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´╗┐Title: History and Practice of the Art of Photography
Author: Snelling, Henry Hunt, 1816-1897
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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This etext was created by Gregory Walker, in Austin, Texas, for the
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THE HISTORY AND PRACTICE OF THE ART OF PHOTOGRAPHY;

OR THE PRODUCTION OF PICTURES THROUGH THE AGENCY OF LIGHT.

CONTAINING ALL THE INSTRUCTIONS NECESSARY FOR THE COMPLETE PRACTICE OF
THE DAGUERREAN AND PHOTOGENIC ART, BOTH ON METALLIC PLATES AND ON PAPER.


By HENRY H. SNELLING.



ILLUSTRATED WITH WOOD CUTS.



New York:  PUBLISHED BY G. P. PUTNAM, 155 Broadway, 1849.



Entered according to act of Congress in the year 1849, by H. H.
Snelling, in the Clerk's office, of the District Court of the Southern
District of New York.


New York:  PRINTED BY BUSTEED & McCOY, 163 Fulton Street.



TO EDWARD ANTHONY, ESQ., AN ESTEEMED FRIEND.

Whose gentlemanly deportment, liberal feelings, and strict integrity
have secured him a large circle of friends, this work is Respectfully
Dedicated By the AUTHOR.



                            PREFACE.


The object of this little work is to fill a void much complained of by
Daguerreotypists--particularly young beginners.

The author has waited a long time in hopes that some more able pen
would be devoted to the subject, but the wants of the numerous, and
constantly increasing, class, just mentioned, induces him to wait no
longer.

All the English works on the subject--particularly on the practical
application, of Photogenic drawing--are deficient in many minute
details, which are essential to a complete understanding of the art.
Many of their methods of operating are entirely different from, and
much inferior to, those practised in the United States: their
apparatus, also, cannot compare with ours for completeness, utility or
simplicity.

I shall, therefore, confine myself principally--so far as Photogenic
drawing upon metalic plates is concerned--to the methods practised by
the most celebrated and experienced operators, drawing upon French and
English authority only in cases where I find it essential to the
purpose for which I design my work, namely:  furnishing a complete
system of Photography; such an one as will enable any gentleman, or
lady, who may wish to practise the art, for profit or amusement, to do
so without the trouble and expense of seeking instruction from
professors, which in many cases within my own knowledge has prevented
persons from embracing the profession.

To English authors I am principally indebted for that portion of my
work relating to Photogenic drawing on paper.  To them we owe nearly
all the most important improvements in that branch of the art.
Besides, it has been but seldom attempted in the United States, and
then without any decided success.  Of these attempts I shall speak
further in the Historical portion of this volume.

Every thing essential, therefore, to a complete knowledge of the whole
art, comprising all the most recent discoveries and improvements down
to the day of publication will be found herein laid down.



CONTENTS

      I.  A BRIEF HISTORY OF THE ART.
     II.  THE THEORY ON LIGHT.--THE PHOTOGRAPHIC PRINCIPLE
    III.  SYNOPSIS OF MR. HUNT'S TREATISE ON "THE INFLUENCE OF THE
          SOLAR RAYS ON COMPOUND BODIES, WITH ESPECIAL REFERENCE TO
          THEIR PHOTOGRAPHIC APPLICATION."
     IV.  A FEW HINTS AND SUGGESTIONS TO DAGUERREOTYPISTS.
      V.  DAGUERREOTYPE APPARATUS.
     VI.  THE DAGUERREOTYPE PROCESS.
    VII.  PAPER DAGUERREOTYPES.--ETCHING DAGUERREOTYPES.
   VIII.  PHOTOGENIC DRAWING ON PAPER.
     IX.  CALOTYPE AND CHRYSOTYPE.
      X.  CYANOTYPE--ENERGIATYPE--CHROMATYPE--ANTHOTYPE--AMPHITYPE
          AND "CRAYON DAGUERREOTYPE."
     XI.  ON THE PROBABILITY OF PRODUCING COLORED PICTURES BY THE SOLAR
          RADIATIONS--PHOTOGRAPHIC DEVIATIONS--LUNAR PICTURES--DRUMMOND
          LIGHT.
    XII.  ON COLORING DAGUERREOTYPES.
   XIII.  THE PHOTOGRAPHOMETER.
          INDEX.



INTRODUCTION


  New York, January 27, 1849.
  E. ANTHONY, ESQ.

Dear Sir,--In submitting the accompanying "History and Practice of
Photography" to your perusal, and for your approbation, I do so with
the utmost confidence in your ability as a practical man, long engaged
in the science of which it treats, as well as your knowledge of the
sciences generally; as well as your regard for candor.  To you,
therefore, I leave the decision whether or no I have accomplished my
purpose, and produced a work which may not only be of practical benefit
to the Daguerrean artist, but of general interest to the reading
public, and your decision will influence me in offering it for, or
withholding it from, publication.

If it meets your approbation, I would most respectfully ask permission
to dedicate it to you, subscribing myself,

  With esteem,
  Ever truly yours,
  HENRY H. SNELLING


  New York, February 1st, 1849.
  Mr. H. H. SNELLING.

Dear Sir--Your note of January 27th, requesting permission to dedicate
to me your "History and Practice of Photography," I esteem a high
compliment, particularly since I have read the manuscript of your work.

Such a treatise has long been needed, and the manner in which you have
handled the subject will make the book as interesting to the reading
public as it is valuable to the Daguerrean artist, or the amateur
dabbler in Photography.  I have read nearly all of the many works upon
this art that have emanated from the London and Paris presses, and I
think the reader will find in yours the pith of them all, with much
practical and useful information that I do not remember to have seen
communicated elsewhere.

There is much in it to arouse the reflective and inventive faculties of
our Daguerreotypists.  They have heretofore stumbled along with very
little knowledge of the true theory of their art, and yet the quality
of their productions is far in advance of those of the French and
English artists, most of whose establishments I have had the pleasure
of visiting I feel therefore, that when a sufficient amount of
theoretic knowledge shall have been added to this practical skill on
the part of our operators, and when they shall have been made fully
acquainted with what has been attained or attempted by others, a still
greater advance in the art will be manifested.

A GOOD Daguerreotypist is by no means a mere machine following a
certain set of fixed rules.  Success in this art requires personal
skill and artistic taste to a much greater degree than the unthinking
public generally imagine; in fact more than is imagined by nine-tenths
of the Daguerreotypists themselves.  And we see as a natural result,
that while the business numbers its thousands of votaries, but few rise
to any degree of eminence.  It is because they look upon their business
as a mere mechanical operation, and having no aim or pride beyond the
earning of their daily bread, they calculate what will be a fair per
centage on the cost of their plate, case, and chemicals, leaving MIND,
which is as much CAPITAL as anything else (where it is exercised,)
entirely out of the question.

The art of taking photographs on PAPER, of which your work treats at
considerable length, has as yet attracted but little attention in this
country, though destined, as I fully believe, to attain an importance
far superior to that to which the Daguerreotype has risen.

The American mind needs a waking up upon the subject, and I think your
book will give a powerful impulse in this direction.  In Germany a high
degree of perfection has been reached, and I hope your countrymen will
not be slow to follow.

Your interesting account of the experiments of Mr. Wattles was entirely
new to me, and is another among the many evidences that when the age is
fully ripe for any great discovery, it is rare that it does not occur
to more than a single mind.

Trusting that your work will meet with the encouragement which your
trouble in preparing it deserves, and with gratitude for the undeserved
compliment paid to me in its dedication,

  I remain, very sincerely,
  Your friend and well wisher,
  E. ANTHONY.



PHOTOGRAPHY.

CHAP. I.

A BRIEF HISTORY OF THE ART.


As in all cases of great and valuable inventions in science and art the
English lay claim to the honor of having first discovered that of
Photogenic drawing.  But we shall see in the progress of this history,
that like many other assumptions of their authors, priority in this is
no more due them, then the invention of steamboats, or the cotton gin.

This claim is founded upon the fact that in 1802 Mr. Wedgwood recorded
an experiment in the Journal of the Royal Institution of the following
nature.

"A piece of paper, or other convenient material, was placed upon a
frame and sponged over with a solution of nitrate of silver; it was
then placed behind a painting on glass and the light traversing the
painting produced a kind of copy upon the prepared paper, those parts
in which the rays were least intercepted being of the darkest hues.
Here, however, terminated the experiment; for although both Mr.
Wedgwood and Sir Humphry Davey experimented carefully, for the purpose
of endeavoring to fix the drawings thus obtained, yet the object could
not be accomplished, and the whole ended in failure."

This, by their own showing, was the earliest attempt of the English
savans.  But this much of the principle was known to the Alchemists at
an early date--although practically produced in another way--as the
following experiment, to be found in old books, amply proves.

"Dissolve chalk in aquafortis to the consistence of milk, and add to it
a strong solution of silver; keep this liquor in a glass bottle well
stopped; then cutting out from a piece of paper the letters you would
have appear, paste it on the decanter, and lay it in the sun's rays in
such a manner that the rays may pass through the spaces cut out of the
paper and fall on the surface of the liquor the part of the glass
through which the rays pass will be turned black, while that under the
paper remains white; but particular care must be observed that the
bottle be not moved during the operation."

Had not the alchemists been so intent upon the desire to discover the
far famed philosopher's stone, as to make them unmindful of the
accidental dawnings of more valuable discoveries, this little
experiment in chemistry might have induced them to prosecute a more
thorough search into the principle, and Photogenic art would not now,
as it is, be a new one.

It is even asserted that the Jugglers of India were for many ages in
possession of a secret by which they were enabled, in a brief space, to
copy the likeness of any individual by the action of light.  This fact,
if fact it be, may account for the celebrated magic mirrors said to be
possessed by these jugglers, and probable cause of their power over the
people.

However, as early as 1556 the fact was established that a combination
of chloride and silver, called, from its appearance, horn silver, was
blackened by the sun's rays; and in the latter part of the last century
Mrs. Fulhame published an experiment by which a change of color was
effected in the chloride of gold by the agency of light; and gave it as
her opinion that words might be written in this way.  These incidents
are considered as the first steps towards the discovery of the
Photogenic art.

Mr. Wedgwood's experiments can scarcely be said to be any improvement
on them since he failed to bring them to practical usefulness, and his
countrymen will have to be satisfied with awarding the honor of its
complete adaptation to practical purposes, to MM.  Niepce and Daguerre
of France, and to Professors Draper, and Morse of New-York.

These gentlemen--MM.  Niepce and Daguerre--pursued the subject
simultaneously, without either, however being aware of the experiments
of his colleague in science.  For several years, each pursued his
researches individually until chance made them acquainted, when they
entered into co-partnership, and conjointly brought the art almost to
perfection.

M. Niepce presented his first paper on the subject to the Royal Society
in 1827, naming his discovery Heliography.  What led him to the study
of the principles of the art I have no means, at present, of knowing,
but it was probably owing to the facts recorded by the Alchemists, Mrs.
Fulhame and others, already mentioned.  But M. Daguerre, who is a
celebrated dioramic painter, being desirous of employing some of the
singularly changeable salts of silver to produce a peculiar class of
effects in his paintings, was led to pursue an investigation which
resulted in the discovery of the Daguerreotype, or Photogenic drawing
on plates of copper coated with silver.

To this gentleman--to his liberality--are we Americans indebted for the
free use of his invention; and the large and increasing class of
Daguerrean artists of this country should hold him in the most profound
respect for it.  He was not willing that it should be confined to a few
individuals who might monopolise the benefits to be derived from its
practice, and shut out all chance of improvement.  Like a true, noble
hearted French gentleman he desired that his invention should spread
freely throughout the whole world.  With these views he opened
negociations with the French government which were concluded most
favorably to both the inventors, and France has the "glory of endowing
the whole world of science and art with one of the most surprising
discoveries that honor the land."

Notwithstanding this, it has been patented in England and the result is
what might have been expected:  English pictures are far below the
standard of excellence of those taken by American artists.  I have seen
some medium portraits, for which a guinea each had been paid, and taken
too, by a celebrated artist, that our poorest Daguerreotypists would be
ashamed to show to a second person, much less suffer to leave their
rooms.

CALOTYPE, the name given to one of the methods of Photogenic drawing on
paper, discovered, and perfected by Mr. Fox Talbot of England, is
precisely in the same predicament, not only in that country but in the
United States, Mr. Talbot being patentee in both.  He is a man of some
wealth, I believe, but he demands so high a price for a single right in
this country, that none can be found who have the temerity to purchase.

The execution of his pictures is also inferior to those taken by the
German artists, and I would remark en passant, that the Messrs.  Mead
exhibited at the last fair of the American Institute, (of 1848,) four
Calotypes, which one of the firm brought from Germany last Spring, that
for beauty, depth of tone and excellence of execution surpass the
finest steel engraving.

When Mr. Talbot's patent for the United States expires and our
ingenious Yankee boys have the opportunity, I have not the slightest
doubt of the Calotype, in their hands, entirely superceding the
Daguerreotype.

Let them, therefore, study the principles of the art as laid down in
this little work, experiment, practice and perfect themselves in it,
and when that time does arrive be prepared to produce that degree of
excellence in Calotype they have already obtained in Daguerreotype.

It is to Professor Samuel F. B. Morse, the distinguished inventor of
the Magnetic Telegraph, of New York, that we are indebted for the
application of Photography, to portrait taking.  He was in Paris, for
the purpose of presenting to the scientific world his Electro-Magnetic
Telegraph, at the time, (1838,) M. Daguerre announced his splendid
discovery, and its astounding results having an important bearing on
the arts of design arrested his attention.  In his letter to me on the
subject, the Professor gives the following interesting facts.

"The process was a secret, and negociations were then in progress, for
the disclosure of it to the public between the French government and
the distinguished discoverer.  M. Daguerre had shown his results to the
king, and to a few only of the distinguished savans, and by the advice
of M. Arago, had determined to wait the action of the French Chambers,
before showing them to any other persons.  I was exceedingly desirous
of seeing them, but knew not how to approach M. Daguerre who was a
stranger to me.  On mentioning my desire to Robert Walsh, Esq., our
worthy Consul, he said to me; 'state that you are an American, the
inventor of the Telegraph, request to see them, and invite him in turn
to see the Telegraph, and I know enough of the urbanity and liberal
feelings of the French, to insure you an invitation.' I was successfull
in my application, and with a young friend, since deceased, the
promising son of Edward Delevan, Esq., I passed a most delightful hour
with M. Daguerre, and his enchanting sun-pictures. My letter containing
an account of this visit, and these pictures, was the first
announcement in this country of this splendid discovery."

"I may here add the singular sequel to this visit.  On the succeeding
day M. Daguerre paid me a visit to see the Telegraph and witness its
operations.  He seemed much gratified and remained with me perhaps two
hours; two melancholy hours to him, as they afterwards proved; or while
he was with me, his buildings, including his diorama, his studio, his
laboratory, with all the beautiful pictures I had seen the day before,
were consumed by fire.  Fortunately for mankind, matter only was
consumed, the soul and mind of the genius, and the process were still
in existence."

On his return home, Professor Morse waited with impatience for the
revelation of M. Daguerre's process, and no sooner was it published
than he procured a copy of the work containing it, and at once
commenced taking Daguerreotype pictures.  At first his object was
solely to furnish his studio with studies from nature; but his
experiments led him into a belief of the practicability of procuring
portraits by the process, and he was undoubtedly the first whose
attempts were attended with success.  Thinking, at that time, that it
was necessary to place the sitters in a very strong light, they were
all taken with their eyes closed.

Others were experimenting at the same time, among them Mr. Wolcott and
Prof. Draper, and Mr. Morse, with his accustomed modesty, thinks that
it would be difficult to say to whom is due the credit of the first
Daguerreotype portrait.  At all events, so far as my knowledge serves
me, Professor Morse deserves the laurel wreath, as from him originated
the first of our inumerable class of Daguerreotypists; and many of his
pupils have carried the manipulation to very great perfection.  In
connection with this matter I will give the concluding paragraph of a
private letter from the Professor to me; He says.

"If mine were the first, other experimenters soon made better results,
and if there are any who dispute that I was first, I shall have no
argument with them; for I was not so anxious to be the first to produce
the result, as to produce it in any way.  I esteem it but the natural
carrying out of the wonderful discovery, and that the credit was after
all due to Daguerre.  I lay no claim to any improvements."

Since I commenced the compilation of this work, I have had the pleasure
of making the acquaintance of an American gentleman--James M. Wattles
Esq.--who as early as 1828--and it will be seen, by what I have already
stated, that this is about the same date of M. Niepce's discovery--had
his attention attracted to the subject of Photography, or as he termed
it "Solar picture drawing," while taking landscape views by means of
the camera-obscura.  When we reflect upon all the circumstances
connected with his experiments, the great disadvantages under which he
labored, and his extreme youthfullness, we cannot but feel a national
pride--yet wonder--that a mere yankee boy, surrounded by the deepest
forests, hundred of miles from the populous portion of our country,
without the necessary materials, or resources for procuring them,
should by the force of his natural genius make a discovery, and put it
in practical use, to accomplish which, the most learned philosophers of
Europe, with every requisite apparatus, and a profound knowledge of
chemistry--spent years of toil to accomplish.  How much more latent
talent may now be slumbering from the very same cause which kept Mr.
Wattles from publicly revealing his discoveries, viz; want of
encouragement--ridicule!

At the time when the idea of taking pictures permanently on paper by
means of the camera-obscura first occurred to him, he was but sixteen
years of age, and under the instructions of Mr. Charles Le Seuer, (a
talented artist from Paris) at the New Harmony school, Indiana.
Drawing and painting being the natural bent of his mind, he was
frequently employed by the professors to make landscape sketches in the
manner mentioned.  The beauty of the image of these landscapes produced
on the paper in the camera-obscura, caused him to pause and admire them
with all the ardor of a young artist, and wish that by some means, he
could fix them there in all their beauty.  From wishing he brought
himself to think that it was not only possible but actually capable of
accomplishment and from thinking it could, he resolved it should be
done.

He was, however, wholly ignorant of even the first principles of
chemistry, and natural philosophy, and all the knowledge he was enabled
to obtain from his teachers was of very little service to him.  To add
to this, whenever he mentioned his hopes to his parents, they laughed
at him, and bade him attend to his studies and let such moonshine
thoughts alone--still he persevered, though secretly, and he met with
the success his perseverance deserved.

For the truth of his statement, Mr. Wattles refers to some of our most
respectable citizens residing at the west, and I am in hopes that I
shall be enabled to receive in time for this publication, a
confirmation from one or more of these gentlemen.  Be that as it may, I
feel confident in the integrity of Mr. Wattles, and can give his
statement to the world without a doubt of its truth.

The following sketch of his experiments and their results will,
undoubtedly, be interesting to every American reader and although some
of the profound philosophers of Europe may smile at his method of
proceeding, it will in some measure show the innate genius of American
minds, and prove that we are not far behind our trans-atlantic brethren
in the arts and sciences.

Mr. Wattles says:  "In my first efforts to effect the desired object,
they were feeble indeed, and owing to my limited knowledge of
chemistry--wholly acquired by questioning my teachers--I met with
repeated failures but following them up with a determined spirit, I at
last produced, what I thought very fair samples--but to proceed to my
experiments."

"I first dipped a quarter sheet of thin white writing paper in a weak
solution of caustic (as I then called it) and dried it in an empty box,
to keep it in the dark; when dry, I placed it in the camera and watched
it with great patience for nearly half an hour, without producing any
visible result; evidently from the solution being to weak.  I then
soaked the same piece of paper in a solution of common potash, and then
again in caustic water a little stronger than the first, and when dry
placed it in the camera.  In about forty-five minutes I plainly
percieved the effect, in the gradual darkening of various parts of the
view, which was the old stone fort in the rear of the school garden,
with the trees, fence, &c.  I then became convinced of the
practicability of producing beautiful solar pictures in this way; but,
alas! my picture vanished and with it, all--no not all--my hopes.  With
renewed determination I began again by studying the nature of the
preparation, and came to the conclusion, that if I could destroy the
part not acted upon by the light without injuring that which was so
acted upon, I could save my pictures.  I then made a strong solution of
sal. soda I had in the house, and soaked my paper in it, and then
washed it off in hot water, which perfectly fixed the view upon the
paper.  This paper was very poor with thick spots, more absorbent than
other parts, and consequently made dark shades in the picture where
they should not have been; but it was enough to convince me that I had
succeeded, and that at some future time, when I had the means and a
more extensive knowledge of chemistry, I could apply myself to it
again.  I have done so since, at various times, with perfect success;
but in every instance laboring under adverse circumstances."

I have very recently learned, that, under the present patent laws of
the United States, every foreign patentee is required to put his
invention, or discovery, into practical use within eighteen months
after taking out his papers, or otherwise forfeit his patent.  With
regard to Mr. Talbot's Calotype patent, this time has nearly, if not
quite expired, and my countrymen are now at perfect liberty to
appropriate the art if they feel disposed.  From the statement of Mr.
Wattles, it will be perceived that this can be done without dishonor,
as in the first instance Mr. Talbot had no positive right to his patent.

Photography; or sun-painting is divided, according to the methods
adopted for producing pictures, into

  DAGUERREOTYPE, CHROMATYPE,
  CALOTYPE,      ENERGIATYPE,
  CHRYSOTYPE,    ANTHOTYPE and
  CYANOTYPE,     AMPHITYPE.



CHAP. II.

THE THEORY ON LIGHT.--THE PHOTOGRAPHIC PRINCIPLE


Some philosophers contend that to the existence of light alone we owe
the beautiful effects produced by the Photogenic art, while others give
sufficient reasons for doubting the correctness of the assumption.
That the results are effected by a principle associated with light and
not by the luminous principle itself, is the most probable conclusion.
The importance of a knowledge of this fact becomes most essential in
practice, as will presently be seen.  To this principle Mr. Hunt gives
the name of ENERGIA.

THE NATURE of Light is not wholly known, but it is generally believed
to be matter, as in its motions it obeys the laws regulating matter.
So closely is it connected with heat and electricity that there can be
little doubt of their all being but different modifications of the same
substance.  I will not, however, enter into a statement of the various
theories of Philosophers on this head, but content myself with that of
Sir Isaac Newton; who supposed rays of light to consist of minute
particles of matter, which are constantly emanating from luminous
bodies and cause vision, as odoriferous particles, proceeding from
certain bodies, cause smelling.

