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´╗┐Title: Principles of Public Health - A Simple Text Book on Hygene Presenting the Principles - Fundamental to the Conservation of Individual and Community - Health
Author: Tuttle, Thos. D.
Language: English
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Copyright Status: Not copyrighted in the United States. If you live elsewhere check the laws of your country before downloading this ebook. See comments about copyright issues at end of book.

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  [Illustration: (publisher's colophon)]



  "Our national health is physically our greatest asset. To prevent
  any possible deterioration of the American stock should be a
  national ambition."--THEODORE ROOSEVELT.

_The conservation of individual and national health is the keynote
of these books_


  By THOS. D. TUTTLE, M.D., Secretary and Executive Officer of the
  State Board of Health of Montana. Illustrated. Cloth. vii + 186
  pages. List price 50 cents, mailing price 60 cents.


  By JOHN W. RITCHIE, of the College of William and Mary in
  Virginia, and JOSEPH S. CALDWELL, of the George Peabody College
  for Teachers, Nashville, Tennessee. Illustrated. Cloth. vi + 184
  pages. List price 40 cents, mailing price 48 cents.


  By JOHN W. RITCHIE. Illustrated. Cloth. vi + 200 pages. List
  price 50 cents, mailing price 60 cents.


  By JOHN W. RITCHIE. Illustrated in black and colors. Cloth. vi +
  362 pages. List price 80 cents, mailing price 96 cents.

  CASPAR W. HODGSON, _Manager_

  _Copyright, 1910, by World Book Company. All rights reserved_


The earliest history of remote ages describes methods employed in
combating disease, and down through all the centuries the struggle
against infection has been going on. The science of health as
applied in recent years reveals wonderful progress in the avoidance
of disease, and in the control of the violent epidemics by which
in the past nations were almost exterminated. Modern methods of
hygiene and sanitation as applied to public health have robbed
smallpox and diphtheria of their death-dealing power; cholera and
yellow fever have been forced to retreat before the victorious
hosts of applied medical science; tuberculosis, the greatest foe
of human life, is slowly but surely receding before the determined
efforts of modern preventive medicine.

By nature man is endowed with resistive power sufficient to ward
off most forms of disease, provided he keeps his health at a normal
standard by right living. If, however, he allows his health to
become impaired by reason of overwork, bad habits, wilful exposure
to contagion or unhealthful surroundings, he readily falls a prey
to disease.

The author of _Principles of Public Health_ has here set forth the
general rules of life by the observance of which every adult and
every child not only can do much to preserve his own health but
also can prove himself a prominent factor in raising the standard
of public health. A campaign of education is demanded to arrest the
enormous loss of life which is carrying so many to untimely graves,
and the instruction given in this volume will be of inestimable
value in teaching people how to avoid avoidable disease.

The author has not attempted to deal with all the diseases that
may be classed as preventable; as the work is intended for use in
the public schools, only such diseases are mentioned as it seems
fitting to present to school children. To teach our children a
proper respect for their own health and for the community welfare
is to fit them for the best citizenship.

  E. A. PIERCE, M. D.



The author wishes to express his sincere appreciation of the
valuable assistance rendered in the preparation of this work
by Dr. S. T. Armstrong, of New York City; Dr. H. Wheeler Bond,
Commissioner of Health, St. Louis, Missouri; Dr. H. M. Bracken,
Secretary and Executive Officer of the State Board of Health of
Minnesota; J. S. Caldwell, Professor of Biology, George Peabody
College for Teachers, Nashville, Tennessee; R. J. Condon,
Superintendent of Schools, Providence, Rhode Island; Mrs. Nona B.
Eddy, of the Public Schools of Helena, Montana; Dr. F. M. McMurray,
of Teachers College, Columbia University, New York City; Miss
Jessie B. Montgomery, Supervising Critic in Training School, State
Normal School, Terre Haute, Indiana; Dr. E. A. Pierce, Secretary
and Executive Officer of the State Board of Health of Oregon.



  CHAPTER                                                    PAGE

       I.  CONSTANT DANGER OF ILLNESS                            1

      II.  THE NECESSITY OF CARING FOR THE BODY                  4

     III.  HOW CLOTHING AFFECTS HEALTH                           9

      IV.  THE USES OF FOOD                                     14

       V.  CARE OF FOOD--MEATS                                  18

      VI.  CARE OF FOOD--MILK                                   22

     VII.  DECOMPOSITION OF FOOD                                30

    VIII.  HARM DONE BY IMPROPER COOKING                        34

             PROMOTE HEALTH                                     37

       X.  DANGERS FROM POOR TEETH                              41


     XII.  REST ESSENTIAL TO HEALTH                             51

    XIII.  CARE OF THE EYE AND EAR                              56

     XIV.  CARE OF THE SKIN                                     60

      XV.  COMMON POISONS TO BE AVOIDED                         64


     XVI.  DISEASE GERMS                                        73

             HABITS                                             75

   XVIII.  FLIES AS CARRIERS OF DISEASE                         79

     XIX.  HOW DISEASE GERMS GET INTO WATER                     85


     XXI.  INSECTS AS CARRIERS OF DISEASE                       92

    XXII.  HOW TO KEEP GERMS OUT OF WOUNDS                      95

   XXIII.  TRANSMISSION OF DIPHTHERIA                          100

    XXIV.  THE CURE OF DIPHTHERIA                              108

     XXV.  HOW TYPHOID FEVER GERMS ARE CARRIED                 113


   XXVII.  HOW SCARLET FEVER IS CARRIED                        123

             DISEASES                                          128

    XXIX.  HOW SMALLPOX IS PREVENTED                           131




  XXXIII.  HOW CONSUMPTION IS CURED                            157

  APPENDIX--SUMMARY OF ANATOMY                                 163

  SUGGESTIONS TO THE TEACHER                                   182

  INDEX                                                        183





Every boy and girl confidently expects to grow into a strong and
healthy man or woman. How often we hear a child say, "When I am a
man," or "When I am a woman;" but I have never heard a boy or a
girl say, "If I live to be a man or woman." When you think of what
you will do when you are grown into men or women, it never occurs
to you that you may be weak and sickly and therefore not able to
do the very things that you would most like to do. This suggests
that sickness is not natural, else the thought that you may perhaps
become sick would enter your mind. As a matter of fact, most
sickness is not natural.

[Sidenote: The fight for life]

There is a constant struggle going on in the world. You see a fight
about you every day among the animals. You see the spider catch the
fly, the snake catch the frog, the bird catch the insect, and the
big fish catch the minnow; and you have heard of wars where men
kill one another.

The greatest enemies that men have to fight, however, are not
other men, or wild animals, but foes that kill more men, women and
children every year than were ever killed in the same length of
time by war. These foes are small, very small, but you must not
think that because things are small they are not dangerous. We
call these foes _disease germs_.

[Illustration: FIG. 1. Looking at cells through a microscope.]

[Illustration: FIG. 2. Some skin cells as seen through a

[Sidenote: The nature of a germ]

The germ is a very, very small body; it is the smallest living
body that we know. Later we shall learn that our bodies are made
up of cells, and that these cells are extremely small--so small
that it takes a very powerful microscope to see one of them. The
germ is still smaller than the cells in our bodies, and it is
made of a single cell. There are a great many kinds of germs in
the world. Fortunately, most of them are not harmful. Some germs
cause disease, but there are other germs that not only are not
harmful, but are actually helpful to men. Among the helpful germs
are those that enrich the ground, and these should be protected;
but all germs that cause disease should be destroyed as rapidly
as possible. These germs are fighting all the time against our
health. They are not armed with guns and cannon, neither do they
build forts from which to fight; but they get inside our bodies and
attack us there.

[Sidenote: How to fight germs]

There are three principal ways by which we fight disease germs:
_first_, by keeping our bodies so well and strong that germs
cannot live in them; _second_, by keeping germs out of our bodies;
_third_, by preventing germs from accumulating in the world--that
is, by killing as many of them as possible.

If it is possible to keep so well and strong that disease germs
cannot live in our bodies, you will naturally infer that there are
other causes of sickness besides disease germs. That is true, for
there are a great many things beside germs that cause our bodies to
get into such a condition that disease germs can enter and grow and
make us ill. We sometimes call this a "run-down" condition. Before
we begin, then, to study the germs that cause disease, we must
learn how to keep our bodies strong and ready to fight these germs.

  =Questions.= 1. What evidence have we that sickness is not
  natural? 2. Name some of the fights going on in the animal world.
  3. What can you say of the amount of illness caused by germs? 4.
  Tell what you have learned about germs. 5. Name three ways of
  fighting germs.

  =Remember.= 1. Most sickness comes from failure to observe
  Nature's laws. 2. We must keep up a constant fight against germs
  that cause sickness. 3. We fight germs by killing as many of them
  as we can, and by keeping our bodies so strong that if a disease
  germ enters it cannot grow.



[Illustration: FIG. 3. The organs of the body.]

[Sidenote: How the body is like an automobile]

These bodies of ours are built somewhat like automobiles. An
automobile is made up of a framework, wheels, body, gasoline tank,
engine, and steering-gear. The human body has much the same form of
construction. We have a frame, which is made of the bones of the
body. We have arms and legs, which correspond to the wheels of the
automobile. We have many little pockets in our bodies in which fat
is stored, and these little pockets answer to the gasoline tank
of the automobile. We have an engine which, like the automobile
engine, is made up of many parts; and we have a head or brain, that
plays the same part as the steering-gear of the automobile.

The automobile has a tank in which is carried the gasoline
necessary to develop power for the machine. If the gasoline gives
out, the engine will not run, and before the owner starts on a
trip, he is always careful to see that the tank is well filled.
In the same way, if we do not provide new fat for the pockets in
our bodies in which the fat is stored, our supply will soon give
out and our bodies will refuse to work, just as the engine of the
automobile will refuse to work when the gasoline is used up.

[Sidenote: What cells are like]

The automobile is made of iron and wood and rubber, and each bit
of iron and wood and rubber is made up of tiny particles. The body
is made of bones and muscles, covered with skin, and all these are
made up of very fine particles that we call cells. Every part of
the body is made of these fine cells. The cells are so small that
they can be seen only with a powerful microscope. If you look at
your hand you cannot see a cell, because it takes a great many
cells to make a spot large enough for you to see. In Figure 1 you
see a boy looking through a microscope, and beside him you see a
picture of what he sees. This picture does not look like the skin
on your hand, neither does it look like the skin on the boy's hand;
but it is nothing more nor less than a piece of skin taken from
that boy's hand, and it looks just as a piece of skin from your
own hand would look if you were to see it through a very strong

[Sidenote: Why cells must not be killed]

The whole body is made up of just such little cells as you see in
Figure 4, and each cell is alive and has a certain work to perform.
It is very important that we keep these cells from dying and that
they perform the work for which they are intended, for if these
cells die or fail to act, the body becomes sick or dies.

[Illustration: FIG. 4. A cell. (a) Cell body; (b) nucleus; (c)

You can scratch some of the paint from your automobile and the
machine will work just as well as ever. Apparently no harm has been
done, but an opening has been made through which moisture and germs
can enter and cause the wood to rot and the iron to rust. You can
remove certain parts of the automobile and still the machine will
do its work; but you cannot take away too much of any one part
without weakening the automobile, and if certain parts are missing
(such as the sparker, the battery, or the steering-gear), the
usefulness of the machine is destroyed. So it is with the body. You
can scratch off some of the skin and not do any apparent harm, but
you have made an opening through which germs may get into the body.
You can remove certain parts of the body, such as the arm or leg,
and still the body will do efficient service. But there are certain
parts of the body that are necessary to life, just as certain parts
of the automobile are necessary to the usefulness of the machine.
You cannot remove the heart and live; you cannot remove the brain
and live.

[Sidenote: How cells are killed]

You are probably thinking that it must be easy to kill such a
little thing as a cell; and so it is. Cells can be killed by too
much heat or too much cold. When you skin your hand, you kill many
cells, and at the same time make an opening for germs to get in and
cause sickness. You can kill cells also by starving them, for they
must have not only enough food, but the right kind of food. If you
feed your bodies on nothing but candy, pie, and cake, most of the
cells will refuse to perform their work and many of them will die.
These cells must have also an abundance of air, and the air must be
pure and fresh. If you breathe the air that others have breathed or
that contains poison of any kind, you will soon find that you are
not feeling well. This simply means that so many of the cells are
being starved for fresh air, that not enough strong ones are left
to do the necessary work. You can kill these cells by overwork, for
they must have a proper amount of rest. If you go to school all
day long and then sit up until midnight every night, you must not
expect the cells of your body to keep strong and well. You can kill
these cells by the use of certain things that act as poisons to
them, such as tobacco, beer, wine, or whisky.

  =Questions.= 1. In what way is the body like an automobile? 2.
  What are cells like? 3. Why must cells not be killed? 4. Name
  five ways by which we kill cells.

  =Remember.= 1. Each part of the body is important to the welfare
  of the whole body. 2. Each part of the body is made up of very
  small particles that we call cells; each cell in the body is
  alive and has a certain work to perform. 3. Cells are very easily
  weakened and killed. 4. There are five principal ways by which
  we kill the cells in our bodies: by too much heat or cold; by not
  giving them the proper kinds of foods; by not giving them enough
  fresh air; by giving them too much work to do; and by poisoning



[Illustration: FIG. 5. Warm, dry clothing necessary for health.]

[Sidenote: Why the body should be equally covered]

The body should always be kept at as nearly uniform a temperature
as possible. In order to do this we wear clothing. Clothing keeps
out the heat on a hot day, just as it keeps the heat in and the
cold out on a cold day. The clothing should be equally heavy on
all parts of the body. It is not right to wear a thick dress over
your chest and leave your shoulders and arms bare, or nearly so.
People who do this are killing a great many cells by letting part
of their bodies become chilled while the rest is warm, probably too

[Sidenote: Why clothing should not be too heavy]

The clothing should be just heavy enough to keep the body warm.
If you wear such heavy clothing indoors that you are constantly
perspiring, your underclothes become damp, and when you go out,
even though you put on your overcoat, your body becomes chilled. If
you begin to sneeze, that is Nature's way of telling you that you
are killing many of your cells by too much cold.

People sometimes get warm from exercising, and then take off their
coats. They should have removed their coats before they began to
exercise. If you take off your coat after you are too warm, your
body becomes chilled. Baseball pitchers know this, and if you watch
a good pitcher, you will see that he always puts on his sweater as
soon as he stops pitching, even though he is very warm. He knows
that if he cools off too quickly, he will become stiff and sore and
cannot pitch good ball.

[Sidenote: When a draft is dangerous]

Sometimes a person sits in a warm room until he begins to perspire
freely. Then he opens a window and sits in the draft. Under
ordinary conditions, the cool wind alone would chill the body, but
now the rapid drying of the perspiration makes the body cool still
more quickly. The sudden chill causes the person to take cold,
which is simply another way of saying that he has killed many cells
and caused others to fall sick, so that they cannot perform their
work. We cannot get too much fresh air. Drafts do not hurt us if
we are thoroughly wrapped up; but it is very dangerous to allow
the wind to strike the body when it is not well protected, and
especially when it is damp with perspiration.

[Illustration: FIG. 6. Properly prepared for wet weather.]

[Sidenote: Why damp clothing is dangerous]

Damp clothing chills the body very rapidly and kills many cells.
Indeed, if a single one of the germs that cause pneumonia were to
enter your lungs while you were wearing damp clothing, it would
grow so rapidly that you might have pneumonia in a very little
while. That is why it is important to change your shoes and
stockings as soon as you get them wet, and to take off immediately
any clothing that becomes damp. It is hard for boys and girls to
keep their feet dry in the winter and spring months, and rubbers
are a nuisance; but if you expect to grow into the strong man or
woman you picture yourself becoming, you must take care to wear
your rubbers. Otherwise you may become weak and sickly, and never
be able to do the things you hope to do.

The feet are not the only part of the body that needs to be kept
dry. A wet coat is just as harmful as wet shoes and stockings;
hence, you should always carry an umbrella or wear a raincoat when
you go out into the rain. Umbrellas are unhandy for boys and girls
to carry, but if you will remember that thousands of little cells
in your body are being injured when you get wet and chilled, you
will be willing to take your umbrella.

[Sidenote: When to wear an overcoat]

In cold weather the same amount of clothing should not be worn in
the house and outdoors; for this reason, we have overcoats. If you
wear your overcoat in the house, you will become overwarm and your
underclothing will then become damp with perspiration; when you go
outdoors into the cold air, this dampness will have just the same
effect as would dampness that comes from outside.

[Illustration: FIGS. 7 and 8. If you keep your overcoat on in the
house, your underclothes become damp from perspiration, and when
you go outdoors your body becomes chilled.]

As soon as the weather gets cold, put on your overcoat every time
you go outdoors, and take it off as soon as you come into the
house. This is troublesome for boys and girls to do, because they
want to run in and out of the house so often; but on the other
hand, think of all the cells you will kill if you do not do this,
and you will certainly consider it worth while to take off your
coat and put it on again.

  =Questions.= 1. How does keeping the body equally covered protect
  the cells? 2. Give reasons for not wearing too heavy clothing. 3.
  When is it safe to sit in a draft, and when dangerous? 4. What
  is the danger of keeping on wet shoes or other damp clothing? 5.
  When and why should overcoats be worn?

  =Remember.= 1. Clothing should be just heavy enough to keep the
  body warm all the time. 2. Never take off your coat or sit in
  a draft when you are too warm. 3. Since wearing damp clothing
  causes a great deal of sickness, change your clothes as soon as
  they become wet or damp. 4. Do not forget to take your umbrella
  when it is raining and to wear your rubbers when the ground is
  wet. 5. In cold weather wear your overcoat when you are outdoors,
  but take it off when you come into the house.



We kill a great many of the cells in our bodies by starving them;
either we do not give them enough food or we do not supply the
right kind of food.

[Sidenote: Why the body needs new cells]

Not only must we feed the cells in our bodies, but we must be
constantly making new ones, for in all our work or play, awake or
asleep, we are constantly using up certain cells. These cells are
used to make the body go, just as the engine uses coal to form the
steam that gives it power to run. Boys and girls grow fast and, of
course, if they expect to become well men and women, they must make
a great many new cells all the time, in addition to those used in
doing the work of the body. If we are to make new cells we must
have the right kind of food with which to make them.

[Sidenote: How the body keeps itself warm]

We want to do something besides make new cells; we want to keep
warm and well the cells we already have. No amount of clothing
would keep you warm if you were not making heat inside your body
all the time, any more than you could make a telephone post warm
by putting your coat on it. Therefore it is necessary to have food
that makes heat in the body, in addition to food that builds cells.

We eat a great many kinds of foods, and all that we eat is used
either for building new cells or for producing heat in the body.
Thus we can divide all our foods into two classes--building
material and heat-producing material. The type of building material
is lean meat, and the type of heat-producing material is fat meat
and starches, such as potatoes and bread. Milk contains much
building material as well as heat-producing material. That is why
a baby grows and keeps warm while he takes nothing but milk.

[Sidenote: The building foods]

Lean meat is the best of all building foods. Eggs are largely a
form of lean meat, and hence constitute a good article of food for
building purposes. Certain vegetables contain a large per cent of
building material; this is especially true of dried beans and peas.
Wheat flour and corn meal (particularly when made of whole wheat
and unbolted meal) contain much building material.

It is possible for one to live and grow when eating only vegetable
matter. But the boy or girl who tries to become a strong man or
woman by eating only vegetables will be disappointed; these are
mostly heat-producing foods and will not make strong bodies.
Experience has proved that the best results are obtained by eating
what is called "a mixed diet," that is, a diet composed partly of
lean meats and partly of fats and vegetables.

[Sidenote: The heat-producing foods]

Of the heat-producing foods, fat is the most powerful. Most of the
fat that we eat is used immediately for producing in the body heat,
and therefore power, but a part of it is stored up for future use.
We see it in all healthy young persons. It is this stored-up fat
that gives the body its rounded form. When any one has been sick he
is thin, because, to produce heat and power while he was sick, he
has had to use the fat stored up in his body. To have such a supply
of fat is like having a bank account to draw on when out of work.
We might call the deposits of fat in our bodies our health banks.

Fat meat is not the only form in which we eat fats; we eat them
in a great many other ways. Certain vegetables, such as beans,
contain an oil that forms fat. Ripe olives contain a great deal
of fatty oil. Butter is a very important form of fat, and cream
contains a large amount of it.

[Sidenote: Cost of suitable foods]

In selecting our foods we should think of two things: _first_, the
value of the food as a heat-producer or as a building material;
and _second_, the cost of the food. We may like butter much better
than bacon, but we should remember that, pound for pound, bacon has
a greater nourishing power than butter, and a pound of bacon will
cost far less than a pound of butter.[1]

Vegetable foods produce heat by means of the starch which they
contain. All vegetables contain starch. This starch is changed
into a kind of sugar in the body, and when thus changed it is used
to produce heat and power. All vegetable foods do not have the
same heat-producing power. There is more heat-producing power in
a pound of oatmeal than there is in ten pounds of cabbage. Ten
cents' worth of dried beans will produce more heat in the body
than will a dollar's worth of lettuce. Thirty cents' worth of corn
meal will do more building in the body than will a piece of mutton
worth a dollar and a half; but you would have to eat a large amount
of corn meal in order to secure the building effect that would
result from eating a small quantity of mutton. In most fruits the
only nourishing quality is in the sugar they contain. This sugar
produces heat in the body just as starch does.

[Sidenote: The real value of advertised foods]

You will see some foods advertised as possessing a wonderful
nourishing power. Do not let such statements deceive you, for no
food can have a greater nourishing power than the things from which
it is made. If the particular food advertised is made from wheat
flour, its nourishing power is just the same as that of an equal
quantity of wheat flour. If it is made from corn meal, it can have
no greater nourishing power than has the meal itself.

We have learned something about the materials necessary in food and
why they are needed. We must now learn why foods that contain these
materials sometimes do not give us as good results as we might hope

  =Questions.= 1. What use does the body make of new cells? 2. How
  does the body keep itself warm? 3. Name two uses that the body
  makes of food. 4. What foods are especially useful for making
  cells? 5. What foods are chiefly used for making heat? 6. Select
  articles of food for two meals of equal nourishing value, one
  meal to be expensive and the other inexpensive. 7. How would you
  determine the real value of any food?

  =Remember.= 1. Foods are used to make heat and power in the body
  and to make the body grow. 2. The foods that make the body grow
  are called building materials, and lean meat is the best kind
  of building material. 3. The foods that produce heat and power
  in the body are called heat-producing materials, and fats and
  starches are the best heat-producers. 4. All vegetables contain
  starch, some of them contain a fatty oil, and most of them
  contain some building material. 5. You can get as much building
  and heat-producing material from cheap foods as you can from
  expensive foods.



[Sidenote: Value of meat as a food]

Meat is one of the most important articles of our diet. It
furnishes essential materials for building cells, and it furnishes
fat for making heat and power in the body.

[Illustration: FIG. 9. A double menace to health; the
slaughterhouse is dirty, and the filth is drained into a stream.]

[Sidenote: Characteristics of good meat]

Since meat is so important an article of food, we should be very
careful to see that it is handled in a way to keep it always
perfectly clean. We should make sure that it comes from animals
absolutely free from any kind of disease, and that no germs have
been allowed to develop poisons in it.

[Sidenote: How meat may be kept clean]

While people know that they ought to pay attention to these things,
as a matter of fact they do not do it. They take very little
interest in the way the meat that they are to eat is handled, and
very few ever go to the slaughterhouse or into the back room of the
butcher shop to see whether things are kept clean or not. Some
people say, "Oh, we do not like to go there because it is such a
horrid place." If these places were kept clean, as they should be,
they would not be "horrid." And if the people who buy the meat
would occasionally visit them, these places would be kept clean.

[Illustration: FIG. 10. Properly displayed foods, protected from
handling and from dirt and flies.]

If the slaughterhouse and the butcher shop where your meats are
handled are not kept clean, the meat is sure to have germs growing
in it, and these germs will cause poisons called _ptomaines_ to
form in the meat. There may not be enough of them to make you
sick, but there will be enough to injure some of the cells of your
body, and to deprive you of much of the nourishment that you would
otherwise get from the meat.

All boys and girls should belong to a "Clean Meat League" and
should try to persuade their parents not to buy meat from any
butcher who does not keep his slaughterhouse and butcher shop clean.

[Sidenote: Dangers from diseased meat]

Sometimes butchers are anxious to make money fast and take little
thought for the number of people they may make ill. They can buy
sick cows very much cheaper than well ones. The meat from a sick
cow looks just like the meat from a healthy cow, and the dishonest
butcher sells both at the same price. The meat from the diseased
cow is not suitable for food. It may cause you to have the same
disease that the cow had, or it may only be changed to such an
extent that it will not give you the nourishment that you should
get from good meat. The butcher who sells you meat from a sick cow
is of course dishonest.

[Illustration: FIG. 11. Improperly displayed foods, exposed to
handling and to dirt and flies.]

[Sidenote: How to prevent the sale of diseased meats]

Ask your father to visit the slaughterhouse where your meat is
killed. The only thing you need to do is to persuade him to go and
see whether the cattle are sick or not. If the cattle look sick,
you will not have to ask him not to buy the meat. No person should
ever eat meat that comes from a diseased animal, no matter what the
nature of the sickness may be. People who will take the trouble to
visit the slaughterhouses occasionally, to investigate these things
for themselves, will not have such meat offered them.

[Sidenote: Importance of giving animals clean food]

Animals that are fed on filthy food are not fit for human
consumption. Butchers often feed the offal (the insides) of animals
to the hogs. This makes the hogs fatten quickly, but it also makes
them diseased. When you go to the slaughterhouse with your father,
ask him to go around to the back door, and if you see hogs eating
this filth, do not buy any more meat from that butcher.

  =Questions.= 1. What use does the body make of meat? 2. What
  conditions are essential for good meat? 3. How can meat be kept
  clean? 4. Why is meat from a diseased animal unfit for food? 5.
  How can you help in preventing the sale of meat from diseased
  animals? 6. Why should animals not be fed with offal?

  =Remember.= 1. Meat that is not handled in a clean manner
  is sure to contain germs that cause a poison to form in the
  meat. 2. Never buy meat from a butcher who does not keep his
  slaughterhouse and butcher shop clean. 3. Meat from a diseased
  animal is not fit for food. 4. Meat from animals fed on filthy
  food should not be eaten. 5. Form a "Clean Meat League" and visit
  the slaughterhouse where your meat is killed.



[Sidenote: Value of milk as a food]

Milk is another important article of food. The Department of
Agriculture at Washington says that milk furnishes sixteen per
cent of the nourishment of the people of the country. Milk is an
excellent food when it is pure, but when it is not pure it is very

[Illustration: FIG. 12. A clean dairy.]

[Sidenote: Milk as a carrier of germs]

Milk has carried the germs of every disease of which the germ is
known; it has also carried many diseases of which we do not know
the germ. Disease germs grow rapidly in milk, and they do not
make the milk look different or taste different from milk that is
perfectly pure. If you could take two bottles of milk entirely free
from disease germs and put typhoid fever germs in one, and should
set both bottles in an ice box for twenty-four hours, you would
not then be able to tell into which one you had put the germs. The
milk in both bottles would look and taste just the same. The only
difference between the milk in the two bottles would be that if you
drank from one it would make you stronger and would furnish you
with both building material and power-producing material, while
if you drank from the other you would become very ill and would
probably die.

[Sidenote: How disease germs get into milk:]

Since we cannot tell from the taste or the appearance of milk
whether or not there are disease germs in it, we must take every
precaution possible to keep them out. The first step is to learn
where the disease germs come from and how they get into the milk.

