summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--.gitattributes3
-rw-r--r--167-0.txt4997
-rw-r--r--167-0.zipbin0 -> 98280 bytes
-rw-r--r--167-h.zipbin0 -> 283655 bytes
-rw-r--r--167-h/167-h.htm6195
-rw-r--r--167-h/images/fig1.gifbin0 -> 9928 bytes
-rw-r--r--167-h/images/fig10.gifbin0 -> 10620 bytes
-rw-r--r--167-h/images/fig11.gifbin0 -> 4937 bytes
-rw-r--r--167-h/images/fig12.gifbin0 -> 10751 bytes
-rw-r--r--167-h/images/fig13.gifbin0 -> 19332 bytes
-rw-r--r--167-h/images/fig2.gifbin0 -> 12111 bytes
-rw-r--r--167-h/images/fig3.gifbin0 -> 59902 bytes
-rw-r--r--167-h/images/fig4.gifbin0 -> 2831 bytes
-rw-r--r--167-h/images/fig5.gifbin0 -> 9393 bytes
-rw-r--r--167-h/images/fig8a.gifbin0 -> 3116 bytes
-rw-r--r--167-h/images/fig8b.gifbin0 -> 4417 bytes
-rw-r--r--167-h/images/fig9.gifbin0 -> 4408 bytes
-rw-r--r--167-h/images/titlepage.gifbin0 -> 29928 bytes
-rw-r--r--LICENSE.txt11
-rw-r--r--README.md2
-rw-r--r--old/167.txt5132
-rw-r--r--old/167.zipbin0 -> 98353 bytes
-rw-r--r--old/2008-07_167-h.zipbin0 -> 283498 bytes
-rw-r--r--old/amdag10.txt5099
-rw-r--r--old/amdag10.zipbin0 -> 104230 bytes
-rw-r--r--old/amdgf10.zipbin0 -> 181384 bytes
26 files changed, 21439 insertions, 0 deletions
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..6833f05
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,3 @@
+* text=auto
+*.txt text
+*.md text
diff --git a/167-0.txt b/167-0.txt
new file mode 100644
index 0000000..796e45b
--- /dev/null
+++ b/167-0.txt
@@ -0,0 +1,4997 @@
+The Project Gutenberg EBook of American Handbook of the Daguerrotype, by Samuel D. Humphrey
+
+This eBook is for the use of anyone anywhere in the United States and most
+other parts of the world at no cost and with almost no restrictions
+whatsoever. You may copy it, give it away or re-use it under the terms of
+the Project Gutenberg License included with this eBook or online at
+www.gutenberg.org. If you are not located in the United States, you'll have
+to check the laws of the country where you are located before using this ebook.
+
+Title: American Handbook of the Daguerrotype
+
+Author: Samuel D. Humphrey
+
+Release Date: September, 1994 [EBook #167]
+[Most recently updated: July 3, 2020]
+
+Language: English
+
+Character set encoding: UTF-8
+
+*** START OF THIS PROJECT GUTENBERG EBOOK AMERICAN HANDBOOK OF THE DAGUERROTYPE ***
+
+
+
+
+Produced by Gregory Walker, for the Digital Daguerreian Archive Project.
+
+[Illustration]
+
+This etext was created by Gregory Walker, Austin, Texas, for the
+Digital Daguerreian Archive Project.
+ Page numbers explicitly referred to in the text are marked at their
+ beginning by “[page ##]” on a separate line. I hope this etext
+ inspires a wider interest in the origins of photography and in the
+ modern practice of the Daguerreian Art.
+
+[Updater’s note: In this version, the above page numbering convention
+has been replaced by “{##}” sequences placed in line with the
+surrounding text.]
+
+AMERICAN HAND BOOK OF THE DAGUERREOTYPE
+
+GIVING THE MOST APPROVED AND CONVENIENT METHODS FOR PREPARING THE
+CHEMICALS, AND THE COMBINATIONS USED IN THE ART.