The effects of light upon other bodies, and how light is effected by
them, involve some of the most important principles, which if properly
understood by Daguerreotypists would enable them to improve and correct
many of the practical operations in their art.  These effects we shall
exhibit in this and the following chapters.  Before we enter on this
subject it will be necessary to become familiar with the

DEFINITIONS of some of the terms used in the science of optics.

Luminous bodies are of two kinds; those which shine by their own light,
and those which shine by reflected light.

Transparent bodies are such as permit rays of light to pass through
them.

Translucent bodies permit light to pass faintly, but without
representing the figure of objects seen through them.

Opaque bodies permit no light to pass through them, but reflect light.

A ray is a line of light.

A beam is a collection of parallel rays.

A pencil is a collection of converging, or diverging rays.

A medium is any space through which light passes.

Incident rays are those which fall upon the surface of a body.

Reflected rays are those which are thrown off from a body.

Parallel rays are such as proceed equally distant from each other
through their whole course.

Converging rays are such as approach and tend to unite at any one
point, as at b.  Fig. 3.

Diverging rays are those which continue to recede from each other, as
at e.  Fig. 3.

A Focus is that point at which converging rays meet.

MOTION OF LIGHT--Rays of light are thrown off from luminous bodies in
every direction, but always in straight lines, which cross each other
at every point; but the particles of which each ray consists are so
minute that the rays do not appear to be impeded by each other.  A ray
of light passing through an aperture into a dark room, proceeds in a
straight line; a fact of which any one may be convinced by going into a
darkened room and admitting light only through a small aperture.

[Illustration: Fig. 1 (hipho_1.gif)]

Light also moves with great velocity, but becomes fainter as it recedes
from the source from which it eminates; in other words, diverging rays
of light diminish in intensity as the square of the distance increases.
For instance let a fig. 1, represent the luminous body from which light
proceeds, and suppose three square boards, b. c. d. severally one,
four and sixteen square inches in size be placed; b one foot, c two
feet, and d four feet from a, it will be perceived that the smallest
board b will throw c into shadow; that is, obstruct all rays of light
that would otherwise fall on c, and if b were removed c would in like
manner hide the light from d--Now, if b recieve as much light as would
fall on c whose surface is four times as large, the light must be four
times as powerful and sixteen times as powerful as that which would
fall on the second and third boards, because the same quantity of light
is diffused over a space four and sixteen times greater.  These same
rays may be collected and their intensity again increased.

Rays of light are reflected from one surface to another; Refracted, or
bent, as they pass from the surface of one transparent medium to
another; and Inflected, or turned from their course, by the attraction
of opaque bodies.  From the first we derive the principles on which
mirrors are constructed; to the second we are indebted for the power of
the lenses, and the blessings of sight,--for the light acts upon the
retina of the eye in the same manner as on the lens of a camera.  The
latter has no important bearing upon our subject.

When a ray of light falls perpendicularly upon an opaque body, it is
reflected bark in the same line in which it proceeds; in this case the
reflected ray returns in the same path the incident ray traversed; but
when a ray falls obliquely, it is reflected obliquely, that is, it is
thrown off in opposite direction, and as far from the perpendicular as
was the incident ray, as shown at Fig. 2; a representing the incident
ray and b the reflected.  The point, or angle c made by the incident
ray, at the surface of the reflector e f, with a line c d,
perpendicular to that surface, is called the angle of incidence, while
the angle formed by the reflected ray b and the perpendicular line d is
called the angle of reflection, and these angles are always equal.

[Illustration: Fig. 2 (hipho_2.gif)]

It is by this reflection of light that objects are made visible; but
unless light falls directly upon the eye they are invisible, and are
not sensibly felt until after a certain series of operations upon the
various coverings and humors of the eye.  Smooth and polished surfaces
reflect light most powerfully, and send to the eye the images of the
objects from which the light proceeded before reflection.  Glass, which
is transparent--transmitting light--would be of no use to us as a
mirror, were it not first coated on one side with a metalic amalgam,
which interrupts the rays in their passage from the glass into the air,
and throws them either directly in the incident line, or in an oblique
direction.  The reason why trees, rocks and animals are not all
mirrors, reflecting other forms instead of their own, is, that their
surfaces are uneven, and rays of light reflected from an uneven surface
are diffused in all directions.

Parallel rays falling obliquely upon a plane mirror are reflected
parallel; converging rays, with the same degree of convergence; and
diverging rays equally divergent.

Stand before a mirror and your image is formed therein, and appears to
be as far behind the glass as you are before it, making the angle of
reflection equal to that of incidence, as before stated.  The incident
ray and the reflected ray form, together, what is called the passage of
reflection, and this will therefore make the actual distance of an
image to appear as far again from the eye as it really is.  Any object
which reflects light is called a radiant.  The point behind a
reflecting surface, from which they appear to diverge, is called the
virtual focus.

Rays of light being reflected at the same angle at which they fall upon
a mirror, two persons can stand in such a position that each can see
the image of the other without seeing his own.  Again; you may see your
whole figure in a mirror half your length, but if you stand before one
a few inches shorter the whole cannot be reflected, as the incident ray
which passes from your feet into the mirror in the former case, will in
the latter fall under it.  Images are always reversed in mirrors.

Convex mirrors reflect light from a rounded surface and disperse the
rays in every direction, causing parallel rays to diverge, diverging
rays to diverge more, and converging rays to converge less--they
represent objects smaller than they really are--because the angle
formed by the reflected ray is rendered more acute by a convex than by
a plane surface, and it is the diminishing of the visual angle, by
causing rays of light to be farther extended before they meet in a
point, which produces the image of convex mirrors.  The greater the
convexity of a mirror, the more will the images of the objects be
diminished, and the nearer will they appear to the surface.  These
mirrors furnish science with many curious and pleasing facts.

Concave mirrors are the reverse of convex; the latter being rounded
outwards, the former hollowed inwards--they render rays of light more
converging--collect rays instead of dispersing them, and magnify
objects while the convex diminishes them.

Rays of light may be collected in the focus of a mirror to such
intensity as to melt metals.  The ordinary burning glass is an
illustration of this fact; although the rays of light are refracted, or
passed through the glass and concentrated into a focus beneath.

When incident rays are parallel, the reflected rays converge to a
focus, but when the incident rays proceed from a focus, or are
divergent, they are reflected parallel.  It is only when an object is
nearer to a concave mirror than its centre of concavity, that its image
is magnified; for when the object is farther from the mirror, this
centre will appear less than the object, and in an inverted position.

The centre of concavity in a concave mirror, is an imaginary point
placed in the centre of a circle formed by continuing the boundary of
the concavity of the mirror from any one point of the edge to another
parallel to and beneath it.

REFRACTION OF LIGHT:--I now pass to the consideration of the passage of
light through bodies.

A ray of light failing perpendicularly through the air upon a surface
of glass or water passes on in a straight line through the body; but if
it, in passing from one medium to another of different density, fall
obliquely, it is bent from its direct course and recedes from it,
either towards the right or left, and this bending is called
refraction; (see Fig. 3, b.) If a ray of light passes from a rarer into
a denser medium it is refracted towards a perpendicular in that medium;
but if it passes from a denser into rarer it is bent further from a
perpendicular in that medium.  Owing to this bending of the rays of
light the angles of refraction and incidence are never equal.

Transparent bodies differ in their power of bending light--as a general
rule, the refractive power is proportioned to the density--but the
chemical constitution of bodies as well as their density, is found to
effect their refracting power.  Inflammable bodies possess this power
to a great degree.

The sines of the angle of incidence and refraction (that is, the
perpendicular drawn from the extremity of an arc to the diameter of a
circle,) are always in the same ratio; viz:  from air into water, the
sine of the angle of refraction is nearly as four to three, whatever be
the position of the ray with respect to the refracting surface.  From
air into sulphur, the sine of the angle of refraction is as two to
one--therefore the rays of light cannot be refracted whenever the sine
of the angle of refraction becomes equal to the radius* of a circle,
and light falling very obliquely upon a transparent medium ceases to be
refracted; this is termed total reflection.

* The RADIUS of a circle is a straight line passing from the centre to
the circumference.

Since the brightness of a reflected image depends upon the quantity of
light, it is quite evident that those images which arise from total
reflection are by far the most vivid, as in ordinary cases of
reflection a portion of light is absorbed.

I should be pleased to enter more fully into this branch of the science
of optics, but the bounds to which I am necessarily limited in a work
of this kind will not admit of it.  In the next chapter, however, I
shall give a synopsis of Mr. Hunt's treatise on the "Influence of the
Solar Rays on Compound Bodies, with especial reference to their
Photographic application"--a work which should be in the hands of every
Daguerreotypist, and which I hope soon to see republished in this
country.  I will conclude this chapter with a brief statement of the
principles upon which the Photographic art is founded.

SOLAR and Stellar light contains three kinds of rays, viz:

1.  Colorific, or rays of color.

2.  Calorific, or rays of heat.

3.  Chemical rays, or those which produce chemical effects.

On the first and third the Photographic principle depends.  In
explaining this principle the accompanying wood cuts, (figs. 3 and 4)
will render it more intelligible.

If a pencil of the sun's rays fall upon a prism, it is bent in passing
through the transparent medium; and some rays being more refracted than
others, we procure an elongated image of the luminous beam, exhibiting
three distinct colors, red, yellow and blue, which are to be regarded
as primitives--and from their interblending, seven, as recorded by
Newton, and shown in the accompanying wood cut.  These rays being
absorbed, or reflected differently by various bodies, give to nature
the charm of color.  Thus to the eve is given the pleasure we derive in
looking upon the green fields and forests, the enumerable varieties of
flowers, the glowing ruby, jasper, topaz, amethist, and emerald, the
brilliant diamond, and all the rich and varied hues of nature, both
animate and inanimate.

[Illustration: Fig. 3 (hipho_3.gif)]

Now, if we allow this prismatic spectrum (b. Fig. 3.) to fall upon any
surface (as at c.) prepared with a sensitive photographic compound, we
shall find that the chemical effect produced bears no relation to the
intensity of the light of any particular colored ray, but that, on the
contrary, it is dispersed over the largest portion of the spectrum,
being most energetic in the least luminous rays, and ever active over
an extensive space, where no traces of light can be detected.  Fig. 4,
will give the student a better idea of this principle.  It is a copy of
the kind of impression which the spectrum, spoken of, would make on a
piece of paper covered with a very sensitive photographic preparation.
The white space a.  corresponds with the most luminous, or yellow ray,
(5, Fig. 3) over limits of which all chemical change is prevented.  A
similar action is also produced by the lower end of the red ray c; but
in the upper portion, however we find a decided change (as at d). The
most active chemical change, you will perceive, is produced by the rays
above the yellow a; viz. 4, 3, 2 and 1 (as at b) the green (4) being
the least active, and the blue (3) and violet (1) rays the most so, the
action still continuing far beyond the point b which is the end of the
luminous image.

[Illustration: Fig. 4 (hipho_4.gif)]

Suppose we wish to copy by the Daguerreotype, or Calotype process, any
objects highly colored--blue, red and yellow, for instance
predominating--the last of course reflects the most light, the blue the
least; but the rays from the blue surface will make the most intense
impression, whilst the red radiations are working very slowly, and the
yellow remains entirely inactive.  This accounts for the difficulty
experienced in copying bright green foliage, or warmly colored
portraits; a large portion of the yellow and red rays entering into the
composition of both--and the imperfections of a Daguerreotype portrait
of a person with a freckled face depends upon the same cause.

A yellow, hazy atmosphere, even when the light is very bright, will
effectually prevent any good photographic result--and in the height of
summer, with the most sensative process, it not unfrequently happens
that the most annoying failures arise from this agency of a yellow
medium.  A building painted of a yellow color, which may reflect the
sun's rays directly into the operator's room will have the same effect.
Daguerreotypists, being ignorant of these facts, are very apt to charge
their want of success to the plates, or chemicals, or any thing but the
real cause; and it would be well to bear these facts constantly in mind
and as far as possible avoid them.  This, may be accomplished, in a
measure, by a choice of location or by having the glass of your windows
tinged with blue; or a screen of thin blue paper may be interposed
between the light and sitter.  In selecting subjects, all striking
contrasts in color should be avoided, and sitters for portraits should
be cautioned not to wear anything that may produce the effect spoken
of--dark dresses always being the best.

The action of light both combines and decomposes bodies.  For instance,
chlorine and hydrogen will remain in a glass vessel without alteration
if kept in the dark; but if exposed to the rays of the sun, they
immediately enter into combination, and produce hydrochloric acid.  On
the other hand, if colorless nitric acid be exposed to the sun, it
becomes yellow, then changes to red, and oxygen is liberated by the
partial decomposition effected by the solar rays.

Of the organic substances none are more readily acted upon by light
than the various combinations of silver.

Of these some are more, and others less sensitive.  If Chloride of
silver, which is a white precipitate formed by adding chloride of
sodium (common salt) to a solution of nitrate of silver, be exposed to
diffused light, it speedily assumes a violet tint, and ultimately
becomes nearly black.  With iodide of silver, bromide of silver,
ammonio-nitrate of silver, and other salts of this metal, the result
will be much the same.

Some bodies, which under the influence of light, undergo chemical
changes, have the power of restoring themselves to their original
condition in the dark.  This is more remarkably displayed in the iodide
of platinum, which readily recieves a photogenic image by darkening
over the exposed surfaces, but speedily loses it by bleaching in the
dark.  The ioduret of Daguerre's plate, and some other iodides, exhibit
the same peculiarity--This leads us to the striking fact, that bodies
which have undergone a change of estate under the influence of
day-light have some latent power by which they can renovate themselves.
Possibly the hours of night are as necessary to inanimate nature as
they are to the animate.  During the day, an excitement which we do not
heed, unless in a state of disease, is maintained by the influence of
light and the hours of repose, during which the equilibrium is
restored, are absolutely necessary to the continuance of health.

Instead of a few chemical compounds of gold and silver, which at first
were alone supposed to be photographic, we are now aware that copper,
platinum, lead, nickel, and indeed, probably all the elements, are
equally liably to change under the sun's influence.  This fact may be
of benefit to engravers, for if steel can be made to take photographic
impressions, the more laborious process of etching may be dispensed
with.  In fact, in the latter part of this work, a process is described
for etching and taking printed impressions from Daguerreotype plates.
As yet this process has produced no decided beneficial results--but
future experiments may accomplish some practical discovery of intrinsic
value to the art of engraving.

A very simple experiment will prove how essential light is to the
coloring of the various species comprising the vegetable and animal
kingdoms.  If we transplant any shrub from the light of day into a dark
cellar, we will soon see it lose its bright green color, and become
perfectly white.

Another effect of light is that it appears to impart to bodies some
power by which they more readily enter into chemical combination with
others.  We have already said that chlorine and hydrogen, if kept in
the dark, will remain unaltered; but if the chlorine alone be
previously exposed to the sun, the chlorine thus solarised will unite
with the hydrogen in the dark.  Sulphate of iron will throw down gold
or silver from their solutions slowly in the dark; but if either
solution be first exposed to sunshine, and the mixture be then made, in
the dark, the precipitation takes place instantly.  Here is again,
evidence of either an absorption of some material agent from the
sunbeam, or an alteration in the chemical constitution of the body.  It
was from understanding these principles and applying them that
philosophers were enabled to produce the Calotype, Daguerreotype, &c.
For the effects and action of light on the camera, see Chapter V.

Some advances have been made towards producing Photographic impressions
in color--the impossibility of which some of our best and oldest
artists have most pertinaciously maintained.  The colored image of the
spectrum has been most faithfully copied, ray for ray, on paper spread
with the juice of the Cochorus Japonica, (a species of plant) and the
fluoride of silver; and on silver plate covered with a thin film of
chloride.  The day may be still remote when this much to be desired
desideratum shall be accomplished in portrait taking; but I am led to
hope that future experiments may master the secret which now causes it
to be looked upon, by many, as an impossibility.

That great advantages have resulted, and that greater still will result
from the discovery of the Photographic art, few will deny.  The
faithful manner in which it copies nature, even to the most minute
details, renders it of much value to the painter; but a few minutes
sufficing to take a view that formerly would have occupied several
days.  Its superiority in portraits, over miniature or oil painting has
been tacitly acknowledged by the thousands who employ it to secure
their own, or a friends likeness, and by the steady increase in the
number of artists who are weekly, aye daily springing up in every town
and village in the land.



CHAP. III.

SYNOPSIS OF MR. HUNT'S TREATISE ON "THE INFLUENCE OF THE SOLAR RAYS ON
COMPOUND BODIES, WITH ESPECIAL REFERENCE TO THEIR PHOTOGRAPHIC
APPLICATION."


OXIDE OF SILVER exposed for a few hours to good sunshine, passes into a
more decided olive color, than characterises it when first prepared by
precipitation from nitrate of silver.  Longer exposure renders this
color very much lighter, and the covered parts, are found much darker,
than those on which the light has acted directly.  In some instances
where the oxide of silver has been spread on the paper a decided
whitening process in some parts, after a few days exposure, is noticed.
Oxide of silver dissolved in ammonia is a valuable photographic fluid;
one application of a strong solution forming an exceedingly sensitive
surface.  The pictures on this paper are easily fixed by salt or weak
ammonia.

NITRATE OF SILVER.--This salt in a state of purity, does not appear to
be sensibly affected by light, but the presence of the smallest portion
of organic matter renders it exceedingly liable to change under
luminous influence.

If a piece of nitrated paper is placed upon hot iron, or held near the
fire, it will be found that at a heat just below that at which the
paper chars, the salt is decomposed.  Where the heat is greatest, the
silver is revived, and immediately around it, the paper becomes a deep
blue; beyond this a pretty decided green color results, and beyond the
green, a yellow or yellow brown stain is made.  This exhibits a
remarkable analogy between heat and light,--before spoken of in chap.
II--and is of some practical importance in the preparation of the paper.

PRISMATIC ANALYSIS.--The method of accomplishing the prismatic
decomposition of rays of light by the spectrum has already been
described on pages 22 and 23.  The color of the impressed spectrum, on
paper washed with nitrate of silver, is at first, a pale brown, which
passes slowly into a deeper shade; that portion corresponding with the
blue rays becoming a blue brown; and under the violet of a peculiar
pinkey shade, a very decided green tint, on the point which corresponds
with the least refrangible blue rays, may be observed, its limits of
action being near the centre of the yellow ray, and its maximum about
the centre of the blue, although the action up to the edge of the
violet ray is continued with very little diminution of effect; beyond
this point the action is very feeble.

When the spectrum is made to act on paper which has been previously
darkened, by exposure to sunshine under cupro-sulphate of ammonia, the
phenomena are materially different.  The photographic spectrum is
lengthened out on the red or negative side by a faint but very visible
red portion, which extends fully up to the end of the red rays, as seen
by the naked eye.  The tint of the general spectrum, too, instead of
brown is dark grey, passing, however, at its most refracted or positive
end into a ruddy brown.

In its Photographic application, the nitrate of silver is the most
valuable of the salts of that metal, as from it most of the other
argentine compounds can be prepared, although it is not of itself
sufficiently sensible to light to render it of much use.

CHLORIDE OF SILVER.--This salt of silver, whether in its precipitated
state, or when fused, changes its color to a fine bluish grey by a very
short exposure to the sun's rays.  If combined with a small quantity of
nitrate, the change is more rapid, it attains a deep brown, then slowly
passes into a fine olive, and eventually, after a few weeks, the
metalic silver is seen to be revived on the surface of the salt.  Great
differences of color are produced on chlorides of silver precipitated
by different muriates.  Nearly every variety in combination with the
nitrate, becomes at last of the same olive color, the following
examples, therefore, have reference to a few minutes exposure, only, to
good sunshine; it must also be recollected that the chloride of silver
in these cases is contaminated with the precipitant.

Muriate of ammonia precipitates chloride to darken to a fine chocolate
brown, whilst muriate of lime produces a brick-red color.  Muriates of
potash and soda afford a precipitate, which darkens speedily to a pure
dark brown, and muriatic acid, or aqueous chlorine, do not appear to
increase the darkening power beyond the lilac to which the pure
chloride of silver changes by exposure.  This difference of color
appears to be owing to the admixture of the earth or alkali used with
the silver salt.

The prismatic impression on paper spread with the chloride of silver is
often very beautifully tinted, the intensity of color varying with the
kind of muriate used.  Spread paper with muriate of ammonia or baryta
and you obtain a range of colors nearly corresponding with the natural
hues of the prismatic spectrum.  Under favorable circumstances the mean
red ray, leaves a red impression, which passes into a green over the
space occupied by the yellow rays.  Above this a leaden hue is
observed, and about the mean blue ray, where the action is greatest, it
rapidly passes through brown into black, and through the most
refrangible rays it gradually declines into a bluish brown, which tint
is continued throughout the invisible rays.  At the least refrangible
end of the spectrum, the very remarkable phenomenon has been observed,
of the extreme red rays exerting a protecting influence, and preserving
the paper from that change, which it would otherwise undergo, under the
influence of the dispersed light which always surrounds the spectrum.
Not only the extreme red ray exerts this very peculiar property, but
the ordinary red ray through nearly its whole length.

In photographic drawing this salt is of the utmost importance.  Mr.
Talbot's application of it will be given hereafter in another portion
of this work.

IODIDE OF SILVER--Perfectly pure, undergoes very little change under
the influence of light or heat; but if a very slight excess of the
nitrate of silver be added it becomes infinitely more sensitive than
the chloride.

The spectrum impressed upon paper prepared with a weak solution of the
hydriodate of potash presents some very remarkable peculiarities.  The
maximum of intensity is found at the edge of the most refrangible
violet rays, or a little beyond it, varying slightly according to the
kind of paper used, and the quantity of free nitrate of silver present.
The action commences at a point nearly coincident with the mean red of
the luminous spectrum, where it gives a dull ash or lead color, while
the most refrangible rays impress a ruddy snuff-brown, the change of
tint coming on rather suddenly about the end of the blue or beginning
of the violet rays of the luminous spectrum.  Beyond the extreme violet
rays, the action rapidly diminishes, but the darkening produced by
these invisible rays, extends a very small space beyond the point at
which they cease to act on the chloride of silver.