[Illustration: FIG. 13. Polluted milk is sure to come from a dairy
where cleanliness is not observed.]

[Sidenote: (_1_) By dirt on the cow]

Every cow has more or less dirt on her sides and udder; some have
a great deal. When the cow is milked, much of the dirt falls into
the milk bucket. This dirt always contains a great many germs of
different kinds, and many of them are germs that cause disease.
Straining the milk will take out much of the dirt, but disease
germs will go through the finest strainer that was ever made.

In Figure 13 we see a man milking a dirty cow. The owner has
allowed his lot to become so dirty that the cow cannot find a clean
place in which to lie down. If the man kept his lot clean, and if
before milking the light dirt on the cow's sides and udder were
wiped off with a damp cloth, no germs would fall into the milk.

[Sidenote: (_2_) By dirt in the cow barn]

Another source of dirt and disease germs in milk is the barn. The
walls of a barn where cows are milked should always be kept clean
and should be whitewashed frequently. If this is done, there will
be comparatively little dirt on the walls to fall into the milk.

[Illustration: FIG. 14. Only clean milk will come from a dairy
where proper precautions are taken.]

Of course the walls and floors of a barn cannot be kept absolutely
clean. There will always be some dirt, and the movements of the
cows shifting their position and switching their tails, will stir
up the dust; so it is important to remove the milk from the barn as
soon as possible. Milk cans should never be kept in the barn. The
milk should be taken directly from the barn to a cooling house and
there strained.

All barns where cows are kept should have plenty of windows, that
there may be an abundance of light and fresh air. Cows need fresh
air just as much as people do, while a barn that is not supplied
with plenty of light is very likely to be a dirty barn.

Keep dirt and disease germs out of the milk by keeping the barn
clean and by taking the milk away from the barn as soon as possible.

[Illustration: FIG. 15. A dirty, insanitary milk-house.]

[Illustration: FIG. 16. A clean, inexpensive milk-house.]

[Sidenote: (3) By dirt on the milkman]

Another source of dirt and disease germs in milk is the milkman or
milkmaid. No matter how careful we may be, our clothes hold more or
less dust, and all dust contains germs, very often disease germs.
When a person is milking a cow, the dust from his clothes is shaken
off into the milk. The only way to avoid this is to wear, while
milking, a special suit of clothes made of white cloth, which may
be washed as soon as it shows the least particle of dirt.

The milker's hands, too, are often dirty. Perhaps he carefully
washes his hands after milking, but not before. It is a common
custom for milkers to moisten their hands with milk while milking,
and to do this frequently. The result is that dirty milk from their
hands is constantly dropping into the milk pail. This is a very
bad habit, and doubly bad if the milkman has not washed his hands
before milking.

Sometimes there are sick people at the dairy farm. Often some one
nurses a sick person until milking time and then goes out and milks
the cows. When this is done, the milker is almost sure to plant the
germs of the disease in the milk. No milk should ever be used from
any dairy where there is an infectious disease; and no one who has
charge of a sick person, no matter what the nature of the sickness,
should ever handle milk that is to be used by others.

[Illustration: FIG. 17. A model bottling establishment.]

[Sidenote: (4) By dirt in cans and bottles]

The cans and bottles in which the milk is placed are frequently
sources of dirt and germs. Milk cans and bottles are supposed to be
thoroughly washed before milk is put into them, and they should be
thoroughly scalded after they are washed. This is not always done,
and sometimes the bottles are not washed at all.

Some dairymen will tell you that the bottles and cans are always
washed and scalded just before the milk is put into them, and that
this is never neglected by any dairyman. That is what a dairyman
once told me. Then I asked him how he accounted for the fact that
I had found a milk ticket in the bottle with the fresh milk. Of
course he could not explain this, though I thought I could explain
it for him. The old milk bottle was returned to the milkman with
the ticket for the new milk inside it. The deliveryman left the
fresh milk, but forgot to take the ticket out of the bottle; and
the man who "washed" the bottles must have forgotten to take out
the ticket too. Of course, the bottle was not washed at all, and if
one bottle goes unwashed, it is reasonable to assume that others
are neglected in the same way.

Milk bottles and cans should always be thoroughly washed before
fresh milk is put into them. This washing cannot be done by little
children; it is work for a man or woman, and careful work at that.

[Sidenote: (5) By polluted water]

I have just told you that milk vessels should be thoroughly washed.
It is true, however, that disease germs may get into the milk
through this very process of washing the vessels. Water sometimes
contains disease germs, especially the germs that cause typhoid
fever, cholera, and other diseases of the intestines. Such water
is said to be polluted. When milk vessels are washed with polluted
water, the germs are left in them and thus get into the milk. If
the water used to wash the cans is thoroughly boiled, the germs
will be killed; hence it is important to scald all milk vessels.

All water used about a dairy should be perfectly pure. If there is
the least suspicion about the quality of the water, it should be
examined by a chemist; and if it is not pure, the milk from such
a dairy should not be used. In order to prevent the possibility
of any infection, all water used to wash milk vessels should be
thoroughly boiled even when the water is known to be pure, and the
vessels should afterward be scalded, to kill any germs that may be
left after washing.

[Sidenote: (6) By flies falling into the milk]

Flies very frequently get into the milk. Later we shall learn more
about how flies carry germs, but at present it is enough to know
that on every fly there are a great many germs, and whenever a fly
gets into milk it plants those germs and they grow very rapidly.
As soon as a cow is milked, the milk should be taken to a clean
cooling house, with screens at all the windows and doors, and there
strained into a vessel and cooled.

[Sidenote: (7) By disease in the cow]

The last way that we will mention by which germs get into milk is
by disease in the cow herself. Cows suffer from many diseases,
just as men do; and when a cow is sick, her milk is very likely
to contain the germs of the disease that is making her sick.
Especially is this true of tuberculosis, or consumption, as it is
called. A great many children get consumption by drinking milk
from consumptive cows. No milk should ever be used from a cow that
is not healthy. All dairy cows should be examined at frequent
intervals by a competent veterinarian to make sure that they are
free from any disease.

  =Questions.= 1. Milk forms what per cent of the food of the
  people of the United States? 2. Why is it important that milk
  should be kept clean? 3. Name some ways by which germs get into
  milk. 4. What is the danger from a dirty cow and barn? 5. How can
  this danger be prevented? 6. How does the milkman allow germs to
  get into the milk, and how can he avoid doing so? 7. How should
  milk cans and bottles be washed? 8. Why is it important that only
  pure water be used about the dairy? 9. How can flies be kept out
  of milk? 10. How should milch cows be tested to make sure that
  they are free from tuberculosis?

  =Remember.= 1. Milk is a very important article of food; it is
  both a building and a heat-producing material. 2. When milk is
  not properly handled, it contains many disease germs. 3. Disease
  germs often get into milk from unwashed bottles and cans; from
  dirty barns; from dirty milkmen; from dirty water used to wash
  the cans and bottles; from flies falling into the milk; from
  diseased cows.



[Illustration: FIG. 18. Partially decayed fruit is not fit for

[Sidenote: Why partially decomposed foods should not be eaten]

Vegetables and fruits that are partially decayed should not be
eaten. Even if an orange is decayed only on one side, the products
of decomposition--that is, the poisons produced by decay--have
extended all through the orange. You cannot see them, but they are
there. It is the same with a decaying apple, potato, or melon. It
never pays to buy partially decayed or stale fruits or vegetables,
for not only are they dangerous to health, but they are so reduced
in nourishing qualities by decomposition that you get little value
for the money you spend. It is always better economy to buy fresh
fruits and vegetables, or even canned vegetables, when the latter
are properly put up.

[Sidenote: What causes decomposition]

All decomposition (rotting) in fruits and vegetables is due to the
action of germs. If you will look at a bunch of old grapes, you
will notice that some of the grapes are rotten, while others have
dried up. Now, if you examine them very carefully, you will find
that all the decomposed grapes have breaks in the skin. The break
may be very small, but it is there, and through this break the
germs that cause decomposition have entered. You will find also
that there is not the slightest break in the skin of any grape that
has dried up. The germs could not enter, hence there has been no
decomposition. It is the same with other fruits and vegetables: if
the germs that cause decomposition cannot get inside, the fruit or
vegetable will dry up, but will not rot.

[Illustration: FIG. 19. Fruits displayed for sale, but properly
protected from flies, dust, and dirty hands.]

Germs can go through a very small opening--so small that you may
not be able to find it; but if there is decomposition, the hole is

The skin of the body acts in the same way as the skin of the grape
and keeps out a great many germs that would make us sick were they
able to get through the skin. They often get through the skin when
we cut ourselves.

Meats decompose as well as fruits and vegetables, and the
decomposition is due to the presence of germs in the meat. We
cannot keep all germs out of meat, but we can keep out a great many
of them by having everything clean about the meat, by keeping it
covered as much of the time as possible, and by handling it only
with clean hands.

[Illustration: FIG. 20. Fruits for sale, not properly protected
from flies, dirt, and other sources of filth.]

[Sidenote: Why foods do not decompose in very cold places]

When meat is kept so cold that it is almost frozen, the germs
cannot grow, and decomposition is prevented. In this way meat can
be kept perfectly free from decomposition for several weeks. After
the meat is taken from the cold storage room, it should be cut as
soon as possible into steaks, roasts, and other pieces for cooking;
and when taken to your home, it should be kept in an ice box until
the time to cook it. You cannot keep meat very long at home without
decomposition starting, because small ice boxes are not cold enough
to check entirely the growth of germs.

Unless the meat is to be eaten hot, it should be cooled after
cooking and placed again in the ice box as soon as possible.
Cooking kills the germs that are in the meat before it is cooked;
but unless it is kept in a very cold place and protected from flies
after it is cooked, germs will get into it again as soon as it is
cold. Cooked meat will decompose just the same as uncooked meat.

[Sidenote: What is formed in food by decomposition]

When germs are allowed to grow in meat, as always happens when it
is not kept in a very cold place, these germs cause the poisons
that we call ptomaines. The people who eat such meat become sick,
and in many cases do not recover. Cooking meat that contains
ptomaines will kill the germs that caused the poison, but it will
not destroy the poison that has already been formed.

[Sidenote: Why some canned meats are poisonous]

People not infrequently are poisoned by eating canned meat.
Sometimes you will hear it said that the poison formed because the
meat was in cans. This is not true; the cans had nothing to do
with the forming of the poison. This was caused by germs that were
allowed to grow in the meat before it was cooked. When the meat was
cooked the germs were killed, but the poison was not destroyed. In
other words, the poison developed before the meat was canned, and
not after it was put into the cans.

  =Questions.= 1. What is the objection to eating fruits when they
  are partially decayed? 2. Why do some foods shrivel while others
  decay? 3. Why does decomposition not go on in cold places? 4.
  What are ptomaines? 5. When are ptomaines formed in canned meats?

  =Remember.= 1. Partially decomposed fruits or vegetables are not
  suitable for foods. 2. Meats in which germs have been allowed to
  grow should not be eaten. 3. Cooking meat kills the germs in it,
  but does not destroy the poisons that the germs have formed. 4.
  When canned meats are poisonous, it is because the poison was
  formed before the meat was canned; the poison is not caused by
  the can.



[Sidenote: Effects of improper cooking]

Nearly all food should be cooked before it is eaten; but if the
cooking is not properly done, much of the nourishing power of the
food is destroyed, and in some instances the food is rendered
actually injurious.

[Sidenote: Why starchy foods should be thoroughly cooked]

Starchy foods should be thoroughly cooked in order that the
coverings which surround the little granules may be broken or
made soft. If starchy foods are not thoroughly cooked, the little
grains go into the stomach as hard as grains of sand; then most of
them are not digested at all, but pass out of the system without
furnishing any nourishment to the body. If starchy foods are fried
in fats, as is the case with doughnuts, the granules of starch
become coated with fat. As the fat is not digested until it comes
to the intestines, the saliva never reaches the coverings of the
starch, and more work is thrown on the other juices of the body.
The result is that the little glands which make these other juices
are overworked, or else the starch is not digested at all and
therefore furnishes no nourishment to the body. When bread is
sticky (we sometimes call it soggy) in the middle of the loaf, it
is because the flour has not been thoroughly cooked and the little
grains or granules of starch are still hard. You cannot feel these
granules between your fingers, but they are hard just the same, and
very little of such food is made use of in the body.

Remember that all starchy foods should be thoroughly cooked, and
remember, too, that all vegetables are chiefly starchy in character.

[Sidenote: How fats should be cooked]

When fats are cooked over a very hot fire, an acid is developed
that is injurious to the body. This does not mean that when the
fire is hot enough to broil a steak well, it causes this acid to
form; neither does it mean that heat sufficient to boil the grease
for cooking doughnuts will cause it to form. Every cook knows
that when she fries fat meat over a fire that is too hot, it has
a bitter taste. This bitter taste is caused by an acid which will
destroy a part of the usefulness of the food in the body and will
cause many of the cells to stop doing their work properly.

[Sidenote: How meats should be cooked]

There is a great difference of opinion in regard to cooking foods,
especially meats. Some people will tell you that meats should not
be cooked at all; that man originally ate his meat raw and that
this is the proper way. Others will tell you that all meat should
be cooked until it does not show a particle of red, even until it
is dry throughout. These are the two extremes; and it is never well
to go to extremes in anything, especially in matters that concern
the health.

Meat should always be cooked, because by being cooked it is made
more easily digestible; but it should not be cooked, until all the
juices, which contain much of the nourishing matter, are dried up
and the meat made hard. Meat that is cooked until it is dry and
hard is more difficult to digest than meat that is not cooked at

  =Questions.= 1. What effect has improper cooking on foods? 2. Why
  should starches be thoroughly cooked? 3. What is the objection
  to starchy foods fried in grease? 4. What changes take place in
  fatty food when it is fried over a very hot fire? 5. Why should
  all meats be cooked? 6. What is the objection to cooking meat
  until the juices are dried out?

  =Remember.= 1. Starchy foods should be thoroughly cooked so that
  the fine grains may be softened and the food thus made more easy
  to digest. 2. Fats should not be fried over a very hot fire
  because too much heat causes a poison to form in the fat. 3.
  Meats should be cooked, but never until they become dry, as the
  juices in the meat contain most of the nourishing material.



[Sidenote: Why mealtime should be pleasant]

The dining table should be the pleasantest and most inviting place
in the house. If you are complaining and quarreling during the
meal, you cannot enjoy the food; you cannot eat it properly; and
your ill temper will so affect your body that you cannot properly
digest what you eat. A dirty table, with flies swarming over the
food, is not very tempting, and when seated at such a table, one
does not eat the things that are best for him and sometimes does
not eat anything at all.

[Illustration: FIG. 21. A clean, inviting dining-room.]

[Sidenote: How uninviting luncheons affect the appetite]

The luncheons that boys and girls take to school with them are
often prepared in so careless a way that they are extremely
uninviting. The substantial school lunch can be made just as
appetizing as the dainty refreshments at an afternoon tea or at
a party. If the same care is devoted to the preparation of the
one as of the other, boys and girls will eat their lunches with
enjoyment and good appetites.

[Sidenote: Why an attractive table calls for pleasing guests]

If the table is made to look clean and inviting, do you not think
that you, in your turn, should make yourself as neat and clean as
possible before you come to it? Dirt on your hands and face not
only does not look well, but contains a great many germs that may
get into your food and thus find their way into your body and try
to make you ill.

[Illustration: FIG. 22. Two lunches. Which is the more tempting?]

[Sidenote: How foods should be eaten]

Besides being eaten in pleasant surroundings, all food should be
eaten slowly. Let us suppose that we are all seated at a clean,
inviting table and everyone is clean and happy. Before the children
is the very kind of food that is best for them. It looks good and
they know it is good, and they want to eat all they can of it. But
they think of a game of jacks or of ball that they want to play as
soon as dinner is over, so they simply "bolt" their food.

What are teeth made for? Why, to chew with, of course. But why are
we given some teeth that are sharp like knives, and some that are
flat like millstones? It seems probable that these different kinds
of teeth are intended for special purposes, and so they are. If
our teeth were intended only for cutting our food into bits small
enough to swallow without causing pain, there would be no need
for any except the sharp, knife-like teeth. But we have the big
grinders, which were made to use, and it is very important that
they be used in the right way.

[Sidenote: Why food should be thoroughly chewed]

We do not chew our food simply to make it fine enough to swallow,
but for quite another reason as well. In our mouths there is a
fluid called _saliva_. Think of something that you are very fond
of eating, and the mere thought of it makes the saliva come into
your mouth. This saliva has a very important duty to perform in
connection with preparing the food for the little cells of the
body. Each little grain of starch--and you will remember that all
vegetable foods are composed largely of starch--has a capsule about
it. This simply means that it is done up in a little package. The
saliva helps to open this capsule by making it soft (just as water
will soften the paper on a package of candy), so that the other
digestive juices can reach the starch and turn it into the kind of
sugar that is used in the body. If you do not chew your food very
fine, the saliva will not reach the starch granules, the little
packages of starch will be hard to open when they go into the
stomach, and much of the starch will never be made use of in the
body. The saliva has much the same action on the coverings of the
little packages of meat, for all the meat that we eat is done up in
similar packages.

A great Englishman, Mr. Gladstone, who lived to be eighty-three,
made a practice of chewing every bite of food twenty times, and he
thought this had a great deal to do with his being such a strong
and well man and living to such an old age.

[Sidenote: When desserts are not harmful]

After you have eaten meats, bread, and vegetables, it will do no
harm to eat a piece of pie or cake, or a dish of ice-cream or some
other dessert. It is not easy, as a rule, to digest these things
(that is, to get them into such shape that they can be used as food
by the little cells in the body), but a moderate amount of them is
very good for boys and girls, as well as for grown people. If you
refuse to eat the meat and bread, but wait until the dessert is
served and then fill your stomach with sweet things, you will be
starving some of the little cells, and you will be reminded of this
very soon. Sometimes you may be reminded of it by having a pain in
your stomach, but more often by getting low grades in your lessons
at school. Your teacher will know it, too, because you will be so
restless and inattentive in your classes that she will have to give
you a low grade in deportment as well.

  =Questions.= 1. What kind of topics should be discussed at
  mealtime? 2. What is the objection to an untidy table? 3. What
  kind of luncheon do you like best? 4. What does a clean table
  call for? 5. What is the importance of eating slowly? 6. Why
  should we chew our food thoroughly? 7. When are desserts not

  =Remember.= 1. The dining table should be the most inviting
  place in the house. 2. Unpleasant subjects should be avoided at
  mealtime. 3. A clean table calls for clean people. 4. Eat slowly
  and chew your food thoroughly, that the saliva may reach each
  grain of starch. 5. Desserts are not harmful if eaten at the end
  of a meal composed of good building and heat-producing materials.



We have learned that chewing is not merely a process of cutting our
food into such lumps as we can swallow without hurting ourselves;
but that the food must be ground up fine and thoroughly mixed with
the saliva, that the saliva may reach every particle of starch. If
we do not have good teeth, we cannot grind our food as fine as it
ought to be ground, and, as a result, a great deal of the starch
will not be reached by the saliva.

Nature starts every child with a full set of good, strong, clean
teeth. These teeth, which we call first, or milk, teeth, are not
very large, but they are perfect in every respect and last until
the second, or permanent, teeth come in. That is, they will last so
long _if they are taken care of_. If they are not taken care of,
they will decay just as the later teeth will decay, and they must
be cared for in the same way.

[Sidenote: Why we have baby or milk teeth]

Boys and girls sometimes wonder why they have a set of teeth that
come out before they can have the teeth that must last them the
rest of their lives. This is simply because there is not room
enough in a child's mouth for the big, permanent teeth. We must
have teeth while our jaws are growing, so we have first a set of
little teeth. Then just as soon as our jaws get large enough for
the big teeth, the little teeth come out and the big ones come in.

Teeth are about the hardest substance in the body. If we take care
of our second teeth, they should last as long as we live. The only
reason they do not last is because we do not take care of them. If
a person would keep his teeth clean all the time, he would rarely
be obliged to have a single permanent tooth pulled.

[Sidenote: Why teeth break easily]

Teeth are so hard that they are brittle, that is, they break
easily. Glass is brittle, and you can chip off a piece of glass
with a pin by sticking the pin into a crack in the glass. In just
the same way you can chip off a piece of a tooth by sticking a pin
between two teeth. That is what often happens when people pick
their teeth with pins, or with any other hard substance. A metal
toothpick is just as bad as a pin.

[Illustration: FIG. 23. Teeth were not intended for nutcrackers.]

Another way by which little pieces are chipped off the teeth is by
biting hard things. Sometimes we see boys and girls cracking nuts
with their teeth; again we see them trying to bite wires in two.
They put their teeth to many uses for which teeth were never made.
They do not realize, while they are abusing their teeth in this
way, that they are probably chipping the enamel, which is the hard,
shiny covering of the tooth, and are destroying the one protection
that their teeth have against decay.

[Sidenote: Why teeth decay]

When a little piece is chipped off a tooth, an opening is made
through the enamel. Through this opening germs may lodge in the
inner part of the tooth, which is soft. When this happens, a little
black speck appears on the tooth, and after a while the tooth
begins to ache. If you have a toothache, you go to a dentist, and
he probably finds that germs have caused the tooth to decay until
there is a hole extending into the very center of it.

Teeth grow very close together, but there is always a little space
between them. Whenever you eat anything, particles of the food get
into these spaces and if allowed to remain there, soon decompose.
These decomposing particles of food between the teeth will
gradually soften even the enamel, and in this way little openings
are made for germs to get into the teeth.

[Sidenote: How to care for the teeth]

Never pick the teeth. You cannot make them clean by picking them.
Every morning and night brush your teeth with a stiff toothbrush
and a little tooth powder. Brush them both crosswise and up and
down, to get out everything from between them. Do not think you
have done your duty if you brush only your front teeth, the ones
that show. Brush the back teeth just as thoroughly as you do the
front teeth. Very few people will see your back teeth, but these
decay just as fast as your front teeth, if they are not kept clean.

[Illustration: FIG. 24. A sanitary wash-basin with a separate bowl
for washing the teeth.]

[Sidenote: How often one should go to the dentist]

Twice each year you should have a dentist examine your teeth, to
see if there are any little spots where decay has started. If you
have kept your teeth perfectly clean all the time, and have not
chipped off little pieces, there will be none of these decayed
spots. But it is a safe plan to have the teeth looked over at least
twice a year, for you may have broken a tooth without knowing it,
and by the time a decayed spot is large enough to cause pain, or
has made a hole that you can feel with your tongue, it has advanced
much farther than it should have been permitted to do.

  =Questions.= 1. Why should you chew your food thoroughly? 2.
  Why is it necessary to have baby teeth? 3. How are teeth easily
  broken? 4. Why do teeth decay? 5. What must you avoid in order to
  protect your teeth? 6. How should your teeth be brushed? 7. Why
  should you have your teeth examined twice each year by a dentist?

  =Remember.= 1. Take care of your teeth and they will last you as
  long as you live. 2. Do not pick them with pins, or toothpicks
  of any kind. 3. Do not use them for nutcrackers or wire-cutters.
  4. Do not use them for tack pullers. 5. Keep them clean at all
  times. 6. Brush them up and down as well as crosswise.



We have learned how the cells of the body are killed by starvation.
Now let us learn how they are choked to death, or killed by lack of

[Sidenote: How air is changed in the body]

The cells of the body need _oxygen_, and the only way we can give
it to them is by means of air. Every time we take air into our
lungs we are giving oxygen to the red corpuscles or cells in the
blood, which distribute it to the other cells in the body. The air
that goes into our lungs, if it is fresh and pure, contains a great
deal of oxygen and a very little of another gas called _carbon
dioxid_. The air that comes out of the lungs contains a very little
oxygen and a great deal of carbon dioxid. The blood not only takes
the oxygen out of the air, but gives carbon dioxid to the air. This
carbon dioxid is very poisonous, and would kill the cells if it
remained in the blood; hence we should never breathe the same air
twice. There is no lack of fresh air in the world, and no excuse
for anyone's ever breathing air that is not pure.

[Sidenote: Effects of impure air]

If you close all the windows and doors in the schoolroom and shut
up the ventilators, you will soon find that you are not able to pay
close attention to your studies, and in a little while you will
begin to feel drowsy. This is because you have used up so much of
the oxygen in the air that there is no longer enough to supply the
demands of the little cells, and because, in addition, you are
taking into your bodies the poisonous carbon dioxid that has been
breathed out into the room. It takes a great deal of fresh air to
supply the body with oxygen--about 1,250 cubic feet of air each
hour. With thirty or forty children in a room, it does not take
long to use up all the oxygen. So there should be a constant supply
of fresh air coming into the room.

[Illustration: FIG. 25. Results of breathing good and bad air.]

[Sidenote: Methods of ventilation]

It is not only in the schoolroom that you need oxygen. When you
are out-of-doors you get an abundance of fresh air, but from a
great many houses every bit of fresh air is shut out. It is always
possible to let an abundance of fresh air into any house without
causing a draft. A piece of board can be made to fit into a window
frame so that when the window is raised, the air will be directed
upward and will not cause a draft. Hot-air furnaces are made with
cold-air pipes. The fresh air from outdoors comes through these
cold-air pipes and, after being heated, is driven into the rooms of
the house. Some people think they will save coal by closing these
drafts. Not only do they not save coal (for the furnace does not
give as much heat when this draft is closed), but they kill their
body cells by refusing to give them oxygen. The cold-air pipe in a
hot-air furnace should always be kept wide open.

In houses heated with steam or hot water, either the windows must
be kept open, or some other way must be provided for admitting
fresh air and taking out foul air. These arrangements constitute
a system of ventilation. Houses heated with stoves must also be
provided with some means of ventilation. The stove, by its draft,
takes out a little of the foul air, but it will not take out more
air than one person poisons.

[Illustration: FIG. 26. Restfulness: Effect of good ventilation in
a sleeping-room, with the right position for sleeping.]

[Illustration: FIG. 27. Restlessness: Effect of poor ventilation in
a sleeping-room, with the wrong position for sleeping.]

[Sidenote: Why windows should be kept open at night]

Many people seem to think that they do not need fresh air at night,
and they close their bedroom windows as tight as they can. Those
people do not sleep well and often have bad colds. You should
always sleep with your windows open. If it is impossible for you
to have your windows open without having a draft, choose the
draft; it will do you no harm if you are well covered, and under
no circumstances will it do you as much harm as the foul air that
you breathe if your window is closed. Some persons (fortunately
they are few nowadays) will tell you that night air is dangerous.
I wonder what kind of air these people expect to breathe at night.
Do they expect to fill the room in the daytime with enough air for
use at night? Such air would certainly not be very fresh. Night air
is the only kind of air that it is possible to breathe at night.

[Sidenote: The ventilation of public assembly rooms]

Churches, theaters, and ten-cent shows are often very poorly
ventilated. You can always tell a poorly ventilated room by the
foul odor when you go into it from the fresh air, and it is not
wise to stay in such a room. You are killing the cells in your body
when you do so, and you will very probably come out of it with a
bad cold. When the fresh air strikes you, you feel chilly and you
may think you are taking cold then, but in reality you took cold in
that room full of foul air.

[Sidenote: Ventilation of workshops]

Workshops are often poorly ventilated. No person should ever work
in a badly ventilated place. The labor unions frequently strike for
higher wages, but until recently a strike for better ventilation
was rarely heard of. Better ventilation would be practically equal
to an increase in wages, because there would be fewer doctors'
bills to pay, and less likelihood of losing work through illness.
Always have plenty of pure, fresh air wherever you are--in school,
in bed, at work, or at play.