+
+CONTAINING THE DAGUERREOTYPE, ELECTROTYPE, AND VARIOUS OTHER PROCESSES
+EMPLOYED IN TAKING HELIOGRAPHIC IMPRESSIONS.
+
+BY S. D. HUMPHREY
+
+FIFTH EDITION
+
+NEW YORK: PUBLISHED BY S. D. HUMPHREY 37 LISPENARD STREET
+ 1858
+
+Entered, according to Act of Congress, in the year 1858, by S. D.
+HUMPHREY, In the Clerk’s Office of the District Court of the Southern
+District of New York.
+
+To J. GURNEY, WHOSE PROFESSIONAL SKILL, SCIENTIFIC ACCURACY, AND
+ENERGETIC PERSEVERANCE, HAVE WON FOR HIM UNIVERSAL ESTEEM, THIS WORK IS
+MOST RESPECTFULLY INSCRIBED.
+
+
+
+
+PREFACE.
+
+
+There is not an Amateur or practical Daguerreotypist, who has not felt
+the want of a manual—Hand Book, giving concise and reliable information
+for the processes, and preparations of the Agents employed in his
+practice.
+
+Since portraits by the Daguerreotype are at this time believed to be
+more durable than any other style of “Sun-drawing,” the author has hit
+upon the present as being an appropriate time for the introduction of
+the Fifth Edition of this work. The earlier edition having a long since
+been wholly; exhausted, the one now before you is presented.
+
+The endeavor has been to point out the readiest and most approved
+Methods of Operation, and condense in its pages; as much practical
+information as its limits will admit. An extended Preface is
+unnecessary, since the aim and scope of this work are sufficiently
+indicated by the title.
+
+S. D. HUMPHREY NEW YORK, 1858.
+
+
+
+
+CONTENTS
+
+
+CHAPTER I.
+
+Polishing the Daguerreotype Plate—Buffing the Plate—Coating the
+Plate—Exposure of the Plate in the Camera—Position Developing the
+Daguerreotype—Exposure to Mercury—Removing the Coating—Gilding or
+fixing the Image—Coloring Daguerreotype, . . . . . 18
+
+CHAPTER II.
+
+Coloring Back Grounds—Transparent ditto—Gilding Dissolvent—Solution for
+removing Specks—Solarized Impression—To Purify Water—Cleaning
+Mercury—Adhesive Paper—Black Stain for Apparatus—Sealing Wax for
+Bottles—Rouge—Rotten Stone—Potassa Solution—Hyposulphite
+Solution—Substitute for do.—Gilding Solution—Solution for increasing
+the Brilliancy of the Daguerreotype—Bleaching Solution;—Cold
+Gilding—Neutralizing Agents—Buff Dryer—Keeping Buffs in order—Cleaning
+Buckskins—Reflector for taking Views, . . . . 52
+
+CHAPTER III.
+
+Bromine and its Compounds—Iodine and its Compounds—Chlorine and its
+Compounds—Cyanide of Potassium—Hyposulphite of Soda—Hyphosulphite of
+Gold—Nitric Acid—Nitro-Muriatic Acid—Hydrochloric Acid—Hydrofluoric
+Acid—Sulphuric Acid—Accelerating Substances—Liquid Sensitives—Dry
+Sensitives, etc., etc., . . . . . 72
+
+CHAPTER IV.
+
+Light—Optics—Solar Spectrum—Decomposition of Light—Light, Heat, and
+Actinism—Blue Paper and Color for the Walls of the Operating
+Room—Proportions of Light, Heat and Actinism composing a
+Sunbeam—Refraction—Reflection—Lenses—Copying Spherical
+Aberration—Chromatic Aberration, . . . 131
+
+CHAPTER V.
+
+To make Plates for the Daguerreotype—Determining the Time of Exposure
+in the Camera—Instantaneous Process for Producing
+Daguerreotype—Galvanizing the Daguerreotype Plate—Silvering
+Solution—Daguerreotype without Mercury—Management of Chemicals—Hints
+and Cautions—Electrotyping—Crayon Daguerreotypes—Illuminated
+Daguerreotypes—Natural Colors in Heliography—Multiplying Daguerreotypes
+on one Plate—Deposit in Gilding—Practical Hints on the Daguerreotype, .