In its photographic application, it is, alone, of very little use; but
in combination with other reagents it becomes exquisitely sensitive.
With gallic acid and the ferrocyanate of potash it forms two of the
most sensitive photographic solutions with which we are acquainted.
These are used in the calotype process.

IODURET OF SILVER.--If upon a plate of polished silver we place a small
piece of iodine, and apply the heat of a lamp beneath the plate for a
moment, a system of rings is speedily formed.  The first ring, which
spreading constantly forms the exterior of the circle, is of a bright
yellow color; within this, there arises, successively, rings of green,
red and blue colors, and then again a fine yellow circle, centred by a
greyish spot on the place occupied by the iodine.  On exposing these to
the light, the outer yellow circle almost instantly changes color, the
others slowly, in the order of their position, the interior yellow
circle resisting for a long time the solar influence.  These rings must
be regarded as films of the ioduret of silver, varying, not only in
thickness, but in the more or less perfect states of combination in
which the iodine and metal are.  The exterior circle is an ioduret in a
very loose state of chemical agregation; the attractive forces increase
as we proceed towards the centre, where a well formed ioduret, or
probably a true iodide of silver, is formed, which is acted upon by
sunlight with difficulty.  The exterior and most sensitive film
constitutes the surface of Daguerreotype plates.  The changes which
these colored rings undergo are remarkable; by a few minutes exposure
to sunlight, an inversion of nearly all the colors takes place, the two
first rings becoming a deep olive green; and a deep blue inclining to
black.

The nature of the change which the ioduret of silver undergoes on
Daguerreotype plates, through the action of light, Mr. Hunt considers
to be a decided case of decomposition, and cites several circumstances
in proof of his position.  These with other facts given by Mr. Hunt in
his great work on the Photographic art, but to voluminous to include in
a volume of the size to which I am obliged to confine myself, should be
thoroughly studied by all Daguerreotypists.

PRISMATIC ANALYSIS.--The most refrangible portion of the spectrum, (on
a Daguerreotype plate) appears, after the plate has been exposed to the
vapor of mercury, to have impressed its colors; the light and delicate
film of mercury, which covers that portion, assuming a fine blue tint
about the central parts, which are gradually shaded off into a pale
grey; and this is again surrounded by a very delicate rose hue, which
is lost in a band of pure white.  Beyond this a protecting influence is
powerfully exerted; and notwithstanding the action of the dispersed
light, which is very evident over the plate, a line is left, perfectly
free from mercurial vapor, and which, consequently, when viewed by a
side light, appears quite dark.  The green rays are represented by a
line of a corresponding tint, considerably less in size than the
luminous green rays.  The yellow rays appear to be without action, or
to act negatively, the space upon which they fall being protected from
the mercurial vapor; and it consequently is seen as a dark band.  A
white line of vapor marks the place of the orange rays.  The red rays
effect the sensitive surface in a peculiar manner; and we have the
mercurial vapor, assuming a molecular arrangement which gives to it a
fine rose hue; this tint is surrounded by a line of white vapor, shaded
at the lowest extremity with a very soft green.  Over the space
occupied by the extreme red rays, a protecting influence is again
exerted; the space is retained free from mercurial vapor and the band
is found to surround the whole of the least refrangible rays, and to
unite itself with the band which surrounds the rays of greatest
refrangibility.  This band is not equally well defined throughout its
whole extent.  It is most evident from the extreme red to the green; it
fades in passing through the blue, and increases again, as it leaves
the indigo, until beyond the invisible chemical rays it is nearly as
strong as it is at the calorific end of the spectrum.

Images on Daguerreotype plates which have been completely obliterated
by rubbing may be restored, by placing it in a tolerably strong
solution of iodine in water.

BROMIDE OF SILVER.--This salt, like the iodide, does not appear to be
readily changed by the action of light; but when combined with the
nitrate of silver it forms a very sensitive photographic preparation.

Paper prepared with this salt, blackens over its whole extent with
nearly equal intensity, when submitted to the prismatic spectrum.  The
most characteristic peculiarity of the spectrum is its extravagant
length.  Instead of terminating at the mean yellow ray, the darkened
portion extends down to the very extremity of the visible red rays.  In
tint it is pretty uniformly of a grey-black over its whole extent,
except that a slight fringe of redness is perceptible at the least
refracted end.  Beyond the red ray, an extended space is protected from
the agency of the dispersed light, and its whiteness maintained; thus
confirming the evidence of some chemical power in action, over a space
beyond the luminous spectrum, which corresponds with the rays of the
least refrangibility.

This salt is extensively used in photographic drawing.

PREPARATIONS OF GOLD.--Chloride of Gold, freed from an excess of acid
is slowly changed under the action of light; a regularly increasing
darkness taking place until it becomes purple, the first action of the
light being to whiten the paper, which, if removed from the light at
this stage, will gradually darken and eventually develope the picture.
This process may be quickened by placing the paper in cold water.

Chloride of gold with nitrate of silver gives a precipitate of a yellow
brown color.  Paper impregnated with the acetate of lead, when washed
with perfectly neutral chloride of gold, acquires a brownish-yellow
hue.  The first impression of light seems rather to whiten than darken
the paper, by discharging the original color, and substituting for it a
pale greyish tint, which by slow degrees increases to a dark slate
color; but if arrested, while yet, not more than a moderate ash grey,
and held in a current of steam, the color of the parts acted upon by
light--and of that only--darkens immediately to a deep purple.

Here I must leave the subject of the action of light upon metalic
compounds--referring to Mr. Hunts work for any further information the
student may desire on the other metals--as I find myself going beyond
my limits.  I cannot, however, entirely dismiss the subject without
giving a few examples of the action of light on the juices of plants,
some of which produce very good photographic effect.

CORCHORUS JAPONICA--The juice of the flowers of this plant impart a
fine yellow color to paper, and, so far as ascertained, is the most
sensitive of any vegetable preparation; but owing to its continuing to
change color even in the dark, photographic images taken on paper
prepared with it soon fade out.

WALL FLOWER.--This flower yields a juice, when expressed with alcohol,
from which subsides, on standing, a bright yellow finely divided
faecula, leaving a greenish-yellow transparent liquid, only slightly
colored supernatant.  The faecula spreads well on paper, and is very
sensitive to light, but appears at the same time to undergo a sort of
chromatic analysis, and to comport itself as if composed of two very
distinct coloring principles, very differently affected.  The one on
which the intensity and sub-orange tint of the color depends, is
speedily destroyed, but the paper is not thereby fully whitened.  A
paler yellow remains as a residual tint, and this on continued exposure
to the light, slowly darkens to brown.  Exposed to the spectrum, the
paper is first reduced nearly to whiteness in the region of the blue
and violet rays.  More slowly, an insulated solar image is whitened in
the less refrangible portion of the red.  Continue the exposure, and a
brown impression begins to be percieved in the midst of the white
streak, which darkens slowly over the region between the lower blue and
extreme violet rays.

THE RED POPPY yields a very beautiful red color, which is entirely
destroyed by light.  When perfectly dried on paper the color becomes
blue.  This blue color is speedily discharged by exposure to the sun's
rays, and papers prepared with it afford very interesting
photographs.--  Future experiments will undoubtedly more fully develope
the photogenic properties of flowers, and practically apply them.

Certain precautions are necessary in extracting the coloring matter of
flowers.  The petals of fresh flowers, carefully selected, are crushed
to a pulp in a mortar, either alone or with the addition of a little
alcohol, and the juice expressed by squeezing the pulp in a clean linen
or cotton cloth.  It is then to be spread upon paper with a flat brush,
and dried in the air.  If alcohol be not added, it must be applied
immediately, as the air changes or destroys the color instantly.

Most flowers give out their coloring matter to alcohol or water--but
the former is found to weaken, and in some cases to discharge
altogether these colors; but they are in most cases restored in drying.
Paper tinged with vegetable colors must be kept perfectly dry and in
darkness.

To secure an eveness of tint on paper it should be first moistened on
the back by sponging, and blotting off with bibulous paper.  It should
then be pinned on a board, the moist side downwards, so that two of its
edges--the right and lower ones--project a little over those of the
board.  Incline the board twenty or thirty degrees to the horizon, and
apply the tincture with a brush in strokes from right to left, taking
care not to go over the edges which rests on the board, but to pass
clearly over those that project; and also observing to carry the tint
from below upwards by quick sweeping strokes, leaving no dry spaces
between them.  Cross these with other strokes from above downwards,
leaving no floating liquid on the paper.  Dry as quickly as possible,
avoiding, however, such heat as may injure the tint.



CHAP. IV.

A FEW HINTS AND SUGGESTIONS TO DAGUERREOTYPISTS.


There are very few who may not be capable of practising the
Photographic art, either on paper, or metalic plates--but, like all
other professions, some are more clever in its various processes than
others.

Impatience is a great drawback to perfect success, and combined with
laziness is a decided enemy.  Besides this, no one can excel in
Photography who does not possess a natural taste for the fine arts, who
is not quick in discerning grace and beauty--is regardless of the
principles of perspective, foreshortening and other rules of drawing,
and who sets about it merely for the sake of gain--without the least
ambition to rise to the first rank, both in its practice and theory.
There is no profession or trade in which a slovenly manner will not
show itself, and none where its effects will be more apparent than this.

In order to be great in any pursuit, we must be ourselves, and keep all
things, in order.  In your show and reception rooms, let neatness
prevail; have your specimens so placed--leaning slightly forward--as
to obtain the strongest light upon them, and at the same time prevent
that glassiness of appearance which detracts so materially from the
effect they are intended to produce.  If possible, let the light be of
a north-western aspect, mellowed by curtains of a semitransparent hue.
Your show-cases, at the door, should be kept well cleaned.  I have
often been disgusted while attempting to examine portraits in the cases
of our artists, at the greasy coating and marks of dirty fingers upon
the glass and frame enclosing them.  Believe it, many a good customer
is lost for no other reason.

In your operating room, dust should be carefully excluded.  It should
be furnished with nothing apt to collect and retain dust; a carpet is
therefore not only a useless article, but very improper.  A bare floor
is to be prefered; but if you must cover it use matting.  There is no
place about your establishment where greater care should be taken to
have order and cleanliness; for it will prevent many failures often
attributed to other causes.  "A place for every thing, and every thing
in its place," should be an absolute maxim with all artists.  Do not
oblige the ladies, on going away from your rooms, to say--"That H. is a
slovenly man; see how my dress is ruined by sitting down in a chair
that looked as if it had just come out of a porter house kitchen and
had not been cleaned for six months."

In choosing your operating room, obtain one with a north-western
aspect, if possible; and either with, or capable of having attached, a
large skylight.  Good pictures may be taken without the sky-light, but
not the most pleasing or effective.

A very important point to be observed, is to keep the camera perfectly
free from dust.  The operator should be careful to see that the
slightest particle be removed, for the act of inserting the
plate-holder will set it in motion, if left, and cause those little
black spots on the plate, by which an otherwise good picture is
spoiled.  The camera should be so placed as to prevent the sun shining
into the lenses.

In taking portraits, the conformation of the sitter should be minutely
studied to enable you to place her or him in a position the most
graceful and easy to be obtained.  The eyes should be fixed on some
object a little above the camera, and to one side--but never into, or
on the instrument, as some direct; the latter generally gives a fixed,
silly, staring, scowling or painful expression to the face.  Care
should also be taken, that the hands and feet, in whatever position,
are not too forward or back ward from the face when that is in good
focus.

If any large surface of white is present, such as the shirt front, or
lady's handkerchief, a piece of dark cloth (a temporary bosom of
nankeen is best,) may be put over it, but quickly withdrawn when the
process is about two thirds finished.

A very pleasing effect is given to portraits, by introducing, behind
the sitter, an engraving or other picture--if a painting, avoid those
in which warm and glowing tints predominate.  The subject of these
pictures may be applicable to the taste or occupation of the person
whose portrait you are taking.  This adds much to the interest of the
picture, which is otherwise frequently dull, cold and inanimate.

Mr. J. H. Whitehurst of Richmond, Va., has introduced a revolving
background, which is set in motion during the operation, and produces a
distinctness and boldness in the image not otherwise to be obtained.
The effect upon the background of the plate is equally pleasing; it
having the appearance of a beautifully clouded sky.

In practising Photographic drawing on paper, the student must bear in
mind that it is positively essential, to secure success in the various
processes, to use the utmost precaution in spreading the solutions, and
washes from the combination of which the sensitive surfaces result.
The same brush should always be used for the same solution, and never
used for any other, and always washed in clean water after having been
employed.  Any metalic mounting on the brushes should be avoided, as
the metal precipitates the silver from its solution.  The brushes
should be made of camels or badger's hair and sufficiently broad and
large to cover the paper in two or three sweeps; for if small ones be
employed, many strokes must be given, which leave corresponding streaks
that will become visible when submitted to light, and spoil the picture.

These few preliminary hints and suggestions, will, I trust, be of some
service to all who adopt this pleasing art as a profession; and will,
with a due attention to the directions given in the practical working
of the Daguerreotype, Calotype, etc., ensure a corresponding measure of
success.



CHAP. V.

DAGUERREOTYPE APPARATUS.


The entire Daguerreotype process is comprised in seven distinct
operations; viz:

1.--Cleaning and polishing the plate.

2.--Applying the sensitive coating.

3--Submitting the plate to the action of light in the camera.

4.--Bringing out the picture; in other words rendering it visible.

5.--Fixing the image, or making it permanent--so that the light may no
longer act upon it.

6.--Gilding:  or covering the picture with a thin film of gold--which
not only protects it, but greatly improves its distinctness and tone of
color.

7.--Coloring the picture.

For these various operations the following articles--which make up the
entire apparatus of a Daguerrean artist--must be procured

1.--THE CAMERA.--(Fig. 5.). The Camera Obscura of the Italian
philosophers, although highly appreciated, on account of the magical
character of the pictures it produced, remained little other than a
scientific toy, until the discovery of M. Daguerre.  The value of this
instrument is now great, and the interest of the process which it so
essentially aids, universally admitted.  A full description of it will
therefore be interesting.

[Illustration: Fig. 5 (hipho_5.gif)]

The camera is a dark box (a), having a tube with lenses (b) placed in
one end of it, through which the radiations from external objects pass,
and form a diminished picture upon the ground glass (g) placed at the
proper distance in the box to receive it; the cap c covering the lenses
at b until the plate is ready to receive the image of the object to be
copied.

Thus a (fig. 6.) representing the lens, and b the object desired to be
represented, the rays (c, c) proceeding from it fall upon the lens, and
are transmitted to a point, which varies with the curvature of the
glass, where an inverted image (d) of b is very accurately formed.  At
this point, termed the focus, the sensitive photographic material is
placed for the purpose of obtaining the required picture.

[Illustration: Fig. 5 (hipho_6.gif)]

The great desideratum in a photographic camera is perfect lenses.  They
should be achromatic, and the utmost transparency should be obtained;
and under the closest inspection of the glass not the slightest wavy
appearance, or dark spot should be detected; and a curvature which as
much as possible prevents spherical aberration should be secured.  The
effect produced by this last defect is a convergence of perpendiculars,
as for instance; two towers of any building, would be represented as
leaning towards each other; and in a portrait the features would seem
contracted, distorted and mingled together, so as to throw the picture
out of drawing and make it look more like a caricature than a likeness.
If the lens be not achromatic, a chromatic aberration takes place,
which produces an indistinct, hazy appearance around the edges of the
picture, arising from the blending of the rays.

The diameter and focal length of a lens must depend in a great measure
on the distance of the object, and also on the superficies of the plate
or paper to be covered.  For portraits one of 1 1/2 inches diameter,
and from 4 1/2 to 5 1/2 inches focus may be used; but for distant
views, one from 2 inches to 3 inches diameter, and from 8 to 12 inches
focal length will answer much better.  For single lenses, the aperture
in front should be placed at a distance from it, corresponding to the
diameter, and of a size not more than one third of the same.  A variety
of movable diaphragms or caps, to cover the aperture in front, are very
useful, as the intensity of the light may be modified by them and more
or less distinctness and clearness of delineation obtained.  These caps
alway come with Voitlander instruments and should be secured by the
purchaser.

Though the single acromatic lens answers very well for copying
engravings; taking views from nature or art, for portraits the double
should always be used.  The extensive manufacture of the most approved
cameras, both in Europe and in this country, obviates all necessity for
any one attempting to construct one for their own use.  Lenses are now
made so perfect by some artisans that, what is called the "quick
working camera" will take a picture in one second, while the ordinary
cameras require from eight to sixty.

The camera in most general use is that manufactured by Voitlander and
Son of Germany.  Their small size consists of two seperate acromatic
lenses; the first, or external one, has a free aperture of 1 1/2
inches; the second, or internal, 1 5/8 inches; and both have the same
focus, viz:  5 3/4 inches.  The larger size differs from the smaller.
The inner lens is an achromatic 3 1/4 inches diameter, its focal length
being 30 inches.  The outer lens is a meniscus--that is bounded by a
concave and convex spherical surface which meet--having a focal length
of 18 inches.  For every distant view, the aperture in front is
contracted by a diaphram to 1/8 of an inch.  By this means the light is
reflected with considerable intensity and the clearness and correctness
of the pictures are truly surprising.

THE AMERICA instruments are constructed on the same principle and many
of them are equally perfect.  Mr. Edward Anthony of 205 Broadway, New
York city, has constructed, and sold cameras fully equal to the German
and for which Voitlander instruments have been refused in exchange by
the purchaser.

The ordinary camera box (see fig. 5, a) varies in size to suit the
tube, and is termed medium, half, or whole.  Within the box is a slide
to assist in regulating the focus, and in enlarging or diminishing the
picture.  In one end of this slide is a springed groove into which the
ground-glass spectrum (g fig. 5) is slid, for the purpose of more
conveniently arranging the focus.  After the plate is prepared it is
placed in the holder--partly seen at e, fig. 5, and covered with the
dark slide f, fig. 5; the spectrum is then withdrawn and the holder
takes its place, and the lids d, d, are closed after removing the dark
slide f.  The plate is now ready to receive the image, and the cap c
may be removed to admit the light into the box.

A camera constructed by Voitlander is thus described by Mr. Fisher.
"It is made entirely of brass, so that variations of climate has no
effect upon it.  It is very portable and when packed in its box, with
all the necessary apparatus and materials for practising the
Daguerreotype art, occupies but very little space.  It is not, however,
well adapted for the Calotype process."

[Illustration: Fig. 7 (hipho_7.gif)]

"The brass foot A (fig. 7.), is placed on a table, or other firm
support, and the pillar B. screwed into it; the body of the camera, C,
C is laid into the double forked bearing D. D. The instrument is now
properly adjusted by means of the set screws, e, e, e, in the brass
foot, or it may be raised, lowered, or moved, by the telescope stand,
and when correct, fixed by the screw b.  The landscape to be delineated
is viewed either through the small lens, g, or with the naked eye on
the ground glass plate H, the focus being adjusted by the screw I. The
optical part of the instrument consist of the small set of achromatic
lenses already described.  When the portrait or view is deliniated on
the ground glass to the entire satisfaction of the operator, the brass
cap L is placed over the lens, and the entire body is removed away into
the dark, taking care not to disturb the position of the stand.  The
body is now detached at the part H, and the prepared paper or plate
enclosed in the brass frame work introduced in its place; the whole is
again placed upon the pedestal, the brass cap L is removed, by which
the paper or plate is exposed to the full influence of the light, after
which the cap is again replaced.

Mr. Woodbridge, of this city, has constructed an instrument for taking
full length portraits on plates 10 by 13 inches, which is worthy of
some notice.  It is a double camera, consisting of two boxes, placed in
a frame, one above the other, and so arranged as to slide easily up and
down.  After the focus has been adjusted, on the object, in both
cameras, the plate is put into the upper box, in the manner already
described, until the superior portion of the figure is complete; it is
then placed in the second box and the lower extremities obtained.  The
adjustment of the instrument is so complete that a perfect union of the
parts is effected in the picture without the least possible line of
demarkation being visible.  Fig. 8 gives a front view of this
instrument.

[Illustration: Fig. 8 (hipho_8.gif)]

Fig. 9 represents Talbot's Calotype Camera,--a very beautiful
instrument.

The copying camera box has an extra slide in the back end, by which it
may be considerably lengthened at pleasure.

II.--CAMERA STAND.--The best constructed stands are made of maple or
black walnut wood, having a cast iron socket (a, Fig. 12,) through
which the sliding rod b passes, and into which the legs c, c, with iron
screw ferules are inserted.  The platform d is made of two pieces,
hinged together, as at e, and having a thumb screw for the purpose of
elevating or depressing the instrument.

[Illustration: Fig. 9 (hipho_9.gif)]

III. MERCURY BATH.--Fig. 13 gives a front view of the mercury bath now
in general use in this country for mercurializing and bringing out the
picture.  It is quite an improvement on those first used.  To make it
more portable it is in three pieces, a b and c; having a groove e on
one side to receive the thermometre tube and scale by which the proper
degree of heating the mercury is ascertained.  Into the top are nicely
fitted two or three iron frames, with shoulders, for the plate to rest
in, suitable for the different sizes of plates.  The bath is heated by
means of a spirit lamp placed under it.  From two to four ounces of
highly purified mercury are put into the bath at a time.

IV. PLATE BLOCKS AND VICES.--There are several kinds of this article in
use; I shall describe the two best only.

[Illustration: Fig. 10 (hipho_10.gif)]

Fig. 10 gives an idea of the improvement on the English hand block.
The top a is perfectly flat and smooth--a little smaller than the
plate, so as to permit the latter to project a very little all
around--having at opposite angles c c two clasps, one fixed the other
moveable, but capable of being fastened by the thumb screw d, so as to
secure the plate tightly upon the block.  This block turns upon a
swivle, b, which is attached to the table by the screw c, This block is
only used for holding the plate while undergoing the first operation in
cleaning.