[Sidenote: Why we should breathe through the nose]

The cells in the skin of the nose secrete a watery fluid, and this
fluid serves to moisten the air as it passes through the nose. Dry
air irritates the mucous membrane which lines the nose, throat, and
lungs, and it is very important that the air be moistened before
it reaches the throat. Air is also warmed as it passes through the
nose. Cold air is irritating to the throat and lungs. The small
hairs in the nose catch the dust and dirt in the air and prevent it
from going into the lungs.

The nose was made to breathe through, and all the air that goes
into your lungs should pass through your nose, in order that it may
be moistened, warmed, and cleansed.

[Illustration: FIG. 28. Showing position of adenoids and tonsils in
the throat.]

[Sidenote: Why some children breathe through the mouth]

Frequently we see boys and girls breathing through the mouth. They
do this because there is something in the nose that prevents the
air from passing freely through it. If there were nothing in the
way, the child would breathe through the nose instead of the mouth,
because the natural way of breathing is through the nose.

The most common reason for mouth-breathing is the growth of small
lumps in the throat just behind the nose. These little lumps are
called adenoids. They are not natural, and should be taken out.
We do not know why they grow in some children and not in others,
but we do know that they should be taken out so that the child can
breathe easily through the nose. Large tonsils also cause boys and
girls to breathe through the mouth. Tonsils that are large enough
to cause the child to breathe through the mouth ought always to be
taken out. Large tonsils and adenoids are often found in the same

[Sidenote: Effects of mouth-breathing]

When a child breathes through his mouth all the time, his face
takes on a peculiar shape. His upper lip grows long, his lower
jaw drops back, and his whole face looks flat. His voice has a
peculiar sound, and he finds it very hard to keep up in his classes
at school. Children with adenoids and large tonsils are always
backward in their school work, and may become deaf if the adenoids
and tonsils are not removed.

If you breathe through your mouth instead of through the nose,
go to the doctor and let him see if you have adenoids or large
tonsils; if you have, let him take them out. You cannot possibly
grow into a strong, healthy man or woman if you have adenoids and
do not have them removed.

  =Questions.= 1. What does the body take out of the air? 2. What
  does the body put into the air? 3. What effect does impure air
  have on the body? 4. Why should one sleep with windows open? 5.
  What causes the unpleasant odor in a crowded room? 6. How would
  workmen benefit by properly ventilated workshops? 7. Name the
  helpful ways in which the air is changed while passing through
  the nose. 8. Why do some children breathe through the mouth? 9.
  What effect comes from mouth-breathing?

  =Remember.= 1. Impure air destroys health. 2. Never sleep in
  a room where the window is closed. 3. Avoid going into public
  places or workshops that are not well ventilated. 4. Air must
  pass through the nose before it is fit for the lungs. 5.
  Mouth-breathing is not natural and is usually due to some defect
  that can easily be cured.



[Sidenote: Why exercise is necessary]

Exercise is necessary to make our bodies grow and become strong.
If we stayed in bed all the time, our muscles would not grow and
we could not even walk. If we did not exercise them, the cells in
our brains would not grow and we should not know anything. Every
part of our body must have exercise, that is, each part must do
some work every day. If we used only one part of the body and did
not give the other parts any work to do, only the part that we used
would grow, while all the rest of the body would be small and weak.

[Sidenote: Proportion of rest required]

While every part should do some work each day, the whole body
needs also to have a proper amount of rest. Even the heart, which
seems to be working all the time, must rest. It rests between each
beat. The muscles with which we breathe rest between each breath.
Every person must have a certain amount of rest each day. A man
should have at least eight hours' sleep in every twenty-four hours;
boys and girls should have from nine to ten hours' sleep in every
twenty-four. It is only while we are sleeping that we have complete

[Sidenote: Effect of overwork]

Everybody should have some work to do. Boys and girls should learn
that work is a part of life, though they should not be expected to
do too much. They should not be required to get up at four o'clock
in the morning and work until eight, then go to school until four
in the afternoon, and then work again until dark. They cannot
do this and keep well. Such children will surely neglect their
lessons and will fail to keep up in their classes. It is not the
children's fault, but the fault of the people who give them so
much to do outside of school.

Sometimes bright children fall behind in their classes and seem to
be sleepy during school hours. Very often these children do not
have to do any work at home, but play all the time they are out of
school. We usually find that these children not only play all the
afternoon, but also go to parties at night and often stay up until

[Illustration: FIG. 29. Children work when they play. The little
girl skipping rope is killing the body cells by overwork; she has
skipped more than one hundred times and is exhausted.]

[Sidenote: Ways in which children overwork their bodies]

You may think it is not work to go to a party, but it really is.
You are working the muscles and the cells of your brain when you
are playing games, and these get tired from play work just as they
do from working. It is more fun to do play work than to do real
work, but the cells are tired and need rest after either kind of
exercise. When you go to a party and stay up until midnight, you do
not get nine hours of sleep. How do you expect the cells of your
bodies to get enough rest when you treat them in this way?

Another thing you do at parties is to eat food that tastes good,
but which is not good building material or nourishing for the cells
of the body. These things eaten late at night stay in your stomach
long after you have gone to bed, and the cells of your stomach do
not have a chance to rest at all.

Children should have their parties in the afternoon. You can have
just as much fun at a party in the afternoon as you can at night,
and then your stomach will have time to dispose of the cake and
candies you have eaten, and will be ready to rest when you go to

Small children should be in bed by eight o'clock at night, and even
big girls and boys should be asleep by ten o'clock every night. If
you do not give your bodies rest, you can never grow into strong
men and women.

[Sidenote: The importance of regular meals]

We have learned that every part of the body needs regular rest.
Your stomach is a part of your body. In the stomach and intestines
all the food is changed so that the little cells can make use of
it. Do you think the cook would serve good meals if she were kept
cooking all the time, both night and day? You know she would soon
stop cooking for you if you did not give her time to rest. Your
stomach does work that is even more important to you than cooking.

[Sidenote: Why meals should be at least four hours apart]

It takes about four hours for your stomach to dispose of what
you give it at a single meal. If you eat your breakfast at eight
o'clock, your stomach is going to be kept busy to get rid of it
by noon. Of course you expect to give it more work to do at noon;
that is, you expect to eat a good luncheon. It will be after four
o'clock by the time your stomach has finished the task you put on
it at noon, and there will be only about an hour and a half for
the stomach to rest before you will be ready to give it another
four hours' task, digesting your supper. This means that your
stomach cannot go to sleep until ten o'clock. If you eat three
meals a day, you will give your stomach just about two hours' rest
between eight in the morning and ten at night. If you let it rest
from ten at night until eight in the morning, it is not likely to
give you any trouble.

[Sidenote: When and why candy eating is harmful]

Some people will not let their stomachs rest at all. Often boys and
girls give their stomachs extra work to do by eating sweetmeats
in the middle of the morning while their stomachs are still busy
with breakfast. Then, as soon as school is out in the afternoon,
they want to eat more cake and candy, and thus take away from the
stomach the little rest it has a right to expect before it goes
to work on supper. Then suppose they go to a party and eat again
about midnight. How much time will the stomach have to rest before

[Sidenote: When candy eating is not harmful]

Now, I have not said that boys and girls must not eat candy; and
what is more, I am not going to say any such thing. You may go home
and tell your mother that candy is good for girls and boys and that
they like it so well they ought to have it--no, not all the time.
Here is the part that some of you will not like. Girls and boys
ought to have all they want just after eating luncheon or dinner.
If you have eaten a hearty meal, it is entirely safe for you to eat
candy then; you will not be giving extra work to your stomach, for
the candy will be taken care of along with the rest of the meal.

  =Questions.= 1. Why should we all take exercise? 2. How much rest
  is needed each day? 3. Name some of the effects of overwork. 4.
  How do children overwork their bodies? 5. Why should children
  have their parties in the afternoon? 6. Why should meal hours
  be regular? 7. When and why is candy eating harmful? 8. When is
  candy eating not harmful?

  =Remember.= 1. Proper rest is necessary to health. 2. Rest from
  play is as necessary as rest from work. 3. You must give the
  stomach rest by having regular meal hours and by eating nothing
  between meals.



[Sidenote: The loss of sight]

Sight is one of the greatest blessings we have. Think how dreadful
it is to be blind. If you take care of your eyes, there is no
reason why you should be blind; but if you do not take care of your
eyes, there is a possibility that you may lose your sight. Most of
the blind people in the world became blind because their eyes were
not given proper care, and most of this lack of care happened when
these people were babies.

[Illustration: FIGS. 30 and 31. The roller towel is a common source
of infection of eyes in schools; every school should have properly
constructed wash-rooms, with individual towels.]

[Sidenote: How germs get into the eyes]

Many of the diseases that affect the eyes are catching. They are
not carried through the air, but are transmitted by the use of a
towel or handkerchief used by someone who had the disease. Never
use the towel or handkerchief that another has used.

Germs may be rubbed into the eyes. Keep your hands away from your
eyes. Your hands may have disease germs on them, and when you rub
your eyes you may put the disease germs into them.

[Sidenote: How eyes are overworked]

Many boys and girls ruin their eyes by making them do too much
work. They do this by reading in a poor light, by reading where
the light strikes into the eyes, or by reading in a bad position,
as when in bed or lying down. When you are reading, drawing, or
doing any work with the eyes, always have the best light possible,
which means that the light should fall on your book or work over
your left shoulder. If you are only reading, it does not make much
difference which shoulder the light comes over, provided it comes
from behind. If you are writing or drawing, and the light comes
over your right shoulder, it makes the shadow of your hand fall
just where you want to see.

[Illustration: FIGS. 32 and 33. Correct positions for reading and

Another way of working your eyes too much is by trying to see when
the eyes are not focused right. Sometimes people are said to be
near-sighted, because they cannot see very well at a distance.
This is due to the fact that the eyeball is too long, so that the
lens does not cause the rays of light to focus on the retina. Some
people are called far-sighted. This means that they can see well
at a distance, but that it is hard for them to see things close to
them. Far-sighted children can usually see things near by, but they
do this by making the muscle that rules the lens of the eye work
too hard.

[Sidenote: Method of testing the eyes]

Probably your teacher has a test chart and can tell you whether
your eyes are properly focused. If your eyes are not focused right,
that is, if you cannot see the line of letters marked =20= when
you are twenty feet from this chart, there is something wrong with
your eyes. In that case, you are not only injuring them by trying
to study, but you are hurting the whole body by overworking a part
of it. If you cannot see the letters on the test card clearly
at a distance of twenty feet, ask your father to send you to a
specialist who will fit you with the proper glasses or will treat
your eyes so that you can see well.

[Sidenote: How to test the hearing]

Sometimes children are backward in their school work because they
cannot hear well. Your teacher can test your hearing by holding a
watch near your ear. If you cannot hear a watch tick when it is
held six feet from your ear, ask your father to take you to your
doctor, that he may treat your ears.

[Sidenote: How to care for the ears]

If your hearing is perfect, the best way to take care of the ears
is to let them alone. Never try to dig into the canal that leads
to the middle ear. The ears must of course be washed to keep them
clean, but in washing the ear you should not touch the delicate
canal leading to the drum. A great specialist once said, "Never put
anything smaller than your elbow into your ear," to which another
great specialist added, "And wrap a towel around your elbow."
Never try to dig the wax out of your ears; it belongs in your ears;
it is there for a purpose, so let it alone. If it becomes hardened,
you cannot get it out and will only injure your ears in trying to
do so. An ear spoon is a dangerous thing.

  =Questions.= 1. State the chief cause of loss of sight. 2. How
  can you keep germs out of your eyes? 3. Name three ways by which
  you may overwork the eyes. 4. Tell how to take care of the ears.

  =Remember.= 1. Overworking the eyes is as injurious as
  overworking the stomach. 2. Keep your hands away from your eyes;
  germs on your hands may get into your eyes and cause them to
  become sore. 3. You overwork your eyes when you try to read or
  write in a poor light or in a bad position, as when lying down.
  4. You overwork your eyes when you try to study with eyes that
  are not properly focused. 5. Keep your fingers out of your ears.
  6. Take care of your ears by letting them alone.



If you break or cut the skin on your body, you make an opening
through which germs can get in. You cannot always help breaking
your skin, but you can always wash the break with soap and water,
and put a clean cloth over it to keep out germs.

[Sidenote: The work of the sweat glands]

The work of the little sweat glands is very important to your
health. These glands are just as important as the kidneys, and if
they did not do their work, you would die very quickly. If your
body is covered with dirt, the work of these glands is seriously
interfered with; and when the sweat glands are not doing their full
amount of work, the kidneys must do more than their share. It is
never right to make one part of your body do the work intended for
another part.

[Illustration: FIG. 34. A model bathroom.]

When the body is dirty, not only are the sweat glands interfered
with, but the little sebaceous (oil) glands become plugged up, and
blackheads appear on the face and body.

[Sidenote: Importance of bathing]

In order that the various glands of the skin may be kept in good
health, it is necessary for us to keep clean. To do this we wash
our faces and hands and bathe our bodies. Someone may ask, "How
often ought a person to take a bath?" The question cannot be
answered, except to say, "Just as often as may be necessary for
you to keep absolutely clean." Some people do not have to bathe as
often as others, but no one can keep clean unless he takes a bath
at least twice a week.

[Sidenote: Hot or cold baths]

Another question that is frequently asked is, "Is it better to
take a bath in cold or hot water?" This is another question that
cannot be answered in the same way for every person. A cold bath
is more stimulating than a warm bath. If, after you have taken a
cold bath and rubbed yourself briskly with a rough towel, the skin
becomes red and warm, a cold bath is best for you. But if, after
you have taken a cold bath and rubbed yourself for not more than
ten minutes, the skin appears bluish and cold, a cold bath is not
good for you, and you should not take it. A cold bath should always
be taken in the morning, just after getting out of bed, and a warm
bath should always be taken in the evening, just before going to

[Illustration: FIG. 35. A nail properly cared for, and a nail not
properly cared for. Which should you prefer to have?]

[Sidenote: How to care for the nails]

The finger nails and toe nails are a part of the skin and they also
need to be taken care of. You will see at the root of your finger
nails a thin layer of skin that is inclined to grow out with the
nail. If this skin is not kept pushed back it becomes rough, breaks
into little shreds, and forms "hang nails." This little band of
skin should always be kept carefully pushed back. The finger nails
should be kept evenly and neatly trimmed, but they should not be
cut so close to the skin that the ends of the fingers project
beyond the nails. The nails are for the protection of the ends of
the fingers and toes. Nails that are trimmed unevenly and nails
that are bitten off are ugly and indicate untidy habits. The shape
of the nails should follow the outline of the ends of the finger.
Neither is it a sensible fashion to trim the nails to points or to
let them grow very long.

The toe nails need attention just as much as do the finger nails.
They should be trimmed to follow the shape of the toe. Failure to
trim the toe nails properly will result in ingrowing nails.

Dirt is very likely to collect under the nails. This should always
be carefully cleaned out. You cannot wash this dirt out unless you
use a stiff nail brush. If you clean your nails just after you wash
your hands, you will find that it will be much easier to get the
dirt out while the dirt and the nail are both softened by the soap
and water. In cleaning your nails, use a dull nail cleaner or a
smooth wooden stick. Do not scrape the inside of the nail with a
sharp knife. This scraping of the inside of the nails will cause
them to catch the dirt more easily, as well as to grow thicker and
thicker until they become very ugly. Neat, clean finger nails help
to make pretty hands; dirty, untidy nails spoil the prettiest hands.

  =Questions.= 1. What are the uses of the sweat glands? 2. How
  often should people take baths? 3. How can you tell whether a hot
  or a cold bath is better for you? 4. Tell how finger nails should
  be cared for. 5. How should toe nails be treated?

  =Remember.= 1. If you do not keep your body clean, the glands of
  the skin cannot do their work properly. 2. Every person should
  take a bath at least twice a week; some persons need a bath
  every day in order to keep clean. 3. If you take a bath in cold
  water, and the skin does not become warm and pink when you rub
  it with a rough towel, a cold bath is not good for you. 4. Cold
  baths should be taken in the morning on getting up. 5. Warm baths
  should be taken in the evening before going to bed. 6. Finger
  nails should always be kept clean and neat; dirty, untidy nails
  make ugly hands.



Many people are killing the cells of their bodies by taking certain
poisons into them. There are many kinds of poisons that can be
taken into the body, but we are going to learn now about only two.
These are tobacco and alcohol.

[Illustration: FIG. 36. Effect of cigarette smoking.]

[Sidenote: Proof that tobacco is a poison]

Tobacco is a poison. Those of you who have tried to smoke know
this, because it made you sick the first time you tried it. There
are many other indications that tobacco is a poison. We know that
it affects the red blood cells in such a way that they do not carry
the oxygen as well as do those of people who do not smoke. We know
that it has a very bad effect on the heart and that it interferes
with the action of the nervous system.

[Sidenote: The extra work caused by tobacco]

When certain poisons get into the body, the blood makes something
that will counteract the effects of those poisons. After one has
used tobacco for some time, the cells of the body will take care of
the tobacco poison by making an antidote for it. More than this,
they begin to want it all the time. The tobacco user forces the
cells of his body to make an antidote for this poison every time he
uses tobacco. Thus he makes the cells do work that is unnecessary,
and keeps them from doing work that is necessary.

[Sidenote: Other bad effects of tobacco: (_1_) On the nose and

Tobacco smoke irritates the cells that line the throat and nose
and causes inflammation. This is why so many smokers have catarrh.
Smoking is not the only cause of catarrh, for people who do not
smoke often have this trouble, but it is one of the most frequent
causes. Smoking also irritates the throat so badly that many of
those who smoke have "smoker's throat." This is a bad form of sore
throat that can be cured only by stopping the use of tobacco.

[Illustration: FIG. 37. The athlete knows that alcohol and tobacco
are foes to speed, strength, and nervous control. (_From photograph
of "The Sprinter," modelled by Dr. R. Tait McKenzie._)]

[Sidenote: (_2_) On the blood]

People who smoke a great deal have fewer red corpuscles (the little
red cells of the blood) than those who do not smoke. Especially is
this true of cigarette smokers. It is the lack of red blood cells
that causes the cigarette smoker to look pale and sallow.

It is probably not the direct effect of tobacco that causes the
loss of red blood cells, but something that is connected with the
act of smoking. When you take smoke into your mouth, you take in
at the same time a gas known as _carbon monoxid_. This gas is
very poisonous to the body, and combines with the red blood cells
in such a way that they cannot take up the oxygen in the lungs and
carry it to the rest of the cells in the body. The cigarette smoker
almost always inhales the smoke, and thus he absorbs a great deal
more of the carbon monoxid than the man who does not inhale the
smoke. Of course, the more of this gas he takes into his body, the
more red blood cells will be affected and the less oxygen will be
taken to the other cells.

[Sidenote: (_3_) On the nervous system]

We do not know just how tobacco affects the cells of the nervous
system. It may be that they are affected mostly by being deprived
of oxygen, or it may be that the tobacco affects them directly.
However the harm is done, we know that the cells of the nervous
system are affected by tobacco. One of the nerves that is most
commonly affected by the use of tobacco is the nerve of the eye,
the nerve that enables us to see. We know that when people use
tobacco a great deal they sometimes lose their sight. This does not
happen to everyone who uses tobacco, but you can never tell whom it
will affect in this way. The only safe thing to do is not to use
tobacco, and then you will know that you will not lose your sight
from this cause.

[Sidenote: (_4_) On the stomach]

The use of tobacco affects the stomach. People who use tobacco
a great deal are likely to have indigestion. The tobacco causes
this probably by depriving the stomach cells of oxygen through its
effect on the blood cells.

[Sidenote: (_5_) On the heart]

Tobacco has a very bad effect on the heart. People who use much
tobacco have what they call "palpitation of the heart," but doctors
call it "tobacco heart," because it is caused by the use of
tobacco. No insurance company will insure a person who has "tobacco

Most boys grow up to be men before they manage to use enough
tobacco to cause tobacco heart. However, long before they are
grown, they show that the tobacco has affected their hearts,
because they are short of breath and stand about as much chance of
winning a race as does a mouth-breather.

[Sidenote: Effects of alcohol:]

The effect of alcohol is a subject on which I want to speak very
plainly and frankly, because I do not want the boys and girls who
read this to get the same idea that I got when I was in school,
or to be affected by it as I was. When I was a little boy I was
taught that if a person drank alcohol in any form the lining of his
stomach would be eaten up. In proof of this statement I was shown
a picture of an ulcerated stomach that was said to have resulted
from drinking whisky. Naturally I expected to find that people who
drank whisky would not be able to eat anything at all, or would be
troubled a great deal with pain in their stomachs. To my surprise,
I found that many people had ulcers of the stomach who never took
an alcoholic drink, while many of those who drank a great deal
seemed to have the best of appetites and were never troubled
with their stomachs. As a result, I came to the conclusion that
all this talk about the evil effects of alcohol was foolishness.
Later I studied medicine, and learned that the effect of alcohol
on the stomach is, in reality, the least of its evils. But I want
to impress upon you that, as a result of forty years' study, I
consider alcohol the most dangerous thing in the world to-day. By
"alcohol" we mean any drink that contains alcohol, such as whisky,
wine, brandy, beer, etc.

[Sidenote: (_1_) On the stomach]

When alcohol is taken into the stomach, it first causes a
congestion; that is, it causes an increase in the quantity of
blood in the blood vessels of the stomach. It might seem that
this would aid digestion in the stomach, but it does not, because
alcohol affects the food in the stomach in such a way that it
prevents the gastric juice from acting on the food. If the use of
alcohol is persisted in, it causes the little cells in the stomach
that make the gastric juice to become filled with fat, and then
those cells cannot make the gastric juice. Thus, continued use of
alcohol causes a smaller supply of gastric juice, and the food
passes from the stomach into the intestines without having been
acted upon by the gastric juice, as it should have been. The result
is that the food decomposes in the intestines and a poison is
formed. This poison is taken up by the vessels that carry the food
from the intestines and kills a great many of the cells of the body.

Alcohol does not burn holes in the stomach, but it destroys the
usefulness of the stomach by its action on the cells that secrete
the gastric juice.

[Sidenote: (_2_) On the liver]

When alcohol is taken into the stomach, very little of it reaches
the intestines. It is rapidly absorbed by the lining of the stomach
and passes into the blood. The blood from the stomach goes directly
to the liver. The alcohol makes the cells of the liver hard and
causes them to become filled with fat, as it does the cells of the
stomach. In this way it destroys the action of these cells and
prevents their doing the work for which they are intended. From the
liver the alcohol goes with the blood to all parts of the body, and
it has its influence on all the cells in the body. This influence
is always harmful.

[Sidenote: (_3_) On the body's powers of resistance]

We know that when a man who is in the habit of drinking gets
pneumonia, he is far more likely to die than is one who is not
in the habit of using alcoholic drinks. The man who drinks cannot
resist the effects of disease as can one who does not drink.
This shows that the use of alcohol reduces our resisting powers,
and puts our cells in such condition that we cannot overcome the
effects of disease.

People who are sick with a slow disease like consumption are often
advised by their friends to take whisky to brace them up. It is
true that the immediate effect of the whisky is to make the patient
feel a little better, but the final effect is to leave him in a
much weaker condition than before. More than this, the cells are
much less able to resist the disease germs than they were before
the alcohol was taken. When people are exposed to such diseases
as scarlet fever and smallpox, they may think that if they take a
drink of whisky they will not be so liable to contract the disease.
It is just the other way. The alcohol reduces the resisting powers
of the cells of the body, and anything that does this renders a
person more liable to contract any disease to which he is exposed.

[Sidenote: (_4_) On the nervous system]

The effect of alcohol on the cells of the nervous system is very
marked. Continued use will injure the nervous system and result
in a kind of insanity called delirium tremens. It will also cause
other forms of insanity. The effect of alcohol on the parent is
passed on to the children of the next generation, and even beyond
this. A large percentage of idiotic children are the offspring of
alcoholic parents.

[Sidenote: (_5_) On the morals]

The use of alcohol numbs the sense of right and wrong. More young
men have become criminals from the use of alcohol than from any
other one cause. Anyone who reads the daily papers can see that
many criminals give the use of alcohol as an excuse for having
committed a crime.

[Sidenote: (_6_) On brain work]

Some people will tell you that alcohol stimulates the brain, so
that one can work faster and better. This is not true. Tests have
been made in this matter, and it has been found that men doing
mental work will work about one tenth slower and make one fourth
more mistakes when given one drink of whisky a day, than they will
when not given any whisky. If _one_ drink of whisky a day thus
reduces a man's power and accuracy in doing mental work, what do
you think three drinks, or ten drinks will do?

[Illustration: FIG. 38. The mind not clouded by alcohol works
quickly and makes few mistakes.]

[Illustration: FIG. 39. The mind clouded by alcohol works slowly
and makes many mistakes.]

[Sidenote: What business men think of men who drink]

Many business men drink, and they know the results of alcohol not
only from the effects they have observed in others, but also from
the effect they know it to have on themselves. When a man applies
to them for a position, these business men almost invariably ask
him if he drinks. The man who does not drink stands nine chances
in ten of securing the position, while the man who drinks stands
only one chance in ten. This shows what business men think of the
effect of alcohol, even when taken in moderate quantities. They
know that it reduces a man's power to do mental as well as physical
work, that it causes him to make mistakes, and that it may finally
destroy his morals and result in his becoming a thief or a criminal.

  =Questions.= 1. How do we know that tobacco is a poison? 2. How
  does tobacco make extra work for the body? 3. What effect does
  tobacco have on the nose and throat? 4. What is the effect of
  tobacco on the blood? 5. On the nervous system? 6. On the heart?
  7. Mention some of the false ideas about the effect of alcohol.
  8. How does alcohol affect the stomach? 9. The liver? 10. In
  what ways does alcohol reduce the resisting powers of the body?
  11. How does alcohol affect the nervous system? 12. How does
  it influence mental work? 13. What do business men think of
  drinkers? 14. What influence has alcohol on the next generation?

  =Remember.= 1. Tobacco is a poison that has a very bad effect on
  the nervous system, the blood, the heart, the stomach, the nose,
  and the throat. 2. Alcohol is a poison and not a food. 3. Alcohol
  injures the stomach, the liver, and the nervous system. 4.
  Alcohol reduces the power to do accurate mental work. 5. Alcohol
  numbs the sense of right and wrong, and encourages crime.





We have learned that the body is made up of cells, and that each
cell is alive. The cells in our bodies cannot live separately.
There are, however, certain animals and plants that are each made
up of a single cell. These animals and plants are called germs, and
some of them cause disease.

[Sidenote: Different germs cause different diseases]

These germs are so exceedingly small that we can see them only
with the aid of a microscope. They differ in appearance one from
another, as a pine tree differs from an ash, or an American child
from a Chinese child. When you plant your garden, you put sweet
peas in one place and asters in another, and you know that you will
have sweet peas growing where you planted the pea seeds, and asters
growing where the aster seeds were put. So it is with these little
germs; you will no more get tuberculosis from typhoid fever germs
than you would get asters from pea seeds.

Now, while there are many, many kinds of germs in the world, there
are only certain ones that cause certain diseases, and we have
learned where these germs like to live and how to kill them. We
also know that they come only from some person or animal sick
with the particular disease which they cause. Typhoid fever germs
are not given off by a person suffering with tuberculosis, nor
are diphtheria germs given off by a typhoid fever patient, but
the germ of each disease is given off by some person or animal
suffering from that particular disease.