+. . 149
+
+CHAPTER VI.
+
+An Account of Wolcott and Johnson’s Early experiments in the
+Daguerreotype, . . . 188
+
+
+
+
+AMERICAN HAND-BOOK of THE DAGUERREOTYPE.
+
+
+
+
+CHAPTER I.
+
+
+Polishing the Daguerreotype Plate—Buffing the Plate—Coating the
+Plate—Exposure of the Plate in the Camera—Position—Developing the
+Daguerreotype—Exposure to Mercury—Removing the Coating—Gilding or
+fixing the Image—Coloring Daguerreotype.
+
+Polishing the Daguerreotype Plate.—I shall endeavor to present to the
+reader the process I have found productive of good and satisfactory
+results, presenting the same in a clear and concise manner, so that any
+one, by following the various manipulations given, will be enabled to
+succeed. If there is any one part of the process in Daguerreotype in
+which operators fail more than all others, it is in not properly
+preparing the plate. It has truly been said that it would take a volume
+to describe all the methods that have been suggested for polishing the
+plate.
+
+I shall confine myself to the following description, which has been
+successfully practised, also most generally adopted by our operators,
+and I believe equal, if not superior to any other method, yet at the
+same time it is not of so much importance what particular method is
+employed, so that it be thoroughly and skillfully carried out.
+
+There is a general tendency with beginners to slight this operation;
+hence the necessity of adopting a system which precludes the
+possibility of doing so. During many years’ study and practice in the
+art, I have tried numerous methods and substances for the better
+accomplishment of the end in view, and have finally settled upon the
+following, as being (so far as experience allows me to Judge) the modus
+operandi, best suited to all circumstances; under no condition would I
+approve of a method less rigorous or precise.
+
+The operator being provided with a bottle of finely prepared rotten
+stone, cover the mouth of the bottle with a piece of thick paper, this
+perforated with a pin so that the rotten stone can be dusted on the
+plate. Fasten the plate on the holder, take the rotten stone (Becker’s
+can always be depended upon), and dust on lightly until the surface is
+freely covered; now drop on the plate’s surface a few drops of an
+alcoholic solution.[1]
+
+ [1] This solution is composed of equal parts of alcohol and water, for
+ the summer, and in winter three parts alcohol to one of water; a few
+ drops of potassa solution may be added, and is known to have a decided
+ effect upon the plate.
+
+Take a patch of Canton flannel; in order to prevent the moisture from
+the hand it should have a thick, firm texture: with this rub the plate
+in circles across, then back covering one-half of the former row of
+circles in each crossing until you have gone over the plate and back to
+the point of beginning, occupying at least half a minute in the
+operation, for a small plate, and so in proportion for the other sizes.
+
+Care should be observed to keep the patch wet with the alcoholic
+solution forming a paste on the surface of the plate; the motion of the
+hand should be brisk and free, not hurried, and the pressure about
+equal to that of a pound weight. When the cotton is disposed to adhere
+to the plate, and slip from under the finger, spread the fore and
+middle fingers a little apart, then pressing down, bring them together
+in such a manner as to form a fold in the cloth between them, by which
+means you will hold it perfectly secure.
+
+Avoid wetting the fingers, and should they perspire, wipe them often,
+as the moisture penetrating the cotton and coming in contact with the
+plate, would cause streaks it would be difficult to remove. I will here
+remark that many operators use much more cotton flannel than there is
+need of. I have found in my experience that a single patch, about one
+and half inch square, will be better for cleaning a number of plates
+than a new piece for every plate. This is the case for the wet, and for
+the dryrubbing two or three pieces will be found to answer. Thus with
+four or five cloths a dozen plates may be prepared.
+
+Some operators use prepared cotton, and think it more convenient than
+the flannel. This may be had prepared free from seeds and in a very
+perfect state, if wished.