[Illustration: Fig. 11 (hipho_11.gif)]

Fig. 11, shows the form of Lewis' newly patented plate vice, which for
durability, simplicity and utility is preferable to all others.  It
consists of a simple platform and arm of cast iron, the former, a,
having a groove, d, in the centre for fixing the different sizes of
plate beds, e--and the latter supporting the leaves, e f.  On this vice
which is secured to a table, or bench, the plate receives its finishing
polish with rouge, or prepared lampblack.  Mr. Lewis gives the
following directions for its use.  "As the cam wears tighten it with
the adjusting screw (g) so as to allow the lever (f) to fall back into
a horizontal position; the plate being in its place at the time.  Oil
the wearing parts occasionally."

Some Daguerreotypists, however, use a foot lathe with buff wheels of
various forms; but this vice is sufficient for all ordinary purposes.

[Illustration: Fig. 12 (hipho_12.gif)]

[Illustration: Fig. 13 (hipho_13.gif)]

V. COATING BOXES.--The usual form for iodine and bromine boxes is see,
at figs. 14 and 15.  They are far superior to those in use with the
English operators.  Each consists of a wooden box (a,) having firmly
embeded within it a stout glass jar (c), the edges of which are ground.
Over this is placed the sliding cover b, double the length of the box,
one half occupied by a piece of ground glass (e), tightly pressed upon
the glass pot by a spring (i) beneath the cross bar g, and fits the pot
so accurately that it effectually prevents the escape of the vapor of
the iodine, bromine or other accelerating liquid contained therein.
The other half of the lid is cut through, shoulders being left at the
four angles for the different sizes of frames, designed to recieve the
plate while undergoing the coating process.  When the plate is put into
the frame, the cover b is shoved under the second lid h and when coated
to the proper degree, it resumes its former position and the plate is
placed in the holder of the camera box.  To test the tightness of the
box, light a piece of paper, put it into the pot and cover it with the
sliding lid.  The burning paper expels the air from the pot, and if it
be perfectly tight you may raise the whole box by the lid.

VI. GLASS FUNNELS.--Are a necessary article to the Daguerreotypist, for
filtering water, solutions, &c.

[Illustration: Fig. 14 (hipho_14.gif)]

VII. GILDING STAND.--For nervous persons the gilding stand is a useful
article.  It is adjusted to a perfect level by thumb screws placed in
its base.

VIII. SPIRIT LAMPS.--The most useful and economical of those made are
the Britania, as they are less liable to break; and the tube for the
wick being fastened to the body by a screw renders it less liable to
get out of order or explode.  Glass is the cheapest, and for an amateur
will do very well, but for a professed artist the Britania should
always be obtained.

IX.  COLOR BOX.--These are generally found on sale at the shops, and
usually contain eight colors, four brushes and a gold cup.  The artist
would, however, do well to obtain, all the colors mentioned in the last
chapter of this work, and be sure to get the very best, as there are
various qualities of the same color, particularly carmine, which is
very expensive, and the cupidity of some may induce them to sell a poor
article for the sake of larger profits.

[Illustration: Fig. 15 (hipho_15.gif)]

STILL.--Daguerreotypists should always use distilled water for
solutions, and washing the plate, as common water holds various
substances in solution which detract very materially from the
excellence of a photograph, and often gives much trouble, quite
unaccountable to many.  For the purpose of distilling water the
apparatus represented at Fig. 16 is both convenient and economical.

It may be either wholly of good stout tin, or of sheet iron tinned on
the inside, and may be used over a common fire, or on a stove.  A is
the body, which may be made to hold from one to four gallons of water,
which is introduced at the opening b, which is then stopped by a cork.
The tube d connects the neck a of the still with the worm tub, or
refrigerator B, at e, which is kept filled with cold water by means of
the funnel c, and drawn off as fast as it becomes warm by the cock f.
The distilled water is condensed in the worm--and passes off at the
cock b, under which a bottle, or other vessel, should be placed to
receive it.  The different joints are rendered tight by lute, or in its
absence, some stiff paste spread upon a piece of linen and wrapped
around them will answer very well; an addition of sealing wax over all
will make them doubly secure.

[Illustration: Fig. 16 (hipho_16.gif)]

HYGROMETER.--This is an instrument never to be found, I believe, in the
rooms of our operators, although it would be of much use to them, for
ascertaining the quantity of moisture floating about the room; and as
it is necessary to have the atmosphere as dry as possible to prevent an
undue absorption of this watery vapor by the iodine &c., and to procure
good pictures,--its detection becomes a matter of importance.  Mason's
hygrometer, manufactured by Mr. Roach and sold by Mr. Anthony, 205
Broadway, New York is the best in use.

It consists of two thermometre tubes placed, side by side, on a metalic
scale, which is graduated equally to both tubes.  The bulb of one of
these tubes communicates, by means of a net-work of cotton, with a
glass reservoir of water attached to the back of the scale.  Fig. 17
and 18 represent a front and back view of this instrument.

Fig. 17 is the front view, showing the tubes with their respective
scales; the bulb b being covered with the network of cotton
communicating with the reservoir c fig. 18, at d.

[Illustration: Fig. 17 (hipho_17.gif)]

[Illustration: Fig. 18 (hipho_18.gif)]

The evaporation of the water from this bulb decreases the temperature
of the mercury in the tube b in proportion to the dryness of the
atmosphere, and the number of degrees the tube b indicates below that
of the other, shows the real state of the atmosphere in the room; for
instance, if b stands at forty and a at sixty-one the room is in a
state of extreme dryness, the difference of twenty-one degrees between
the thermometers--let a stand at any one point--gives this result.  If
they do not differ, or there is only four or five degrees variation,
the atmosphere of the room is very moist and means should be taken to
expel the superfluous quantity.

HEAD RESTS.--The button head rest with chair back clip, A fig.  19--is
much the best for travelling artists, as it can be taken apart, into
several pieces and closely packed; is easily and firmly fixed to the
back of a chair by the clamp and screw a and b, and is readily adjusted
to the head, as the buttons c, c and arms d, d are movable.

Sometimes the button rest is fixed to a pole, which is screwed to the
chair; but this method is not so secure and solid as the clip and
occupies more room in packing.  Both the pole and clip, are furnished
in some cases with brass band rests instead of the button; but the only
recommendation these can possibly possess in the eyes of any artist, is
their cheapness.

[Illustration: Fig. 19 (hipho_19.gif)]

For a Daguerreotypist permanently located the independent iron
head-rest, B fig. 19, is the most preferable, principally on account of
its solidity.  It is entirely of iron, is supported by a tripod (a) of
the same metal and can be elevated by means of a rod (b) passing
through the body of the tripod, to a height sufficient for a person,
standing, to rest against.

[Illustration: Fig. 20 (hipho_20.gif)]

GALVANIC BATTERY.--This article is used for the purpose of giving to
imperfectly coated plates a thicker covering of silver.  The form of
battery now most universally employed for electrotype, and other
galvanic purposes, is Smee's--Fig. 20.  It consists of a piece of
platinized silver, A, on the top of which is fixed a beam of wood, B,
to prevent contact with the silver.  A binding screw C is soldered on
to the silver plate to connect it with any desired object, by means of
the copper wire, e.  A plate of amalgamated zinc, D, varying with the
fancy of the operator from one half to the entire width of the silver
is placed on each side of the wood.  This is set into a glass vessel,
P,--the extreme ends of the wood resting upon its edge--on which the
acid with which it is charged has no effect.  The jar is charged with
sulphuric acid, (common oil of vitriol) diluted in eight parts its bulk
of water.  The zinc plates of the battery have been amalgamated with
quicksilver, and when the battery is set into the jar of acid there
should be no action percieved upon them when the poles F, G, are not in
contact.  Should any action be percieved, it indicates imperfect
amalgamation; this can be easily remedied by pouring a little mercury
upon them immediately after removing them from the acid, taking care to
get none upon the centre plate A.

Directions for use.--A sheet of silver must be attached to the wire
connected with the centre plate A of the battery, and placed in the
silver solution--prepared as directed below.  The plate to be silvered
is first cleaned with diluted sulphuric acid, and then attached to the
wire, G, proceeding from the zinc plates D, D, and placed in the silver
solution, opposite the silver plate attached to the pole F, and about
half an inch from it.  A slight effervescence will now be percieved
from the battery, and the silver will be deposited upon the
Daguerreotype plate, while at the same time a portion of the silver
plate is dissolved.

To prepare the solution of silver.--Dissolve one ounce of chloride of
silver in a solution of two ounces of cyanide of potassium, previously
dissolved in one quart of water.  The oxide of silver may be used
instead of the chloride.  This solution is put into a tumbler, or other
vessel.

[Illustration: Fig. 21 (hipho_21.gif)]

[Illustration: Fig. 22 (hipho_22.gif)]

This battery with the necessary articles for using it may be obtained
of E. Anthony, 205 Broadway, New York city.

The other articles required by every operator may be simply enumerated,
viz:

Sticking, or sealing paper.

A pair of pliers, or forceps.

Porcelain pans or dishes, for applying the hyposulphite of soda and
washing after the imagine is fixed, something in form like fig. 23.

A support for holding the plate while being washed, like fig. 24.

[Updater's note: Figures 23 and 24 were missing from the image set.]

[Illustration: Fig. 25 (hipho_25.gif)]

BUFF STICKS.--Fig. 25.--These are usually from one to three feet in
length, and about three inches wide--some think two and a half
sufficient.  The underside, which is convex, is covered with a strip of
finely prepared buckskin, or velvet, well padded with cotton or tow.

All the articles enumerated in this chapter may be obtained, of the
very best quality and at the most reasonable rates, of Mr. E. Anthony,
205, Broadway, New York.



CHAP. VI.

THE DAGUERREOTYPE PROCESS.

The process of taking Daguerreotype pictures differs very materially
from all others of the photographic art, inasmuch as the production of
the image is effected upon plates of copper coated with silver.  The
silver employed should be as pure as possible; the thickness of the
plate is of little consequence, provided there be sufficient silver to
bear the cleaning and polishing--is free from copper spots, is
susceptible of a high polish, an exquisitely sensitive coating and a
pleasing tone.  These qualities are possessed to an eminent degree by
the French plates.

Having already enumerated the various processes--and the apparatus
necessary for the manipulation, I will here give a list of the
chemicals to be used, and then proceed to explain them more fully.  The
requisite chemicals are--

  NITRIC ACID,             ROUGE,
  DRY IODINE,              MERCURY,
  DRYING POWDER,           HYPOSULPHITE OF SODA,
  CYANIDE OF POTASSIUM,    CHLORIDE OF GOLD; OR
  ROTTENSTONE,             HYPOSULPHITE OF GOLD.
  TRIPOLI,                 CHLORIDE OF SILVER.
  CHLORIDE OF IODINE,  } their compounds, or other
  BROMINE              } accelerating mixtures.

FIRST OPERATION.--Cleaning and polishing the plate.--For this purpose
the operator will require the--

Plate Blocks,

Plate Vice

Spirit Lamp,

Polishing Buffs,

Nitric Acid, diluted in fifteen times its bulk of water

Galvanic Battery, to galvanize the plate, if it is too imperfect to be
used without, previous cleaning it, as directed in the last chapter.

Rottenstone,

Tripoli, which is too often dispensed with.

Rouge, or lampblack--the first being most preferable.  The English
operators mix the two together.

Prepared cotton Wool, or Canton flannel.  If the first is used, it
should be excluded from the dust, as it is not so easily cleansed as
the latter.

The plate is secured, with its silver side upward, to the block, by the
means described on page 58--having previously turned the edges backward
all around.  The amount of cleaning a plate requires, depends upon the
state it is in.  We will suppose one in the worst condition; dirty,
scratched, and full of mercury spots, all of which imperfections are
more or less to be encountered.  The mercury spots are to be removed by
burning the plate.  To do this hold the plate over the flame of a
spirit lamp, more particularly under the mercury spots, until they,
assume a dull appearance, when the lamp is to be removed, and the plate
allowed to cool, after which it is attached to the block.

Place the block upon the swivle, and hold it firmly with the left hand;
take a small knot or pellet of cotton, or, if you like it better, a
small piece of canton flannel--wet it with a little diluted nitric
acid; then sift some finely prepared rottenstone--Davie's,* if you can
get it--upon it, and rub it over the plate with a continual circular
motion, till all traces of the dirt and scratches are removed; then
wipe off the rottenstone with a clean piece of cotton, adopting, as
before, a slight circular motion, at the same time wiping the edges of
the plate.  Even the back should not be neglected, but throughly
cleansed from any dirt or greasy film it may have received from
handling.

* Sold by E. Anthony.

When this is thoroughly accomplished, mix a portion of your tripoli
with the dilute nitric acid, to the consistence of thick cream.  Then
take a pellet of cotton and well polish the plate with this mixture, in
the same manner as with the rottenstone.  Continue the process till, on
removing the tripoli with a clean pellet, the plate exhibits a clear,
smooth, bright surface, free from all spots, or scratches.  Any remains
of the acid on the plate may be entirely removed By sifting on it a
little Drying powder, and then wiping it carefully off with a fine
camels hair brush, or duster.  The finishing polish is now to be given.

For this purpose the rouge--or a mixture of rouge and lamp-black, in
the proportion of one part of the former to seven of the latter--is
used.  It should be kept either in a muslin bag, or wide mouth bottle,
over which a piece of muslin is tied--in fact, both the rottenstone and
tripoli should be preserved from the dust in the same manner.  With a
little of this powder spread over the buff--described on page 53--the
plate recieves its final polish; the circular motion is changed for a
straight one across the plate, which, if intended for a portrait,
should be buffed the narrow way; but if, for a landscape or view of a
house, the length way of the plate.

The operation of cleaning the plate at first appears difficult and
tedious, and many have been deterred from attempting this interesting
art on that account; but, in reality, it is more simple in practice
than in description, and with a little patience and observation, all
difficulties are easily overcome.  Great care must be taken to keep the
buff free from all extraneous matter, and perfectly dry, and when not
in use it should be wrapped up in tissue paper, or placed in a tight
box.

The plate should be buffed immediately before the sensitive coating is
given; particles of dust are thus effectually removed; the temperature
of the plate is also increased by the friction, and the required tint
more readily obtained.

SECOND OPERATION.--Applying the sensative coating.--The apparatus and
chemicals required, are an

Iodine box--see fig. 14 page 53.

Bromine box--similar to the iodine box but a trifle deeper.

Dry Iodine.

Bromine, or a compound of Bromine and Chloride of Iodine, or other
sensitive mixture.

Most of our best operators use the compound Bromine and Chloride of
Iodine.  In the early days of the Daguerreotype, Iodine alone was used
in preparing the plate, and although it still plays a very important
part, other preparations, called accelerating liquids, quickstuff, &c.,
are used, and the discovery of which has alone ensured the application
of the Daguerreotype successfully to portrait taking--for when first
introduced among us it took from five to ten minutes to produce a
tolerable good view, while now but the fraction of a minute is required
to obtain an accurate likeness.

To iodize the plate perfectly it must be placed over the iodine vapor
immediately after buffing.  Scatter from a sixteenth to the eighth of
an ounce of dry iodine over the bottom of your coating box, and
slightly cover it with cotton wool.  The plate is then dropped into the
frame b, fig. 12, with its silvered surface downward, and thrust under
the lid h.  The bright surface of the plate is soon coated with a film
of iodine of a fine yellow color; it is then removed and placed over
the accelerating solution.  It is not absolutely necessary to perform
this operation in the dark, although a bright light should be avoided.
Not so the next part of the process, viz; giving the plate its extreme
sensitiveness, or coating with the accelerating liquids.  In this great
caution should be used to prevent the slightest ray of light impringing
directly on the plate, and in examining the color reflected light
should always be used.  A convenient method of examining the plate, is
to make a small hole in the partition of the closet in which you coat,
and cover it with a piece of tissue paper; by quickly turning the plate
so that the paper is reflected upon it the color is very distinctly
shown.  Most of our operators are not so particular in this respect as
they should be.

ACCELERATING LIQUID.--Of these there are several kinds, which differ
both in composition and action--some acting very quickly, others giving
a finer tone to the picture although they are not so expeditious in
there operations; or in other words, not so sensitive to the action of
light.  These are adopted by Daguerreotypists according to their tastes
and prejudices.  They are all applied in the same way as the coating of
iodine.  The following are the best.

Bromine water--This solution is much used in France, and, I shall
therefore give its preparation, and the method of using it, in the
words of M. Figeau.  "Put into a bottle of pure water, a large excess
of bromine; shake the mixture well, and before using it, let all the
bromine be taken up.  An ascertained quantity of this saturated water
is then diluted in a given quantity of distilled water, which gives a
solution of bromine that is always identical." M. Figeau recommends one
part of the saturated solution to thirty parts its bulk of water; but
M. Lesebour finds it more manageable if diluted with forty times.  In
case pure distilled, or rain water cannot be procured, a few drops of
nitric acid--say six to the quart--should be added to the common water.

Put into the bromine box a given quantity of this solution, sufficient
to well cover the bottom; the plate, having been iodized to a deep
yellow, is placed over it; the time the plate should be exposed must be
ascertained by making a few trials; it averages from twelve to forty
seconds.  When once ascertained, it is the same for any number of
plates, as the solution, which of course would become weaker and
weaker, is changed after every operation, the same quantity being
always put into the pot.

Chloride of Iodine.--This is prepared by introducing chlorine gass into
a glass vessel containing iodine; the iodine is liquified, and the
above named compound is the result.  Operators need not, however, be at
the trouble and expense of preparing it, as it can be obtained
perfectly pure of Mr. Anthony, 205 Broadway, N. Y., as also all of the
chemicals herein enumerated.  The compound is diluted with distilled
water, and the plate submitted to its action till it is of a rose
color.  Chloride of iodine alone, is seldom if ever used now by
American operators, as it does not sufficiently come up to their
locomotive principle of progression.  The next is also eschewed by the
majority, although many of our best artists use no other, on account of
the very fine tone it gives to pictures.

Bromide of Iodine.--This is a compound of bromine and chloride of
iodine.  In mixing it, much depends upon the strength of the
ingredients; an equal portion of each being generally used.  Perhaps
the best method of preparing it, is to make a solution in alcohol of
half an ounce of chloride of iodine, and add the bromine drop by drop,
until the mixture becomes of a dark red color; then dilute with
distilled water, till it assumes a bright yellow.  Put about half an
ounce of this compound into the pot, and coat over it to a violet
color, change the solution when it becomes too weak to produce the
desired effect.

Another.--Mix half an ounce of bromine with one ounce of chloride of
iodine, add two quarts pure distilled water, shake it well and let it
stand for twelve hours then add twenty-five drops of muriatic acid, and
let it stand another twelve hours, occasionally shaking it up well.
Dilute six parts of this solution in sixteen of water.  Coat over dry
iodine to a deep yellow, then over the sensitive to a deep rose
color--approaching purple--then back, over dry iodine from four to
eight seconds.

Roach's Tripple Compound.--This is one of the very best sensitive
solutions, and is very popular among Daguerreotypists.  To use this,
take one part in weight, say one drachm, of the compound and dilute it
with twelve of water; coat over dry iodine to yellow, then over the
compound to a rosy red.  The effect in the camera is quick, and
produces a picture of a fine white tone.

Gurney's Sensitive.--This is another preparation of bromine, and gives
a fine tone.  To two parts of water add one of the sensitive, and put
just sufficient in the box to cover the bottom, or enable you to coat
in from eight to ten seconds.  Coat over dry iodine to a dark yellow,
and over the quick till you see a good change, then back over the dry
iodine from two to three seconds.

Bromide of Lime, or Dry Sensitive.--This is a compound but recently
introduced, and is becoming somewhat of it favorite, owing principally
to the slight trouble it gives in its preparation, and the tone it
imparts to the picture.  To prepare it, fill your jar about half or
quarter full of dry slacked lime, then drop into it bromine, till it
becomes a bright orange red.  The plate is generally coated over this
compound, after the iodine coating to yellow, to a violet, or plum
color; but it will work well under any circumstances, the color being
of little consequence, if coated from thirty to ninety seconds,
according to its strength.

Mead's Accelerator.--I merely mention this as being in the market, not
knowing any thing in regard to its merits.  The directions given for
its use are as follows: Mix one-third of a bottle with a wine glass
full of water, coat the plate over dry iodine to a dark gold color,
then over the accelerator to a violet, then back over dry iodine, or
chloride of iodine, from three to five seconds.

Chloride of Bromine.--M. Bissou, a French experimentalist, has found
that bromine associated with chlorine, prepared in a similar manner to
chloride of iodine, already described, a solution of bromine being
substituted for the iodine, is a very sensitive solution; by means of
it daguerreotype proofs are obtained in half a second, and, thus very
fugitive subjects are represented, making it the very best compound for
taking children.  So quick is its operation, that even persons or
animals may be taken in the act of walking.

Hungarian Liquid.--This, I believe, has never been used here, or
imported into this country, and the composition of it is not generally
known, even in Europe, where it has taken precedence of all others.  It
acts quickly and with considerable certainty.  It is used by diluting
it with from ten to fifteen times its bulk of water, putting a
sufficient quantity into the jar to cover the bottom.  The plate being
previously iodized to a light yellow, is submitted to this mixture till
it assumes a light rose tint.

Bromine and Fluoric Acid, in combination, are used by some Daguerrean
artists as a sensitive, but any of the above compounds are better;
besides this, the fluoric acid is a dangerous poison, and the quick
made from it will not repay the risk to the health in using it.

As I have before said, great caution should be observed in examining
the color of the plate, even by the feeble light allowed, which, when
attained, must be immediately placed in the holder belonging to the
camera and covered with the dark slide.  You then pass to the

THIRD OPERATION.--Submitting the Plate to the action of Light in the
Camera.--Experience alone must guide the operator as to the time the
plate should be exposed to the influence of the light; this being
dependent on a variety of circumstances, as clearness of the
atmosphere--and here, a reference to the hygrometer will be of
advantage--time of day, object to be taken, and the degree of
sensitiveness imparted to the plate by the quickstuff.  As I have
before said, the artist should be careful to see that the interior of
the camera is clean and free from dust, as the small particles flying
about, or set in motion by the sliding of the holder into the box,
attach themselves to the plate, and cause the little black spots, by
which an otherwise good picture is frequently spoiled.  Care should
also be taken in withdrawing the dark slide, in front of the plate,
from the holder, as the same effect may be produced by a too hasty
movement.  The lens is the last thing to be uncovered, by withdrawing
the cap c. fig. 5., which should not be done until you have placed the
sitter in the most desirable position.  When, according to the judgment
and experience of the operator, the plate has remained long enough to
receive a good impression, the cap is replaced over the lens, and the
dark slide over the plate, which is then removed from the camera.

