of, 26

Owls, intestinal flora of, 83

Ownership, collective, 229, 230

Parodi, on old age, 332

Parr, Thomas, 87

Parrots, duration of life, 41
scanty intestinal flora of, 79

Pasquier, Dr. du, on constipation, 67

Pasteur, discovery of lactic microbe, 105, 167

Paulsen, criticism of Kant, 314

Pensions, old age, 3, 4, 133

Pessimism, 129, 233, 234, 239, 241, 249, 266

Pessimist, study of life-history of a, 249 _et seq._

Pflüger, on longevity, 93

Phagocytes, 18, 19

Phagocytosis, examples of, 25, 37

Phalansteries, 229

_Pilidium_, 109 _et seq._

Pitres, M., hysteric patients of, 200

Plague, 323

Plants, death of, 99, 103

Plasmodia, of Myxomycetes, 215, 216

_Pleurotrocha haffkini_, 112, 113

Pochon, Dr., experiments on use of lactic bacilli, 169

Poehl, Dr., on spermine, 139, 140

Pohl, Dr., on growth of hair, 17, 18

_Ponogenes_, as cause of sleep, 120

Potatoes, improved by Burbank, 326

Poushkin, 236

Predestination, and plants, 103

Preyer, Dr., on _Ponogenes_, 120

Prichard, on longevity of negroes, 88

Productivity compared with fecundity, 57, 58

Prostokwacha, 172, 176

Prolongation of life, 132 _et seq._

Prothalli, life of, 99

Psychids, death of, 117

Ptolemy, fear of Hegesias’ philosophy, 235

Punishment, capital, 305

Purgatives, use of, in intestinal putrefaction, 157

Putrefaction, intestinal, 151 _et seq._, 161, 163, 164

Quételet, on stature of the aged, 9

Rabbit, fecundity of, 58

Ravens, absence of putrefaction in intestines of, 75

Reagents, action of, in distorting tissues, 20

Renouvier, C., on his own death, 127

Reproduction, organs of, rudiments in, 189

Reptiles, longevity of, 50

Rhea, cæca of, 60, 77

Rhinoceros, longevity of, 54

_Rhytina_, 213

Riley, James, on food of Arabs, 174

Rimpau, on cultivation of rye, 326, 328

Rist and Khoury, on milk, 178

Rist, M., on ferment of Egyptian milk, 105

Rivière, M., on defecation in ostriches, 76, 78, 79

Robineau, Mde., 5, 6, 7, 8, 128, 159

“_Roman Elegies_,” Goethe’s, 268, 273

Rotifera, duration of life, 39
death of, 112

Roux, anti-syphilitic ointment, 146

Rovighi, on Kephir, 173

Rudimentary organs, 185 _et seq._

Rye, duration of life of, 100
Rimpau’s improvement of, 326

Salpétrière, hysterical patients at, 201
old women in the, 4, 5

Sand, M., on senile brain, 20

Sargent, on age of Sequoia, 98

Sauer-kraut, 165, 171

Sauvage, M., on atheroma, 30

Savage, on character of anthropoids, 193

Saxe-Weimar, Grand Duke of, and Goethe, 274

Schaudinn, spirillum of syphilis, 31

Schiller, Goethe on, 271

Schiller, on moral conduct, 310

Schlanstedt, rye of, 326

Schmidt, on microbes in constipation, 70

Schopenhauer, 235, 247, 255, 277, 330

Schumann, a degenerate, 134

Science, and morality, 301 _et seq._

Sclerosis, in the aged, 31

Sea-anemones, longevity of, 47, 48

Sea-cow, 213

Selection, medical, 134

Seneca, 132, 235

Senescence, Brown-Séquard’s specific against, 139
mechanism of, 25
phagocytosis as cause of, 35

Senility, characters of, 8, 14
and digestive system, 59
theories of causation of, 15 _et seq._

Sensation, analysis of, with regard to pain and pleasure, 243

Sense of life, 26
of obstacles, 258

Sense, organs of, rudimentary structures in, 186, 187

“Sermon on the Mount,” 321

Serums, cytotoxic, 147, 148, 149

Servants, care of, 321

Sex, and longevity, 57

Sexuality, Goethe and, 273 _et seq._
and old age, 276
moral problems of, 305

Sexual organs, abnormalities of, 224

Sexual power and genius, 272

Shakespeare, quotations, 239, 307

Sheep, digestion of, 74
longevity, 55

Sight, rudimentary organs of, 189

Silos, 165

Siphonophora, 217

Skeleton, atrophy of, in the aged, 29

Sleep, and anæmia of brain, 122
and auto-intoxication, 120
and death compared, 125