[Sidenote: How sickness due to germs can be prevented]

If we kill all the germs that come from people sick with a certain
disease, no one else can catch that disease. Knowing this, it seems
unnecessary for anyone ever to be sick with disease that is caused
by a germ. This is literally true, and the only reason that we have
germ diseases is because we do not kill the germs that come from
the sick people.

Professor Irving Fisher of Yale University has said, "It is
entirely possible to wipe out consumption within a single
generation." It may not actually be done so quickly, but it is
certain that the disease can finally be wiped out, though it may
require many generations to accomplish it.

Why, then, are germ diseases allowed to exist? Simply because
so many people do not know the facts; and because many who do
know will not take the trouble to kill the germs, even when they
realize that some one else may get the disease as a result of their
carelessness. What do you think of a woman who said, "I do not care
if my neighbor's children do get scarlet fever from us; she is not
a friend of mine, any way"? A woman has been heard to make such a
statement to a health officer. It is just such people as this who
spread disease.

  =Questions.= 1. How may germs be compared to seeds? 2. What do we
  know about disease germs that will help us to get rid of them?
  3. How is it possible for us to get rid of consumption and other
  germ diseases?

  =Remember.= 1. While there are many kinds of germs in the world,
  only a few cause disease. 2. The germ that causes a certain
  disease will cause that disease and no other. 3. It is entirely
  possible to kill all the germs that cause disease.



We shall not try to learn here all the ways by which it is possible
to destroy the germs of disease as they come from sick people.
But there are certain rules (we sometimes call them fundamental
principles) that you must know, if you hope to keep well and to
prevent others from getting sick.

[Illustration: FIG. 40. How diseases are frequently transmitted to

[Sidenote: Why we should stay away from the sickroom]

The first of these rules is: _Do not go into the room where any one
is sick unless it is absolutely necessary_. No one but the nurse
should sleep in the room with a sick person. We know that certain
diseases are communicable (catching), but it has not yet been
determined whether some others are communicable or not. It has not
been proved, for instance, that we cannot catch rheumatism from
another person. Only a few years ago it was believed that one could
not take consumption from another person, but now we know that this
is the very way to get it. Therefore, stay away from sick people
as much as possible. It is not good for the patient to have people
around him, and it is dangerous for the well to come in contact
with the sick.

[Sidenote: Not using things used by the sick]

The second rule is: _Do not use anything used by a sick person
until it has been washed_. This is a good rule to apply to things
used by a well person also. It is neither safe nor pleasant to eat
from the spoon or fork, or to use the napkin or towel which has
been used by someone else.

Sometimes children think the food prepared for a sick person is
ever so much nicer than that set before themselves, and wish they
could have a little of it. How often have we seen a sick mother
give her little ones "a taste" from the spoon with which she is
eating. This is very dangerous, and if she knew it, the mother
would cut her hand off before exposing her children to this danger.

[Sidenote: Reason for scalding things used by the sick]

Third: _Everything taken from a sickroom should be boiled before
it is used again_. The knives, forks, and plates should not be put
with other dishes until after they have been separately washed and
boiled. Towels, napkins, bedding, and clothing from a sickroom
should not be washed with other bedding and clothing, but should be
washed and boiled separately. Some people send out the clothes from
the sickroom with the rest of their washing, and in this way give
disease to others.

[Sidenote: How excreta from the sick should be treated]

Fourth: _All discharges (sputum, urine, bowel discharges, and
matter from sores) from any sick person should be thoroughly
disinfected before being finally disposed of_. The sputum should be
received on little rags or paper napkins, and burned; and the other
discharges should be disinfected with some poison that will kill
the germs. We shall say more about disinfection when we come to
study the prevention of special diseases.

[Sidenote: Necessity of washing the hands after touching the sick]

Fifth: _Every person who touches a sick person, or handles anything
that comes from a sickroom, should immediately wash his hands_.
Unless he washes his hands at once, the germs which may be on them
may get into his mouth.

[Sidenote: How dirt causes disease]

Sixth: _Dirt, which is an indirect cause of disease, must not be
allowed to accumulate_. If your yard were full of dirt, garbage,
and manure, it would not cause disease unless the germs of some
disease became planted there. But such a place is an indirect cause
of disease, in that it furnishes a fine place for germs to grow in.
If a fly with typhoid germs on its feet were to alight in such a
yard, the germs would be planted in a most favorable spot and would
grow very fast.

[Illustration: FIG. 41. A place that is an indirect cause of
disease, since it furnishes a fine place for germs to grow in.]

None of the disease germs like sunshine; neither do they like
dry places. They die very quickly in the sunlight, and grow very
slowly, if at all, in dry places; but in damp, dark places they
grow very fast. Dirty back yards make ideal gardens for germs.

Let a fly with germs on its feet alight in a clean yard where
sunshine can reach every corner, and what chance will the germs
have to grow? They will not even get a start. Hence, while disease
cannot be caused by dirt, disease germs stand a very good chance of
living where there is plenty of dirt and no sunshine. Filthy habits
are on an equality with filthy conditions, and go hand in hand with
them. One of the worst of habits, and a cause of much sickness, is
that of answering Nature's calls in places other than the closet.

  =Questions.= 1. Why should you never make unnecessary visits
  to a sick person? 2. Why should you avoid anything used by a
  sick person? 3. Why should everything taken from a sickroom be
  scalded? 4. What should be done with all discharges from a sick
  person? 5. How is dirt a source of disease?

  =Remember.= 1. Unless it is necessary, do not go into a room
  where anyone is sick. 2. Never sleep in a room with a sick
  person. 3. Never eat from a spoon or plate that has been used by
  another. 4. Boil all the articles taken from the room of a sick
  person. 5. Always wash your hands after touching a sick person or
  anything that comes from his room. 6. Sunshine kills germs; let
  the sunshine into every corner of your house.



[Sidenote: How germs get into our bodies]

Disease germs get into our bodies in three principal ways: they are
eaten with our food; they are taken in with the air we breathe; and
they get in through breaks in our skin, even though these breaks be
very small, as when made by the bite of a mosquito or other insect.

[Sidenote: How germs get into our food:]

[Sidenote: (_1_) From the air]

How do germs get into our food or drink? You must remember that
these germs are extremely small, so small that many of them can be
carried by a particle of dust that you can see only in a ray of
sunshine. When the germs become dried, they float about on these
particles of dust, the dust alights on our food, which is moist and
warm, and the germs immediately begin to grow.

[Sidenote: (_2_) From the hands]

Another way by which germs get on food is from the hands through
which it passes. Did you ever think how many people handle an
apple? First, the man who picks it from the tree; then the examiner
in the packing house where apples are taken to see that they are
the right kind to be packed in a certain box. Then it is wiped off
by a boy or girl--handling number three; then it is wrapped in
paper--number four. Next it is packed in a box, but in this case
the paper protects the apple from dirty hands. When the merchant
buys the apples he feels several of them, and puts them out on the
display shelf; this makes handling number five. Everyone who thinks
of buying apples will touch one or more of them, and when they are
sold the clerk handles them again. In other words, every apple goes
through the hands of at least seven people before you get it. Do
you not think it needs washing?

Go into a butcher shop and see how many people will put their dirty
fingers on the meat. Some of them even keep their gloves on when
they do this. Imagine how many germs may be planted on the finger
of a glove.

Our whole method of displaying foods for sale is wrong. The
customer can see the fruits, vegetables, and meats just as well
in a glass case as when they are on an open counter or shelf, and
nothing is gained by poking a dirty finger into a piece of beef, or
by rubbing your hands over the apples. A glass case not only will
protect the fruits and meats from such practices, but will keep out
germ-laden dust and flies whose feet are covered with germs.

[Illustration: FIG. 42. The foot of a fly, highly magnified.]

[Sidenote: (_3_) From flies]

_Probably the most common source of germs on food is the fly._ Did
you ever watch a fly very closely for a long time? Did you ever
happen to see a manure pile early in the morning and notice how
many tiny flies are on it? These flies have just been hatched.

[Sidenote: Breeding places of flies]

Flies like manure because it is the best place they can find in
which to lay their eggs. Each female fly lays about three hundred
eggs. They do not hatch directly into flies, as hen's eggs hatch
into chickens, but when the fly's eggs hatch you find maggots, and
these maggots later hatch into flies.

[Sidenote: The journey of the fly]

Turn over the manure some spring morning, and you will see it full
of white specks. These specks are maggots that will hatch into
flies. Watch the flies as they leave the manure pile and see where
they go. If there is a dead dog or cat or a filthy garbage can
near, they will fly to it. Then they will go into the water-closet
and crawl over the filth there. Their next trip will probably bring
them to the kitchen, where they will crawl over the food. From here
they will go to the cuspidor and take a drink of water, and will
get their feet covered with the dirt that is in the cuspidor. Next
they will try a walk over the nipple of the baby's bottle, or they
will light on your face, or get into the butter or milk.

After the fly has been in dirty places, he "washes" his face and
hands, that is, he rubs his feet together and then rubs them over
his head. Did you ever see a fly wash himself with water? No, you
never did.

[Illustration: FIG. 43. Where a fly has walked; each little spot
represents a growth of germs left by the fly.]

After a fly has made his journey, you would suppose that his feet
would be covered with dirt and germs, and so they are. Not only
does he carry germs on his feet and body but he also eats dirty and
diseased things. Moreover, fly specks contain the germs of disease,
and the fly is not at all particular about where he puts his specks.

[Sidenote: Proof that the fly is a germ carrier]

If you let a fly walk over a culture plate, there will be a growth
of germs wherever his feet touch. A culture plate is simply a
glass plate covered with gelatine or something else in which
these germs like to grow, and where they can easily be seen. Each
germ will multiply so fast that there will soon be a spot of them
large enough to be seen readily with the naked eye. In the picture
showing a culture plate over which a fly has walked (Fig. 43), the
little specks are not single germs, but each speck represents a
growth containing many thousands of germs.

[Illustration: FIG. 44. Flies go from filth to food.]

[Sidenote: How to get rid of the fly:]

How are we going to get rid of flies? We cannot get rid of them
entirely, but there are a great many ways by which we can prevent
there being so many of them, and whereby we may keep them out of
our houses and away from our food.

[Sidenote: (_1_) By removal of manure]

We have learned that flies are always found about horse manure,
because it makes a good place in which to hatch their eggs. If we
could dispose of the manure, there would be one place less for the
fly to lay her eggs. Behind barns we usually find piles of manure.
It is in these heaps that the fly lays her eggs, not in the little
lumps found in the streets. Now, there is no sense in keeping this
great pile of manure about any barn. In towns the manure can be put
into a box with a cover, so that the flies cannot get at it. In the
country every well-managed farm has the barns cleaned out every
day, and it would not be much more trouble for the farmer to throw
the manure into a wagon and take it to the fields with him, than
it is to pile it up beside his barn. If he did this, he would find
that there would be few flies about his house.

[Sidenote: (_2_) By covering garbage cans]

Even if we were to take every particle of manure away as fast as
possible, we should still have some flies, for when flies do not
find manure for their hatching places, they will take the next best
thing. It must be something dirty; clean things will not answer
at all for a fly's home. Next to the manure pile, the fly likes a
dirty garbage can, a dead animal, or anything that is decomposing.
If she cannot find anything better, she will take a rotting apple;
but she does not really like this, and if she cannot find anything
better than an old apple in your yard, she will probably go
elsewhere to lay her eggs.

[Sidenote: (_3_) By keeping clean yards]

We cannot entirely stop the hatching of flies, but if we do
away with the old manure piles, keep fresh manure and garbage
cans covered, and keep our yards free from everything that can
decompose, we shall have very few flies about our houses.

[Sidenote: How to keep flies out of the house]

Since we cannot get rid of all the flies, the next best thing is
to keep the few that may be left out of our houses and away from
our food. This we can do by means of wire screens and netting. Wire
screens are very cheap, and if there are no wire screens on your
house, you should persuade your father to buy some. But a screen
will not keep flies out unless it is kept closed, so do your part
by never leaving the screen door open for a second longer than is
necessary for you to go in or out.

Our houses are not the only places that need screens.
Slaughterhouses, butcher shops, candy stores, grocery stores--every
place where any kind of food is handled or sold--should be
screened. Flies should never be allowed to alight on anything which
is to be eaten.

  =Questions.= 1. Name three ways by which germs get into our
  bodies. 2. How do germs get into our food? 3. Why should foods be
  screened? 4. Trace the fly from his birth-place to our food. 5.
  How do we know that flies have germs on their feet? 6. Tell how
  we can get rid of most of the flies. 7. How can we keep flies out
  of the house? 8. What can boys and girls do to help keep them out?

  =Remember.= 1. Always wash an apple, pear, or any other fruit
  before you eat it. 2. All foods are handled by many people, and
  are not clean until they have been washed. 3. Flies like to live
  in dirty places, and their feet and legs are covered with germs;
  get rid of the flies. 4. Flies hatch in manure piles and other
  dirty places; keep your yard and lot clean so that flies will
  have no place to lay their eggs. 5. Put screens on the house to
  keep flies out, and keep the screens closed.



The water that we drink frequently contains disease germs. It is
not always the clearest water that is freest from disease germs,
for the germs do not make the water cloudy.

[Illustration: FIG. 45. An improperly located well; notice lines of

[Sidenote: Why sewage should not be put into streams]

Water does not get disease germs from the ground, but from man.
Almost every town has a sewer system that empties into some stream.
This practice was started a long time ago when men thought that
running water would purify itself in the course of a few miles. We
have learned, however, that this is not true. Germs will continue
to live in running water just as they do in any other water, and
disease germs will live in a stream from twenty-five to thirty-five
days. Estimate how far a stream will flow in that length of time,
and you will know how far disease germs will travel in that way. No
sewage should ever be allowed to get into a stream until the germs
in the sewage have been killed.

[Sidenote: Other sources of germs in streams]

Sewage is not the only means by which disease germs are carried
into streams. Often we find people building barns, slaughterhouses,
and mills on the banks of a stream. The filth from barns and
slaughterhouses always contains disease germs, and often the filth
of mills contains poisons that are just as harmful as germs when
taken into our bodies. None of these things should ever be allowed
to get into a stream. Water is a very important article of food,
and we should take every care to keep it pure.

[Illustration: FIG. 46. A properly located well.]

[Sidenote: How germs get into wells]

The water from most wells is clear and cool, but nevertheless
may contain many disease germs. "How does this happen?" you ask.
Because the well is too close to an out-house or some other source
of filth. When a man in the country or in a small town builds a
house, he immediately thinks of digging a well just as close to the
house as he can, so that he need not carry the water far. Next he
thinks of locating the closet, and this, too, he wants near the
house. The well and the closet are often near each other, and often
the closet is on higher ground than the well. The vault under the
closet is seldom water-tight. In fact, the intention of the owner
is that a great part of the vault contents shall soak away.

In many localities the ground is an open gravel, and the vault
contents run through this gravel into the well, carrying disease
germs with them. In one little town, with wells as a source of
drinking water, the health officers found that the closet of every
house was draining directly into its well. In some countries vaults
can be used; but in any region where there is a gravel subsoil, the
contents of the closet will find their way into the well, unless
the closet is lower than the bottom of the well. In such places the
vault must be made water-tight, in order to keep the vault contents
out of the well.[2]

[Sidenote: Why springs are not always pure]

Springs are usually sources of pure water, but do not think that
every particle of water that oozes from the ground is a spring.
Near a certain town is a so-called "very fine spring." This
"spring" appeared after a man had made a cesspool on the hill
above, and is simply the drainage from the cesspool. Springs that
come from deep sources, however, nearly always contain pure water.

[Sidenote: The safest sources of water]

The safest source of water for domestic use is a stream that is
known to be free from contamination, or a well so deep in the
ground that it is hard for any polluting matter to reach it. But
remember that sewage may follow a well pipe along the outside and
thus reach even a deep well, if the well is not properly protected
at the top.

Keep disease germs out of your drinking water. You cannot drown
them out and you cannot strain them out, so do not let them get in,
for you cannot drink water containing disease germs without running
the risk of becoming sick.

  =Questions.= 1. Mention more than one way in which germs get into
  streams. 2. How long may disease germs live in running water?
  3. Mention some instances showing that running water does not
  purify itself. 4. How do disease germs get into milk? 5. Describe
  the proper location of a well in regard to refuse. 6. How may
  springs become polluted? 7. What are the best sources of water
  for domestic use?

  =Remember.= 1. Disease germs get into water from dirty places
  along the banks of the streams; they do not come from the ground.
  2. Clear water is not always pure; germs do not make the water
  cloudy or muddy. 3. Wells often become infected by matter from
  closets seeping into them; make your closet water-tight. 4.
  Spring water is usually pure, but not all water that oozes out of
  the ground is spring water.



[Sidenote: Disease germs in the air]

We take germs into our bodies with the air that we breathe. Since
we cannot stop breathing and live, we must see to it that the air
we breathe is kept pure.

[Illustration: FIG. 47. (a) Prevalence of germs in air of thickly
populated districts. (b) Prevalence of germs in air of sparsely
populated districts.]

There are always more germs in the air of places in which people
live closely crowded together than where there are only a few
people. This is proved by Figure 47, which shows that many more
germs were found on a culture plate exposed in the downtown part of
New York City than on another plate exposed far uptown, where there
are not so many people. Remember, however, that all germs are not
disease germs.

[Sidenote: How we may keep disease germs out of the air:]

How do the disease germs get into the air? When one sneezes, a
spray of droplets is thrown into the air. If the person sneezing
has the grip, these droplets contain the germs that cause grip.
Whenever a person with consumption coughs, he sprays droplets which
contain the germs that cause consumption.

[Sidenote: (_1_) When coughing or sneezing]

If a person would hold a handkerchief before his mouth when he
coughs or sneezes, these droplets of moisture would not be sprayed
into the air, and the disease germs in them would not be scattered
about. You ask, "Shall everyone who is sick hold a handkerchief
before the mouth when sneezing or coughing?" Everyone, whether
sick or well, ought to hold a handkerchief before the mouth when
sneezing or coughing. Learn to do this at once, and never forget it.

[Sidenote: (_2_) When spitting]

Another way by which disease germs get into the air is from the
sputum. People spit on the floor or the sidewalk, and the sputum
becomes dried; it is then blown about as dust. The germs of disease
are not killed by drying, and when they get into our bodies with
the dust which we breathe in, they immediately begin to grow.
Disease germs get into the air chiefly through careless habits of
coughing, sneezing, and spitting, and these careless habits can
easily be prevented.

[Sidenote: Why well people should not spit on floor or sidewalk]

A boy once said that if he saw a consumptive spit on the sidewalk,
he would want to hit him, and to emphasize his remarks he spat
on the floor of the room, just as you have seen boys spit on the
ground when they were thinking of fighting. There might have been
some germs of consumption in the sputum this boy left on the floor.
Of course he was very positive that he did not have consumption,
but this was no proof that his sputum was free from the germs of
this disease.

Remember that it is not only the sick who should never spit on
the floor or sidewalk, but that no person should ever spit on
any floor or sidewalk, or into any place except into a cuspidor,
handkerchief, or spit-cup of some kind. If you spit into a
handkerchief, a paper napkin, or a bit of cloth, be sure to burn it
as soon as you can, before it becomes dry.

  =Questions.= 1. In what places do we find germs most abundant in
  the air? 2. How do well-bred people avoid putting disease germs
  into the air? 3. Why is it important for well people to take the
  same precautions as sick people?

  =Remember.= 1. Every person should hold a handkerchief before
  the face when coughing or sneezing. 2. Never spit except into a
  cuspidor, handkerchief, spit-cup, or other special receptacle.
  3. If well people will practice clean habits, the sick will be
  helped and encouraged to follow their example. 4. Remember: No
  spit, no consumption.



[Sidenote: Some insects that carry disease]

Certain diseases are given to human beings by the bites of insects.
We know that certain ticks and mosquitoes carry certain germs. It
is also probable that disease germs are transferred from diseased
to well persons by bedbugs and other insects that bite.

[Sidenote: How yellow fever is transmitted]

For a long time it was thought that yellow fever was carried
through the air, but now it has been proved that yellow fever is
not carried in this way. A well person can sleep with one who has
yellow fever and not catch the disease. Yellow fever infection is
carried from a yellow fever patient to a healthy person only by a
certain mosquito. Keep this mosquito away from the yellow fever
patients and there can be no spread of the disease.

[Illustration: FIG. 48. The mosquito that carries yellow fever.]

It is not many years since yellow fever was one of the most dreaded
diseases in warm countries. To-day there is not the same fear of
it, for the source of the disease has been discovered and practical
methods have been devised to get rid of the mosquito which carries

[Sidenote: How malaria is transmitted]

Malarial fever is another disease transmitted by the bite of a
mosquito, but the mosquito that carries malarial fever is not
the same as the one that carries yellow fever. For a long time
it was supposed that malaria came from the gases which rise from
marshes. To-day it is known that it is not the gases that cause
the sickness, but a mosquito which lives and grows in the marshes.
Many countries that have heretofore been practically worthless on
account of malarial fever, are being made valuable by draining the
marshes and doing away with places where mosquitoes can hatch.

[Illustration: FIG. 49. One of the places where mosquitoes hatch.]

[Sidenote: How to get rid of the mosquito]

It might seem a very hard task to get rid of mosquitoes in
countries where there are so many of them; but it can be done.
The mosquito must have still water in which to lay her eggs. In
countries where there is danger of yellow fever or malaria, the
rain barrel and the cistern should be screened, and the swamps and
water holes filled up. Puddles of water should not be allowed to
form anywhere, and low places where water might stand should be
drained. By giving her no place in which to lay her eggs, we can
get rid of the mosquito; and when the mosquito disappears, yellow
fever and malaria disappear also.

[Sidenote: How wood-ticks transmit disease]

In certain portions of Montana, Washington, Idaho, Utah, and
Wyoming, there is a peculiar disease known as Rocky Mountain
spotted (tick) fever. It is now known that this disease is
transmitted to people by the bite of a wood-tick. Not all
wood-ticks carry this fever, and for people living in districts
where this disease does not exist there is no danger in the bite
of a wood-tick; but in a part of the country where the disease
prevails, the wood-tick should be avoided.

[Sidenote: How disease-bearing insects can be destroyed]

All insects that are known to transmit diseases can be destroyed.
If we will do away with stagnant water, the mosquito cannot hatch;
if we will cut out underbrush and oil the domestic animals, the
wood-tick will not find a place to grow. If we wish to get rid of
disease, we must spend money and labor; but it is worth while, for
human life is at stake.

  =Questions.= 1. What insects are known to transmit diseases to
  man? 2. How is yellow fever transmitted? 3. Malarial fever? 4.
  What disease is transmitted by the wood-tick? 5. How can we get
  rid of the mosquito? 6. How can we get rid of ticks?

  =Remember.= 1. It is a proved fact that diseases are transmitted
  to man by the bites of mosquitoes and wood-ticks. 2. It is
  possible to do away with both the mosquito and the wood-tick
  almost completely, although it requires a great deal of work and
  the expenditure of a large amount of money. 3. Health is the most
  valuable thing we have, and it is foolish to hesitate in giving
  the work and money necessary to exterminate disease-bearing
  insects, as well as the many other causes of sickness.



[Sidenote: How germs get through the skin]

Germs get into our bodies through breaks in the skin. These breaks
may be made by a cut or a scratch, by the bite of an insect, or
even by the pulling out of a hair. There are some special germs,
such as those which cause yellow fever, which are introduced by the
bite of an insect; but at present we will consider only those germs
that would naturally enter through any break in the skin.

[Illustration: FIG. 50. Small, deep wounds are very liable to
become infected.]

[Sidenote: Effect of germs in wounds]

The skin of the human body acts as an armor against certain germs
that are constantly trying to get through it. There are several
germs of this class. Some of them cause white pus, or matter, but
this is the least dangerous kind of all. Another kind causes boils
or even blood poisoning, and another kind causes erysipelas.

We cannot get rid of these germs, for they are everywhere, to a
greater or less degree; but they are more abundant in dirty than
in clean places. They cause every degree of inflammation, from
a slight redness of the skin to the blood poisoning that brings

[Sidenote: Real cause of suppuration]

Sometimes you will hear people say that a wound suppurated (that
is, became inflamed and full of matter) because the blood was
in bad condition. As a matter of fact, there would have been no
suppuration if germs had not got into the wound. It was not the
condition of the blood that caused the suppuration, but the germs.

Sometimes, when only a few germs get into a wound, and when the
cells of the body are all in good condition and doing their work
properly, the suppuration will be very slight, because the healthy
cells of the body will kill the germs. But if very many germs get
in, even healthy body cells cannot kill them all.

We have said that the germs which cause suppuration are everywhere,
so it would seem almost impossible to keep them out of a wound.
This is true in a sense; but even after they have got into a
wound, you can wash them out if you use plenty of soap and water
to cleanse the wound thoroughly. When I said that it is impossible
to keep them out of a wound, I meant an accidental wound, for
it is quite possible to keep them out of a wound that is made
intentionally, as is done by the surgeon.

[Sidenote: How the surgeon prevents suppuration]

Do you know how a surgeon gets ready to do an operation? The first
thing he does is to see that the room is perfectly clean. He has
the carpet taken up, the curtains taken down, and the floor and
walls washed. This is to get rid of all the dirt and germs in the
room. If you should look at the surgeon's instruments, so clean and
bright, you would think it impossible for a germ to find a place
to live on; but the surgeon knows how closely the germs cling, and
therefore he boils all the instruments he is going to use. Then he
puts the towels into a place where they are made so hot by steam
that all the germs on them are killed. After everything in the room
is perfectly clean, the surgeon cleans his patient with a very
stiff brush, using plenty of soap and water which has been boiled
to kill all the germs in it. He scrubs the part where the wound is
to be made and the skin around it until it is red. Even then he is
not satisfied, for he washes it off with alcohol and ether, to be
sure that any germs that might be sticking in the fat are removed.
He scrubs his hands in the same way. After all this is done, he
can perform the operation without fear that any of the germs which
cause suppuration will get in, for he knows that he has killed all
of them that would touch the wound.

[Illustration: FIGS. 51 and 52. Always wash the simplest cut with
soap and water; failure to do this may result in infection and much

[Sidenote: How to prevent suppuration]

Boys and girls cannot do all this before they cut their hands or
skin their shins, but they can do the next best thing--they can
keep their hands and the rest of their bodies clean at all times,
and thus have as few germs on them as possible. Then, when they
have cut themselves, they can go straight to some place where there
is soap and water, and can wash the wound thoroughly. After this is
done, a clean bandage should be placed on the cut part to prevent
any other germs from getting in. If this is done every time you cut
yourself, you will probably never have an infection--that is, a
wound that suppurates.

Two boys were playing together one day. They ran into each other
and each got a little cut on his hand. One boy went home at once,
washed the wound, and put on a clean bandage. He lost a little
time from his play, but was soon back and never had any trouble on
account of the cut. The other boy thought it was foolish to quit
his play to take care of such a little thing, so he tied his hand
up in a dirty handkerchief. Two weeks later he was very ill. His
arm was badly swollen and had to be cut open in several places;
indeed, he came near losing his arm. It always pays to take care of
a wound, be it never so slight.

Deep wounds made with small instruments, such as small knives,
nails or toy pistols, are especially dangerous, because they are
hard to clean and because they quickly heal up on the surface and
leave the germs to grow at the bottom of the wound. Such wounds as
these are dangerous for another reason.