Daguerreotypists generally mark time by their watches, arriving at the
nearest possible period for producing a good picture by making several
trials.  As a ready method of marking short intervals of time is,
however, a very important consideration, and as any instrument which
will enable an artist to arrive at the exact period, must be an
improvement, and worthy of universal adoption, I will here describe one
invented by Mr. Constable of England, which he calls a

Sand Clock, or Time Keeper.--"It consists of a glass tube, about twelve
inches long, by one in diameter, half filled with fine sand, similar to
that used for the ordinary minute glasses, and, like them, it has a
diaphram, with a small hole in the centre through which the sand runs.
The tube is attached to a board which revolves on a centre pin; on the
side is a graduated scale, divided into half seconds; the tube is also
provided with a moveable index.  This instrument is attached, in a
conspicuous place, to the wall.  The glass tube being revolved on its
centre, the index is set to the number of half seconds required, and
the sand running down, the required time is marked without the
possibility of error.  In practice it will be found to be a far more
convenient instrument for the purpose than either a clock or a seconds
watch, and is applicable both for the camera and mercury box."

If the artist finds it desirable or necessary to take the object to be
copied in its right position, that is reverse the image on the
spectrum, he can do so by attaching a mirror (which may be had of Mr.
Anthony, or Mr. Roach) to the camera tube, at an angle of forty-five
degrees.

If, after taking the plate from the camera, it be examined, no picture
will yet be visible, but this is brought about by the

FOURTH PROCESS.--Bringing out the Picture, or rendering it Visible.--We
now come to the use of the mercury bath, Fig. 11.  To the bath a
thermometer is attached, to indicate the proper degree of beat
required, which should never be raised above 170 deg. Fahrenheit.  The
plate maybe put into one of the frames (see Fig. 11,) over the mercury,
face downwards, and examined from time to time, by simply raising it
with the fingers, or a pair of plyers.  This operation, as well as the
others, should take place in the dark closet.

[Illustration: Fig. 26 (hipho_26.gif)]

[Updater's note: hipho_26.gif and hipho27.gif are both captioned Figure
27.]

Sometimes, to prevent the necessity of raising the plate, an additional
cover or top is made use of.  It consists of a box fitted closely to
the inner rim of the bath, and having an inclined top (a, Fig. 27.) The
top is cut through and fitted with frames for each size of plate, like
those already described, and in the back is a piece of glass (b,)
through which to view the progress of mercurialization, and an
additional piece (c,) on one side, colored yellow, to admit the light.
The outline only of the top is here given, in order to show every
portion of it at one view.

The picture, being fully developed, is now taken out and examined; it
must not, however, be exposed to too strong a light.  If any glaring
defects be perceived, it is better not to proceed with it, but place it
on one side to be re-polished; if, on the contrary, it appears perfect,
you may advance to the

FIFTH OPERATION.--Fixing the Image so that the light can no longer act
upon it.--The following articles are required for this purpose:

Two or three porcelain or glass dishes, in form, something like fig. 24.

A plate support, fig. 25.  Few, I believe, now make use of this,
although it is a very convenient article.

Hyposulphite of Soda,

A pair of Plyers.

In Europe, they also use a drying apparatus, Fig. 27, but this, like
the plate support, is a matter of little consequence, and may be
dispensed with.  I will, however, describe it, for the benefit of those
who may wish to use it.

[Illustration: Fig. 27 (hipho_27.gif)]

[Updater's note: hipho_26.gif and hipho27.gif are both captioned Figure
27.]

A vessel made of copper or brass, tinned inside, and large enough to
take in the largest plate, but not more than half an inch wide, is the
most convenient.  It must be kept perfectly clean.  Hot distilled water
is poured into it, and the temperature kept up by a spirit lamp.

Hyposulphite of Soda.--Having made a solution of hyposulphite of soda,
and well filtered it--the strength is immaterial; about half an ounce
of the salt to a pint of distilled water is sufficient--pour it into
one of the porcelain dishes, put into another plain, and into a third
distilled water.  Immerse the plate with its face downwards into the
hyposulphite, and the whole of the sensitive is removed, and the light
has no farther action upon it; it is then to be removed from the
hyposulphite and plunged into the plain water, or placed upon the
support, fig. 25, and the water poured over it.  It is then washed in a
similar manner with the distilled water and well examined, to see that
not the slightest particle of dust rests on the surface.  The next step
is to dry it.

This may be readily accomplished by holding the plate with your plyers,
and pouring distilled water over it--if it is hot, so much the better.
Apply the spirit lamp to the back, at the corner held by the plyers, at
the same time facilitating the operation with the breath; pass the lamp
gradually downwards, finishing at the extreme corner.  The last drop
may now be removed by a little bibulous paper.  A single drop, even, of
distilled water allowed to dry on any part of the surface, is certain
to leave a stain which no after process can remove.

To illustrate the necessity for having perfectly clean water, and free
from all foreign matter--only to be avoided by using that which is
distilled--in these processes, I will relate a little anecdote.

An operator in this city (New York) frequently made complaint to me,
that his plates were occasionally very bad; coming out all over in
little black and white spots and spoiling many very good pictures,
regretting at the same time that perfect plates were not made, for he
had lost many customers in consequence of these defects.  These
complaints being somewhat periodical, I suggested that the fault might
be in the hyposulphite, or chloride of gold solutions, or particles of
dust floating about in the room, and not in the plate.

A few days after he stated, that his plates having served him again in
the same way, he procured a fresh supply of hyposulphite of soda and
chloride of gold, but after applying them the result was no better.  He
then, by my advice, thoroughly cleaned his wash dishes, bottles and
water pail, made fresh solutions and had no further trouble, becoming
satisfied that the plates suffered an undue share of censure.

SIXTH PROCESS.--Gilding the Picture.--This is an improvement the honor
of which is due to M. Figeau, and may take place either before the
drying process, or at any subsequent period; but it improves the
picture so materially that it should never be neglected.  The articles
necessary for gilding are--

A Pair of Plyers; or a Gilding Stand (see fig. 19) and Chloride of
Gold; or Hyposulphite of Gold.

The latter is imported by Mr. E. Anthony, 205 Broadway, New York, and
is decidedly the best article for the purpose.  One bottle simply
dissolved in a quart of water will make a very strong solution, and
gives a richness to the picture impossible to be obtained from the
chloride of gold.  The process is precisely similar to that described
below for chloride of gold, taking care to cease the moment the bubbles
are well defined over the surface of the plate.  Many Daguerreotypists,
after a superficial trial, discard the hyposulphite of gold as
inferior; but I have no hesitation in asserting that the fault lies
with themselves; for in every case within my knowledge, where its use
has been persisted in until the correct method has been ascertained and
the nature of the gilding has become familiar, it is always preferred.
In illustration of this fact I will relate an anecdote:

A gentleman to whom it had been recommended, purchased a bottle, and
after making one or two trials of it, wrote to his correspondent--"Send
me two bottles of chloride of gold, for I want no more of the
hyposulphite; it is good for nothing." A few weeks after he sent for
three bottles of the condemned article, confessing that he had found
fault unnecessarily; for, that since he had become familiar to its use,
he must acknowledge its superiority, and would use no other gilding.

The Solution of Chloride of Gold is prepared by dissolving in a pint of
distilled water, fifteen grains of chrystalized chloride of gold.  This
solution will be of a yellow tint.  In another pint of distilled water
dissolve fifty-five grains of hyposulphite of soda; pour gradually, in
very small quantities, the gold into the hyposulphite of soda, stirring
the solution at intervals; when finished the mixture should be nearly
colorless.

Place the plate on its stand, or hold it in the plyers, in a perfectly
horizontal position--silver surface upward--having previously slightly
turned up the edges, so that it may hold the solution.  Wet the surface
with alcohol, letting any superfluous quantity drain off.  The alcohol
is of no farther use than to facilitate the flowing of the gold mixture
over the surface.  Now pour on, carefully, as much of the preparation
of gold as will remain on the plate.  The under part of the plate is
then to be heated as uniformly as possible with the spirit lamp; small
bubbles will arise, and the appearance of the portrait or view very
sensibly improved.  The process must not be carried too far, but as
soon as the bubbles disappear the lamp should be removed, and the plate
immersed in distilled water, and dried as before directed.

7th. COLORING THE PICTURE.--I very much doubt the propriety of coloring
the daguerreotypes, as I am of opinion, that they are little, if any,
improved by the operation, at least as it is now generally practised.

There are several things requisite in an artist to enable him to color
a head, or even a landscape effectively, and correctly, and I must say
that very few of these are possessed by our operators as a class.
These requirements are, a talent for drawing--taste--due discrimination
of effect--strict observance of the characteristic points in the
features of the subject--quick perception of the beautiful, and a
knowledge of the art of mixing colors, and blending tints.

The method now pursued, I do not hesitate to say, and have no fears of
being contradicted by those capable of critisizing is on the whole
ruinous to any daguerreotype, and to a perfect one absolutely
disgusting.  The day may come when accurate coloring may be obtained in
the camera.  Until that day, if we cannot lead taste into the right
channel, we will endeavor to give such instructions that
Daguerreotypists may proceed with this part of his work with a better
understanding of the principles involved.  For this purpose I have
prepared a short chapter on the art of coloring, which may be found in
the latter part of this volume.

To Preserve Daguerreotypes they must be well sealed and secured in a
case, or frame.  These, of course, are selected according to the taste
of the customer, the principal requisite being good glass.  Most
Daguerreotypists prefer the white French plate glass--and many think,
very erroneously, that none is good unless it is thick--but the great
desideratum is clearness and freedom from blisters; even glass a little
tinged with green or yellow is to be preferred to the French plate when
cloudy or blistered and there is very little of it comes to this market
that is not so.  It is to be hoped that some of our glass factories
will manage to manufacture an article expressly for daguerreotypes; and
I would recommend them to do so, for they would find it quite an item
of profit annually.

Before enclosing the picture in the case you should be careful to wipe
the glass perfectly clean, and blow from the picture any particles of
dust which may have fallen upon it.  Then take strips of sticking
paper, about half or three quarters of an inch wide, and firmly and
neatly secure it to the glass, having first placed a "mat" between them
to prevent the plate being scratched by the glass.

TO MAKE SEALING PAPER.--Dissolve one ounce of gum arabic, and a quarter
of an ounce of gum tragicanth in a pint of water; then add a
teaspoonful of benzoin.  Spread this evenly on one side of good stout
tissue paper; let it dry, and then cut it up in stripes, about half or
three quarters of an inch wide, for use.  If it becomes too soft for
summer use, add gum arabic; if too hard and cracking, add benzoin or
gum tragicanth; if it gets too thick, add water.

COLORED DAGUERREOTYPES ON COPPER.--To effect this, take a polished
plate of copper and expose it to the vapor of iodine, or bromine, or
the two substances combined; or either of them in combination with
chlorine.  This gives a sensitive coating to the surface of the plate,
which may then be submitted to the action of light in the camera.
After remaining a sufficient time in the camera, the plate is taken out
and exposed to the vapor of sulphuretted hydrogen.  This vapor produces
various colors on the plate, according to the intensity with which the
light has acted on the different parts; consequently a colored
photographic picture is obtained.  No further process is necessary as
exposure to light does not effect the picture.

By this process we have an advantage over the silvered plate, both in
economy, and in the production of the picture in colors.

INSTANTANEOUS PICTURES BY MEANS OF GALVANISM.--It will be seen by the
following valuable communication that galvanism can be successfully
applied in producing pictures instantly; a process of great importance
in securing the likeness of a child, or in taking views of animated
nature.  Colonel Whitney informs me that he once took a view of the
steeple of the St. Louis Court House after sundown by this means, and
also secured the image of a man in the act of stepping into a store,
and before he had time to place his foot, raised for that purpose, on
the door step.  Mr. Whitney is well known as the talented editor of the
Sunday Morning news.



  New York, January 16, 1849.
  Mr. H. H. SNELLING.

Dear Sir,--As you are about publishing a history of the Daguerreotype,
and request a description of my mode of taking pictures instantaneously
by the aid of galvanism, I comply with great pleasure.

In the year 1841, while practicing the art in St. Louis, Mo., I was at
times, during the summer, much troubled with the electric influence of
the atmosphere, especially on the approach of a thunder-storm. At such
times I found the coating of my plates much more sensitive than when
the atmosphere was comparatively free from the electric fluid, and the
effect was so irregular that no calculation could counteract the
difficulty.  This satisfied me that electricity was in some measure an
important agent in the chemical process, and it occurred to me that the
element might be turned to advantage.  I determined, therefore, to
enter on a series of experiments to test my theory.  Finding it
impossible to obtain an electric machine, and unwilling to abandon the
examination, it occurred to me, that the galvanic influence might
answer the same purpose.  I therefore proceeded to make a galvanic
battery in the following simple manner.  I obtained a piece of zinc
about two inches long, one inch wide, and an eighth of an inch thick.
On this I soldered a narrow strip of copper, about six inches long, the
soldered end laid on one side of the zinc, and extending its whole
length.  The battery was completed by placing the zinc in a glass
tumbler, two-thirds full of dilute sulphuric acid, strong enough to
produce a free action of the metals.  The upper end of the copper slip
extending above the tumbler was sharpened to a point, and bent a little
over the glass.

The method of using, was thus:--After preparing the plate in the usual
manner and placing it in the camera, in such manner as to expose the
back of the plate to view, the battery was prepared by placing the zinc
in the acid, and as soon as the galvanic fluid began to traverse (as
could be known by the effervescence of the acid, operating on the zinc
and copper) the cap of the camera was removed, and the plate exposed to
the sitter; at the same instant the point of the battery was brought
quickly against the back of the plate, and the cap replaced instantly.
If the plate is exposed more than an instant after the contact the
picture will generally be found solarized.  By this process I have
taken pictures of persons in the act of walking, and in taking the
pictures of infants and young children I found it very useful.

  Very respectfully yours,
  THOMAS R. WHITNEY.



CHAP. VII

PAPER DAGUERREOTYPES.--ETCHING DAGUERREOTYPES.


Mr. Hunt describes a process, discovered by himself by which the
Daguerrean art may be applied to paper.  His description is as
follows:--

"Placing the paper on some hard body, wash it over on one side--by
means of a very soft camel's hair pencil--with a solution of sixty
grains of bromide of potassium, in two fluid ounces of distilled water,
and then dry it quickly by the fire.  Being dry, it is again washed
over with the same solution, and dried as before.  A solution of
nitrate of silver--one hundred grains to an ounce of distilled
water--is to be applied over the same surface, and the paper quickly
dried in the dark.  In this state the papers may be kept for use.

"When they are required, the above solution of silver is to be
plentifully applied, and the paper placed wet in the camera, the
greatest care being taken that no day light--not even the faintest
gleam--falls upon it until the moment when you are prepared, by
removing the dark slide, to permit the light, radiating from the object
you wish to copy, to act in producing the picture.  After a few seconds
the light must be again shut off, and the camera removed into a dark
room." The necessity of removing the camera is now avoided by the use
of the dark slide, already described, covering the picture in the
holder, which alone may be removed.--Amer. Aut.

"It will be found by taking the paper from the holder, that there is
but a very faint outline--if any--yet visible.  Place it aside, in
perfect darkness until quite dry; then place it in the mercurial vapor
box (meaning bath) and apply a very gentle heat to the bottom.  The
moment the mercury vaporizes, the picture will begin to develope
itself.  The spirit lamp must now be removed for a short time, and when
the action of the mercury appears to cease, it is to be very carefully
applied again, until a well defined picture is visible.  The
vaporization must then be suddenly stopped, and the photograph removed
from the box.  The drawing will then be very beautiful and distinct;
but much detail is still clouded, for the developement of which it is
only necessary to place it in the dark and suffer it to remain
undisturbed for some hours.  There is now an inexpressible charm about
the pictures, equaling the delicate beauty of the daguerreotype; but
being very susceptible of change, it must be viewed by the light of a
taper only.  The nitrate of silver must now be removed from the paper,
by well washing it in soft water, to which a small quantity of salt has
been added, and it should afterwards be soaked in water only.  When the
picture has been dried, wash it quickly over with a soft brush dipped
in a warm solution of hyposulphite of soda, and then wash it for some
time in distilled water, in order that all the hyposulphite may be
removed.  The drawing is now fixed and we may use it to procure
positive copies, (the original being termed a negative,) many of which
may be taken from one original."

"The action of light on this preparation, does indeed appear to be
instantaneous.  The exquisite delicacy of this preparation may be
imagined, when I state that in five seconds in the camera, I have,
during sunshine, obtained perfect pictures, and that when the sky is
overcast, one minute is quite sufficient to produce a most decided
effect."

"This very beautiful process is not without its difficulties; and the
author cannot promise that, even with the closest attention to the
above directions, annoying failures will not occur.  It often happens
that some accidental circumstance--generally a projecting film or a
little dust--will occasion the mercurial vapor to act with great energy
on one part of the paper, and blacken it before the other portions are
at all effected.  Again, the mercury will sometimes accumulate along
the lines made by the brush, and give a streaky appearance to the
picture, although these lines are not at all evident before the
mercurial vapor was applied.  (A brush sufficiently large--and they may
be easily obtained--will, in a measure, prevent this difficulty.--Amer
Au.) I have stated that the paper should be placed wet in the camera;
the same paper may be used dry, which often is a great convenience.
When in the dry state a little longer exposure is required; and instead
of taking a picture in four or five seconds, two or three minutes are
necessary."

The durability of daguerreotypes has been, and is still, doubted by
many, but experiment has proved that they are more permanent than oil
paintings or engravings.

ETCHING DAGUERREOTYPES.--There are several methods of accomplishing
this object; discovered and applied by different individuals.

The first process was published at Vienna by Dr. Berres, and consisted
in covering the plate with the mucilage of gum arabic, and then
immersing the plate in nitric acid of different strengths.

Mr. Figeau, of whom I have already spoken, likewise discovered a
process for the engraving of Daguerreotypes; and founded on the belief
that the lights of a Daguerreotype plate consists of unaltered silver,
while the dark or shadows consists of mercury or an amalgam of mercury
with silver.  He finds that a compound acid, consisting of a mixture of
nitric, nitrous, and muriatic acids, or of nitric mixed with nitrate of
potass and common salt, has the property of attaching the silver in
presence of the mercury without acting upon the latter.  Bi-chloride of
copper answers the purpose also, but less completely.

"When the clean surface of a Daguerreotype plate is exposed to the
action of this menstruum, particularly if warm, the white parts, or
lights are not altered, but the dark parts are attacked, and chloride
of silver is formed, of which an insoluble coating is soon deposited,
and the action of the acid soon ceases.  This coat of chloride of
silver is removed by a solution of ammonia, and then the acid applied
again, and so on, until the depth of biting in is sufficient.  However,
it is not possible, by repeating this process, to get a sufficient
force of impression; a second operation is required, in order to obtain
such a depth as will hold the ink, to give a dark impression; for this
purpose the whole plate is covered with drying oil; this is cleared off
with the hand, exactly in the way a copper plate printer cleans his
plate.  The oil is thus left in the sinkings, or dark bitten in parts
only.  The whole plate is now placed in a suitable apparatus, and the
lights or prominent parts of the face are gilt by the electrotype
process.  The whole surface is now touched with what the French
engravers call the "Resin Grain," (grain de resine), a species of
partial stopping out, and it is at once bitten in to a sufficient depth
with nitric acid, the gilding preserving the lights from all action of
the acid.  The resin grain gives a surface to the corroded parts
suitable for holding the ink, and the plate is now finished and fit to
give impressions resembling aquatint.  But as silver is so soft a metal
that the surface of the plate might be expected to wear rapidly, the
discoverer proposes to shield it by depositing over its whole surface a
very thin coat of copper by the electrotype process; which when worn
may be removed at pleasure down to the surface of the noble metal
beneath, and again a fresh coat of copper deposited; and so an
unlimited number of impressions obtained without injuring the plate
itself."

If, as has been asserted, steel may be rendered sufficiently sensitive,
to take photographic impressions, to what a revolution will the art of
engraving be subject by the discovery of this process.



CHAP. VIII.

PHOTOGENIC DRAWING ON PAPER.


We shall now proceed to describe the various processes for Photogenic
drawing on paper; first, however, impressing on the mind of the
experimenter, the necessity which exists for extreme care in every
stage of the manipulation.  In this portion of my work I am entirely
indebted to the works of Professors Hunt, Fisher and others.

I. APPARATUS AND MATERIALS.--Paper.--The principal difficulty to be
contended with in using paper, is the different power of imbibition
which we often find possessed in the same sheet, owing to trifling
inequalities in its texture.  This is, to a certain extent, to be
overcome by a careful examination of each sheet, by the light of a
candle or lamp at night, or in the dark.  By extending each sheet
between the light and the eye, and slowly moving it up and down, and
from left to right, the variations in its texture will be seen by the
different quantities of light which pass through it in different parts;
and it is always the safest course to reject every sheet in which
inequalities exist.  Paper sometimes contains minute portions of
thread, black or brown specks, and other imperfections, all of which
materially interfere with the process.  Some paper has an artificial
substance given to it by sulphate of lime (Plaster of Paris); this
defect only exists, however, in the cheaper sorts of demy, and
therefore can be easily avoided.  In all cases such paper should be
rejected, as no really sensitive material can be obtained with it.
Paper-makers, as is well known, often affix their name to one half the
sheet; this moiety should also be placed aside, as the letters must
frequently come out with annoying distinctness.  Well sized paper is by
no means objectionable, indeed, is rather to be preferred, since the
size tends to exalt the sensitive powers of the silver.  The principal
thing to be avoided, is the absorption of the sensitive solution into
the pores; and it must be evident that this desideratum cannot be
obtained by unsized paper.  Taking all things into consideration, the
paper known as satin post would appear to be preferable, although the
precautions already recommended should be taken in its selection.