Sleepiness, compared with hunger, 125

Sleeping-sickness, 124

Small-pox, and mortality rates, 144

Smell, analysis of, 243

Smell, rudimentary organs of sense of, 187

Smoking and longevity, 93

Social animals, 214, 220 _et seq._

Socialism, 228, 229

Society _v._ the individual, 223 _et seq._

Society, and morality, 306

Sociology, dependent on biology, 231

Sollier, Dr., on sensations at death, 130

Solomon, quotation from “Ecclesiastes,” 233

Somnambulism, analysis of, 200 _et seq._

Sorbose, fermentation of, 106

Soured milk, use of, 171, 181, 182

Sparrow, fecundity of, 58

Spencer, Herbert, criticism of Kant, 310
criticism of socialism, 230
theory of morality, 316, 322, 324, 327

Spermatozoa, in old age, 35

Spermine, 139, 140

Stadelmann, on lactic acid in diabetes, 170

Statistics on suicide, 3

Stature, in old age, 8, 9

Stein, Mde. von, 267, 268, 273

Steller’s sea-cow, 213

Stern, M., on disinfection of intestine, 156

Stohmann, on digestion in sheep, 74

Stoics, 309

Stragesco, Dr., on digestion in mammals, 63

Strasburger, on disinfection of intestine, 156, 157
on microbes in constipation, 70

Suicide, 3, 4, 237, 238, 265, 311

Sully-Prudhomme, definition of morality, 303

Suprarenal capsules, and atheroma, 32

Swimming, instinctive power of, 197, 198, 207

Syphilis, 31, 37, 145, 146, 302, 304

Switzerland, centenarians rare in, 91

Tanacol, as an intestinal antiseptic, 156

Taoism and immortality, 137, 138

Taste, analysis of, 243

Tavel, M., operations on large intestine, 152 _et seq._

Taylor, Bayard, translation of _Faust_, 285

Termites, 220, 221

Testis, emulsion of, as used by Brown-Séquard, 139
resistance of, to senescence, 35

Thanatology, 131

Theophrastus, 132

Thymol, as an intestinal antiseptic, 157

Thyroid, effects of extirpation of, 32, 33, 34

_Timon of Athens_, quotation from, 307

Tissier, Dr., on _Bacillus bifidus_, 161
on use of lactic microbes, 181

Tissier, and Martelly, on putrid food, 164

Tobacco and longevity, 93

Tokarsky, on natural death, 126

Tolstoi, and death, 94
“Death of Ivan Ilyitch,” 318

Tortoise, 11, 12, 13, 51

Touch, sense of, in the blind, 257

Troubat, M., on instinctive swimming, 198

Trees, age and death of, 96, 97, 98

_Trypanosoma_, 124

Unicellular organisms, death of, 95

Urine, analysis of, in a centenarian, 7

Utilitarianism, 305

Vacherot, criticism of Kant, 313

Varenetz, 172

Vascular glands, relation to old age, 33, 34

Verworn, Max, on death in infusoria, 95

Vinegar, in preservation of food, 165

Vivisection, 301

Voisin, M., criticism of neuronophagy, 20

Voltaire, 92, 235

Volz, on swimming power of gibbons, 198

Wales, Mr., quotation from Riley, 174

Weber, Dr., on regimen for old age, 140, 141

Weichardt, on cause of fatigue, 122, 123

Weinberg, Dr., on preparation of human serums, 150
on thyroid gland in aged, 33

Weiske, on digestion in sheep, 78

Weismann, A., on cause of old age, 15, 16
on death in infusoria, 95
on duration of life, 41, 43, 45, 51

“Weltschmerz,” in German poetry, 236

_Werther_, Goethe’s, 263, 267

Westergaard, statistics of mortality, 142, 144

Wiedersheim, on intestinal tract, 60

Wine, Goethe and, 271, 279

Wolff, J. H., Goethe’s friend, 271

Women, education, 224 _et seq._

Yahourth, use in intestinal putrefaction, 168, 170, 175, 177, 178

Yeast, conditions of growth, 106

Zeigan, Dr., on adrenaline, 122

Zell, Dr., on blind persons, 259

Zelter, Goethe’s friend, 265

Zola, “La Joie de Vivre,” 248

Zoological Gardens of London, 51, 81

Zortay, Pierre, age of, 87

*** End of this LibraryBlog Digital Book "The Prolongation of Life - Optimistic Studies" ***

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