[Sidenote: Where germs of lockjaw grow]

There is a germ that gets into wounds but does not cause
suppuration. It is the germ of tetanus, or lockjaw. It lives in
the ground, especially in the ground about barns, and its peculiar
feature is that it will not grow in the air. If it gets into a
large, open wound, it is easily killed, because it cannot grow
where there is air. But when it gets into a small, deep wound
where it cannot be reached, it stays there until the wound heals
over on the surface, and then it begins to grow. It does not make
the parts swell, as the germs of suppuration do, but quietly
continues to grow, without the wound showing any sign of infection.
Finally it develops a very severe poison that is taken up by the
blood; then the victim suddenly begins to have spasms about the
face, and finally these spasms extend to the entire body and
kill him. Whenever you get a wound so deep that you cannot wash
it thoroughly, go to a doctor and let him clean it out with some
medicine that will kill the germs that cannot be reached by washing.

[Sidenote: How boils are caused]

Sometimes the germs that cause suppuration get under the skin at a
point where a hair has been pulled out, or even work down beside
the hair itself. When this happens, they cause suppuration under
the skin, and the result is a boil. A boil is merely an infection
with the germs that cause suppuration.

  =Questions.= 1. How do germs get through the skin? 2. Can we
  get rid of all the germs that cause suppuration? 3. Why is it
  impossible for "bad blood" alone to cause suppuration? 4. How
  does the surgeon prevent suppuration? 5. How may you prevent
  suppuration? 6. What is the danger of cutting corns with an
  ordinary knife or razor? 7. Where do germs of lockjaw grow? 8.
  What causes boils?

  =Remember.= 1. Germs and not "bad blood" are the cause of
  suppuration. 2. Always keep as clean as possible, and immediately
  wash any cut, no matter how small. 3. If you have a deep wound,
  go at once to a doctor, and let him clean it out and kill the
  germs that may be at the bottom of the wound.



[Sidenote: How germs may cause sickness without entering the body]

Some germs that cause disease do not get into the body, but grow
upon its surface, that is, they grow on the mucous membranes--the
skin of the mouth, the throat, and the nose. As they grow, they
develop poisons that are absorbed by the body, and that make us
very sick. The germs that cause diphtheria belong to this class.

[Sidenote: Prevalence of diphtheria]

Diphtheria is one of the most common of all the preventable
diseases. It causes more deaths than any of the other diseases
that can be prevented, except tuberculosis. The great prevalence
of diphtheria is due to lack of care on the part of those who have
this disease and of those who come in contact with them.

[Sidenote: Where the diphtheria germ comes from]

The germ that causes diphtheria always comes from some person or
animal that has diphtheria. It never "just happens." If you went
into your yard in the morning and found some beets growing in your
flower bed, you would know positively that beet seeds had got into
your flower bed in some way. You would not say that the beets just
happened to grow there. So diphtheria will not "just happen."
Diphtheria is always caused by germs that come from some one who
has diphtheria. They may have come in a letter that was written in
the room with the sick person. They may have come from the library
in a book that had been used by some one ill with diphtheria. They
may have come on some toy that had been played with by a child that
had the disease. There are a thousand ways by which the germs may
be brought to you without your knowing where they come from.

[Sidenote: How to confine diphtheria germs]

The public health officers try hard to keep these germs from
being brought to you. In order to do this, they have to shut away
from other people those who have diphtheria germs; that is, they
make the sick ones stay at home until they are free from the germs
of the disease. We call this _quarantine_. Quarantine means that
you must stay away from other people when you are sick with a
communicable disease, and that other people must stay away from
you. People are not put in quarantine because they are sick, but
because they are dangerous, and because we are trying to prevent
other people from getting the same disease. Do not think the health
officers unreasonable when they tell you that you must stay at home
and that no one can come in to see you. This is done to protect
other people and to keep them from getting the same disease that
you have. If you ever have diphtheria, or any other communicable
disease, you must remember that if any of your playmates come in to
see you, they may get the same disease.

[Illustration: FIG. 53. Disease germs are as deadly as guns.]

[Sidenote: Seriousness of breaking quarantine]

Diphtheria kills a great many children, and to play with your
friends after you have had diphtheria, and before the health
officer tells you that you may, is almost like trying to kill
them. They might be very sick and die, or they might be very sick
and get well, or they might not be sick at all; but you never can
tell what will happen if they are exposed to the disease. If you
were to take a gun and shoot at a friend, you might kill him, or
you might shoot his leg off, or you might not hit him at all; but
you would be trying to hit him, and it would not be your fault if
you did not. It is just the same if you play with a friend when you
have a communicable disease; you shoot the disease germ at him, and
if you do not hit him, it is not your fault.

[Sidenote: Why quarantine is not raised sooner]

Sometimes people who have been sick with a communicable disease
feel perfectly well, but the health officer tells them he cannot
let them out of quarantine. This is because he knows that such
people still have in their bodies the germs that cause the disease,
and that as long as these germs are there they can give the disease
to other people. It is not pleasant to have to stay in quarantine
when you feel that you are well, and children, as well as older
people, are very likely to become restless under the circumstances.
You see an illustration of such a patient in Figure 60, where the
little girl, who is under quarantine for scarlet fever, but who is
feeling quite well, is giving a book to two of her friends. The
book contains the germs that cause scarlet fever, and the boys are
very likely to contract the disease by handling the book.

[Sidenote: Why some cases of diphtheria escape quarantine:]

[Sidenote: (_1_) From failure to detect mild cases]

If every case of diphtheria were quarantined, and the people obeyed
the health officer, there would soon be no more diphtheria. But how
does it happen that every case of diphtheria is not quarantined?
Diphtheria is a very peculiar disease. Sometimes it makes people
so sick that they die in spite of everything that can be done for
them; sometimes it makes the throat only a little sore, and the
child seems so slightly ill that his mother says to herself, "He
is fretful," and does not call the doctor. In the latter case the
child often keeps on going to school, and exposes other children
to the disease; some of them catch it, and become very sick or
even die. In still other cases, the mother thinks that a child has
only a case of tonsillitis and does not call a doctor; the child's
brothers and sisters go to school and may carry the germs to other
children. I have known a great many cases of diphtheria to be
spread in this way.

[Illustration: FIG. 54. The old, insanitary slates and sponges
have gone out of use, but many people of to-day still follow the
dangerous habit of putting pencils into their mouths.]

Sometimes a dairyman thinks that his child has nothing more serious
than tonsillitis, and goes on selling milk. A great many epidemics
have resulted from such cases. Sore throats should not be treated
lightly, for the most severe forms of diphtheria may develop from
germs that come from a throat that is only slightly sore. If there
is a case of diphtheria in the town where you live, and if your
throat feels the least bit sore, have your doctor examine it at
once. If you do not wish to have your family doctor look at your
throat, go to the health officer. Had you not rather stay at home
for a week or two than see your best friends ill or dead because of
your carelessness?

[Sidenote: (_2_) From diphtheria germs in throats that are not sore]

There is another peculiar thing about the germ of diphtheria. It
will often get into a throat and grow a little, just enough to keep
alive, but without making the throat sore at all. The person in
whose throat the germs are will have no idea that they are there,
but when he comes in contact with some one who has a delicate
throat, he may give diphtheria to that person. The disease does not
develop in some throats because the body cells are all healthy and
doing their work so well that, when the diphtheria germs try to
take hold, they are driven off and not allowed to grow. This is the
reason that, before he raises the quarantine, the careful health
officer takes a "culture" from the throat of everyone in a house
where there has been diphtheria.

[Sidenote: How mild cases may be detected]

The health officer takes a culture by wiping the throat with a
little cotton on a long stick, which he then puts down into a long
glass tube containing some substance that diphtheria germs like to
grow on. If there are any diphtheria germs in the throat, they will
soon show on this culture material. Then the health officer will
say, "No, we cannot let you out yet, for the germs are still in
your throat." No person who has been staying in a house where there
is diphtheria should be allowed to go out until a culture proves
that his throat is free from the germs of diphtheria.

You see how hard it is to quarantine all cases of diphtheria, when
children are sometimes allowed even to go to school with sore
throats that are really diphtheritic. Only two things are necessary
for getting rid of diphtheria: one is to quarantine every case, and
the other, to have the people do just what they are told when under
quarantine. This latter is just as important as the quarantine
itself, for people often do not obey the health officer's
directions. Now let us see what are some of these directions.

[Illustration: FIG. 55. How pets may become carriers of disease.]

[Sidenote: Rules of quarantine]

If you are the patient, the health officer will say that you must
be put in a room where there is just enough furniture to make you
comfortable, and that no one except the nurse and the doctor is to
go into that room. He will say that the nurse must stay in your
room all the time, or that she must at least not go into any other
room in the house; that your meals must be left outside your door,
and that the person who brings them must go away before the door is
opened by the nurse. Furthermore, as everything in the room that
cannot be boiled, or otherwise disinfected, will have to be burned
when you are well, your pet books and toys had better not be taken

Finally, nothing is to be carried from the room until it has been
put into a solution that will kill the germs, and this means not
only dishes, bedding, and clothing, but even books and letters. The
nurse must see that all discharges from the throat and nose are
received on little cloths, which are to be burned immediately.

[Sidenote: How quarantine rules are broken]

These are the things that the health officer will tell your parents
must be done. Now let us see what sometimes happens. Your mother
will want to see her little child so much that she cannot wait
until you are well, so she will slip into your room, kiss your
forehead, and hold you tight against her. When a little later she
kisses your baby brother, and is so thankful that he is not sick
too, she does not realize that she is kissing the very same disease
into his little throat. Or, perhaps your mother is the nurse, and
in the night she hears your little brother crying; she thinks,
"Surely I can slip out and just cover him up; it will not hurt him
just for once," and she does so. What happens? In a few days your
doctor tells you that your little brother will have to come in and
stay with you.

Perhaps your father grows anxious to see you, and one morning he
says he cannot stand it another minute, so he slips in for a few
moments before going to business. In a few days one of his clerks
fails to come to work. Your father sends a messenger to see what
the trouble is, and the word comes back, "He has diphtheria." Then
your father says, "What are these health officers doing that they
do not stop this thing?" He is very indignant, but it never occurs
to him that he himself has spread the disease by doing just what he
promised the health officer he would not do.

[Sidenote: How dogs and cats carry disease germs]

The doctor told your mother not to take anything from the room
until it had been disinfected. But you do not consider Towser, your
dog, and Tabby, your cat, "anything," so you persuade your mother
to let them come in, and you have a good play with them. You let
them rub against your face and romp on your bed, and do everything
that pet dogs and cats like to do, and in the meantime their fur
is getting full of diphtheria germs. Then Towser and Tabby run
out-of-doors and play with the boys and girls of the neighborhood.
Soon the parents are wondering why the health officers do not stop
the spread of the disease. No dog or cat should ever be permitted
to come into a house where there is a contagious disease.

These are not all the ways in which people disobey the orders of
the health officer and of the doctor, but these are enough to show
you that it is a very important thing to do just what they tell
you. It is not always easy to follow all these rules, but it is far
better to follow these, and many more, than to have to think that
you have caused the death of either a friend or a stranger.

  =Questions.= 1. How does the poison of diphtheria get into the
  system? 2. Where does the diphtheria germ come from? 3. What is
  quarantine? 4. What is the danger in breaking quarantine? 5.
  Why is quarantine continued after you feel well? 6. How does it
  happen that some cases of diphtheria are not quarantined? 7. What
  is a diphtheria culture? 8. What rules should you observe while
  in quarantine? 9. Tell some of the ways by which quarantine is
  broken. 10. How do pet dogs and cats sometimes get disease germs?

  =Remember.= 1. The germs that cause diphtheria always come
  from some person or animal that carries diphtheria germs. 2.
  Diphtheria is always caused by the diphtheria germ, and the
  diphtheria germ cannot cause any other disease. 3. People are
  quarantined to prevent other people from getting the disease.
  4. If there is diphtheria in your neighborhood, and your throat
  becomes sore, have the doctor examine it. 5. Every person who
  has been staying in a house where there is a case of diphtheria
  should have his throat examined to make sure he is not carrying
  germs. 6. Never play with dogs or cats when you have a contagious
  disease. 7. People who do not obey quarantine regulations cause a
  great deal of suffering and many deaths.



[Sidenote: Nature of diphtheria poison]

The germs of diphtheria do not get into the blood through the
skin, but grow on the surface of the mucous membrane (skin of
the throat), and there produce a poison that gets into the blood
through this membrane. It is this poison that makes you sick,
and it is called a _toxin_. You already know that when people
have diphtheria, they are sometimes very sick and sometimes only
slightly sick, and that the germ can live in some throats without
causing any ill effects whatever.

[Sidenote: How diphtheria toxin is fought]

As soon as the diphtheria germ begins to grow in a throat, the
little cells of the body begin to make a certain substance and to
pour it into the blood. This substance we call _antitoxin_, which
means opposed to the toxin in the blood. If the little cells make
the substance fast enough, the germs will stop growing, or in some
cases they never really get started growing, because they cannot
exist where there is much antitoxin. Antitoxin looks like clear
water. The following experiment will show you something that acts
in very much the same way that antitoxin does.

If you take a solution of litmus that is made alkaline, it will
be very blue, like indigo; but if you drop a few drops of lemon
juice into this solution it will turn red.[3] Lemon juice is acid,
and is just the opposite of alkali. Now, if you put a few drops of
ammonia, which is alkali, into the red solution, it will turn blue
again. If you put a little more lemon juice, very carefully, drop
by drop, into the blue solution, it will gradually turn lighter,
until it is entirely clear.

[Sidenote: How antitoxin acts]

We will suppose that the blue is due to the toxin produced by the
diphtheria germ, and that the lemon juice is the antitoxin produced
by the cells in the body. If the antitoxin is made fast enough,
the blue disappears; but if the toxin is made faster than the
antitoxin, the blue remains. It is the same way in the body, only
it is not litmus and acids and alkalies that we have to deal with.
If the toxin is made faster than the antitoxin, the germs grow, and
we get sicker and sicker; but if the antitoxin is made faster than
the toxin, then the germs cannot grow, and we soon get well, or
perhaps do not get sick at all.

[Sidenote: How antitoxin was discovered]

Doctors knew that this was what happened, but for a great many
years they could not discover the composition of the antitoxin that
is made in the body. One day a doctor suggested, "If we cannot
find out the chemical nature of this thing that is made in the
body, why can we not make it in the body of some animal and then
use the blood of the animal?" And that is just what they did. They
put diphtheria germs into beef tea, and let them grow very fast
and make all the toxin they could. Then the doctors strained the
germs out by passing the beef tea through a fine filter, in this
way getting the poison, and not the germs. Then they gave a strong,
healthy horse a small quantity of this poison; they did not feed
it to him, but injected it into his blood. Of course the horse was
sick for a while, but soon he began to get well again, for the
cells in his body immediately went to work making antitoxin.

When the horse was well, the doctors gave him more of the poison;
this time he was not so sick and got well even more quickly. This
treatment with toxin was repeated in gradually increasing doses
until the poison did not affect the horse at all. Then the doctors
said, "His blood is full of antitoxin, and we will see what it will
do when injected into some other animal." So they drew off some of
the horse's blood and took out all the little red cells, leaving
nothing but the clear fluid of the blood. They planted diphtheria
germs in a rabbit's throat, and when the rabbit became very sick,
they gave him some of the antitoxin from the horse. The rabbit
immediately got well. Afterward they gave some of this antitoxin to
a little boy who was very sick with diphtheria, and he, too, got
well. Ever since then the doctors have been saving many lives by
the use of antitoxin.

[Illustration: FIG. 56. Showing the number of deaths in 100 cases
of diphtheria when antitoxin is used on the first, second, third,
fourth, and fifth days.]

[Sidenote: Evidences that antitoxin saves lives]

Someone may ask, "How do we know that it is the antitoxin that
saves lives?" In just this way: before we knew anything about
antitoxin, about half of all the people with diphtheria died; but
since we have had antitoxin, only about twelve die out of every
hundred who have this disease. More than this, we know that when
the antitoxin is given within the first twenty-four hours after the
patient is taken sick, there is only about one death for every one
thousand cases of diphtheria. Do you not think that this is strong
proof that antitoxin saves lives?

[Sidenote: How antitoxin saves lives]

Antitoxin saves lives not only by curing those who have diphtheria,
but by preventing others from having it. If a person who has been
where there is a case of diphtheria is given a dose of antitoxin,
he will not have the disease, because his blood will contain enough
antitoxin to destroy the diphtheria toxin present. If you will
watch a careful doctor when he makes his first visit to a case
of diphtheria, you will notice that, as soon as he gets through
treating the patient, he gives all members of the family who have
been near the patient a dose of antitoxin to keep them from getting

[Sidenote: Antitoxin not a poison]

Some people may tell you that antitoxin is a poison and should not
be used. The statement that it is in itself a poison is true. But
it is also true that in your body there are many things that would
poison you if you got too much of them. For instance, there is a
gland in your throat (the thyroid) which secretes a substance that
is necessary for your health, but if you were to take the secretion
of ten such glands it would kill you at once. Now, if the cells in
your body make antitoxin when you have diphtheria, it is probable
that antitoxin is the very thing needed. And if you can help these
cells by giving them antitoxin, ready-made, does it not seem a
reasonable thing to do? People who give the name of poison to a
substance which is known to have saved many lives are not worthy of
attention. Anything may prove a poison if taken in excess; too much
play will prove a poison, and too much work also.

  =Questions.= 1. What is the poison of diphtheria called? 2. What
  is antitoxin? 3. Compare the action of antitoxin on the blood
  with the action of an acid on the litmus solution. 4. Tell about
  the discovery of antitoxin. 5. How do we know that antitoxin
  saves lives? 6. How does antitoxin prevent diphtheria? 7. Why
  should antitoxin not be regarded as a poison?

  =Remember.= 1. Antitoxin is what the cells in your body make
  when you have diphtheria. 2. By using the antitoxin taken from
  a horse, you save your own cells the struggle necessary to make
  it fast enough to kill the diphtheria germs. 3. If you have
  diphtheria, and antitoxin is given promptly, you will get well.
  4. If you have been exposed to diphtheria, antitoxin will prevent
  your having the disease. 5. Antitoxin is no more a poison than
  are many other medicines.



[Sidenote: How typhoid fever germs get into the system]

There are certain diseases, the germs of which get into bodies
through our mouths. That is, we eat or drink them. Some of these
diseases are typhoid fever, cholera, the summer complaints of
children, tuberculosis, and diphtheria. At present we shall learn
about the germ that causes typhoid fever, how it gets into our food
and drink, and how we may prevent the disease by getting rid of
this germ.

Typhoid fever, like all other diseases caused by germs, is caused
by one kind of germ, and one kind only. You cannot get typhoid
fever by eating cholera germs any more than you can get diphtheria
from typhoid germs.

[Sidenote: Animals free from typhoid]

So far as we know, there is no animal except man that has typhoid
fever. Since the germs of any disease must come from an animal
suffering from that disease, and as man is the only animal that
has typhoid fever, it naturally follows that the only way to get
typhoid fever is from some person who has the fever or has had it.

[Sidenote: How typhoid germs leave the body]

We know that typhoid fever germs get into the body with food, but
how do they get out? Once in a great while germs are found in the
matter that the patient vomits, or spits up, but this is a rare
occurrence, so rare that we need hardly consider it. The germs are
present in the blood of the sufferer, but other people do not get
his blood on their hands or in their food. There are two things
that come from the patient that are loaded with these germs, and
these are the urine and bowel discharges. In these two excretions
of the body are found practically all the typhoid germs that come
from the patient, and these are the causes of other infections.
In other words, it is from these two excretions that the germs get
into food and drink.

[Sidenote: How typhoid germs get into water]

How do the typhoid germs get into our food? What is done with the
excretions after they come from the body? You will probably say
that the nurse throws them into the sewer. Very true; but where do
they go when they are thrown into the sewer? The sewer must empty
somewhere, and in most instances it empties into a stream, the
water of which is used for drinking purposes.

[Illustration: FIG. 57. Pollution of a stream with sewage.]

[Sidenote: The widespread evil due to the sickness of one person]

You may think that the germs from one person would not make much
difference, but that is where you are mistaken. There is a town
in Pennsylvania of about eight thousand inhabitants, which gets
its water from a stream that flows down from the mountains. One
cold winter, while the stream was frozen, a man living on the bank
of the stream was taken sick with typhoid fever. His nurse threw
the urine and the discharges from his bowels on the ice on the
bank of the creek. When the ice melted, the typhoid germs in the
discharges found their way to the stream that furnished drinking
water to people farther down, and in a very short time there were
over one thousand cases of typhoid fever in that town. Before the
ice melted there had not been a single case of typhoid, and every
one of the thousand cases came from the water into which had been
allowed to flow the discharges from one man with typhoid fever. You
see what germs from one person may do.

[Sidenote: How long typhoid fever germs live in a stream]

Sometimes people say that a stream purifies itself every few miles.
It does purify itself of some things, but disease germs live from
twenty-five to thirty-five days in water, and a stream flows a long
way in thirty days.

[Sidenote: The pollution of streams with sewage]

Sometimes we hear people say that it is safe to put sewage into
a certain stream, because no town uses that stream for drinking
water. But of this they can never be sure. Not long ago certain
people said that the water from the river which flowed through
their town was used only by two dairymen and a vegetable gardener,
and therefore there was no danger in running sewage into the
stream. Yet the dairymen and the gardener sold all their produce
in that very town. The townspeople never considered that the water
into which they ran their sewage was used by the dairymen for
washing their milk vessels (and perhaps for diluting the milk), and
by the gardener for washing his lettuce and other vegetables. Thus
the germs of disease were brought directly back to the town.

Do not think that you are safe in polluting a stream with sewage
because no town uses the water from that stream. The individual on
the farm is entitled to protection just as much as the individual
in the town. Always remember that when you pollute with disease the
water used by the farmer, he may bring that disease back into the
town with the produce of his farm.

No sewage, no matter how small the amount, should ever be
permitted to go into a stream until all the disease germs it
contains have been killed. This can be done, though it will cost
something; but we cannot get rid of disease germs without work, and
work cannot be done without being paid for.

There are other ways of scattering typhoid germs besides running
sewage into streams. Sometimes the nurse does not throw the
discharges from a typhoid fever patient into a sewer at all, but
into a closet vault. Remember how the material from a closet vault
goes through open ground into a well, and you will understand what
happens. The germs get into the well, and the whole family may then
have typhoid fever.

Let us suppose that the nurse did not throw the discharges either
into the closet or into the sewer, but carelessly threw them out
on the ground behind the house, where, as it was winter time, they
froze as hard as rocks. It does not seem to hurt typhoid germs
in the least to be frozen; when they get warm again they are as
lively as ever. Let us suppose these particular germs lay there all
winter, but in the spring when everything melted the germs were
still alive and ready to spread disease. It happened that they did
not get into the well or into the milk, but they did get on your
food, and made you ill with typhoid fever.

[Sidenote: How flies carry typhoid germs]

How did the germs get to your food? About the time that the germs
were thawed out, and were beginning to double in number every
hour or two, along came a fly and thought that spot an attractive
one for a lunch. Accordingly he walked over this mass of filth,
collecting a supply of germs on his feet, and then came in and
tracked them over your bread and butter or other food.

[Illustration: FIG. 58. Flies crawling on the edge of the glass or
falling into the milk leave germs that cause disease.]

[Sidenote: How typhoid germs get into milk]

That is how you got the fever; but the trouble did not stop with
you. When you fell sick, your father thought it was time to clean
the yard, but he was not very careful what he did with the dirt,
including the typhoid fever discharges which the nurse threw out on
the snow during the winter. There was a low place in the barnyard
and there he dumped the dirt. One of the cows thought this fresh
pile of dirt would make a comfortable place to lie down in. The
next morning the milkman milked her without first washing her sides
and udder, and hundreds of little particles of dirt, each one
loaded with germs, fell into the milk. The milk from all the cows
was mixed together, and by the time it got to town these germs had
grown into many thousands. Some of the people who drank the milk
became ill with typhoid fever and wondered afterward where they had
taken this disease.

[Sidenote: Why the recovered patient is dangerous]

The discharges from a typhoid fever patient contain typhoid germs
not only while the disease lasts, but for many months after the
patient is well. In some cases they are present for years after the
illness is over.

[Sidenote: The story of the careless nurses]

Here is a story about typhoid fever that illustrates the importance
of washing and boiling everything that comes from a sickroom. A few
years ago there was an epidemic of typhoid fever in a certain town.
One of the hospitals was very much crowded, and it became necessary
to employ several extra nurses. All the nurses knew the importance
of washing their hands after handling the patients, and the old
nurses had seen so many bad results from failure to observe this
rule that they were very careful. Three of the new nurses, however,
thought it a great deal of trouble to be washing their hands all
the time, so more and more they neglected this important duty. The
result was that all three of these girls got typhoid fever and
died. They paid the penalty for neglecting the duty that they well
knew they should have performed.

Typhoid fever can be wiped out by attention to neglected
details--that is, by disinfecting discharges before throwing them
away; by disposing of excretions only in places that are made for
them; by adding lime to the closet vault every day to kill any
germs present; by making the closet in such a way that flies cannot
get into it; and by not permitting sewage to enter any stream until
all the disease germs have been killed. All these things can be
done. It will require a little work; but had you not rather take
a little extra care than run the risk of catching or spreading
typhoid fever?

  =Questions.= 1. How do typhoid fever germs get into the body? 2.
  What is one source of these germs? 3. How do these germs leave
  the body? 4. Name several ways by which typhoid germs in a stream
  may get into foods. 5. How do flies carry typhoid fever germs? 6.
  How do these germs get into milk?

  =Remember.= 1. Typhoid germs come from people who have typhoid
  fever; they are found in the urine and bowel discharges. 2. No
  one should ever answer Nature's calls except in a place provided
  for that purpose. 3. No sewage should be allowed to go into any
  stream until all the germs in it have been killed. 4. Disease
  germs will live in running water fully as long as they will in
  still water. 5. The discharges from a single person may infect a
  whole city. 6. When typhoid fever germs get into milk, they grow
  very rapidly; hundreds of people have been given typhoid fever by
  drinking the milk from a dairy where there was a single person
  sick with this disease. 7. People who have had typhoid often
  carry the germs for several months after they are well.



Hookworm disease and amoebic dysentery resemble typhoid fever in
one respect, in that they, too are spread by the improper disposal
of human excreta.

[Sidenote: Where hookworm disease prevails]

Hookworm disease is found almost exclusively in tropical or
subtropical climates. In the United States it is rarely seen north
of the Potomac and Ohio rivers.

[Illustration: FIG. 59. A full-grown hookworm, magnified; the short
line shows the average length of the hookworm.]

[Sidenote: What the hookworm is]

This disease is not caused by a germ, as is typhoid fever, but by
a worm from a quarter to half an inch long, and about as thick
as a small hairpin. These worms get into a person's intestinal
canal, and there lay their eggs, which are later given off in the
bowel discharges. When these discharges are thrown on the ground,
or are put into an open water-closet, they may be carried about
by chickens, flies, and pigs. Then the eggs hatch in the soil and
tiny hookworms result. When human excreta are not properly disposed
of, in climates where hookworm disease prevails, the soil becomes
practically full of these little worms, and from the soil they find
their way into the bodies of the people.

[Sidenote: How it enters the body]

There are two principal ways by which the hookworm may enter
the body. One is through the mouth, which these worms reach in
practically the same way as do typhoid fever germs. The hookworm
may enter the body through the skin also. Some authorities state
that the worm bores its way in; but it is probable that it does not
actually bore through sound skin, but enters at some point where
there is a small break.