Brushes.--The necessary solutions are to be laid upon the paper by
brushes.  Some persons pass the paper over the surface of the
solutions, thus licking up, as it were, a portion of the fluid; but
this method is apt to give an uneven surface; it also rapidly spoils
the solutions.  At all events, the brush is the most ready and the most
effectual means.

Distilled Water.--All the water used, both for mixing the solutions,
washing the paper, or cleaning the brushes, must be distilled, to
obtain good results, for reasons before specified.

Blotting Paper.--In many instances, the prepared paper requires to be
lightly dried with bibulous paper.  The best description is the white
sort.  In each stage of the preparation distinct portions of bibulous
paper must be used.  If these be kept seperate and marked, they can be
again employed for the same stage; but it would not do, for example, to
dry the finished picture in the same folds in which the sensitive paper
had been pressed.  A very convenient method is to have two or three
quarto size books of bibulous paper, one for each seperate process.

Nitrate of Silver.--In the practice of the photographic art, much
depends on the nitrate of silver.  Care should be taken to procure the
best; the crystalized salt is most suitable for the purpose.  While in
the form of crystal it is not injured by exposure to light, but the
bottles containing the solutions of this salt should at all times be
kept wrapped in dark paper, and excluded from daylight.

II. DIFFERENT METHODS OF PREPARING THE PAPER.--Preparation of the
Paper.--Dip the paper to be prepared into a weak solution of common
salt.  The solution should not be saturated, but six or eight times
diluted with water.  When perfectly moistened, wipe it dry with a
towel, or press it between bibulous paper, by which operation the salt
is uniformly dispersed through its substance.  Then brush over it, on
one side only, a solution of nitrate of silver.  The strength of this
solution must vary according to the color and sensitiveness required.
Mr. Talbot recommends about fifty grains of the salt to an ounce of
distilled water.  Some advise twenty grains only, while others say
eighty grains to the ounce.  When dried in a dark room, the paper is
fit for use.  To render this paper still more sensitive, it must again
be washed with salt and water, and afterwards with the same solution of
nitrate of silver, drying it between times.  This paper, if carefully
made, is very useful for all ordinary photographic purposes.  For
example, nothing can be more perfect than the images it gives of leaves
and flowers, especially with a summer's sun; the light, passing through
the leaves, delineates every ramification of their fibres.  In
conducting this operation, however, it will be found that the results
are sometimes more and sometimes less satisfactory, in consequence of
small and accidental variations in the proportions employed.  It
happens sometimes that the chloride of silver formed on the surface of
the paper is disposed to blacken of itself, without any exposure to
light.  This shows that the attempt to give it sensibility has been
carried too far.  The object is, to approach as nearly to this
condition as possible without reaching it; so that the preparation may
be in a state ready to yield to the slightest extraneous force, such as
the feeblest effect of light.

Cooper's Method.--Soak the paper in a boiling hot solution of chlorate
of potash (the strength matters not) for a few minutes; then take it
out, dry it, and wet it with a brush, on one side only, dipped in a
solution of nitrate of silver, sixty grains to an ounce of distilled
water, or, if not required to be so sensitive, thirty grains to the
ounce will do.  This paper possesses a great advantage over any other,
for the image can be fixed by mere washing.  It is, however, very apt
to become discolored even in the washing, or shortly afterwards, and
is, besides, not so sensitive, nor does it become so dark as that made
according to Mr. Talbot's method.

Daguerre's Method.--Immerse the paper in hydrochloric (or as it is more
commonly called, muriatic) ether, which has been kept sufficiently long
to become acid; the paper is then carefully and completely dried, as
this is essential to its proper preparation.  It is then dipped into a
solution of nitrate of silver, and dried without artificial heat in a
room from which every ray of light is carefully excluded.  By this
process it acquires a very remarkable facility in being blackened on a
very slight exposure to light, even when the latter is by no means
intense.  The paper, however, rapidly loses its extreme sensitiveness
to light, and finally becomes no more impressionable by the solar beams
than common nitrate paper.

Bromide Paper.--Of all common photographic paper, the best, because the
least troublesome in making, and the most satisfactory in result, is
that which is termed bromine paper, and which is thus
prepared:--Dissolve one hundred grains of bromide of potassium in one
ounce of distilled water, and soak the paper in this solution.  Take
off the superfluous moisture, by means of your bibulous paper, and when
nearly dry, brush it over on one side only, with a solution of one
hundred grains of nitrate of silver to an ounce of distilled water.
The paper should then be dried in a dark room, and, if required to be
very sensitive, should a second time be brushed over with the nitrate
of silver solution.

In preparing the papers mentioned above, there are two circumstances
which require particular attention.  In the first place, it is
necessary to mark the paper on the side spread with the solutions of
nitrate of silver, near one of the extreme corners.  This answers two
purposes:  in the first place it serves to inform the experimentalist
of the sensitive surface; and secondly, it will be a guide as to which
portion of the papers has been handled during the application of the
solution, as the impress of the fingers will probably come out upon the
photograph.  The second caution is, that the application of the
sensitive solution (nitrate of silver,) and the subsequent drying of
the paper, must be always conducted in a perfectly dark room, the light
of a candle alone being used.

[Illustration: Fig. 29 (hipho_29.gif)]

III. PHOTOGENIC PROCESS ON PAPER.--Method.--The simplest mode is to
procure a flat board and a square of glass, larger in size than the
object intended to be copied.  On the board place the photographic
paper with the prepared side upwards, and upon it the object to be
copied; over both lay the glass and secure them so that they are in
close connection by means of binding screws or clamps, similar to g. g.
fig. 29.  Should the object to be copied be of unequal thickness, such
as a leaf, grass, &c., it will be necessary to place on the board,
first, a soft cushion, which may be made of a piece of fine flannel and
cotton wool.  By this means the object is brought into closer contact
with the paper, which is of great consequence, and adds materially to
the clearness of the copy.  The paper is now exposed to diffused
daylight, or, still better, to the direct rays of the sun, when that
part of the paper not covered by the object will become tinged with a
violet color, and if the paper be well prepared, it will in a short
time pass to a deep brown or bronze color.  It must then be removed, as
no advantage will be obtained by keeping it longer exposed; on the
contrary, the delicate parts yet uncolored will become in some degree
affected.  The photogenic paper will now show a more or less white and
distinct representation of the object.  The apparatus figured at 29
consists of a wooden frame similar to a picture frame; a piece of plate
glass is fixed in front; and it is provided with a sliding cover of
wood, c., which is removed when the paper is ready to be exposed to the
action of the light.  The back, d., which is furnished with a cushion,
as just described, is made to remove for the purpose of introducing the
object to be copied, and upon it the prepared paper; the back is then
replaced, and, by aid of the cross piece and screw, e., the whole is
brought into close contact with the glass.

The objects best delineated on these photographic papers, are lace,
feathers, dried plants, particularly the ferns, sea-weeds and the light
grasses, impressions of copper plate and wood engravings, particularly
if they have considerable contrast of light and shade--(these should be
placed with the face downwards, having been previously prepared as
hereafter directed)--paintings on glass, etchings, &c.

To fix the Drawings.--Mr. Talbot recommends that the drawings should be
dipped in salt and water, and in many instances this method will
succeed, but at times it is equally unsuccessful.  Iodide of potassium,
or, as it is frequently called, hydriodate of potash, dissolved in
water, and very much diluted, (twenty-five grains to one ounce of
water,) is a more useful preparation to wash the drawings with; it must
be used very weak or it will not dissolve the unchanged muriate only,
as is intended but the black oxide also, and the drawing be thereby
spoiled.

But the most certain material to be used is the hyposulphite of soda.
One ounce of this salt should be dissolved in about a pint of distilled
water.  Having previously washed the drawing in a little lukewarm
water, which of itself removes a large portion of the muriate of silver
which is to be got rid of, it should be dipped once or twice in the
hyposulphite solution.  By this operation the muriate which lies upon
the lighter parts will become so altered in its nature as to be
unchanged by light, while the rest remains dark as before.

It will be evident from the nature of the process, that the lights and
shadows of an object are reversed.  That which is originally opaque
will intercept the light, and consequently those parts of the
photogenic paper will be least influenced by light, while any part of
the object which is transparent, by admitting the light through it,
will suffer the effect to be greater or less in exact proportion to its
degree of transparency.  The object wholly intercepting the light will
show a white impression; in selecting, for example, a butterfly for an
object, the insect, being more or less transparent, leaves a
proportionate gradation of light and shade, the most opaque parts
showing the whitest.  It may be said, therefore, that this is not
natural, and in order to obtain a true picture--or, as it is termed, a
positive picture--we must place our first acquired photograph upon a
second piece of photogenic paper.  Before we do this, however, we must
render our photograph transparent, otherwise the opacity of the paper
will mar our efforts.

To accomplish this object, the back of the paper containing the
negative, or first acquired photograph, should be covered with white or
virgin wax.  This may be done by scraping the wax upon the paper, and
then, after placing it between two other pieces of paper, passing a
heated iron over it.  The picture, being thus rendered transparent,
should now be applied to a second piece of photogenic paper, and
exposed, in the manner before directed, either to diffused day-light or
to the direct rays of the sun.  The light will now penetrate the white
parts, and the second photograph be the reverse of the first, or a true
picture of the original.

Instead of wax, boiled linseed oil--it must be the best and most
transparent kind--may be used.  The back of the negative photograph
should be smeared with the oil, and then placed between sheets of
bibulous paper.  When dry the paper is highly transparent.

IV. APPLICATION OF PHOTOGENIC DRAWING.--This method of photogenic
drawing may be applied to useful purposes, such as the copying of
paintings on glass by the light thrown through them on the prepared
paper--Imitations of etchings, which may be accomplished by covering a
piece of glass with a thick coat of white oil paint; when dry, with the
point of a needle, lines or scratches are to be made through the white
lead ground, so as to lay the glass bare; then place the glass upon a
piece of prepared paper, and expose it to the light.  Of course every
line will be represented beneath of a black color, and thus an
imitation etching will be produced.  It is also applicable to the
delineation of microscopic objects, architecture, sculpture, landscapes
and external nature.

A novel application of this art has been recently suggested, which
would doubtless prove useful in very many instances.  By rendering the
wood used for engravings sensitive to light, impressions may be at once
made thereon, without the aid of the artist's pencil.  The preparation
of the wood is simply as follows:--Place its face or smooth side
downwards, in a plate containing twenty grains of common salt dissolved
in an ounce of water; here let it remain for five minutes, take it out
and dry it; then place it again face downwards in another plate
containing sixty grains of nitrate of silver to an ounce of water; here
let it rest one minute, when taken out and dried in the dark it will be
fit for use, and will become, on exposure to the light, of a fine brown
color.  Should it be required more sensitive, it must be immersed in
each solution a second time, for a few seconds only.  It will now be
very soon effected by a very diffused light.

This process may be useful to carvers and wood engravers not only to
those who cut the fine objects of artistical design, but still more to
those who cut patterns and blocks for lace, muslin, calico-printing,
paper hangings, etc., as by this means the errors, expense and time of
the draughtsman may be wholly saved, and in a minute or two the most
elaborate picture or design, or the most complicated machinery, be
delineated with the utmost truth and clearness.



CHAP. IX.

CALOTYPE AND CHRYSOTYPE.


The materials and apparatus necessary for the Calotype process are--

Two or Three Shallow Dishes, for holding distilled water, iodide,
potassium, &c.--the same water never being used for two different
operations.

White Bibulous Paper.

Photogenic Camera--Fig. 9.

Pressure Frame--Fig 29.

Paper, of the very best quality--directions for the choice of which
have been already given.

A Screen of Yellow Glass.

Camels' or Badgers' hair Brushes:--A seperate one being kept for each
wash and solution, and which should be thoroughly cleansed immediately
after using in distilled water.  That used for the gallo-nitrate is
soon destroyed, owing to the rapid decomposition of that preparation.

A Graduated Measure.

Three or Four Flat Boards, to which the paper may be fixed with drawing
pins.

A Hot Water Drying Apparatus, for drying the paper will also be found
useful.

In preparing the Calotype paper, it is necessary to be extremely
careful, not only to prevent the daylight from impringing upon it, but
also to exclude, if possible, the strong glare of the candle or lamp.
This may be effected by using a shade of yellow glass or gauze, which
must be placed around the light.  Light passing through such a medium
will scarcely affect the sensitive compounds, the yellow glass
intercepting the chemical rays.

Preparation of the Iodized Paper.--Dissolve one hundred grains of
crystalized nitrate of silver in six ounces of distilled water, and
having fixed the paper to one of the boards, brush it over with a soft
brush on one side only with this solution, a mark being placed on that
side whereby it may be known.  When nearly dry dip it into a solution
of iodide of potassium, containing five hundred grains of that salt
dissolved in a pint of water.  When perfectly saturated with this
solution, it should be washed in distilled water, drained and allowed
to dry.  This is the first part of the process, and the paper so
prepared is called iodized paper.  It should be kept in a port-folio or
drawer until required: with this care it may be preserved for any
length of time without spoiling or undergoing any change.

Mr. Cundell finds a stronger solution of nitrate of silver preferable,
and employs thirty grains to the ounce of distilled water: he also adds
fifty grains of common salt to the iodide of potassium, which he
applies to the marked side of the paper only.  This is the first
process.

Preparation of the paper for the Camera.--The second process consists
in applying to the above a solution which has been named by Mr. Talbot
the "Gallo-Nitrate of Silver;" it is prepared in the following manner:
Dissolve one hundred grains of crystalized nitrate of silver in two
ounces of distilled water, to which is added two and two-third drachms
of strong acetic acid.  This solution should be kept in a bottle
carefully excluded from the light.  Now, make a solution of gallic acid
in cold distilled water:  the quantity dissolved is very small.  When
it is required to take a picture, the two liquids above described
should be mixed together in equal quantities; but as it speedily
undergoes decomposition, and will not keep good for many minutes, only
just sufficient for the time should be prepared, and that used without
delay.  It is also well not to make much of the gallic acid solution,
as it will not keep for more than a few days without spoiling.  A sheet
of the iodized paper should be washed over with a brush with this mixed
solution, care being taken that it be applied to the marked side.  This
operation must be performed by candle light.  Let the paper rest half a
minute, then dip it into one of the dishes of water, passing it beneath
the surface several times; it is now allowed to drain, and dried by
placing its marked side upwards, on the drying apparatus.  It is better
not to touch the surface with bibulous paper.  It is now highly
sensitive, and ready to receive the impression.  In practice it is
found better and more economical not to mix the nitrate of silver and
gallic acid, but only to brush the paper with the solution of the
nitrate.

Mr. Talbot has recently proposed some modifications in his method of
preparing the calotype paper.  The paper is first iodized in the usual
way; it is then washed over with a saturated solution of gallic acid in
distilled water and dried.  Thus prepared he calls it the io-gallic
paper: it will remain good for a considerable time if kept in a press
or portfolio.  When required for use, it is washed with a solution of
nitrate of silver (fifty grains to the ounce of distilled water), and
it is then fit for the camera.

Exposure in the Camera.--The calotype paper thus prepared possesses a
very high degree of sensibility when exposed to light, and we are thus
provided with a medium by which, with the aid of the photogenic camera,
we may effectually copy views from nature, figures, buildings, and even
take portraits from the shadows thrown on the paper by the living face.
The paper may be used somewhat damp.  The best plan for fixing it in
the camera is to place it between a piece of plate glass and some other
material with a flat surface, as a piece of smooth slate or an iron
plate, which latter, if made warm, renders the paper more sensitive,
and consequently the picture is obtained more rapidly.

Time of Exposure.--With regard to the time which should be allowed for
the paper to remain in the camera, no direct rules can be laid down;
this will depend altogether upon the nature of the object to be copied,
and the light which prevails.  All that can be said is, that the time
necessary for forming a good picture varies from thirty seconds to five
minutes, and it will be naturally the first object of the operator to
gain by experience this important knowledge.

Bringing Out the Picture.--The paper when taken from the camera, which
should be done so as to exclude every ray of light--and here the dark
slide of the camera plate holder becomes of great use--bears no
resemblance to the picture which in reality is formed.  The impression
is latent and invisible, and its existence would not be suspected by
any one not acquainted with the process by previous experiment.  The
method of bringing out the image is very simple.  It consists in
washing the paper with the gallo-nitrate of silver, prepared in the way
already described, and then warming it gently, being careful at the
same time not to let any portion become perfectly dry.  In a few
seconds the part of the paper upon which the light has acted will begin
to darken, and finally grow entirely black, while the other parts
retain their original color.  Even a weak impression may be brought out
by again washing the paper in the gallo-nitrate, and once more gently
warming it.  When the paper is quite black, as is generally the case,
it is a highly curious and beautiful phenomenon to witness the
commencement of the picture, first tracing out the stronger outlines,
and then gradually filling up all the numerous and complicated details.
The artist should watch the picture as it developes itself, and when in
his judgment it has attained the greatest degree of strength and
clearness, he shall stop further proceedings by washing it with the
fixing liquid.  Here again the mixed solution need not be used, but the
picture simply brushed over with the gallic acid.

The Fixing Process.--In order to fix the picture thus obtained, first
dip it into water; then partly dry it with bibulous paper, and wash it
with a solution of bromide of potassium--containing one hundred grains
of that salt dissolved in eight or ten ounces of distilled water.  The
picture is again washed with distilled water, and then finally dried.
Instead of bromide of potassium, a solution of hyposulphite of soda, as
before directed, may be used with equal advantage.

The original calotype picture, like the photographic one described in
the last chapter, is negative, that is to say, it has its lights and
shades reversed, giving the whole an appearance not conformable to
nature.  But it is easy from this picture to obtain another which shall
be conformable to nature; viz., in which the lights shall be
represented by lights, and the shades by shades.  It is only necessary
to take a sheet of photographic paper (the bromide paper is the best),
and place it in contact with a calotype picture previously rendered
transparent by wax or oil as before directed.  Fix it in the frame,
Fig. 29, expose it in the sunshine for a short time, and an image or
copy will be formed on the photogenic paper.  The calotype paper itself
may be used to take the second, or positive, picture, but this Mr.
Talbot does not recommend, for although it takes a much longer time to
take a copy on the photogenic paper, yet the tints of such copy are
generally more harmonious and agreeable.  After a calotype picture has
furnished a number of copies it sometimes grows faint, and the
subsequent copies are inferior.  This may be prevented by means of a
process which revives the strength of the calotype pictures.  In order
to do this, it is only necessary to wash them by candlelight with
gallo-nitrate of silver, and then warm them.  This causes all the
shades of the picture to darken considerably, while the white parts are
unaffected.  After this the picture is of course to be fixed a second
time.  It will then yield a second series of copies, and, in this way,
a great number may frequently be made.

The calotype pictures when prepared as we have stated, possess a
yellowish tint, which impedes the process of taking copies from them.
In order to remedy this defect, Mr. Talbot has devised the following
method.  The calotype picture is plunged into a solution consisting of
hyposulphite of soda dissolved in about ten times its weight of water,
and heated nearly to the boiling point.  The picture should remain in
about ten minutes; it must then be removed, washed and dried.  By this
process the picture is rendered more transparent, and its lights become
whiter.  It is also rendered exceedingly permanent.  After this process
the picture may be waxed, and thus its transparency increased.  This
process is applicable to all photographic papers prepared with
solutions of silver.

Having thus fully, and it is hoped clearly, considered the process, it
may be necessary before dismissing the calotype from notice, to add one
or two remarks from the observations and labors of some who have
experimented in this art.  Dr. Ryan in his lectures before the Royal
Polytechnic Institution, has observed, that in the iodizing process the
sensitiveness of the paper is materially injured by keeping it too long
in the solution of iodide of potassium, owing to the newly formed
iodide of silver being so exceedingly solvable in excess of iodide of
potassium as in a few minutes to be completely removed.  The paper
should be dipped in the solution and instantly removed.  There is
another point, too, in the preparation of the iodized paper in which
suggestions for a slight deviation from Mr. Talbot's plan have been
made.  In the first instance, it is recommended that the paper be
brushed over with the iodide of potassium, instead of the nitrate of
silver, transposing, in fact, the application of the first two
solutions.  The paper, having been brushed over with the iodide of
potassium in solution, is washed in distilled water and dried.  It is
then brushed over with nitrate of silver, and after drying is dipped
for, a moment in a fresh solution of iodide of potassium of only
one-fourth the strength of the first, that is to say, one hundred and
twenty-five grains of the salt to a pint of water.  After this it is
again washed and dried.  The advantage derived from this method, is a
more sensitive paper, and a more even distribution of the compounds
over the surface.

Another deviation from Mr. Talbot's method has been suggested, as
follows:

Brush the paper over with a solution of one hundred grains of nitrate
of silver to an ounce of water.  When nearly, but not quite, dry, dip
it into a solution of twenty-five grains of iodide of potassium to one
ounce of distilled water, drain it, wash it in distilled water and
again drain it.  Now brush it over with aceto-nitrate of silver, made
by dissolving fifty grains of nitrate of silver in one ounce of
distilled water, to which is added one sixth of its volume of strong
acetic acid.  Dry it with bibulous paper, and it is ready for receiving
the image.  When the impression has been received, which will require
from one to five minutes according to the state of the weather, it must
be washed with a saturated solution of gallic acid to which a few drops
of the aceto-nitrate of silver, made as above, have been added.  The
image will thus be gradually brought out, and may be fixed with
hyposulphite of soda.  To obtain the positive picture, paper must be
used brushed over with an ammonio-nitrate of silver, made thus: forty
grains of nitrate of silver is to be dissolved in one ounce of
distilled water, and liquid ammonia cautiously added till it
re-dissolves the precipitate.

A pleasing effect may be given to calotype, or indeed to all
photographic pictures, by waxing them at the back, and mounting them on
white paper, or if colored paper be used, various beautiful tones of
color are produced.

POSITIVE CALOTYPE.