+
+In going over the plate, great care should be observed, in touching its
+surface as equally as possible. The greatest care should be taken
+neither to touch the plate with the fingers, nor that part of the
+cotton flannel which is to come in contact with its surface; take a
+clean piece of flannel by one corner, snap it smartly to free it from
+dust and loose fibres, lay it face-side upward, dust on a little fine
+rotten stone; with this, polish around, or across, or in circles,
+lightly and briskly, passing gradually over the whole surface of the
+plate, as was done before with the wet. The plate should now exhibit a
+bright, clear, uniform surface, with a strong metallic lustre,
+perfectly free from any appearance of film; if not, the last polished
+should be continued until the effect is obtained, and when once
+obtained, the plate is ready for buffing.
+
+Buffing the Plate.—There are a variety of ways and means employed in
+this part of the operation. Some choose wheels, and others prefer the
+ordinary hand-buff. I have been unable to detect any peculiar advantage
+in the use of the wheel except in the facility of the operation; no
+doubt, however, but there is a saving of time, particularly in the
+preparation of the larger plates. For general use, we have not seen a
+wheel better adapted for this purpose than the one patented by Messrs.
+Lewis.
+
+It is generally well to use a hand-buff before placing the plate on the
+wheel; this is in order to prevent, as far as possible, the dust or
+other substance that may be on the surface of the plate from coming in
+contact with the cover of the wheel. I will here follow out the use of
+the hand-buffs (two are necessary) as they are mostly used.
+
+In the morning, before using the buffs, brush both as clean as
+possible, in order to free them from dust; then with the blade of a
+pair of shears, held perpendicular, rub the buffs from end to end; then
+knock them both together in order to free them from all dust or other
+substances, occasionally exposing them to the sun or to the fire.
+
+With one of the buffs (reserving the finest and softest for the last
+operation), powder its face with fine rouge and brush off slightly,
+leaving only the finest particles in it. Every operator should have two
+plate-holders; one for cleaning and one for buffing the plate; for when
+using only one, the rotten stone is liable to get on the buff and
+scratch the plate.
+
+Rest the fingers of the left hand on the back of the buff, near the
+farther end, with about the same pressure as in cleaning, while with
+the right you bear on the handle to correspond, and give the buff a
+free, easy, horizontal motion, passing it very nearly the whole length
+over the plate each time. Continue this operation in such a manner that
+the plate will on all parts of its surface have received an equal
+amount of polish. This buff once well filled with polish, add but
+little after, say a small quantity once in two or three plates. The
+polish as well as the buffs must be kept perfectly dry.
+
+The second buff should always be in the best order, and if this is the
+case, but little polish after the first need be used. Much depends upon
+the last finish of the surface of the plate, and as a fine impression
+is desired in the same ratio, the operator must exercise care and skill
+in this operation. Some buff the smaller plates on the hands, by
+resting them on the fingers in such a manner that the buff cannot touch
+them; some by holding the edges with thumb and little finger, with the
+remaining fingers under, or on the back; and others buff on the holder.
+When this last method is adopted, it requires the greatest caution to
+prevent the dust from getting on the buff. The holder should be wiped
+clean.
+
+The plate frequently slips off or around, and the buff comes in contact
+with the bed of the holder. When, however, the operator is so
+unfortunate as to meet with this mishap, the utmost care must be
+observed in thoroughly cleaning the buff cover before further buffing.
+In this last buffing it may be continued as before, except without the
+application of polish powder to the last buff. Examine the surface
+occasionally, and buff more lightly towards the close of the operation,
+using at last the mere weight of the buff. This last buffing should
+occupy as long a time as the first.
+
+The point to be aimed at is, the production of a surface of such
+exquisite polish as to be itself invisible, like the surface of a
+mirror. The secret of producing pictures discernible in any light, lies
+in this: the more dark, deep and mirror-like the surface of the plate,
+the more nearly do we approach to perfection.