[Sidenote: Where it lives in the body]

After the worm gets through the skin, it is taken into the blood
and carried to the lungs, and from there it finds its way to
the throat and is swallowed. It makes no difference whether the
hookworm is swallowed or enters the body through the skin; it
finally reaches the intestinal canal, where it then makes its home.
Sometimes thousands of these worms are found in a single person,
and each one of them entered the body through the mouth or through
the skin. The worms do not multiply in the body, and the eggs they
lay never hatch until after they have left the body.

[Sidenote: How it affects the patient]

When the hookworm gets into the intestinal canal, it fastens itself
to the wall and sucks the blood from it, at the same time giving
off a poison that enters the blood of the victim. The loss of
blood and the effects of the poison soon cause the person in whose
body these worms are living to become weak, pale, and thin. He is
not able to do much work, if any, and the result is that people
suffering from this disease are often called lazy. They are not
lazy; they are sick, and many of them die.

[Sidenote: How hookworm disease can be prevented]

All this sickness and all these deaths might be prevented simply
by the proper disposal of human excreta. No human excreta should
ever be put anywhere except into a properly constructed sewer or
properly constructed privy. If this rule were always observed, both
hookworm disease and typhoid fever would be abolished.

[Sidenote: Where amoebic dysentery prevails]

Amoebic dysentery is another disease that is confined almost
entirely to tropical and subtropical climates, though cases
sometimes occur in colder regions.

[Sidenote: How it is spread and how it may be prevented]

This disease, like typhoid fever, is caused by a germ that leaves
the body with the bowel discharges. The germ makes its way into
the body in the same way that the typhoid germ enters; that is, it
is taken in with food or drink. The various means by which this
germ gets into our food are the same as those by which the typhoid
germ gets in; and the precautions that will prevent the spread of
typhoid fever will also prevent dysentery. Amoebic dysentery kills
a great many people in warm climates, though it does not kill as
many as does typhoid fever. If it does not cause immediate death,
it often leaves the patient very weak and sickly for months or

  =Questions.= 1. In what climates are hookworm disease and amoebic
  dysentery commonly found? 2. In what respects do they resemble
  typhoid fever? 3. How does the hookworm enter the body? 4. Where
  do the hookworm eggs hatch? 5. How can hookworm disease be
  prevented? 6. What other diseases can be prevented by the same

  =Remember.= 1. Typhoid fever, hookworm disease, and amoebic
  dysentery are all caused by the improper disposal of human
  excreta. 2. Most of the sickness that can be prevented is the
  result of dirty habits; if all people would keep clean and see
  that everything about them was kept clean, a great deal of
  sickness would be prevented and a great many lives would be saved.



There are certain diseases that we know to be communicable (that
is, "catching"), but as yet we do not know the germ that causes
them, and therefore we cannot tell just how they are carried about.
We do know that they are transferred from one person to another;
but not being able to locate the cause, as we can in the diseases
of which we do know the germ, we cannot explain how it is done.

[Sidenote: How scarlet fever is like diphtheria]

Among the diseases of this class we find scarlet fever. In one
respect scarlet fever acts much the same as diphtheria. A person
may have it and not be very sick, sometimes hardly sick at all.
At night a child may have a high fever, with a slightly sore
throat, and the next morning he may feel perfectly well. The mother
supposes that the fever was due to an "upset stomach," thinks no
more about it, and sends the child to school. The next time the
child takes a bath, he perhaps notices that the skin peels off over
some parts of the body. This means that the high fever was due to
scarlet fever, but the breaking-out (rash) was so fine that it was
not noticed. It also means that all the children in the school have
been exposed to the disease. These very mild cases are the most
dangerous because so often they are not recognized.

[Sidenote: Why mild cases are dangerous:]

[Sidenote: (_1_) For the severe cases they cause]

There are two things to be remembered in connection with these mild
forms of scarlet fever, as well as of every other communicable
disease. The first is that the same cause which produces a mild
form of the disease in one child may produce its most severe form
in another child. You can contract a mild form of the disease from
exposure to a severe case; and you can contract a severe form from
exposure to a mild case. The character of the case to which you are
exposed will give no indication of the form the disease will assume
in your body.

[Sidenote: (_2_) For the bad after effects]

The next thing to be remembered about the mild form of scarlet
fever is that, though the child may not be made very sick at the
time, there may later be very bad results. A child who has had
scarlet fever in such a mild form that he hardly knew he was sick,
may, for a while, appear to be quite well; then suddenly he has an
earache, and an abscess forms. This abscess is due to the scarlet
fever germs which have gone from the throat to the ear, and as a
result the child may lose his hearing entirely.

The child may not, perhaps, have an abscess, but after a time he
may begin to lose flesh, and to grow pale. He does not care for
his meals, does not care to play, says he is tired, and wants to
lie still all the time. Finally his mother thinks it might be a
good idea to have a doctor see him. The doctor examines his body
carefully, and then asks for a sample of his urine. When he has
examined this, he looks very serious and asks the mother when the
child was sick last, and what the disease was. Perhaps she has
forgotten all about the slight attack of fever, and the doctor
must question her very carefully before she recalls it. At length
it occurs to her, and then the doctor asks, "After this attack of
fever, did you notice that the skin came off his hands and body?"
She replies that she did, and then the doctor tells her that the
child really had scarlet fever, and, owing to lack of care, he now
has kidney disease. This is a very serious trouble, from which
he may never recover, or, in case of recovery, he may always be
weak and sickly. Even a mild attack of scarlet fever is not to
be neglected; it is a severe and dangerous disease in its very
mildest form. It not only kills a great many boys and girls, but
it makes delicate in health for all their lives many of those who
apparently recover.

[Illustration: FIG. 60. One of the ways by which quarantine is

[Sidenote: How confusion of names causes mild cases to go

We often hear people speak of two diseases which they think are
not scarlet fever. These two diseases are scarlatina and scarlet
rash. Now scarlatina is simply the scientific name for scarlet
fever. Some doctors will tell you that you have scarlatina and that
it is not exactly scarlet fever. A doctor who says this either is
deceiving you or does not know any better. In either case, he ought
not to be a doctor, for he lets children be exposed to a disease
that is likely to kill many of them. It is the same with scarlet
rash. This, too, is simply another name for scarlet fever. Changing
the name does not change the disease, and you may call it scarlet
fever, scarlatina, or scarlet rash--it makes no difference which;
the disease is one and the same.

[Sidenote: Why quarantine is necessary for scarlet fever]

Quarantine is the only way known for preventing the spread of
scarlet fever, as well as of diphtheria. If every case of scarlet
fever were quarantined, we could soon stop this disease; but every
case is not quarantined, because some of them are so mild that
they are not recognized.

[Sidenote: How breaking quarantine shows selfishness]

Even when a case is quarantined, the people sometimes neglect
the instructions given, just as they do when there is a case of
diphtheria. Then there are cases that are known to be scarlet fever
but are not reported to the health officers, because the people
do not want to be quarantined. They simply do not want to be put
to any inconvenience themselves, and although this seems a very
strange way for people to act, it happens very often. There are
many selfish people in the world; there are even people who will
not report a case of scarlet fever because to do so might prevent
their going to a party. Selfishness is at the bottom of it.

It is extremely important that a child should be absolutely free
from all the little scales of skin which are thrown off after
scarlet fever, before he returns to school or mingles again with
others. If there is a discharge from the nose or ears after the
scales have disappeared from the skin, there is still danger of
spreading the disease, for these discharges often retain the
infection for many months.

  =Questions.= 1. Give two reasons why mild cases of scarlet fever
  should be carefully treated. 2. Why is quarantine necessary? 3.
  How does selfishness lead people to spread scarlet fever? 4. When
  is it safe to let a scarlet fever patient mingle with well people?

  =Remember.= 1. If you have scarlet fever and are not very sick,
  do not think that you will not be dangerous to others; severe
  cases sometimes come from exposure to the mildest cases. 2.
  Mild cases of scarlet fever often leave very bad results, if
  the patient is not cared for. 3. Be very careful until you are
  entirely well. 4. Scarlatina and scarlet rash are nothing but
  scarlet fever; keep away from people who have them. 5. Quarantine
  is the only way by which we can prevent the spread of scarlet
  fever; there is no medicine that will prevent it. 6. People who
  violate quarantine regulations are both selfish and stupid.



Measles is a disease in the same class as scarlet fever. We do not
know the cause, but we do know that it is communicable.

[Sidenote: Why measles should be avoided]

Measles is usually not a severe disease; that is, it does not
kill as many persons in proportion to the number of cases as does
scarlet fever. It does, however, kill more people than most of us
think; a great many little babies die of it. How often we hear
mothers say, "I wish my children would have measles and be done
with it." It would be very convenient if they could have measles in
a mild way and "be done with it." The trouble is, that we cannot
tell whether it will take a mild form, and, worse than this, we do
not know when they will be done with it.

If you should go into the children's wards of a large hospital,
you would know why measles should be avoided. There you would hear
the doctors questioning the mothers about the previous diseases of
the little ones. You would be surprised at the number who replied,
"He has not had anything but measles." Then you would hear the
question, "How long since he had the measles?" "He was just over it
when he was taken sick with this trouble." What is "this trouble"?
Follow the doctor along from bed to bed and see the cases of
pneumonia that started when the child "was just over measles"; see
how many cases of empyema (abscess in the chest) began just after
the measles ended; how many cases of abscess in the bone, how many
cases of disease of the kidneys appeared after the child recovered
from the measles. Then go down into the eye and ear wards and see
how many diseased eyes and ears have followed an attack of the
measles. The children would not have had these troubles had they
not first had measles.

[Sidenote: Necessity of care in measles]

If you have measles, do not let others come near you, and do not
think that, because you do not feel very sick, you can run about
as usual. If you do not take good care of yourself, you may have
some of the diseases that so often begin when children are getting
over measles. Measles causes more deaths than is commonly supposed,
especially among young children and very old people; and a great
many children die of diseases which they never would have had if
they had not first had the measles. Avoid people who have measles,
and if you should get the disease, do not treat it as a slight
thing, but consult your doctor at once.


  _Whooping Cough_    _Scarlet Fever_    _Measles_    _Smallpox_
      _4,856_             _4,309_         _4,302_        _74_

FIG. 61. Deaths in 1907 from four common communicable diseases
reported to the United States Census Bureau.]

[Sidenote: Evil effects of whooping cough]

Whooping cough is much the same as measles in this respect. It
kills many children, and, in cases where it does not kill them,
their bodies become so weakened that they are liable to contract
some other disease that may prove fatal. Avoid people who have
whooping cough.

  =Questions.= 1. Why should people avoid measles? 2. Why should
  one take care of himself when he has measles? 3. Why is whooping
  cough to be avoided?

  =Remember.= 1. Measles is more fatal, especially among babies,
  than people realize. 2. Measles causes more diseases of the
  bones, ears, and eyes than any other communicable disease.
  3. Measles is not dangerous if properly cared for, but when
  neglected, it causes much suffering and many deaths. 4. Whooping
  cough causes almost as many deaths as does measles.



We now come to the study of a disease, the cause of which has not
been positively recognized. We know that it is very communicable;
but we know also that there is absolutely no reason for anyone's
ever contracting it, since there is a way by which it may easily be

[Sidenote: Fatality of smallpox before the discovery of vaccination]

Something over a hundred years ago, smallpox was one of the most
fatal diseases known. It is estimated that during the eighteenth
century it killed over 60,000,000 people.

Up to the time when the Spaniards invaded Mexico, there had been
no smallpox there. The Spaniards brought the disease with them,
and historians tell us that out of the 12,000,000 people living in
Mexico at that time, at least 6,000,000 died from smallpox. At that
time the disease was considered fatal throughout the world; when
it broke out in a community, people fled without stopping to bury
their dead. It was a rare thing to see a person not more or less
disfigured by the marks the disease leaves on the face and body.

To-day we find a very different condition. There are now fewer
fatalities from smallpox than from almost any other communicable
disease. During 1906 and 1907 only 169 deaths from smallpox were
reported from all over the United States to the Census Bureau at
Washington. What has caused this marked falling off in the fatality
of the disease?

[Sidenote: Discovery of vaccination]

During the time that smallpox was killing so many people, all the
doctors were trying to find something that would cure the disease
or that would prevent it. In the latter part of the eighteenth
century Dr. Edward Jenner, an English physician, noticed that
milkmaids did not have smallpox as much as did people of other
occupations. He also noticed cows with little sores on their udders
that looked very much like the sores that come with smallpox. He
therefore tried making on the arms of people sores just like those
on the udders of the cows. He did this by taking a little of the
matter from the sores on the cows and putting it into the scratches
on the people's arms. After these sores had healed, the people who
had been thus treated did not have smallpox. This simple practice
has caused one of the most deadly diseases known to man to become
one of the most easily controlled.

[Sidenote: Prevention of smallpox by vaccination:]

Though it is well known that before the discovery of vaccination
smallpox was a fatal disease, there are still some persons who say
that vaccination has done nothing to reduce the mortality. When you
learn some of the facts, you can judge for yourself whether or not
vaccination does prevent smallpox.

[Sidenote: (_1_) In the Franco-Prussian War]

During the Franco-Prussian War in 1870-71, the German soldiers were
all vaccinated, and only a part of the French army was vaccinated.
Smallpox broke out in the two armies. As a result, 6,000 of the
French died from smallpox and only 278 of the Germans. In many
instances, the German and the French soldiers were confined
in the same hospitals, with exactly the same opportunities to
contract the disease. But, you might ask, if vaccination prevents
smallpox, how did it happen that there were _any_ cases among the
German soldiers? In order to prevent smallpox, vaccination must
be successful; that is, it must "take." We will tell you about
different kinds of vaccination a little later.

[Illustration: FIG. 62. In Sweden, before vaccination, smallpox
caused 2,050 deaths per million population (represented by the
large square). Since the introduction of vaccination the death rate
has dropped to 2 per million population (represented by the two
small squares).]

[Sidenote: (_2_) In Sweden]

In Sweden we find strong evidence that vaccination prevents
smallpox. Up to 1801, before vaccination was introduced into that
country, the yearly death rate from smallpox was 2,050 out of each
million of the population. In 1801 vaccination was introduced
into Sweden, but the people were allowed to be vaccinated or not,
just as they pleased. During the ten years ending with 1811, the
annual death rate from smallpox had dropped from 2,050 per million
of the population to 686 per million. Later, vaccination was
made compulsory (that is, everybody in Sweden was obliged to be
vaccinated), and in 1894 the death rate had dropped to only two
deaths a year per million population. Is it merely a coincidence
that this great falling off in deaths from smallpox came after
vaccination was discovered, or was it due to vaccination?

[Sidenote: (_3_) In the Philippine Islands]

Before the Philippine Islands were occupied by the Americans,
vaccination was very little practiced, and a large percentage
of the deaths in those islands was caused by smallpox. In 1897
smallpox caused about 40,000 deaths. A few years later the
Americans enforced vaccination among the inhabitants of the
Philippines, and the result was that in 1907 there were only 304
deaths from smallpox. There has been practically no quarantine for
smallpox and no disinfection; the only cause of the suppression of
the disease in the Philippine Islands is vaccination--nothing else.

[Sidenote: (_4_) In Gloucester, England]

In Gloucester, England, there used to be a great many people who
did not believe in vaccination, though it is doubtful if they
themselves could have explained why they did not. They seem to
have been much like the man who, when asked, "What do you think of
this?" replied, "I don't know anything about it, but I am against
it." In 1890 Gloucester had a population of 42,000 people, most
of whom had never been vaccinated. In the latter part of 1895,
smallpox broke out. Quarantine was strictly carried out, but the
disease continued to spread. As the people saw the number of
victims rapidly increasing, many of them concluded that they had
rather be vaccinated than have smallpox, even though they did
not really believe in vaccination. By the first of April, 1896,
over 36,000 people had been vaccinated in Gloucester, and by the
first of August there was not a case of smallpox in the city. But
what had happened in the meantime? There had been 1,979 cases
of smallpox; a very large amount of money had been expended in
quarantining; hundreds of persons had been disfigured for life; and
439 lives had been lost. And all this simply because the people did
not believe in vaccination.

Quarantining smallpox is a most expensive luxury, which may
possibly retard the progress of this disease, but was never known
to check an epidemic of it. Every epidemic of smallpox during the
last one hundred years has been checked by vaccination.

[Sidenote: Why some diseases do not return]

There are certain diseases which you are not likely to have more
than once; one attack protects against another. Why and how does
one attack of a certain disease protect against another? When a
person is taken sick with one of these diseases, the cells of his
body immediately begin to make a substance called antitoxin. We
learned something about antitoxin when we were studying diphtheria.
In diseases like scarlet fever, measles, and smallpox, in which
one attack protects against another, the antitoxin that is formed
in the body when you are sick stays there for a long time, in some
cases as long as you live. While this antitoxin is present in the
blood, the cause of the disease cannot live in the body; hence you
cannot have the disease again. After some diseases this antitoxin
seems to disappear from the blood in a short time; after others,
it seems to remain for several years; and after still others it
remains as long as you live. After diphtheria it stays in the blood
only a short time, so that one may have diphtheria a second time
within a few years. Some people have smallpox, measles, or scarlet
fever a second time, but with most people these diseases never

If we knew how to make the cells of our bodies produce this
antitoxin and keep it stored up in the blood all the time, we
should never have any of these diseases. But in many cases we do
not know how to cause the cells to manufacture this antitoxin.
However, in one or two diseases we do know how to persuade them to
make the antitoxin, and the one in which we know how to accomplish
this best is smallpox. This is just what is done by vaccination.

[Sidenote: How vaccination prevents smallpox]

The object of vaccination is to put the cells of the body to work
making antitoxin. To do this, it is necessary to get some of the
toxin into the body. We want to get in just enough to make the
cells work, and no more. Therefore we make a very small scratch,
and put into it some of the vaccine which contains the toxin of
smallpox. It is impossible to have these germs in your body and
not be affected by them to some degree. If you did not feel a
little sick, the cells would not be making antitoxin, for the thing
that makes you sick is what makes the cells go to work. But this
sickness is only a matter of a day or two, and after the cells have
made the antitoxin, it will stay in your body a long time, longer
in some cases than in others.

Some people, after they have once been vaccinated, can never be
successfully vaccinated again; neither can such people ever have
smallpox. Most people, however, can be successfully vaccinated
every five to seven years, and there are a few people who will
"take" if vaccinated every year or two. These conditions indicate
the length of time that the antitoxin of smallpox will live in
the bodies of these different persons. If vaccination, properly
performed, does not take, the person is not in a condition at that
time to catch smallpox; and if vaccination, properly performed,
does take, it is positive evidence that if this person had been
exposed to smallpox, he would have taken the disease.

[Sidenote: Necessity of repeated vaccination]

It is frequently asked, "How long will vaccination protect against
smallpox?" You can no more answer this question than you can tell
how long the antitoxin will live in the blood of any particular
person. The only safe thing to do is to be vaccinated every few
years, and if smallpox is present in your community, get vaccinated
every year until the vaccination takes. If it takes, it shows that
you were in a condition to catch the disease; and if it does not
take, you may feel safe from smallpox for a while, at least.

  =Questions.= 1. Why was smallpox formerly more widespread and
  more often fatal than it is now? 2. Tell of the discovery
  of vaccination. 3. Give instances to show the influence of
  vaccination on smallpox epidemics. 4. Why must there be repeated
  vaccinations? 5. Show how vaccinating for smallpox is like taking
  antitoxin to prevent diphtheria.

  =Remember.= 1. Before the introduction of vaccination, smallpox
  was one of the most dangerous diseases known. 2. All evidence
  of history tends to show that vaccination has caused smallpox
  to become a very mild disease and a comparatively rare one. 3.
  Successful vaccination repeated at proper intervals will prevent
  smallpox. 4. Vaccination must be repeated because we do not know
  just how long the material developed in the body from a single
  vaccination will last.



[Sidenote: What constitutes a successful vaccination]

How does it happen that those who have been recently vaccinated
sometimes have smallpox? It is _successful_ vaccination that
prevents smallpox, not recent vaccination; there is a vast
difference between the two. A _successful_ vaccination is one that
results in a sore identical with the sores of smallpox. Such a sore
is secured only as a result of the action of the germs that cause

If the arm is red from the shoulder to the wrist and so swollen
that you cannot use it for weeks, it does not necessarily mean that
you have had a successful vaccination.

Such arms are not the result of vaccination itself, any more than a
railroad wreck is the result of the fact that there is steam in the
engine. The railroad wreck is caused by carelessness on the part
of some operator, and the badly inflamed and swollen arm is due
to lack of care or knowledge on the part of the vaccinator or the
person vaccinated.

[Sidenote: Some pretended vaccinations]

A fly blister is not a successful vaccination. Such a statement
may not seem necessary, until you hear this story. A man showed a
sore on his arm, asserting that it was a successful vaccination. He
was told that it was nothing but the result of a blister, and not
vaccination, and that the work had been done by putting a small bit
of blistering plaster on his arm. He admitted this to be the fact,
and said that the "doctor" who did it told him that it was a new
way of vaccinating. The doctors who say that vaccination will not
prevent smallpox belong to the class who use fly blisters and call
them vaccinations. When the patient gets smallpox, those who are
opposed to vaccinations say that here is an illustration of their
claim that vaccination will not prevent smallpox.

[Illustration: FIG. 63. How vaccinated arms are sometimes infected.]

Some people who honestly think they were vaccinated have smallpox.
There are sometimes instances in which a person recently vaccinated
with apparent success nevertheless contracts smallpox; there are
still other cases in which the disease develops after a vaccination
that would not take. Here is an example:

A doctor vaccinates a child in the usual manner. At the end of
four or five days, the dressing is taken from the arm, and the
only thing to be seen is a little black scab. The child scratches
this off. In a few days the spot becomes red and a small abscess
forms, resembling a smallpox sore. Naturally, this is taken for
a completely successful vaccination, but it is not really so.
When the child scratched off the scab, the vaccination wound was
nearly healed, and the little abscess was caused by some very
mild pus germs, which were under the finger nails with which he
scratched the wound. The abscess was in no wise connected with the
vaccination, but was simply such an infection as a child might get
at any time that he scratched his arm. No one has ever claimed that
such an abscess will prevent smallpox any more than that a boil
will prevent it.

_A successful vaccination will prevent smallpox._ The length of
time for which it will prevent the disease varies in different
individuals. Some it will protect only for a year or two, while in
others it will last through life.

Dr. H. W. Bond, Health Commissioner of St. Louis, Missouri, states:

"The experience of this department, based on the observation of
thousands of cases, is that a well-pitted mark gives at least ten
years' immunity. We have never seen a case of smallpox in a person
with a well-pitted scar less than ten years old--that is, the scar
less than ten years old."

[Sidenote: A sore arm not always due to successful vaccination]

One of the strongest objections made against vaccination is that
the arm sometimes becomes very sore from it. This is true, but
the sore arm is not a common occurrence and is never caused by
vaccination properly performed. There is always some cause for the
bad arm besides the vaccination.

[Sidenote: Cause of sore arms]

The usual cause of a bad arm is improper vaccination; this means
the lack of proper precautions on the part of the person who does
the vaccinating. Years ago, before vaccination was performed with
the great care which is given it to-day, bad arms could not be
prevented; but to-day the cause of the trouble is not the vaccine,
but the vaccinator. Sometimes a father thinks he will save a dollar
by vaccinating his child himself, and he is likely to injure the
child by attempting to vaccinate him without taking antiseptic
precautions. The same surgical preparations must be made for a
vaccination as for an operation. If this is not done, a bad arm
will result, not because of the vaccination, but because of the
negligence of the vaccinator.

Never allow any person, doctor or otherwise, to vaccinate you until
the skin surface has been well washed with soap and water, rinsed
clean, and wiped off with alcohol. See that the vaccine is fresh
and has been properly kept. When it begins to "take," keep the spot
absolutely clean and covered with a clean cloth, renewed daily.
_Never scratch or rub it._ These precautions will prevent the
dreaded soreness of the arm.

[Sidenote: How people themselves infect their arms with pus germs]

The person operated on is himself often responsible for the bad
arm. A careful doctor will put a dressing on the arm, after he has
supplied the vaccine, and will tell you to let that dressing alone,
for he wishes to take it off himself. About the third or fourth
day after the vaccination, your arm begins to itch. Possibly you
have forgotten what the doctor told you; at any rate, you pay no
attention to directions and take the dressing off to scratch the
arm. When you scratch the wound, you introduce pus germs into it,
and you have no reason to expect anything but a sore arm. In this
case, it is not the fault of the vaccinator or of the vaccination;
it is your own fault. Never touch a vaccination sore; in fact, it
is dangerous to touch any sore.

  =Questions.= 1. How is a successful vaccination determined? 2.
  What are some pretended vaccinations? 3. Mention some of the
  things that cause bad arms after vaccination.

  =Remember.= 1. A successful vaccination causes a sore identical
  with the sores that result from smallpox. 2. A fly blister is
  not a vaccination in any sense of the word. 3. A very sore arm
  does not result from a properly performed vaccination, but
  from carelessness on the part of the vaccinator or the person



Tuberculosis, or consumption, has been known for many centuries. It
was known long before Rome was ever heard of. Hippocrates, a Greek
physician, studied it, and said that if it were treated in its
early stages, it could be cured.

[Sidenote: Why consumption is called the Great White Plague]

Tuberculosis is called the Great White Plague. It is called the
Great Plague, because it kills more people than does any other one
disease; the White Plague, because people who suffer from it become
so pale and white.

[Sidenote: Consumption more destructive than war]

It is estimated that nearly 200,000 people die from tuberculosis
every year in the United States. This means that in this country
there is one death from consumption every two minutes and
thirty-six seconds. Is it not fearful to think of nearly 200,000
people dying every year, in the United States alone, from a disease
that we know can be prevented? Do you not think that we ought to do
everything we can to prevent this disease from spreading?

During the Civil War 205,070 soldiers were killed in both armies.
This war lasted four years. During the same length of time there
were 640,000 deaths from tuberculosis in the United States. This
means that consumption killed over three times as many people as
were killed during the same length of time in the Civil War. In
some parts of the country one out of every seven deaths is caused
by this disease, but the average throughout the country is one
death out of every ten.

[Illustration: FIG. 64. Comparing 640,000 deaths from tuberculosis
the United States during four years with the 205,070 deaths in the
Civil War.]

[Sidenote: Prevalence of tuberculosis]

There are more than 700,000 people sick from tuberculosis every
year in the United States alone. Of this number nearly 200,000 die
every year. Tuberculosis is a disease that can be prevented. It may
take a long time to get rid of it, but it can be abolished. When
you think of all the people that are sick from tuberculosis, and of
all those who die from it every year, you will surely want to do
all you can to help prevent this suffering and death.

[Sidenote: Tuberculosis a disease of various parts of the body:]

When people speak of consumption they usually mean tuberculosis of
the lungs; but tuberculosis is not confined to the lungs. The germs
that cause tuberculosis may attack any part of the body, and from
one part may go to other parts, setting up a growth wherever they

[Sidenote: (_1_) Of the throat]

Tuberculosis of the throat is a common form of the disease. When
the germs of tuberculosis settle in the throat, they destroy the
tissues very rapidly and, as a rule, kill the patient much more
quickly than they do when they start in the lungs.

[Sidenote: (_2_) Of the joints]

Another frequent form of tuberculosis in occurs in the knee; this
is popularly called "white swelling." It quickly destroys the knee
joint and results in a stiff leg. The growth may stop there, but
more often it extends from the knee to other parts of the body.