At a meeting of the British Association, Professor Grove described a
process by which positive calotype pictures could be directly obtained;
and thus the necessity to transfer by which the imperfections of the
paper are shown, and which is moreover a troublesome and tedious
process, is avoided.  As light favors most chemical actions, Mr. Grove
was led to believe that a paper darkened by the sun (which darkening is
supposed to result from the precipitation of silver) might be bleached
by using a solvent which would not attack the silver in the dark, but
would do so in the light.  The plan found to be the most successful is
as follows: ordinary calotype paper is darkened till it assumes a deep
brown color, almost amounting to black; it is then redipped into the
ordinary solution of iodide of potassium, and dried.  When required for
use it is drawn over dilute nitric acid--one part acid to two and a
half parts water.  In this state, those parts exposed to the light are
rapidly bleached, while the parts not exposed remain unchanged.  It is
fixed by washing in water, and subsequently in hyposulphite of soda, or
bromide of potassium.

Mr. Grove also describes a process for converting a negative calotype
into a positive one, which promises, when carried out, to be of great
utility.

Let an ordinary calotype image or portrait be taken in the camera, and
developed by gallic acid; then drawn over iodide of potassium and
dilute nitric acid and exposed to full sunshine; while bleaching the
dark parts, the light is redarkening the newly precipitated iodide in
the lighter portions and thus the negative picture is converted into a
positive one.

The calotype process has been applied to the art of printing, in
England, but it possesses no advantages whatever over the method, with
type, now so gloriously brought to perfection; and I can hardly think
it will ever be made of any utility.  For the benefit of the curious,
however, I will give Mr. Talbot's method.

Some pages of letter-press are taken printed on one side only; and
waxed, to render them more transparent; the letters are then cut out
and sorted.  To compose a new page lines are ruled on a sheet of white
paper, and the words are formed by fixing the seperate letters in their
proper order.  The page being ready, a negative photograph is produced
from it, from which the requisite number of positive photogenic copies
may be obtained.

Another method, which requires the use of the camera, consists in
employing large letters painted on rectangular pieces of wood, colored
white.  These are arranged in lines on a tablet or board, by slipping
them into grooves which keep them steady and upright, thus forming a
page on an enlarged scale.  It is now placed before a camera, and a
reduced image of it of the required size is thrown upon the sensitive
paper.  The adjustments must be kept invariable, so that the
consecutive pages may not vary from one another in the size of the
type.  Mr. Talbot has patented his process, but what benefit he expects
to derive from it, I am at a loss to determine.

Enlarged copies of calotype or Daguerreotype portraits may be obtained
by throwing magnified images of them, by means of lenses, upon calotype
paper.

THE CHRYSOTYPE.

A modification of Mr. Talbot's process, to which the name of Chrysotype
was given by its discoverer, Sir John Herschel, was communicated in
June 1843 to the Royal Society, by that distinguished philosopher.
This modification would appear to unite the simplicity of photography
with all the distinctness and clearness of calotype.  This preparation
is as follows.

The paper is to be washed in a solution of ammonio-citrate of iron; it
must then be dried, and subsequently brushed over with a solution of
the ferro-sesquicyanuret of potassium.  This paper, when dried in a
perfectly dark room, is ready for use in the same manner as if
otherwise prepared, the image being subsequently brought out by any
neutral solution of gold.  Such was the first declaration of his
discovery, but he has since found that a neutral solution of silver is
equally useful in bringing out the picture.  Photographic pictures
taken on this paper are distinguished by a clearness of outline foreign
to all other methods.



CHAP. X.

CYANOTYPE--ENERGIATYPE--CHROMATYPE--ANTHOTYPE--AMPHITYPE AND "CRAYON
DAGUERREOTYPE."


The several processes enumerated at the head of this chapter, are all
discoveries of English philosophers, with the exception of the third
and last named.  Anthotype was first attempted by M. Ponton a French
savan, although it was reserved to Mr. Hunt to bring the process to its
present state.  The "Crayon Daguerreotype" is an improvement made by J.
A Whipple, Esq., of Boston.


I. CYANOTYPE.

So called from the circumstance of cyanogen in its combinations with
iron performing a leading part in the process.  It was discovered by
Sir John Herschel.  The process is a simple one, and the resulting
pictures are blue.

Brush the paper over with a solution of the ammonio-citrate of iron.
This solution should be sufficiently strong to resemble sherry wine in
color.  Expose the paper in the usual way, and pass over it very
sparingly and evenly a wash of the common yellow ferro-cyanate of
potass.  As soon as the liquid is applied, the negative picture
vanishes, and is replaced by a positive one, of a violet blue color, on
a greenish yellow ground, which at a certain time possesses a high
degree of sharpness, and singular beauty of tint.

A curious process was discovered by Sir John Herschel, by which dormant
pictures are produced capable of developement by the breath, or by
keeping in a moist atmosphere.  It is as follows.

If nitrate of silver, specific gravity 1.200 be added to ferro-tartaric
acid, specific gravity 1.023, a precipitate falls, which is in a great
measure redissolved by a gentle heat, leaving a black sediment, which,
being cleared by subsidence, a liquid of a pale yellow color is
obtained, in which the further addition of the nitrate causes no
turbidness.  When the total quantity of the nitrated solution added
amounts to about half the bulk of the ferro-tartaric acid, it is
enough.  The liquid so prepared does not alter if kept in the dark.
Spread on paper, and exposed wet to the sunshine (partly shaded) for a
few seconds, no impression seems to be made, but by degrees, although
withdrawn from the action of light, it developes itself spontaneously,
and at length becomes very intense.  But if the paper be thoroughly
dried in the dark, (in which state it is of a very pale greenish yellow
color,) it possesses the singular property of receiving a dormant or
invisible picture, to produce which from thirty to sixty seconds'
exposure to sunshine is requisite.  It should not be exposed too long,
as not only is the ultimate effect less striking, but a picture begins
to be visibly produced, which darkens spontaneously after it is
withdrawn.  But if the exposure be discontinued before this effect
comes on, an invisible impression is the result, to develope which all
that is necessary is to breathe upon it, when it immediately appears,
and very speedily acquires an extraordinary intensity and sharpness, as
if by magic.  Instead of the breath, it may be subject to the regular
action of aqueous vapor, by laying it in a blotting paper book, of
which some of the outer leaves on both sides have been dampened, or by
holding over warm water.


II. ENERGIATYPE.

Under this title a process has been brought forward by Mr. Hunt.  It
consists of the application of a solution of succinic acid to paper,
which is subsequently washed over with nitrate of silver.  The image is
then to be taken either in the camera or otherwise, as required, and is
brought out by the application of the sulphate of iron in solution.
Although this process has not come into general use, its exact
description may be interesting to the general reader, and we therefore
subjoin it.

The solution with which the paper is first washed is to be prepared as
follows:  succinic acid, two drachms; common salt, five grains;
mucilage of gum arabic, half a fluid drachm; distilled water, one fluid
drachm and a half.  When the paper is nearly dry, it is to be brushed
over with a solution of nitrate of silver, containing a drachm of the
salt, to an ounce of distilled water.  It is now ready for exposure in
the camera.  To bring out the dormant picture it is necessary to wash
it with a mixture of a drachm of concentrated solution of the green
sulphate of iron and two drachms and a half of mucilage of gum arabic.

Subsequently, however, it has been found that the sulphate of iron
produces upon all the salts of silver effects quite as beautiful as in
the succinate.  On the iodide, bromide, acetate, and benzoate, the
effects are far more pleasing and striking.  When pictures are
produced, or the dormant camera image brought out, by the agency of
sulphate of iron, it is remarkable how rapidly the effect takes place.
Engravings can be thus copied almost instantaneously, and camera views
obtained in one or two minutes on almost any preparation of silver.
The common sulphate of copper solution has the same property.


III. CHROMATYPE.

Many efforts have been made to render chromatic acid an active agent in
the production of photographs.  M. Ponton used a paper saturated with
bichromate of potash, and this was one of the earliest photogenic
processes.  M. Becquerel improved upon this process by sizing the paper
with starch previous to the application of the bichromate of potash
solution, which enabled him to convert the negative picture into a
positive one, by the use of a solution of iodine, which combined with
that portion of the starch on which the light had not acted.  But by
neither of these processes could clear and distinct pictures be formed.
Mr. Hunt has, however, discovered a process which is so exceedingly
simple, and the resulting pictures of so pleasing a character, that,
although it is not sufficiently sensitive for use in the camera, it
will be found of the greatest value for copying botanical specimens,
engravings, or the like.

The paper to be prepared is washed over with a solution of sulphate of
copper--about one drachm to an ounce of water--and partially dried; it
is then washed with a moderately strong solution of bichromate of
potash, and dried at a little distance from the fire.  Paper thus
prepared may be kept any length of time, in a portfolio, and are always
ready for use.

When exposed to the sunshine for a time, varying with the intensity of
the light, from five to fifteen or twenty minutes, the result is
generally a negative picture.  It is now to be washed over with a
solution of nitrate of silver, which immediately produces a very
beautiful deep orange picture upon a light dim colored, or sometimes
perfectly white ground.  This picture must be quickly fixed, by being
washed in pure water, and dried.  With regard to the strength of the
solutions, it is a remarkable fact, that, if saturated solutions be
employed, a negative picture is first produced, but if the solutions be
three or four times their bulk of water, the first action of the sun's
rays darkens the picture, and then a very bleaching effect follows,
giving an exceedingly faint positive picture, which is brought out with
great delicacy by the silver solution.

It is necessary that pure water should be used for the fixing, as the
presence of any muriate damages the picture, and here arises another
pleasing variation of the Chromatype.  If the positive picture be
placed in a very weak solution of common salt the image slowly fades
out, leaving a faint negative outline.  If it now be removed from the
saline solution, dried, and again exposed to sunshine, a positive
picture of a lilac color will be produced by a few minutes exposure.
Several other of the chromates may be used in this process, but none is
so successful as the chromate of copper.


IV. ANTHOTYPE.

The expressed juice, alcoholic, or watery infusion of flowers, or
vegetable substances, may be made the media of photogenic action.  This
fact was first discovered by Sir John Herschel.  We have already given
a few examples of this in the third chapter.

Certain precautions are necessary in extracting the coloring matter of
flowers.  The petals of fresh flowers are carefully selected, and
crushed to a pulp in a marble mortar, either alone or with the addition
of a little alcohol, and the juice expressed by squeezing the pulp in a
clean linen or cotton cloth.  It is then to be spread upon paper with a
flat brush, and dried in the air without artificial heat.  If alcohol
be not added, the application on paper must be performed immediately,
as the air (even in a few minutes), irrecoverably changes or destroys
their color.  If alcohol be present this change is much retarded, and
in some cases is entirely prevented.

Most flowers give out their coloring matter to alcohol or water.  Some,
however, refuse to do so, and require the addition of alkalies, others
of acid, &c. Alcohol has, however, been found to enfeeble, and in many
cases to discharge altogether these colors; but they are, in most
cases, restored upon drying, when spread over paper.  Papers tinged
with vegetable colors must always be kept in the dark, and perfectly
dry.

The color of a flower is by no means always, or usually, that which its
expressed juice imparts to white paper.  Sir John Herschel attributes
these changes to the escape of carbonic acid in some cases; to a
chemical alteration, depending upon the absorption of oxygen, in
others; and again in others, especially where the expressed juice
coagulates on standing, to a loss of vitality, or disorganization of
the molecules.  To secure an eveness of tint on paper, the following
manipulation is recommended:--The paper should be moistened on the back
by sponging and blotting off.  It should then be pinned on a board, the
moist side downwards, so that two of its edges (suppose the right-hand
and lower ones) shall project a little beyond those of the board.  The
board then being inclined twenty or thirty degrees to the horizon, the
alcoholic tincture (mixed with a very little water, if the petals
themselves be not very juicy) is to be applied with a brush in strokes
from left to right, taking care not to go over the edges which rest on
the board; but to pass clearly over those that project; and observing
also to carry the tint from below upwards by quick sweeping strokes,
leaving no dry spaces between them, but keeping up a continuity of wet
spaces.  When all is wet, cross them by another set of strokes from
above downwards, so managing the brush as to leave no floating liquid
on the paper.  It must then be dried as quickly as possible over a
stove, or in a warm current of air, avoiding, however, such heat as may
injure the tint.

In addition to the flowers already mentioned in my third chapter, the
following are among those experimented upon and found to give tolerable
good photographic sensitives.  I can only enumerate them, referring the
student, for any further information he may desire on the subject, to
Mr. Hunt's work; although what I have said above is sufficient for all
practical purposes; and any one, with the ambition, can readily
experiment upon them, without further research, on any other flower he
may choose.

Viola Odorata--or sweet sented violet, yields to alcohol a rich blue
color, which it imparts in high perfection to paper

Senecio Splendens--or double purple groundsel, yields a beautiful color
to paper.

The leaves of the laurel, common cabbage, and the grasses, are found
sufficiently sensitive.

Common Merrigold yields an invaluable faecula, which appears identical
with that produced by the Wall-flower, and Cochorus japonica mentioned
before, and is very sensitive, but photographs procured upon it cannot
be preserved, the color is so fugitive.

From an examination of the researches of Sir John Herschel on the
coloring matter of plants, it will be seen that the action of the sun's
rays is to destroy the color, effecting a sort of chromatic analysis,
in which two distinct elements of color are separated, by destroying
the one and leaving the other outstanding.  The action is confined
within the visible spectrum, and thus a broad distinction is exhibited
between the action of the sun's rays on vegetable juices and on
argentine compounds, the latter being most sensibly affected by the
invisible rays beyond the violet.

It may also be observed, that the rays effective in destroying a given
tint, are in a great many cases, those whose union produces a color
complementary to the tint destroyed, or, at least, one belonging to
that class of colors to which such complementary tint may be preferred.
For instance, yellows tending towards orange are destroyed with more
energy by the blue rays; blues by the red, orange and yellow rays;
purples and pinks by yellow and green rays.


V. AMPHITYPE.

This process is a discovery of Sir John Herschel and receives its name
from the fact that both negative and positive photographs can be
produced by one process.  The positive pictures obtained by it have a
perfect resemblance to impressions of engravings with common printer's
ink.  The process, although not yet fully carried out, promises to be
of vast utility.

Paper proper for producing an amphitype picture may be prepared either
with the ferro-tartrate or the ferro-citrate of the protoxide, or the
peroxide of mercury, or of the protoxide of lead, by using creams of
these salts, or by successive applications of the nitrates of the
respective oxides, singly or in mixture, to the paper, alternating with
solutions of the ammonia-tartrate or the ammonia-citrate of iron, the
latter solution being last applied, and in more or less excess.  I
purposely avoid stating proportions, as I have not yet been able to fix
upon any which certainly succeed.  Paper so prepared and dried takes a
negative picture, in a time varying from half an hour to five or six
hours, according to the intensity of the light; and the impression
produced varies in apparent force from a faint and hardly perceptible
picture to one of the highest conceivable fulness and richness both of
tint and detail, the color being in this case a superb velvety brown.
This extreme richness of effect is not produced unless lead be present,
either in the ingredients used, or in the paper itself.  It is not, as
I originally supposed, due to the presence of free tartaric acid.  The
pictures in this state are not permanent.  They fade in the dark,
though with very different degrees of rapidity, some (especially if
free tartaric or citric acid be present) in a few days, while others
remain for weeks unimpaired, and require whole years for their total
obliteration.  But though entirely faded out in appearance, the picture
is only rendered dormant, and may be restored, changing its character
from negative to positive, and its colors from brown to black, (in the
shadows), by the following process:--A bath being prepared by pouring a
small quantity of solution of pernitrate of mercury into a large
quantity of water, and letting the subnitrated precipitates subside,
the picture may be immersed in it, (carefully and repeatedly clearing
off all air bubbles,) and allowed to remain till the picture (if any
where visible,) is entirely destroyed; or if faded, till it is judged
sufficient from previous experience; a term which is often marked by
the appearance of a feeble positive picture, of a bright yellow hue, on
the pale yellow ground of the paper.  A long time (several weeks) is
often required for this, but heat accelerates the action, and it is
often completed in a few hours.  In this state the picture is to be
very thoroughly rinsed and soaked in pure warm water, and then dried.
It is then to be well ironed with a smooth iron, heated so as barely
not to injure the paper, placing it, for greater security against
scorching, between clean smooth paper.  If then the process have been
successful, a perfectly black positive picture is at once developed.
At first it most commonly happens that the whole picture is sooty or
dingy to such a degree that it is condemned as spoiled, but on keeping
it between the leaves of a book, especially in a moist atmosphere, by
extremely slow degrees this dinginess disappears, and the picture
disengages itself with continually increasing sharpness and clearness,
and acquires the exact effect of a copper-plate engraving on a paper
more or less tinted with a pale yellow.

I ought to observe, that the best and most uniform specimens which I
have procured have been on paper previously washed with certain
preparations of uric acid, which is a very remarkable and powerful
photographic element.  The intensity of the original negative picture
is no criterion of what may be expected in the positive.  It is from
the production by one and the same action of light, of either a
positive or negative picture according to the subsequent manipulations,
that I have designated the process, thus generally sketched out, by the
term Amphitype,--a name suggested by Mr. Talbot, to whom I communicated
this singular result; and to this process or class of processes (which
I cannot doubt when pursued will lead to some very beautiful results,)
I propose to restrict the name in question, though it applies even more
appropriately to the following exceedingly curious and remarkable one,
in which silver is concerned:

At the last meeting I announced a mode of producing, by means of a
solution of silver, in conjunction with ferro-tartaric acid, a dormant
picture brought into a forcible negative impression by the breath or
moist air.  (See Cyanotype.) The solution then described, and which had
at that time been prepared some weeks, I may here incidentally remark,
has retained its limpidity and photogenic properties, quite unimpaired
during the whole year since elapsed, and is now as sensitive as
ever,--a property of no small value.  Now, when a picture (for example
an impression from an engraving) is taken on paper washed with this
solution, it shows no sign of a picture on its back, whether that on
its face is developed or not; but if, while the actinic influence is
still fresh upon the face, (i.e., as soon as it is removed from the
light), the back be exposed for a very few seconds to the sunshine, and
then removed to a gloomy place, a positive picture, the exact
complement of the negative one on the other side, though wanting of
course in sharpness if the paper be thick, slowly and gradually makes
its appearance there, and in half an hour or an hour acquires a
considerable intensity.  I ought to mention that the "ferro-tartaric
acid" in question is prepared by precipitating the ferro-tartrate of
ammonia (ammonia-tartrate of iron) by acetate of lead, and decomposing
the precipitate by dilute sulphuric acid.  When lead is used in the
preparation of Amphitype paper, the parts upon which the light has
acted are found to be in a very high degree rendered water proof.--Sir
J. Herschel.

This process is a new invention of our countryman, J. A. Whipple, Esq.,
of Boston, and has been patented by M. A. Root, Esq., of Philadelphia.
It will be seen, however, from the previous pages of my work that Mr.
Root is mistaken in regard to his being the first improvement patented
in this country, although it is unquestionably the first by an
American.  Of this improvement Mr. Root says:


VI. "CRAYON DAGUERREOTYPE."

"The improvement to which you refer is denominated "The Crayon
Daguerreotype."  This invention made by Mr. J. A. Whipple, is the only
improvement in Daguerreotyping, I believe, for which Letters Patent for
the United States were ever issued.  The pictures produced by this
process--which is of the simplest description imaginable--have the
appearance and effect of very fine "Crayon Drawings," from which the
improvement takes its name.  Some of our most distinguished artists
have given it their unqualified admiration.  Among them, our Mezzotinto
Engravers, especially John Sartain, Esq., who, from his rich
embellishments to most of the leading Magazines and Annuals of the
country, as well as from the celebrity of the superb Magazine which
bears his name, is so well known and so well qualified to judge of its
merits.  As an auxiliary to the artist, in furnishing heads to the
Magazines, or other works, it is invaluable; the great object which it
accomplishes being to give a finer effect and more distinct expression
to all the features--the whole power of the instrument being directed
to, and confined to the head."

"The late hour at which this subject has been brought to our notice
prevents so full a description as we would otherwise have been glad to
furnish.  The New England States have been disposed of; negotiations
for any of the others can be made through M. A. Root, 140 Chestnut
street, Philadelphia."

"A series of beautiful portraits are about being prepared by the
"Crayton Process" for the express purpose of being placed on the
exhibition at the "Art Union," when amateurs, artists, and the public
generally will have an opportunity of witnessing its effect.  We are
especially gratified with this striking improvement, from the
advantages which it promises to the Daguerrean art."

"It is admirably designed to excite a new interest on the subject
through the community, and in this way--and from its tendency to render
the art more generally useful, and to elevate and distinguish it--to
make it to all a matter of more general importance."

  "Yours respectfully,
  "M. A. ROOT."

In our second edition, we hope--with Mr. Root's permission--to lay the
whole process before the public, although our artists must bear in mind
that Mr. Root's patent secures to him the exclusive right of its
application.



CHAP. XI.

ON THE PROBABILITY OF PRODUCING COLORED PICTURES BY THE SOLAR
RADIATIONS--PHOTOGRAPHIC DEVIATIONS--LUNAR PICTURES--DRUMMOND LIGHT.


Having before noticed the fact that some advances had been made towards
taking Daguerreotypes in color, by means of solar rays, and expressed
the hope that the day was not far distant when this might be
accomplished, I here subjoin Mr. Hunt's remarks on this subject.

Mr. Biot, in 1840, speaking of Mr. Fox Talbot's beautiful calotype
pictures, considers as an illusion "the hope to reconcile, not only the
intensity but the tints of the chemical impressions produced by
radiations, with the colors of the object from which these radiations
emanated." It is true that three years have passed away, and we have
not yet produced colored images; yet I am not inclined to consider the
hope as entirely illusive.

It must be remembered that the color of bodies depends entirely upon
the arrangement of their molecules.  We have numerous very beautiful
experiments in proof of this.  The bi-niodide of mercury is a fine
scarlet when precipitated.  If this precipitate is heated between
plates of glass, it is converted into crystals of a fine sulphur
yellow, which remain of that color if undisturbed, but which becomes
very speedily scarlet if touched with any pointed instrument.  This
very curious optical phenomena has been investigated by Mr. Talbot and
by Mr. Warrington.  Perfectly dry sulphate of copper is white; the
slightest moisture turns it blue.  Muriate of cobalt is of a pale pink
color; a very slight heat, by removing a little moisture, changes it to
a green.  These are a few instances selected from many which might be
given.