+
+In all cases, very light and long continued buffing is productive of
+the greater success, since by that means a more perfect polish can be
+obtained.
+
+The question is often asked, why is it that the plates receive the
+coating so unevenly? I will answer by saying that it may arise from two
+causes: the first and most general cause is that those parts of the
+plate’s surface which will receive the heaviest coating have been more
+thoroughly polished, and the consequence is that it is more sensitive
+to the chemical operation; second, and might perhaps be considered a
+part of the first, the heat of the plate may not be equal in all its
+parts; this may arise from the heat caused by the friction in buffing.
+It is a well known fact, with which every observing practitioner is
+familiar, that a silver plate at a temperature of 45 deg. or less,
+exposed to the vapors of iodine, is less sensitive and takes a longer
+time to coat, than when it is at a temperature of 60 deg. or more.
+
+Whenever a view is to be taken, or any impression which requires the
+plate to be turned on the side, it should be buffed in the other
+direction, so that the marks will always be horizontal, when the
+picture is in position. With the finest possible polish, the plate is
+ready for the coating box.
+
+The question is often asked by operators, what is the state of the
+plate when polished and allowed to stand for a time before using? To
+meet this point we hare only to consider the silver and the power
+acting upon it. Pure atmosphere does not act upon silver; but we do not
+have this about in our operating rooms, as it is more or less charged
+with sulphurated hydrogen, which soon tarnishes the surface of the
+plate with a film of brown sulphurate. It is this that sometimes causes
+the specks which appear on finishing the impression, and are a great
+annoyance. Hence we see that the plate should be buffed just before
+receiving the vapor of iodine. Mr Hunt gives his opinion of the use of
+diluted nitric acid as the best solution for freeing, the surface of
+the plate; he says:
+
+“Numerous experiments on plated copper, pure silver plates, and on
+silvered glass and paper, have convinced me that the first operation of
+polishing with nitric acid, etc., is essential to the production of the
+most sensitive surface. All who will take the trouble to examine the
+subject, will soon be convinced that the acid softens the silver,
+bringing it to a state in which it is extremely susceptible of being
+either oxydized or iodized, according as the circumstances may occur of
+its exposure to the atmosphere or the iodine.”
+
+I cannot see the objection to this solution; not, however, in general
+use. Our operators do not find it of sufficient importance to the
+success of their pictures to accept it, the alcoholic solution being in
+its nature less objectionable.
+
+I will say here, that a plate submitted to only an ordinary polish is
+found to contain numberless minute particles of the powder made use of.
+Should the same plate be buffed for a long time, the polish will nearly
+all disappear, leaving the cavities in the surface free for the action
+of agents employed in subsequent operation. For this reason, I find
+that great amount of polishing powder should not be applied to the last
+buff, and it is obvious that three buffs can be employed to adventure;
+the two last should not receive any polishing materials. I have
+examined a plate that was considered to possess a fine finish, and
+similar had produced good impressions; these same plates, when
+subjected to a long and light buffing, would present a surface no finer
+in appearance to the naked eye; but upon exposure to the solar
+radiation, would produce a well-defined image in one fourth less time
+than the plate without the extra buffing.
+
+Coating the Plate.—For this purpose our mechanics and artists have
+provided a simple apparatus called a coating-box, which is so arranged
+as to be perfectly tight, retaining the vapor of the iodine or
+accelerators, and at the same time allowing, by means of a slide, the
+exposure of the plate to these vapors. They can readily be obtained by
+application to any dealer, all of whom can furnish them.
+
+The principal difficulty in coating the plate, is that of preserving
+the exact proportion between the quantity of iodine and bromine, or
+quick. It is here necessary to say, that hardly any two persons see
+alike the same degree of color, so as to be enabled to judge correctly
+the exact tint, i. e. what one might describe as light rose red, might
+appear to another as bright or cherry red; consequently, the only rule
+for the student in Daguerreotype, is to study what appears to him to be
+the particular tint or shade required to aid him to produce the desired
+result. Practise has proved that but a slight variation in the chemical
+coating, of the Daguerreotype plate will very materially affect the
+final result.