Often we see a little boy or girl wearing one shoe with a sole much
thicker than the other. This is because one leg is shorter than the
other, and we notice that the shortened leg is deformed as well.
This condition sometimes results from an injury, but it is far
more likely to be caused by tuberculosis of the hip joint.

[Sidenote: (_3_) Of the spine]

Again we see boys and girls with diseases of the spine, so
that they have "hunch backs" or are twisted to one side. These
conditions result from tuberculosis of the bones of the spine.

[Illustration: FIG. 65. One of the effects of tuberculosis.]

[Sidenote: (_4_) Of the glands]

Sometimes we see children and grown people with swellings on their
necks. These swellings may look smooth, but they feel as if they
were made up of little bunches of grapes or plums under the skin.
They are almost always due to the growth of the germs that cause
tuberculosis of the little glands of the neck.

[Sidenote: (_5_) Of the stomach]

Any one of the other glands of the body is just as liable to
become affected by tuberculosis as are the glands of the neck.
Tuberculosis of the stomach or bowels is not at all uncommon.

The germs of tuberculosis are likely to attack any of the tissues
of the body, especially if the cells composing these tissues are
for any reason weakened so that they cannot do the work required
of them. When the tuberculosis germs grow in tissues, the tissues
finally break down and an abscess forms. A tubercular abscess is
sometimes called a "cold abscess."

All such abscesses finally break and an open sore results. The
matter that comes from the open sore and from the abscess when it
is first opened is full of the germs that cause tuberculosis. If
this matter is allowed to become dry, the germs are blown about in
the dust. Then other people may inhale them or take them into their
bodies through the mouth or skin and thus contract consumption.

[Sidenote: The old belief that consumption is inherited]

Until a few years ago it was generally believed that consumption
was inherited. That is, it was thought that children whose father
or mother had consumption were born with the disease. Even to-day
many people hold to this idea, because they have not studied or
learned of the discoveries made in recent years. These people still
believe that if a child's father or mother dies of tuberculosis,
the child will die of tuberculosis, too, no matter how careful he
may be or how much of a fight he may make against it.

It is true that many people whose parents have died of consumption
also die from this disease; but this does not prove that they were
born with consumption. It merely shows that they had a good chance
to catch the disease by being continually with some one who had it.
It is also true that a great many people die from consumption whose
parents did not have it. If consumption is an inherited disease,
where did these people get it?

[Sidenote: How the germ of tuberculosis was discovered]

About thirty years ago, Dr. Robert Koch discovered that all
consumptives have in their sputum a long, slender germ which he
called the tubercle bacillus. Some of these germs he injected
into guinea pigs, and he found that they caused the pigs to have
consumption. Then he made many other experiments, and proved beyond
question that it is this very germ that causes tuberculosis, and
that no one has consumption unless he has this germ in his body.

[Sidenote: Evidence that consumption is not inherited]

Then the question arose, "Is the baby whose parents have
consumption born with this germ in its body?" This question
could not at first be answered; but tests were made by taking
the children of consumptive parents away from their parents, and
keeping them in homes where there were no consumptives. It was
found that these babies did not develop the disease. From these
and many other tests, it has been proved that consumption is not
inherited, and that the reason the child of the consumptive so
often has consumption is because he lives with people having the

[Sidenote: Evidence that consumption is a house disease]

Consumption seems to be confined to certain families, and this has
led many people to think that the disease is inherited, regardless
of the proof that it is not. When we carefully study the facts
in various cases, we find that the disease is not confined to a
certain family, so much as it is to the _house_ in which the family

The record of a single house will illustrate how tuberculosis
sticks to the house rather than to the family. From 1880 to
1901, a particular house was occupied by a father, mother, and
six children, of whom four died of consumption. From 1902 to
1903 the house was occupied by another father and mother with
eight children. They moved away because of the great amount of
sickness in the family. At present this father and one of his
children have tuberculosis. In 1904 the house was occupied by
still another family, consisting likewise of a father, mother,
and eight children. Now it is known that four of the children
have tuberculosis, and it is feared that three others have also
contracted the disease. In 1905 a son of the first occupant, with
his wife and two children, returned to live in the house. The
father of this family died of tuberculosis. Up to 1906 the total
results from this house, scattered through four families, were as
follows: five deaths, six cases in people still living, and three
suspected cases.

[Illustration: FIG. 66. The constant danger of infection in railway
cars, where germs can live as well as in a house.]

[Sidenote: Why consumption is a house disease]

When the consumptive coughs, he sends fine droplets of moisture
into the air. These droplets contain the germs that cause
tuberculosis. The moisture evaporates and the germs are left
sticking to the floors, the walls, the curtains, and the furniture
of the room. When the room is swept or dusted, the germs are
stirred up with the dust and people inhale them. The germ that
causes consumption will live for a long time in a house; you cannot
see it, but it is there. Wherever a consumptive has lived, he has
left the germs of this disease behind him.

[Sidenote: How to disinfect houses]

If a house in which a consumptive has lived is thoroughly
disinfected, all the germs he left there will be killed. Scattering
disinfectants about a room does no good. The only proper way to
disinfect is to close the house, for if the disinfectant is strong
enough to kill the disease germs, no human being can stay in the
house while it is being used. Disinfecting should be done by the
health officer, because he knows how much disinfectant is needed to
kill every germ in the house and how it should be used.

[Sidenote: Fraudulent disinfectants]

Sometimes you will see an advertisement saying that certain
disinfectants will kill the germs of disease but will not affect
the people. Always remember that any disinfectant that is strong
enough to kill the disease germs will also kill human beings, and
do not be fooled by such advertisements.

_Never move into a house that has been previously occupied, until
the house has been disinfected._ Do not take it for granted that
the people who lived there before had no communicable disease.
Do not take the word of the agent or of any one else that there
has never been sickness in the house. People sometimes have
tuberculosis without knowing it; people sometimes have tuberculosis
or other communicable diseases without telling of it.

It does not cost much to disinfect a house, and if the disinfection
is properly done the disease germs will be killed. "An ounce of
prevention is worth a pound of cure." Try to convince your father
that by having the new home disinfected he may save not only
doctor's fees, but perhaps the lives of himself and his family.

There are a great many things that boys and girls can do to help
fight this disease. This "scourge" can be wiped out; but if the
boys and girls do not help in this great work, it will never be

  =Questions.= 1. Why do people call consumption the Great White
  Plague? 2. What is the annual death rate from consumption in the
  United States? 3. Compare the fatality from consumption with the
  number of soldiers killed during the Civil War. 4. What amount of
  illness in the United States is due to consumption? 5. Describe
  at least four forms of tuberculosis. 6. What determines the part
  of the body in which the germ of tuberculosis grows?

  =Remember.= 1. Tuberculosis and consumption are the same disease.
  2. This disease kills more people than war, although it might be
  prevented. 3. Tuberculosis is not confined to the lungs but may
  attack the tissues of any part of the body. 4. Consumption is not
  inherited; it is a house disease rather than a family disease. 5.
  A house should be disinfected by the health officer before it is
  occupied by a new tenant.



[Sidenote: How tuberculosis germs leave the body:]

The sputum (spit) of the consumptive and the discharges from
tubercular sores contain the germs that cause tuberculosis.
Sometimes these germs are so numerous that thousands of them would
be found clinging to the point of a needle dipped into the sputum
or discharges from a patient. When the consumptive coughs, he sends
into the air many of the germs that cause tuberculosis.

We cannot kill the germs while they are in the body of the
consumptive; but we can kill them after they have left the body, by
seeing that none of the sputum or discharge from tubercular wounds
or sores is allowed to become dried and blown about as dust.

[Sidenote: (_1_) In discharges from sores]

When the discharge from a tubercular sore becomes dried and blows
about with the dust, the germs are inhaled into the lungs of
other people, or fall into other sores and cause them to become
tubercular. Since this is one of the most frequent ways by which
this dread disease is spread, you will say at once, "Why, every
particle of matter from a tubercular sore ought to be burned, so
that there would be no possibility of the germs being scattered."
This of course ought to be done, but this is not enough.

People sometimes have consumption and are not aware that they have
it. Others may have tubercular sores and not know them to be such.
Any sore, whether it is tubercular or not, contains disease germs.
They may not be the germs of tuberculosis, but even the least
dangerous of them is the germ that causes pus (matter).

Since we are trying to get rid not only of the germs that cause
tuberculosis, but also of the germs that cause all communicable
diseases, it would be better to say, "All discharges from _any_
sore should be burned immediately."

[Sidenote: (_2_) In the sputum]

When people spit on the sidewalk or on the floor, the sputum will
of course become dry. Sometimes a lady drags her dress through the
sputum on the sidewalk or on the floor; it sticks to her dress and
she takes the germs home with her. The sputum of the consumptive is
loaded with the germs that cause tuberculosis, and if this sputum
is allowed to be blown about with the dust, people will inhale it
and thus get the germs into their lungs. Certainly the consumptive
should never spit on the sidewalk or on the floor, or in the mine,
workshop, or in any place where the sputum may become dry and form
dust. Of course he should not fill the air about him with germs by
coughing into it; everybody knows that.

[Illustration: FIG. 67. A sputum cup of waterproof pasteboard.]

[Sidenote: Why everybody should be careful about spitting and

But _no_ man or woman, boy or girl, should ever spit on the floor
or sidewalk. In the first place it is bad manners. No person does
this who is well brought up. In the second place, we must remember
that the consumptive does not like to have others know that he has
consumption; this feeling is a part of the disease. If you expect
the consumptive to refrain from spitting on the floor or sidewalk,
you must help him by your example. You cannot expect him to be the
only one to hunt up a cuspidor, when you yourself are spitting
on floor or sidewalk. If you expect the consumptive to take the
precaution necessary to protect you from this disease, you must
take the same precaution yourself.

In the matter of coughing, the same rules hold true. If you expect
the consumptive to hold a handkerchief before his mouth when he
coughs, you must do the same.

[Sidenote: How to avoid spitting on the floor or sidewalk:]

Since it is not right that the consumptive should spit on the floor
or sidewalk, it will naturally be asked, "What is the consumptive
to do with what he coughs up?"

[Sidenote: (_1_) By using paper napkins]

At a very small cost he can buy paper napkins and envelopes
which have been treated with paraffin to prevent moisture going
through them. If every one with a cough or with any such trouble
as catarrh, which makes him want to spit frequently, would carry
a supply of these paper napkins and paraffin envelopes, he would
always have a suitable place in which to spit. When you cough up
anything, spit into one of these little napkins, put the napkin
into the envelope, and when you get home burn the whole thing.

[Illustration: FIG. 68. A pocket cuspidor.]

[Sidenote: (_2_) By using pocket cuspidors]

There are other conveniences which can easily be carried in the
pocket, called pocket cuspidors. Some are made of thin cardboard,
treated with paraffin, and filled with cotton to hold all the
moisture of the sputum; others are made of glass, shaped like a
bottle, with a wide mouth. Those made of cardboard should be burned
as soon as possible and the glass ones should be thoroughly washed
with boiling water.

[Sidenote: (_3_) By having public cuspidors]

In some cities cuspidors have been placed at the edge of the
sidewalk in an effort to lessen the spread of disease caused by
spitting. These cuspidors have a stream of water running through
them constantly and are connected with the sewer. They are so made
that they cannot easily be kicked over or upset, and they are
placed on stands just high enough to make it easy to spit into
them. If properly made, they are not unsightly. Would it not be a
good thing if your town would put such cuspidors on your streets,
and if the merchants would put them into their stores? Every
office, every workshop, every store, every railway and street car
should be provided with cuspidors.

[Illustration: FIG. 69. The common drinking cup--a fruitful source
of infection.]

[Illustration: FIG. 70. The individual drinking cup--each cup clean
and free from disease germs.]

[Sidenote: How consumption is spread from the lips:]

We know that the substance which people cough up when they have
consumption contains the germs that cause this disease. When they
spit this matter out, many of the germs stick to the lips. This is
true not only of consumption, but of the germs of other diseases,
such as diphtheria, measles, and scarlet fever.

[Sidenote: (_1_) By drinking cups]

When there are disease germs on the lips, it is impossible for a
person to drink and not leave some of the germs sticking to the
edge of the cup or glass. If the germs of disease are in the mouth,
every time that the person suffering from this disease drinks from
a cup, he leaves some of the germs on the edge of it. The next
person to drink from that cup may get the germs into his mouth.

[Illustration: FIG. 71. A sanitary drinking fountain for public

Always avoid drinking from a cup or glass from which another person
has been drinking. You can never tell who may have disease germs in
his mouth, or when you may get them on your lips by drinking from
the same cup. Each individual should have his own cup and should
never let any one else drink from it.

[Sidenote: (_2_) By putting pencils into the mouth]

When you put the point of your pencil into your mouth, you will
leave germs on it just as you do on the edge of a cup when you
drink. Never put your pencil into your mouth; never use any other
person's pencil; never trade pencils.

[Sidenote: (_3_) By the common bite]

Sometimes we see a child giving his friends a bite of his apple or
candy or cake. Of course when disease germs are in the mouth of the
one who takes a bite, the germs will be left on the apple, candy,
or cake. By no means should a boy or girl be selfish, but if you
have something to share with your friends, break it or cut it into
pieces. Never take into your mouth anything from which another
person has taken a bite.

[Sidenote: How tubercular cows cause consumption]

Milk that comes from consumptive cows may contain the germs that
cause tuberculosis. When you drink the milk from such cows, you
take these germs into your body. They find their way from the
stomach and intestine into the blood, and there they travel about
until they find a spot where the cells are dead or are not doing
their work properly. When they find such a place, they settle down
and begin to grow; and the first thing you know, you will have
tuberculosis in that part of your body. Sometimes the germs do not
have to go out of the stomach or intestines to find a favorable
opportunity to take hold and grow. When this happens, we have
consumption of the bowels.

One cannot tell by looking at milk or by tasting it whether or not
the germs of tuberculosis are present. They do not make the milk
sour; neither do they make it look different from pure milk.

One cannot tell by looking at a cow whether or not she has
tuberculosis. Sometimes a cow will have tuberculosis and yet look
very healthy. There is, however, a way by which we can tell when a
cow has this disease, no matter how healthy she may look. This is
what is known as the tuberculin test.

[Sidenote: How to detect tuberculosis in a cow]

If a little tuberculin is injected under the skin of a cow that has
tuberculosis, it will make her have a fever and appear sick for a
day or two. If she is free from tuberculosis, it will not make her
sick at all.

It would seem as if all people who sell milk would want to know
whether their cows have consumption so as not to run any risk of
conveying the disease to their customers. Some of them do take this
precaution, but a great many of them do not want to go to this
trouble. Sometimes you will hear them say, "Oh, I do not believe in
this tuberculin test." They do not want to believe in it because
they know that the cows, if tested and found to have tuberculosis,
will have to be killed.

The reason that dairymen sell us milk from tubercular cows is the
same that makes the man with scarlet fever in his house fail to
tell the health officer about it; the same that makes the butcher
buy and sell meat from diseased cattle; the same that makes some
people absolutely regardless of the welfare of others--it is

  =Questions.= 1. How does a patient give off tuberculosis germs?
  2. Why should even well people refrain from spitting in public?
  3. Why should the sputum be taken care of? 4. Why should we avoid
  the common drinking cup? 5. What is the danger from putting
  pencils into the mouth? 6. Is it safe to use another person's
  pencil? 7. What is the best way of sharing food? 8. How can one
  be protected from tubercular milk?

  =Remember.= 1. The sputum and discharges from all sores should
  be immediately burned or disposed of in such a way that they
  cannot become dry and be blown about as dust. 2. Consumption
  may be contracted by the use of the common drinking cup, or by
  putting into your mouth such things as pencils and coins. 3. The
  milk from a cow suffering from consumption contains the germ of
  tuberculosis. 4. A cow may have tuberculosis and not appear to be
  sick. 5. The only way to determine whether a cow has tuberculosis
  is by using the tuberculin test. 6. Every milch cow should be
  tuberculin tested.



[Sidenote: Consumption should be recognized early]

When people first get consumption, they seldom realize that they
are seriously sick. Most of them think they have a bad cold, or
are overworked, or that they have been staying too closely in the
house. Often they will not even see a doctor until they are so sick
that the doctor cannot do much for them.

When you have a slight cough that "hangs on"; when you feel
feverish every afternoon; when you are short of breath; when you
get tired very easily; when you do not feel like eating anything
except candies and cakes--then you should think of consumption.
These are not all the signs, but they are enough to make you go at
once to a doctor.

A long time ago the doctor would have felt badly if he had been
obliged to tell you that you had consumption; but now he knows that
if you go to him early in the disease and follow his directions,
you will get well.

[Sidenote: How consumption is cured: (_1_) By rest]

When the doctor finds that a person has consumption, the first
thing he orders is rest. By this he means absolute _rest_. He does
not mean that the patient can go to school or to the office part of
the day and rest the remainder of the day. The doctor will want to
watch him constantly. Then there comes a time when he must begin to
take a little exercise; the doctor tells him just how much exercise
to take, and just what form of exercise is best for him.

[Sidenote: (_2_) By fresh air]

The consumptive must have plenty of fresh air all the time; he must
be out-of-doors as much as possible. You will wonder how the doctor
expects him to be out-of-doors when he has been told that he must
have absolute rest. Later we will show you how one can practically
be out-of-doors and yet at the same time be in bed.

[Sidenote: (_3_) By sunshine]

Sunshine will kill the germs of any disease more quickly than
almost anything we know of, and a consumptive must have all the
sunshine that he can get. Of course it cannot get into the body to
kill the germs, but it strengthens the cells of the body so much
that they can fight with just that much more energy.

[Illustration: FIGS. 72 and 73. Living outdoors in cold weather.]

[Sidenote: (_4_) By nourishing food]

Nothing is more important than pure food in building up the body
and in making heat and power. In consumption the food that is
stored up in the body burns itself up very fast. The consumptive
must therefore take not only the food needed to supply the usual
demands of the body, but enough to make something extra for the
disease to burn up without drawing on the reserve fund stored in
the body. In order to do this, he will have to eat a great deal,
and what he eats must be of the kind that makes the best building
material and the most nourishing material. He cannot tax his
stomach by eating things that are not nourishing; all the work his
stomach can do must be devoted to the foods he really needs.

The weapons with which we fight consumption are rest, good food,
fresh air, and sunshine. These will do more good than all the
medicine in the world. Fresh air is not only one of the best things
for the cure of consumption, but it is one of the best things for
the prevention of consumption. You should always breathe plenty of
fresh air night and day, and there is plenty of fresh air to be had
if you will take it.

[Illustration: FIG. 74. A window tent. (Invented by Dr. W. E.

[Sidenote: How to have fresh air at home:]

If you have only a single window in your room, try to sleep with
your head in the fresh air. It is not always easy to arrange a room
in such a way that you can have fresh air without placing your bed
in a draft, but even this difficulty can be overcome.

[Sidenote: (_1_) By window tents]

There are several devices, called window tents, which you can buy.
By the use of such a tent, your head will be out-of-doors all the
time; yet the draft cannot strike your body, because a part of the
tent fits around your neck and cuts off the air from the rest of
your body. One of these tents is shown in Figure 74. You do not put
your head out of the window; your head is on your pillow just as if
the tent were not there. Your bed is placed directly in front of
the window and the tent comes down over your pillow, allowing your
head practically to be out-of-doors, but keeping the cold air out
of the room. Sleeping under a window tent is the next best thing to
sleeping out-of-doors.

[Illustration: FIG. 75. A sleeping porch built in a house.]

[Sidenote: (_2_) By sleeping porches]

Many of our modern houses are built with sleeping porches on which
one can sleep outdoors summer and winter. Where there is not a
special sleeping porch on the house, an ordinary porch may often be
made to serve the purpose, or a very inexpensive sleeping porch can
be added to the house.

[Sidenote: (_3_) By tent cots]

Sometimes people cannot get the use of a porch of any kind. In such
cases it may be possible to put up a tent in the yard. If the yard
is very small, a tent cot may be used. This is simply a cot with
a tent on it, which can be closed up and put away in the daytime
and set up again at night. In a large city where the houses have
no yards at all, this arrangement can be used by setting it up on
the roof of the house. There is almost always some way of securing
fresh air at night if we will only give a little thought to the

[Sidenote: Fresh air in schoolrooms]

Unfortunately, many of our school buildings are not provided with
good ventilating plants. A proper system of ventilation furnishes
at least 1200 cubic feet of fresh air per hour for each child in
each room.

[Illustration: FIG. 76. An open-air schoolroom for consumptive

[Sidenote: The necessity for playgrounds]

In large cities it is often impossible to find outdoor space in
which boys and girls may play during recess. Even this difficulty
can be overcome by turning the roof of the school building into a
playground, with a high wire netting around it.

Every school yard should be provided with swings, bars, and
gymnasium apparatus to encourage the children to take plenty of
exercise. Children who live in crowded towns need exercise during
vacation as well as during school days, and the school yards should
be open to them at all times. A summer teacher who shows the
children the best way to exercise, has work fully as important as
that of any other teacher during the school term.

A sound body is more valuable than education itself, but a good
education and a sound body together are the best assets any man or
woman can have.

  =Questions.= 1. State the four things necessary to cure
  consumption; show the value of each. 2. What is the value of
  fresh air to every one? 3. How may an abundance of fresh air be
  secured in the home? 4. In the school?

  =Remember.= 1. Rest, fresh air, sunshine, and nourishing food
  are the cures for consumption. 2. All these things can be
  secured in any climate and by every person. 3. =Tuberculosis is
  a communicable disease.= 4. =Tuberculosis can be prevented.= 5.
  =Tuberculosis can be cured.=




[Sidenote: The framework of the body]

The framework of the body is composed of bones. There are 206 bones
(not including the teeth) in the body. The bones of the body are
divided into four classes--long bones, short bones, flat bones, and
irregular bones.

[Sidenote: Construction of bones]

Regardless of their shape, all bones are composed in the same way.
Every bone has an outer and an inner portion. The outer portion
is a dense layer called _compact bone_. The inner portion is more
open, and is much weaker; this is called _cancellated bone_ (from
_cancella_, a sponge). In the smaller bones, the marrow, which is
quite soft, runs through the spongy bone; in the larger long bones,
the marrow is distinct and is enclosed by the spongy bone.

[Sidenote: The periosteum]

Every bone is covered by a thick, tough layer, the _periosteum_,
which has three uses. When the bone is injured by disease or
accident, the periosteum makes new bone to fill in and repair the
break. It also builds new bone on the surface of the old as long as
the body is growing. Finally, the periosteum gives strong and firm
attachment to the muscles, which send tendons into it.

[Sidenote: Joints]

Every bone in the body (except the hyoid bone, to which the tongue
is attached) is joined with some other bone. Most of them join with
two or more bones. In most instances the end of a bone which joins
with another is rounded off and made very smooth, so that it can
slide easily over the other bone. There are three principal kinds
of joints in the body. They are called the _ball and socket_ joint,
the _hinge_ joint, and the _serrated_ or _saw-tooth_ joint.

[Illustration: FIG. 77. The skeleton.]

[Sidenote: The ball and socket joint]

The ball and socket joint is one that can move freely in all
directions. We see it illustrated in the joints of the shoulder
and hip. In these joints one of the bones has a deep depression
in it, and this depression forms the _socket_. The other bone has
a rounded head that fits into the depression. We call this rounded
head the _ball_.

[Illustration: FIG. 78. The structure of a bone.]

[Sidenote: The hinge joint]

The hinge joint is illustrated in the knee and elbow joints. These
joints can move backward and forward in one plane like a hinge, but
they cannot move in a circle like the ball and socket joints. You
cannot swing your forearm about on a pivot at the elbow as you can
your whole arm, nor will the knee joint bend in every direction as
does the joint at the hip.

[Sidenote: Serrated joints]

Serrated joints do not move. The bones having serrated joints are
fitted tightly together so that they form practically one bone. We
find this kind of joint illustrated in the way the bones of the
skull are put together.

[Sidenote: Ligaments]

The joints of the body are not held together by rivets, pins or
bolts as are the joints of a machine, but by bands of very tough
tissue placed about a joint in such a way as to allow it to move
freely, although the bones are all the time held firmly together.
These bands are called _ligaments_. Ligaments are much better than
bolts or pegs would be, because they stretch a little, and thus
prevent the breaking of the bones when the joint is put under a
severe strain.

[Illustration: FIG. 79. The muscles.]


[Sidenote: What muscle is]

The lean meat of any animal is composed entirely of muscle tissue.
It is the function of the muscles to move the body.

[Illustration: FIG. 80. The biceps muscle contracted.]

[Sidenote: How the muscles work]

The muscles are nearly all attached to the bones. They are just
long enough to let the joint straighten out when the muscles are at
rest, but when the joint bends the muscle contracts. When a muscle
contracts it becomes shorter and thicker. Sometimes it becomes very
much thicker in one place. Every boy knows how much thicker the arm
muscle (_biceps_) becomes when he bends his elbow hard. He calls
this "showing his muscle."

[Sidenote: Tendons]

There is not room enough on most of the bones for all the muscles
to be attached directly to them. Instead of being thus attached
directly to the bone, they end in what we call _tendons_. These
tendons are hard and strong, and a very small tendon will lift as
much without breaking as quite a large muscle. The muscles are soft
and would have to be attached over a large area in order to secure
the required strength. The tendons, being so much stronger than
the muscles, can be attached to a very small area and yet secure
the same amount of power as would result from attaching the muscle

The tendons pass directly into the periosteum, the thick, strong
covering of the bones. So strong is this attachment that the bone
will often break before the tendon will pull loose.


[Sidenote: The skin as an armor]

The entire body is covered with skin, which regulates the heat of
the body and acts as an armor against blows and cuts which would
otherwise injure the delicate nerves and blood vessels beneath. It
also serves to some extent to keep out the germs of disease. The
skin appears to be smooth, but if you examine it through a strong
magnifying glass you will see that it is divided into little areas.
The dividing lines do not run straight, however, and the areas are
not square like those you find on a checkerboard.

[Illustration: FIG. 81. A section of the skin, highly magnified.]

[Sidenote: Sweat glands]

After looking at the skin with a strong magnifying glass you will
think that you must have seen all its irregularities, but if you
will look at it with a powerful microscope you will find out many
other things. In the first place you will see many little openings
in the skin. These little openings make the ridges which divide the
skin into little areas. Some of the openings are _sweat glands_,
and there is always some perspiration coming out of them. When you
are very warm you can see, without the aid of the glass, the drops
of perspiration as they come out on the surface of the skin. When
you are not very warm you cannot see these drops of perspiration,
but they are nevertheless coming out all the time. When the
perspiration comes so slowly that you cannot see it, it is called
_insensible perspiration_.

[Sidenote: Hair]

The whole body is covered with hair. You can see the hair on your
head and some of the hair on your arms and the backs of your hands,
but most of the hair on the body is so fine that you cannot see it
without a microscope. Each of the fine hairs on the body has a root
that goes through the skin just as the root from each hair on your
head goes through it.

[Sidenote: Sebaceous glands]

Opening into the little pockets in which the hairs stand, are
glands that secrete a kind of oily material. They are called
_sebaceous glands_ or _follicles_. Sometimes these follicles
become stopped up; then the material they secrete becomes thick
and cheesy, and the little black points appear on the skin which
we call _blackheads_. The white matter which comes out of these
blackheads is merely the secretion of the glands from which the
water has been absorbed, leaving the solid or cheesy portion.

[Sidenote: Nails]

There is a part of the skin that we do not usually think of as
skin. We mean the _nails_. The finger nails and the toe nails do
not look like the rest of the skin of the body, but they are made
of just the same kind of cells. The cells of the nails are flat,
dead, and closely packed together. There are no sweat glands, or
sebaceous glands, or any hairs in the nails.