If we receive a prismatic spectrum on some papers, we have evidence
that the molecular or chemical disturbance bears some relation to the
color of each ray, or, in other words, that colored light so modifies
the action of ENERGIA that the impression it makes is in proportion to
the color of the light it accompanies, and hence there results a
molecular arrangement capable of reflecting colors differently.  Some
instances have been given in which the rays impressed correspond with
the colors of the luminous rays in a very remarkable manner.* One of
the most decided cases is that of the paper prepared with the fluoride
of soda and nitrate of silver.  Sir John Herschel was, however, the
first to obtain any good specimens of photographically impressed
prismatic colorations.

* See Mr. Hunt's "Researches on Light."

It was noticed by Daguerre that a red house gave a reddish image on his
iodized silver plate in the camera obscura; and Mr. Talbot observed,
very early in his researches, that the red of a colored print was
copied of a red color, on paper spread with the chloride of silver.**

** In 1842, I had shown me a picture of a house in the Bowery, which
had been repaired a few days previous, and in the wall a red brick
left.  This brick was brought out on the Daguerreotype plate of
precisely the same color as the brick itself.  The same artist also
exhibited to me, the full length portrait of a gentleman who were a
pair of pantaloons having a blue striped figure.  This blue stripe was
fully brought out, of the same color, in the picture.--AMER. ED.

"In 1840 I communicated to Sir John Herschel some very curious results
obtained by the use of colored media, which he did me the honor of
publishing in one of his memoirs on the subject from which I again copy
it."

"A paper prepared with muriate of barytes and nitrate of silver,
allowed to darken whilst wet in the sunshine to a chocolate color, was
placed under a frame containing a red, a yellow, a green, and a blue
glass.  After a week's exposure to diffused light, it became red under
the red glass, a dirty yellow under the yellow glass, a dark green
under the green, and a light olive under the blue.

"The above paper washed with a solution of salt of iodine, is very
sensitive to light, and gives a beautiful picture.  A picture thus
taken was placed beneath the above glasses, and another beneath four
flat bottles containing colored fluids.  In a few days, under the red
glass and fluid, the picture became a dark blue, under the yellow a
light blue, under the green it remained unchanged, whilst under the
blue it became a rose red, which in about three weeks changed into
green.  Many other experiments of a similar nature have been tried
since that time with like results.

"In the summer of 1843, when engaged in some experiments on papers
prepared according to the principles of Mr. Talbot's calotype, I had
placed in a camera obscura a paper prepared with the bromide of silver
and gallic acid.  The camera embraced a picture of a clear blue sky,
stucco-fronted houses, and a green field.  The paper was unavoidably
exposed for a longer period than was intended--about fifteen
minutes,--a very beautiful picture was impressed, which, when held
between the eye and the light, exhibited a curious order of colors.
The sky was of a crimson hue, the houses of a slaty blue, and the green
fields of a brick red tint.  Surely these results appear to encourage
the hope, that we may eventually arrive at a process by which external
nature may be made to impress its images on prepared surfaces, in all
the beauty of their native coloration."


PHOTOGRAPHIC DEVIATIONS.

Before taking leave of the subject of photogenic drawing, I must
mention one or two facts, which may be of essential service to
operators.

It has been observed by Daguerre, and others, in Europe, and probably
by some of our own artists, that the sun two hours after it has passed
the meridian, is much less effective in the photographic process, than
it is two hours previous to its having reached that point.  This may
depend upon an absorptive power of the air, which may reasonably be
supposed to be more charged with vapor two hours before noon.  The fuse
of the hygrometer may possibly establish the truth or falsity of this
supposition.  The fact, however, of a better result being produced
before noon being established, persons wishing their portraits taken,
will see the advantage of obtaining an early sitting, if they wish good
pictures.  On the other hand, if the supposition above mentioned prove
true, a too early sitting must be avoided.

If we take a considerable thickness of a dense purple fluid, as, for
instance, a solution of the ammonia-sulphate of copper, we shall find
that the quantity of light is considerably diminished, at least
four-fifths of the luminous rays being absorbed, while the chemical
rays permeate it with the greatest facility, and sensitive preparations
are affected by its influence, notwithstanding the deficiency of light,
nearly as powerfully as if exposed to the undecomposed sunbeams.

It was first imagined that under the brilliant sun and clear skies of
the south, photographic pictures would be produced with much greater
quickness than they could be in the atmosphere of Paris.  It is found,
however, that a much longer time is required.  Even in the clear and
beautiful light of the higher Alps, it has been proved that the
production of the photographic picture requires many minutes more, even
with the most sensitive preparations, than it does in London.  It has
also been found that under the brilliant light of Mexico, twenty
minutes, and half an hour, are required to produce effects which in
England would occupy but a minute; and travellers engaged in copying
the antiquities of Yucatan have on several occasions abandoned the use
of the photographic camera, and taken to their sketch books.  Dr.
Draper* has observed a similar difference between the chemical action
of light in New York and Virginia.  This can be only explained by the
supposition that the intensity of the light and heat of these climes
interferes with the action of the ENERGIC rays on those sensitive
preparations which are employed.

* I would here take occasion to remark that our country man, Dr.
Draper, is very frequently quoted by Mr. Hunt in his "Researches."


LUNAR PICTURES--DRUMMOND LIGHT.

The Roman Astronomers state that they have procured Daguerreotype
impressions of the Nebula of the sword of Orion.  Signor Rondini has a
secret method of receiving photographic images on lithographic stone;
on such a prepared stone they have succeeded in impressing an image of
the Nebula and its stars; "and from that stone they have been enabled
to take impressions on paper, unlimited in number, of singular beauty,
and of perfect precision." Experiments have, however, proved that "no
heating power exists in the moon's rays, and that lunar light will not
act chemically upon the iduret of silver."

It was at one time supposed that terrestrial or artificial light
possessed no chemical rays, but this is incorrect--Mr. Brande
discovered that although the concentrated light of the moon, or the
light even of olefiant gas, however intense, had no effect on chloride
of silver, or on a mixture of chloride and hydrogen, yet the light
emitted by electerized charcoal blackens the salt.  At the Royal
Polytechnic Institution pictures have been taken by means of sensitive
paper acted upon by the Drummond Light; but it must of course be
distinctly understood, that they are inferior to those taken by the
light of the sun, or diffused daylight.

If our operators could manage to produce good pictures in this way they
would put money in their pockets, as many who cannot find time during
the day would resort to their rooms at night.  I throw out the hint in
hopes some one will make the experiment.

I have learned, since the above was written, that an operator in Boston
succeeded a short time since in procuring very good pictures by the aid
of the Drummond Light; but that the intensity of the light falling
directly upon the sitter's face caused great difficulty, and he
abandoned it.  This may, probably, be remedied by interposing a screen
of very thin tissue paper tinged slightly of a bluish color.



CHAP. XII.

ON COLORING DAGUERREOTYPES.


Nearly, if not quite all the various colors used in painting may be
made from the five primitive colors, black, white, blue, red and
yellow, but for the Daguerrean artist it would be the best policy to
obtain such as are required by their art already prepared.  In a
majority of cases, the following will be found sufficient, viz.

  Carmine.
  Prussian Blue.
  White.
  Chrome Yellow, Gamboge, Yellow Ochre; or all three.*
    *Gamboge is best for drapery; Ochre for the face.
  Light Red.
  Indigo.
  Burnt Sienna.
  Bistre, or Burnt Umber.

If, in coloring any part of a lady's or gentleman's apparel, it is
found necessary to produce other tints and shades, the following
combinations may be used:

Orange--Mix yellow with red, making it darker or lighter by using more
or less red.

Purple--This is made with Prussian blue, or indigo and red.  Carmine
and Prussian blue producing the richest color, which may be deepened in
the shadows by a slight addition of indigo or brown.

Greens--Prussian blue and gamboge makes a very fine green, which may be
varied to suit the taste of the sitter or operator, by larger portions
of either, or by adding white, burnt sienna, indigo, and red, as the
case may require.  These combinations, under different modifications,
give almost endless varieties of green.

Brown--May be made of different shades of umber, carmine and lamp-black.

Neutral tint--Is composed of indigo and lamp-black.

Crimson--Mix carmine and white, deepening the shaded parts of the
picture with additional carmine.

Flesh Color--The best representative of flesh color is light red,
brightened in the more glowing or warmer parts, with carmine, softened
off in the lighter portions with white, and shaded with purple and
burnt sienna.

Lead Color--Mix indigo and white in proportions to suit.

Scarlet--Carmine and light red.

For Jewelry cups of gold and silver preparations accompany each box for
Daguerreotypists, or may be procured separately.

The method of laying colors on Daguerreotypes is one of considerable
difficulty, inasmuch as they are used in the form of perfectly dry
impalpable powder.  The author of this little work is now
experimenting, in order, if possible, to discover some more easy,
artistic and unexceptionable method.  If successful, the result will be
published in a future edition.

The rules we shall give for coloring Daguerreotypes depends, and are
founded, upon those observed in miniature painting, and are intended
more as hints to Daguerrean artists, in hopes of leading them to
attempt improvements, than as instructions wholly to be observed.

The writer is confident that some compound or ingredient may yet be
discovered which, when mixed with the colors, will give a more
delicate, pleasing, and natural appearance to the picture than is
derived from the present mode of laying them on, which in his
estimation is more like plastering than coloring.

IN COLORING DAGUERREOTYPES, the principal shades of the head are to be
made with bistre, mixed with burnt sienna, touching some places with a
mixture of carmine and indigo.  The flesh tints are produced by the use
of light red, deepened towards the shaded parts with yellow ochre, blue
and carmine mixed with indigo, while the warmer, or more highly colored
parts have a slight excess of carmine or lake.  Color the shades about
the mouth and neck with yellow ochre, blue, and a very little carmine,
heightening the color of the lips with carmine and light red, letting
the light red predominate on the upper, and the carmine on the lower
lip; the shades in the corner of the mouth being touched slightly with
burnt sienna, mixed with carmine.

In coloring the eyes, the artist will of course be guided by nature,
observing a very delicate touch in laying on the colors, so as to
preserve as much transparency as possible.  A slight touch of
blue--ultramarine would be best if it would adhere to the Daguerreotype
plate--in the whites of the eye near the iris, will produce a good
effect.

In coloring the heads of men it will be necessary to use the darker
tints with more freedom, according to the complexion of the sitter.
For women, the warmer tints should predominate, and in order to give
that transparency so universal with the softer sex--and which gives so
much loveliness and beauty to the face--a little white may be
judiciously intermingled with the red tints about the lighter portions
of the face.

In taking a picture of a lady with light or auburn hair, by the
Daguerrean process, much of the beauty of the face is destroyed, on
account of the imperfect manner in which light conveys the image of
light objects to the spectrum of the camera.  This may be obviated in
some measure by proper coloring.  To do this, touch the shaded parts
with burnt sienna and bistre, filling up the lighter portions with
yellow ochre, delicate touches of burnt sienna, and in those parts
which naturally have a bluish tint, add very delicate touches of
purple--so delicate in fact as hardly to be perceived.  The roots of
the hair at the forehead should also be touched with blue, and the
eyebrows near the temples made of a pinkish tint.

The chin of a woman is nearly of the same color as the cheeks in the
most glowing parts.  In men it is stronger, and of a bluish tint, in
order to produce the effect given by the beard.

In portraits of women--the middle tints on the side of the light, which
are perceived on the bosom and arms, are made of a slight mixture of
ochre, blue and lake, (or carmine), to which add, on the shaded sides,
ochre, bistre and purple, the latter in the darker parts.  The tints of
the hands should be the same as the other parts of the flesh, the ends
of the fingers being a little pinkish and the nails of a violet hue.
If any portion of the fleshy parts is shaded by portions of the dress,
or by the position of the hand, this shade should be colored with umber
mixed with purple.

TO COLOR THE DRAPERY.--Violet Velvet--Use purple made of Prussian blue
and carmine, touching up the shaded parts with indigo blue.

Green Velvet--Mix Prussian blue and red-orpiment, shade with purple,
and touch up the lights with a little white.

Red Velvet--Mix a very little brown with carmine, shading with purple,
marking the lights in the strongest parts with pure carmine, and touch
the most brilliant slightly with white.

White Feathers--May be improved by delicately touching the shaded parts
with a little blue mixed with white.  White muslin, linen, lace, satin,
silk, etc., may also be colored in the same way, being careful not to
lay the color on too heavily.

FURS--Red Furs may be imitated by using light red and a little
masticot, shaded with umber.  Gray Furs--black and white mixed and
shaded with bistre.  Sable--white shaded lightly with yellow ochre.

These few directions are quite sufficient for the art, and it is quite
unnecessary for me to pursue the subject further.  I would, however,
remark that the Daguerreotypists would find it greatly to their
advantage to visit the studies of our best artists, our public
galleries of paintings, and statuary, and wherever else they can obtain
a sight of fine paintings, and study the various styles of coloring,
attitudes, folds of drapery and other points of the art.  In coloring
Daguerreotypes, artists will find the magnifying glass of much
advantage in detecting any imperfections in the plate or in the image,
which may be remedied by the brush.  In selecting brushes choose those
most susceptible of a fine point, which may be ascertained by wetting
them between the lips, or in a glass of water.



CHAP. XIII.

THE PHOTOGRAPHOMETER.


The last number (for March, 1849) of the London Art-Journal, gives the
following description of a recent improvement in Photographic
Manipulation, and as I am desirous of furnishing everything new in the
art, I stop the press to add it, entire, to my work.

"Since the photographic power of the solar rays bears no direct
relation to their luminous influence, it becomes a question of
considerable importance to those who practice the beautiful art of
photography, to have the means of readily measuring the ever changing
activity of this force.  Several plans more or less successful, have
been devised by Sir John Herschel, Messrs. Jordan, Shaw and Hunt.  The
instrument, however, which is now brought forward by Mr. Claudet, who
is well known as one of our most successful Daguerreotypists, appears
admirably suited to all those purposes which the practical man
requires.  The great difficulty which continually annoys the
photographic amateur and artist, is the determination of the
sensibility of each tablet employed, relatively to the amount of
radiation, luminous and chemical, with which he is working.  With the
photographometer of Mr. Claudet this is easily ascertained.  The
following woodcuts and concise description will sufficiently indicate
this useful and simple apparatus.

[Illustration: Fig. 30 (hipho_30.gif)]

"For an instrument of this kind it is important in the first place to
have a motion always uniform, without complicated or expensive
mechanism.  This is obtained by means founded upon the principle of the
fall of bodies sliding down an inclined plane.  The sensitive surface
is exposed to the light by the rapid and uniform passage of a metal
plate, A, B, (Fig. 31,) having openings of different length, which
follow a geometric progression.  It is evident that the exposure to
light will be the same for each experiment, because the plate furnished
with the proportional openings falls always with the same rapidity, the
height of the fall being constant, and the angle of the inclined plane
the same.  Each opening of this moveable plate allows the light to pass
during the same space of time, and the effect upon the sensitive
surface indicates exactly the intensity of the chemical rays.  The
rapidity of the fall may be augmented or diminished by altering the
inclination of the plane by means of a graduated arc, C, D, (Fig. 30,)
furnished with a screw, E, by which it may be fixed at any angle.  The
same result may be obtained by modifying the height of the fall or the
weight of the moveable plate.  The photogenic surface, whether it be
the Daguerreotype plate, the Talbotype paper, or any other preparation
sensitive to light, is placed near the bottom of the inclined plane, F.
It is covered by a thin plate of metal, pierced with circular holes,
which correspond to the openings of the moveable plate at the moment of
the passage of the latter, during which the sensitive surface receives
the light wherever the circular holes leave it exposed.

[Illustration: Fig. 31 (hipho_31.gif)]

"The part of the apparatus which contains the sensitive surface is an
independent frame, and it slides from a dark box into an opening on the
side of the inclined plane.

"A covering of black cloth impermeable to light is, attached to the
sides of the moveable plate, enveloping the whole inclined plane,
rolling freely over two rollers, R, R, placed the one at the upper and
the other at the lower part of the inclined plane.  This cloth prevents
the light striking the sensitive surface before and after the passage
of the moveable plate.

"It will be seen that this apparatus enables the experimentalist to
ascertain with great precision the exact length of time which is
required to produce a given amount of actinic change upon any sensitive
photographic surface, whether on metal or paper.  Although at present
some calculation is necessary to determine the difference between the
time which is necessary for exposure in direct radiation, and to the
action of the secondary radiations of the camera obscura; this is,
however, a very simple matter, and it appears to us exceedingly easy to
adapt an instrument of this description to the camera itself.

"By this instrument Mr. Claudet has already determined many very
important points.  Among others, he has proved that on the most
sensitive Daguerreotype plate an exposure of .0001 part of a second is
sufficient to produce a decided effect.

"Regarding photography as an auxiliary aid to the artist of no mean
value, we are pleased to record a description of an instrument which,
without being complicated, promises to be exceedingly useful.  In this
opinion we are not singular; at a recent meeting of the Photographic
Club, to which this instrument was exhibited, it was with much real
satisfaction that we learned that several of our most eminent artists
were now eager and most successful students in Photography.  The
beautiful productions of the more prominent members of this club
excited the admiration of all, particularly the copies of architectural
beauties, and small bits of landscape, by Messrs. Cundell and Owen.  We
think that now the artist sees the advantage he may derive from the aid
of science, that both will gain by the union."

I hope the above description will induce our townsman, Mr. Roach, to
successfully produce an instrument that will meet the wants of our
artists in that part of the Daguerrean process referred to.



FINIS.



INDEX.


  Accelerating Liquids.  65
  Amphitype.  116
  Anthotype.  113
  Apparatus. Daguerreotype.  43
     Calotype  97
     Photogenic  87
  Application of Photogenic Drawing.  95
  Applying the Sensitive.  64

  Bringing out the Picture.  71
  Bromine Box.  51
     Chloride of  68
     Roach's Tripple Compound of  67
     water.  65
  Bromide of Iodine.  67
     of Lime.  68
     Paper.  91
     of silver.  35
  Brushes.  88
  Buff Sticks.  60

  Calotype process.  97
     paper. Exposure in Camera of  100
     Pictures. Bringing out  ib.
        Fixing  101
  Camera. Description of the  43
     Stand.  49
     Woodbridge's  ib.
     Calotype.  50
     Voigtlander  45
  Chloride of Bromine.  68
     of Gold.  36
        to make a solution of  75
     of Iodine.  66
     of Silver.  31
  Chromatype.  112
  Chrysotype.  106
  Cleaning and Polishing the plate.  61
  Coating Boxes.  51
  Color Boxes.  53
  Colored Daguerreotypes on Copper.  77
  Coloring the Picture.  76
     Daguerreotypes.  129
  Concave Mirrors.  19
  Convex Mirrors  19
  Corchorus Japonica.  37
  Crayon Daguerreotypes.  120
  Cyanotype  109

  Daguerreotype Apparatus.  43
     Process.  61
     Plates.  62
  Daguerreotypes. Crayon  77
     on paper  81
  Dedication.  iii
  Definitions of terms used in optics,  15
  Different methods of preparing photogenic paper.  89
  Directions for use of Galvanic Battery.  58
  Distilled water  88
  Drummond light.  128
  Dry Sensitive.  68
  Drying apparatus.  72

  Effects of light on bodies  25
  Energiatype  111
  Etching Daguerreotypes.  83

  Fifth operation. Fixing the picture.  61
  First operation. Cleaning the plate  61
  Fluoric acid.  69
  Fourth operation-Bringing out the picture.  71
  Funnels.  53

  Galvanic Battery.  57
        Solution for use of  58
  Gilding stand.  53
     the picture.  74
  Gold. Chloride of  36
        To make solution of  75
     Hyposulphite; or Salt of  74
     Preparation of.  36
  Gurney's Sensitive.  67

  Head Rests.  57
  Hints and Suggestions.  39
  History of Photography.  3
  Hungarian Liquid.  69
  Hygrometers.  55
  Hyposulphite of Gold.  74
        of Soda.  28

  Instantaneous pictures by means of Galvanism.  77
  Introduction.  i
  Iodine, Dry  64
     Chloride of  66
     Bromide of  67
     Box.  51
  Iodide of silver.  32
  Ioduret of silver.  33
  Iodize the Plate. To  64
  Iodized Paper for Calotypes. To prepare  98
        To prepare for the Camera  ib.

  Lamps, Spirit  53
  Light. Theory on  14
     Motion of  16
     Reflection of  17
     Refraction of  20
     on bodies. Effects of  25
     Prismatic analysis of  22
  Lime, Bromide of  68
  Lunar Pictures.  127

  Mead's Accelerator.  68
  Mercury Bath  50

  Nitrate of Silver.  89

  Oxide of Silver.  29
  On coloring Daguerreotypes  129
  On the probability of Producing colored Photographs.  123

  Paper. blotting; or bibulous,  88
     Daguerreotypes.  81
     preparation of  89
     suitable for Photographs.  87
     Photogenic drawing on  ib
  Photographic principle, the  22
  Photographic process on paper.  92
        drawing. Application of  95
           To fix the  93
        deviations.  126
  Photographometer, The  135
  Plate Support.  59
     Blocks.  50
     Vice.  51
  Poppy, The Red  37
  Porcelain dishes.  59
  Positive Calotype  104
  Preface.  v
  Preparation of Iodized Paper.  98
        of Gold.  36
  Prismatic Spectrum.  22
        Analysis of Light.  ib

  Reflection of Light.  17
  Refraction of Light.  20
  Roach's Tripple Compound of Bromine.  67

  Sand Clock.  70
  Sealing paper. To make  77
  Second operation.  94
  Sensitive.  ib
  Silver. Bromide of  35
     Chloride of  31
     Iodide of  32
     Ioduret of  33
     Nitrate of  89
     Oxide of  28
     Solution of Chloride of  59
  Sixth operation.  74
  Soda Hyposulphite of  72
  Solar and Stellar Light.  21
  Still for purifying water,  54
  Submitting the Plate to the action of Light  69
  Synopsis of Mr. Hunt's Treatise on Light,  29

  Talbotype Camera.  50
  Theory on Light.  14
  Third operation.  69

  Wall Flower.  37





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