[Sidenote: The alimentary canal]

The digestive system is the part of our bodies in which the food we
eat is so changed that it can be made use of by the little cells
in the body. It is composed of a long canal with many parts and
enlargements, each part necessary for a certain required work. This
canal as a whole is called the _alimentary canal_.

[Sidenote: Teeth]

The mouth does the first part of the work for the digestive system.
Here we find the teeth, which are used for grinding the food. The
teeth are composed of three parts, the _head_ (or _crown_), the
_neck_ and the _root_. The head, or crown, is very hard. Each
tooth is hollow, and in the hollow portion there are nerves and
blood vessels.

[Sidenote: The salivary glands]

Opening into the mouth are three pairs of glands known as _salivary
glands_. One pair of glands is located just above the angle of the
jaw. It is these glands that become swollen when we have mumps.
Another pair of glands is placed just inside the jaw bone, near the
root of the tongue, and the third pair is located under the tongue.
These three pairs of glands secrete the saliva which moistens the
food and aids in digesting the starch.

[Illustration: FIG. 82. The alimentary canal.]

[Sidenote: The esophagus]

The food passes from the mouth; through a passage called the
_esophagus_, or gullet, to the _stomach_.

[Sidenote: The stomach]

The stomach is one of the enlarged parts of the alimentary canal.
Its walls are quite thick, and in these walls are thousands of
little glands. These glands secrete a fluid called _gastric juice_.
When the food enters the stomach it is held there for a long time,
and the walls of the stomach squeeze upon it so that the food is
mixed with the gastric juice until every bit of it that will be
of any use to the body has become fluid in character. Not only
does the gastric juice make the food liquid, but it acts on it
and changes some of it so that it will be suitable for use by the
little cells of the body. As fast as the food is made liquid by
the juices of the stomach it is allowed to pass into the intestine
through an opening called the _pyloric opening_.

[Sidenote: The intestine]

The intestine is a long, narrow, twisting and turning tube that is
divided into two principal parts, the large and small intestine. In
the walls of the intestine are many little glands that secrete a
fluid that helps in digesting the food. Two fluids, one made by the
liver, the other by the pancreas, are brought into the intestine by
two small tubes, which come together in the wall of the intestine
six or seven inches below the pyloric opening. These fluids perform
a very important part in the digestion of all the different

[Sidenote: Villi and lymphatics]

Besides the little glands in the walls of the intestine there
are many thousands of little finger-like projections standing up
from the walls. These are called _villi_. Each villus has in it
very small vessels, into which the food passes after it has been
digested. These vessels are of two sorts: blood vessels, which
take up the digested starch and proteid foods, and another sort
known as _lymphatics_, which take up the fats. All the lymphatics
combine into a single vessel which empties into the great vein at
the base of the neck. Thus the fatty foods pass into the blood and
are mingled with the food materials taken up directly by the blood


[Sidenote: Two kinds of blood vessels]

There are two kinds of blood vessels in the body. We call them
_arteries_ and _veins_. The arteries serve to carry the blood from
the heart to all parts of the body, and the veins serve to carry
the blood back to the heart. The heart is really a part of the
blood vessels, half of each side being like the veins and half like
the arteries.

[Sidenote: Arteries and veins]

The walls of the arteries are thicker than those of the veins. Two
sets of arteries leave the heart, one from each side. The artery
that starts from the right side of the heart goes to the lungs and
carries _venous blood_, which has a very poor supply of oxygen and
is full of impurities. We call this the _pulmonary artery_. The
artery that leaves the left side of the heart goes to all parts of
the body but the lungs and carries _arterial blood_, which has much
more oxygen and is much more free from impurities.

[Sidenote: Capillaries]

If we follow the blood as it circulates we will see how it reaches
all parts of the body. The big artery that leaves the left side of
the heart divides into smaller and smaller arteries until there
are branches going to every part of the body. These branches keep
dividing until they are so small that we call them _arterioles_,
and these little arterioles again divide and become so small that
we call them _capillaries_.

[Sidenote: Changes in the blood]

While the blood is passing through the arterioles and the
capillaries, something is happening to it. The little cells with
which these small vessels come in contact have been taking the
oxygen and the nourishing material out of the blood. At the same
time they have been putting something into the blood. In place of
the oxygen they have been putting in carbon dioxid and in place
of the nourishing material they have been putting in the worn-out
materials from the cells. As the blood passes through certain parts
of the body, such as the kidneys, the worn-out materials from the
cells are taken out of the blood and sent out of the body. The
carbon dioxid is left in the blood until it goes to the lungs.

[Illustration: FIG. 83. The white vessels represent the circulation
of the arterial blood; the gray, the circulation of the venous

[Sidenote: Venous blood]

The blood has now been followed to the capillaries, where oxygen
and nourishing material have been taken out of it, and where
something else has been added to it. As we follow a little
capillary, we find that instead of dividing again, it joins others
and gradually grows larger. As these blood vessels grow larger the
walls do not become so thick as the walls of the arteries of the
same size. These larger vessels formed by the union of capillaries
are called _veins_. In other words, the veins are simply
continuations of the arteries that have divided into extremely
small branches and have now come together again. The blood which
has been changed is now called _venous blood_. It has much less
oxygen in it, but has received a great deal of carbon dioxid. The
veins continue to come together, until finally they form a single
large vein which empties into the upper half of the right side of
the heart. From there the blood is driven into the lower half of
the right side of the heart and thence to the pulmonary artery,
which goes to the lungs. The blood is not changed in the heart, so
what goes into the pulmonary artery is still venous blood.

[Sidenote: Arterial blood]

The blood goes straight from the heart to the lungs and there it is
changed into arterial blood. The change consists in taking oxygen
from the air and giving off carbon dioxid to the air. From the
lungs the blood goes through the capillaries again into the veins,
the small capillaries in the lungs uniting to form the pulmonary
veins. These veins finally unite into one vein that empties into
the upper half of the left side of the heart, and from there the
blood goes to the lower half of the same side. The blood has now
reached its starting point and is ready to begin its journey again.
The journey of the blood is as follows:

[Sidenote: Entire circulation]

From the right side of the heart to the arteries; from arteries
into arterioles; from arterioles to capillaries; from capillaries
into veins; from veins into the heart; from the heart to the lungs;
and from the lungs back to the heart again.


[Sidenote: Use of the respiratory system]

That portion of the body by which we breathe is called the
respiratory system. This system is composed of the _nasal passage_,
the _pharynx_, the _larynx_, the _trachea_, the _bronchi_, and the
_lungs_. The mouth is not a part of the respiratory system; we
should never breathe through our mouths.

[Sidenote: The use of the nose in breathing]

As the air passes through the nasal passage it is warmed and
moistened, and a great deal of dust and dirt is taken out of it.
Thus the nasal passage serves to warm, to moisten, and to clean the
air we breathe, and is a very important part of the respiratory
system, since either cold or dry air is very irritating to the

[Illustration: FIG. 84. The air passages of the head and throat.]

[Sidenote: Pharynx, larynx, and trachea]

There is only one tube leading from the back of the nasal passage
to the lungs. Different parts of this tube are given different
names. The pharynx is that part that extends from the back of
the nose to the vocal chords. The larynx is the part of the
throat where the vocal chords are located. We sometimes call it
the "Adam's apple." It is very prominent in some men, but seldom
noticeable in women. The trachea is the part of the tube leading
down from the larynx. At the lower end of the trachea the tube
divides into two parts that we call the bronchi, one leading to
each lung.

[Sidenote: The bronchi]

The bronchi carry the air from the trachea to the lungs. They
divide again and again until they become so small that there is a
branch for each little air cell in the lungs.

[Illustration: FIG. 85. The lungs.]

[Sidenote: The lungs]

The lungs are the most important part of the respiratory system.
They are made up of lobes. There are two lobes in the left lung
and three in the right. Each lobe is divided into _lobules_, which
means small lobes. Each lobule is divided into air spaces. In these
air spaces, or cells, the work of the lungs is performed.

[Sidenote: Air cells]

The capillaries run in the thin walls of the air spaces. The walls
of these fine blood vessels are so very thin that the air in the
air cells comes in almost direct contact with the blood in the
vessels. While the blood is passing through the vessels in the
walls of the air spaces, something happens to both the blood and
the air. The air we take into our lungs contains a great deal of
oxygen and very little carbon dioxid. The air that comes out of our
lungs contains a great deal of carbon dioxid and much less oxygen.
In other words, the oxygen from the air goes into the blood, and
the carbon dioxid from the blood goes out into the air.

[Sidenote: Necessity of pure air]

If the air we breathe is not pure and does not contain enough
oxygen, the blood cannot get all the oxygen we need, and the cells
of the body become sick and die. If, when we breathe, we do not
fill each little air cell in our lungs with air, a great deal of
the blood sent to the lungs for oxygen cannot get it. If we wear
very tight clothing we cannot take a full breath and hence cannot
fill all the air spaces with air. If the air spaces in the lungs
are not filled, the blood does not get the oxygen it needs, as
there is no other place in the body to get it.


[Sidenote: The eye compared to a camera]

The eye is one of the most important organs in the body and also
one of the most delicate. It is very much like a camera.

[Sidenote: The cornea and the sclera]

When you look at an eye you are likely to think that the front of
it is blue or brown. The colored part is not the front of the eye.
If you look at the eye from the side you will see that there is a
curved part in front of the colored part and that the curved part
is perfectly clear. This curved clear part of the eye we call the
_cornea_. The cornea connects with the white part of the eye, and
this white part extends all around the rest of the eye, except at a
small point in the back where the _optic nerve_ comes through. This
white part we call the _sclera_.

[Sidenote: Aqueous humor]

The space between the cornea and the colored part of the eye is
filled with a clear fluid that is called the _aqueous humor_, which
means watery fluid. The space occupied by this fluid is called the
_anterior chamber_ of the eye.

[Sidenote: The iris]

The iris, which is the colored portion of the eye, is a curtain
that is hung between the anterior and posterior chambers of the
eye. It prevents any light getting into the posterior chamber
except that which passes through a round hole in the iris called
the _pupil_. The pupil grows larger or smaller according to the
amount of light needed by the eye. If you look away from a bright
light at something in the dark, the pupil grows larger; if you
look back at the light, it grows smaller. You can see this in a
hand mirror.

[Sidenote: Lens]

Behind the pupil is a clear mass shaped like a very strong
magnifying glass. This is the _lens_. The lens causes to be formed
on the back of the eye a clear picture of whatever you are looking
at. When you focus a camera, you move the back towards or away from
the lens. When you focus your eye you cannot move the back of the
eye, but you can make the lens more or less convex as may be needed
to make a clear picture.

[Illustration: FIG. 86. A cross-section of the eye.]

[Sidenote: Vitreous humor]

Behind the iris and the lens, we find the posterior chamber of
the eye. This occupies by far the greater portion of the ball
and corresponds to the dark chamber of a camera. This chamber is
filled with a clear fluid called the _vitreous humor_, which means
jelly-like fluid. It is a clear, gelatinous substance.

[Sidenote: The retina and the optic nerve]

The optic nerve enters the eyeball from the back and spreads
its fibers out in a thin membrane called the _retina_, which
corresponds to the sensitive plate in a camera. The lens focuses on
the retina the image of any object you look at. The impression made
on the minute nerve endings in the retina is carried by the optic
nerve fibers to the brain. When this impression reaches the brain
we see the object.

[Sidenote: Movements of the eye]

Each eye has six muscles that turn it in whatever direction you
want to look. These muscles are very delicate, and for true
sight they must be exactly adjusted. If the muscles on one side
of the eye are stronger than those on the other side, you will
be cross-eyed or wall-eyed. If one of the muscles in one eye is
stronger than the corresponding muscle in the other eye, it pulls
the eyeball out of place and you "see double."

[Sidenote: The use of the outer ear]

The portion of the ear that you see on the side of your head has as
much to do with hearing as the outer rim of the horn into which you
speak has to do with making a record for the phonograph. You know
that the record is really made at the little end of the horn, while
the big end simply collects the sound. The outside portion of the
ear simply collects sounds, and the real hearing is done with the
portion of the ear that is not seen.

[Illustration: FIG. 87. The ear, showing the outer, middle, and the
inner part.]

The outer ear connects with the short tube that leads to the
_drum_, which is a thin membrane that separates the middle ear from
the outer ear. This drum does not have so much to do with hearing
as is supposed. To have a hole in the drum does not mean that you
cannot hear.

[Sidenote: The middle ear]

The middle ear is that portion which is just inside the drum. In
this we find a chain of little bones. The one attached to the
drum is shaped much like a hammer, and is called the _malleus_,
which means mallet or hammer. The next one is shaped like an anvil
and is called _incus_, which means anvil, and the third is called
_stapes_, which means stirrup. The flat part of the stapes fits
into a small opening that leads to the internal ear.

[Sidenote: The inner ear]

The internal ear is shaped like a snail shell. It makes several
turns, which are hollow like the ends of a conch shell. In these
channels the nerve that receives the impressions made by the sounds
is distributed. This nerve carries the impressions to the brain.

[Illustration: FIG. 88. The nervous system.]


[Sidenote: Importance of the nervous system]

This system is so important in its use and so difficult to
understand in its details, that a description of it should have
more space than can be given in this summary. Can you imagine
having no feeling and being unable to move? This would be your
condition if you had no nerves.

[Sidenote: Nerves compared to telegraph system]

Briefly, the nerves might be called the telegraph system of the
body. There is a great central station called the brain where
messages are received and sent out; there are many sub-stations
that make up the spinal cord. Twelve great nerves pass directly
from the brain to the body; all others pass from the spinal cord.

[Sidenote: Extent of nervous system]

Every nerve leaving these centres divides and sub-divides into
little threads as the arteries divide and sub-divide into
arterioles and capillaries, until every part of the body--every
muscle and part of the skin--has its nerve.

[Sidenote: Voluntary and reflex action]

Every time you _choose_ to move your hand, your brain sends to the
necessary muscles an instantaneous order to act. This is called
_voluntary action_. If you put your finger against a hot stove
you jerk it away before you could have time to _choose_ to do it.
This happens as an order from a sub-station and is called _reflex

Messages travel both ways and it is necessary that the nervous
connection with every part of the body remain unbroken, and
important that the nervous condition be kept healthy.


A false delicacy has often prevented the teaching of vital lessons
to growing children. The day is how at hand when foolish sentiment
must no longer prevent the spread of any knowledge which is
necessary to exterminate the plagues that have afflicted the race.

In chapters 17, 18, 19 and 32, unpleasant facts are given in plain
language. They are facts that parents do not teach their children
and that most teachers will not frankly treat with classes in a
school. Though they are disagreeable to discuss, they are essential
for children of school age to know. Now that the dependence of
public health upon personal hygiene is recognized, personal habits
and sanitary conditions are more frankly dealt with than formerly.

It is an excellent thing occasionally, to have one or two points of
an assigned lesson answered in writing. Any topic that the teacher
may think advisable to treat in this manner may be discussed on
paper at the beginning of the recitation, five or six minutes being
allowed for that purpose. Even a whole chapter may be assigned to
be studied with a view of answering in writing the questions at the
end of the chapter. The written test can then take the place of the
usual oral recitation. This method is suggested to the teacher who
hesitates to discuss orally certain plain but essential facts.

Chapter 32 on the Spread and Prevention of Consumption can be
treated with best results orally, if the pupils are first made
to _feel_ the great danger of consumption and to realize the
possibility of preventing the vast havoc wrought by that dread
disease. The attitude of teacher and pupils should be that while
the discussion may be disagreeable, the disgusting habits referred
to in the text are so commonly practised that unless their dangers
are taught this disease can never be wiped out.


  Adenoids, 49, 50

  Air, amount necessary for health, 45;
    effects of impure, 45-48;
    fresh air, when needed, 45-48;
    how secured, 46, 47;
    how changed in body, 45;
    necessity of pure air, 45-48

  Air cells, 175

  Alcohol, effect of, on body, 67-70;
    on brain work, 70;
    on consumptives, 69;
    on descendants, 69;
    on liver, 68;
    on morals, 69;
    on nervous system, 69;
    on powers of resistance, 68;
    on stomach, 67;
    false ideas about effects of, 67;
    what business men think of, 70

  Alimentary canal, 169, 170

  Amoebic dysentery, how prevented, 122;
    how spread, 122;
    where prevalent, 122

  Animals free from typhoid fever, 113

  Antitoxin, how it acts, 108-110;
    how discovered, 109;
    sometimes considered a poison, 111;
    prevents diphtheria, 110;
    saves lives, 110

  Aqueous humor, 177

  Arterial blood, 172

  Arteries, 171

  Articles used by the sick, dangers from, 75;
    how to treat, 76

  Bathing, importance of, 60;
    frequency of, 60

  Baths, hot, 61;
    cold, 61

  Bedtime for children, 51

  Blood, arterial, 172;
    how changed in the body, 174;
    venous, 171, 172

  Boils, how caused, 95, 99

  Bones, 163

  Bronchi, 175

  Building foods, 14, 15

  Candy, when harmful, 54;
    when not harmful, 54

  Canned meats, why poisonous, 32

  Capillaries, 172

  Cells, are alive, 6;
    body made of, 6;
    body needs new, 14;
    how killed, 7;
    must not be killed, 6;
    size of a, 5;
    what they are like, 5

  Circulation of the blood, 171-174

  Clothing, effect of damp, 11;
    promotes health, 9;
    proper weight of, 10

  Common drinking cup, 153

  Consumption. _See Tuberculosis_

  Cooking, effects of improper, 34, 35;
    fatty foods, 34;
    meats, 35;
    starchy foods, 34

  Cornea, 177

  Coughing, dangers from, 147, 150-153;
    how to prevent dangers from, 152, 153

  Cuspidors, in public buildings, 152;
    pocket, 152;
    street, 152

  Dairy, sickness about a, 26, 103, 115

  Decomposed foods dangerous, 30, 32

  Decomposition, cause of, 30;
    effect of cold on, 31;
    of foods, 30-32

  Desserts, when harmful, 40;
    when not harmful, 40

  Dining table, effect of dirty, 37;
    cheerfulness at, 37

  Diphtheria, cure of, 108-111;
    germs present after recovery, 101, 102;
    germs present when throat is not sore, 104;
    how to confine germs, 100;
    how poison is fought, 108-110;
    mild cases, how detected, 104;
    nature of the poison, 108;
    prevalence of, 100;
    where germs come from, 100;
    why some cases are not quarantined, 102-104

  Dirt, a cause of sickness, 77, 78;
    getting into milk from cows, 23, 117;
    from cow barns, 23-25;
    from milk cans and bottles, 26, 27;
    from milkmen, 25;
    from flies, 28, 80, 81

  Diseased animals, effect on meats, 19-21;
    effect on milk, 28;
    tuberculosis from, 28, 155

  Drafts, evil effects of, 10;
    how to prevent harm from, 10

  Ear, care of, 58;
    drum, 179;
    inner ear, 181;
    middle ear, 179;
    outer ear, 179

  Esophagus, 170

  Excreta from sick, how dispose of, 76, 118

  Exercise, necessity of, 51, 161

  Eye, how germs get into, 56;
    how overworked, 57;
    method of testing, 58

  Far sight, 58

  Flies, breeding places for, 77, 80;
    as germ carriers, 80, 81, 116;
    how to get rid of, 82, 83;
    how to keep out, 83

  Fly screens, where needed, 83

  Foods, advertised, 16;
    building, 14-16;
    decomposition of, 30-32;
    heat-producing, 14-16;
    improper cooking of, 34, 35;
    cost of suitable, 16;
    uses of foods, 14-17;
    uses of starches, 14;
    uses of fats, 15;
    value of meat as a, 15;
    value of milk as a, 14

  Garbage cans, should be covered, 83

  Germs, cause of poison in meats, 31, 32;
    carried by dogs and cats, 106;
    effect of, in wounds, 95-99;
    how, get through the skin, 95;
    how, get into the body, 79;
    how, get into foods, 79, 80;
    how put into the air, 147, 150;
    how kept out of the air, 151, 152;
    how to fight, 74;
    of lockjaw, 98;
    man's greatest foe, 1;
    nature of a, 73;
    not alike, 73;
    not killed by running water, 115

  Hair, 169

  Hearing, how tested, 58

  Heat, how kept up in the body, 14

  Hookworm disease, character of the worm, 120;
    how it enters the body, 121;
    how prevented, 122;
    nature of the disease, 121;
    where worm lives in the body, 121;
    where prevalent, 122

  Insects that carry disease, 92-94

  Intestines, 171

  Iris, 177

  Joints, 163

  Larynx, 174, 175

  Lens, the, 178

  Ligaments, 165

  Lungs, 175

  Lymphatics, 171

  Malaria, how transmitted, 92;
    how prevented, 93

  Manure, a hatching place for flies, 80, 82;
    how to dispose of, 82

  Meal times, frequency of, 53;
    regularity of, 53;
    should be pleasant, 37, 38

  Measles, after effects of, 128;
    fatality of, 128;
    necessity of care in, 129;
    seriousness of, 128;
    why to avoid, 128

  Meats, characteristics of good, 18;
    Clean Meat League, 19;
    from diseased animals, 19-21;
    germs cause poison in, 19, 32;
    how kept clean, 18;
    should be cooked, 35;
    value of, as a food, 18

  Milk, as carrier of disease, 22, 117;
    effect of germs on, 22;
    effect of disease in cow on, 28;
    flies in, 28;
    how germs get into, 23-28;
    impure, dangerous, 22;
    polluted water in, 27;
    typhoid fever carried by, 117;
    value of, as a food, 14, 20

  Mosquitoes, as disease carriers, 92, 93;
    how to get rid of, 94

  Mouth, why some breathe through, 49

  Mouth-breathing, effect of, 50

  Muscles, attachment of, 167

  Nails, how to care for, 61, 62

  Near sight, 57

  Nerves, compared to telegraph system, 181;
    distribution of, 181

  Nose, importance of breathing through, 48

  Overcoats, necessity of, 12

  Overwork, effect of, 51, 52

  Paper napkins for consumptives, 152

  Parties, time for, 53

  Pencils in mouth, 155

  Pharynx, 175

  Play a form of work, 52

  Playgrounds, 161

  Pocket cuspidors, 152

  Ptomaines, 19

  Quarantine, breaking, shows selfishness, 126;
    how broken by family, 105;
    rules of, 105;
    seriousness of breaking, 101;
    when safe to raise, 102;
    why necessary, 101;
    why some cases escape, 102-104

  Reflex action, 181

  Respiratory system, 174-177

  Rest, proper amount of, 51

  Retina, 178

  Rocky Mountain Spotted (Tick) Fever, how transmitted, 94

  Rubbers, necessity of wearing, 11

  Saliva, effect of, on starches, 39, 41

  Salivary glands, 170

  Scarlet fever, a dangerous disease, 124;
    mild cases dangerous, 123, 124

  Scarlatina, 125

  Scarlet rash, why quarantine is necessary in, 125

  School lunches, 37

  Sclera, 177

  Sebaceous glands, 169

  Sewage, effect of, on water, 85-87, 115

  Sickness about a dairy, 26, 103, 115;
    due to germs, how prevented, 3

  Sick room, stay away from, 75

  Skin, care of, 60, 61

  Smallpox, fatality of, 131;
    how prevented, 135-137;
    during Franco-Prussian War, 132;
    in Sweden, 133;
    in Gloucester, 134;
    in the Philippine Islands, 134

  Spitting, dangers from, 151;
    how avoided, 152;
    where to spit, 152, 153;
    where not to spit, 151

  Springs, how polluted, 87

  Street cuspidors, 152

  Sunshine, effect of, on germs, 77, 78

  Suppuration, how the surgeon prevents, 96;
    how you may prevent, 97;
    real cause of, 96

  Sweat glands, the work of, 60

  Teeth, brittle, 42;
    dangers from poor, 41-43;
    how to care for, 43;
    necessity of baby teeth, 41;
    uses of teeth, 41;
    why, decay, 42

  Tendons, 167

  Tobacco, a poison, 64;
    effect of, on blood, 65;
      on heart, 66;
      on nervous system, 66;
      on nose and throat, 65;
      on stomach, 66;
    extra work caused by, 64

  Toilets, improper construction of, 86;
    proper construction of, 87;
    relation to wells, 85-87

  Tonsils, 49, 50

  Trachea, 175

  Tuberculin test, 155, 156

  Tuberculosis, can be prevented, 142, 148, 157;
    fatality of, 142;
    fresh air in, 157, 158;
    germ, discovery of the, 145;
    how to get, out of a house, 147, 148;
    how germs leave the body, 150, 151;
    how spread from cows, 28, 155;
    how spread from the lips, 153-155;
    how detected in cows, 155;
    a house disease, 146, 147;
    not inherited, 146;
    of the glands, 144;
    of the joints, 143;
    of the spine, 144;
    of the stomach, 144;
    of the throat, 143;
    prevalence of, 142;
    pure food in, 158;
    rest in, 157;
    should be recognized early, 157;
    sunshine in, 158;
    why called the Great White Plague, 142

  Typhoid fever, animals free from, 113;
    carried by flies, 80, 81, 116;
    carried by milk, 22, 117;
    effect of a single case, 114;
    how germs leave the body, 113;
    how germs get into the body, 113;
    how germs get into water, 114;
    importance of cleanliness, 117, 118;
    life of germs in a stream, 115;
    recovered patient dangerous, 117

  Umbrellas, necessity of, 11

  Vaccination, cause of sore arms after, 140, 141;
    discovery of, 132;
    how, prevents smallpox, 135;
    necessity of repeating, 137;
    pretended vaccination, 138;
    when successful, 138

  Ventilation, in homes, 46, 159;
    in public buildings, 48, 161;
    in workshops, 48

  Veins, 171

  Venous blood, 171, 172

  Villi, 171

  Vitreous humor, 178

  Voluntary action, 181

  Water, avoid polluting, 85-88, 115;
    effect of sewage on, 85, 115;
    how germs get into, 85-88;
    polluted, in milk, 27;
    safe sources of, 88

  Wells, how polluted, 86, 87;
    relation of toilets to, 86, 87

  Windows, should be kept open, 45-47;
    should be screened, 83

  Wood-ticks, as disease carriers, 93;
    how abolished, 94

  Wounds, importance of keeping clean, 97

  Yards should be clean, 77

  Yellow fever, how transmitted, 92;
    how prevented, 92


[1] Bujar and Baier state that the nourishing power of bacon is
represented by 2,767, while the nourishing power of butter is
represented by 2,610.

[2] The cleaning out of these cemented vaults is an exceedingly
unpleasant task. Some prefer to have a strong, water-tight box
placed under the closet seats. When this box is nearly full, it
can be removed to some place where fertilizer is needed, and there
emptied, the contents being plowed into the ground. In order to
make this task as simple as possible, it is a good plan to put the
box on skids, and have a heavy strip in one end with a bolt and
ring through it, so that a horse can be hitched to the box to draw
it away. If a little dry earth or lime is put into the box each
day, there will be no unpleasant odor.

[3] The teacher should demonstrate the action of acids and alkalies
on a solution of litmus.

[4] At the request of many practical teachers the author has
appended this brief summary of anatomy. The material is intended to
be used for reference or to be assigned as lessons in connection
with the chapters of the book, at the discretion of the teacher.

*** End of this Doctrine Publishing Corporation Digital Book "Principles of Public Health - A Simple Text Book on Hygene Presenting the Principles - Fundamental to the Conservation of Individual and Community - Health" ***

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