+
+The operator will proportion the coating of iodine and bromine or
+accelerators according to the strength and composition of the latter.
+
+Experience proves that the common impressions, iodized to a rather
+light yellow gold tint, and brought by the bromine to a very light,
+rose color, have their whites very intense, and their deep shades very
+black. It is also known that if you employ a thicker coating of iodine
+and apply upon it a proportionate tint of bromine, so as to obtain a
+deep rose tint, delineations will be less marked, and the image have a
+softer tone. This effect has been obvious to everyone who has practised
+the art. Thus I may observe that the light coatings produce strong
+contrast of light and shade, and that this contrast grows gradually
+less, until in the very heavy coating it almost wholly disappears. From
+this it will readily be perceived that the middle shades are the ones
+to be desired for representing the harmonious blending of the lights
+and shades.
+
+Then, if we examine, with respect to strength, or depth of tone, and
+sharpness of impression, we see that the light coating, produces a very
+sharp but shallow impression; while the other extreme gives a deep but
+very dull one. Here, then, are still better reasons for avoiding either
+extreme. The changes through which the plate passes in coating may be
+considered a yellow straw color or dark orange yellow, a rose color
+more or less dark in tint, or red violet, steel blue or indigo, and
+lastly green. After attaining this latter color, the plate resumes a
+light yellow tint, and continues to pass successively a second time,
+with very few exceptions, through all the shades above mentioned.
+
+I will here present some excellent remarks upon this subject by Mr.
+Finley. This gentleman says:
+
+“It is well known to all who have given much attention to the subject,
+that an excess of iodine gives the light portions of objects with
+peculiar strength and clearness, while the darker parts are retarded,
+as it were, and not brought out by that length of exposure which
+suffices for the former. Hence, statuary, monuments, and all objects of
+like character, were remarkably well delineated by the original process
+of Daguerre; the plate being coated with iodine alone. An excess of
+bromine, to a certain degree, has the opposite effect; the white
+portions of the impression appearing of a dull, leaden hue, while those
+which should be black, or dark, appear quite light. This being the
+case, I conclude there must be a point between the two extremes where
+light and dark objects will be in photogenic equilibrium. The great
+object, therefore, is to maintain, as nearly as possible, a perfect
+balance between the two elements entering into union to form the
+sensitive coating of the plate, in order that the lights and shades be
+truly and faithfully represented, and that all objects, whether light
+or dark, be made to appear so far conformable to nature, as is
+consistent with the difference in the photogenic energy of the
+different colored rays of light. It is this nicely-balanced combination
+which ensures, in the highest degree, a union of the essential
+qualities of a fine Daguerreotype, viz., clearness and strength, with
+softness and purity of tone.
+
+“So far as I know, it is the universal practice of operators to judge
+of the proportion of iodine and bromine in coating the plate, by two
+standards of color the one fixed upon for the iodine, the other for the
+additional coating of bromine. Now I maintain that these alone form a
+very fallacious standard; first, because the color appears to the eye
+either lighter or darker, according as there is more or less light by
+which we inspect the coating; and secondly, because if it occur that we
+are deceived in obtaining the exact tint for the first coating, we are
+worse misled in obtaining the second, for if the iodine coating be too
+light, then an undue proportion of bromine is used in order to bring it
+to the second standard, and vice versa.”
+
+The iodine box should be kept clean and dry. The plate immediately
+after the last buffing, should be placed over the iodine, and the
+coating will depend upon the character of the tone of the impression
+desired. Coating over dry iodine to an orange color, then over the
+accelerator, to a light rose, and back over iodine one sixth as long as
+first coating, will produce a fine, soft tone, and is the coating
+generally used for most accelerators. The plate iodized to a dark
+orange yellow, or tinged slightly with incipient rose color, coated
+over the accelerator to a deep rose red, then back over iodine
+one-tenth as long as at first coating, gives a clear, strong, bold,
+deep impression.
+
+I will here state a singular fact, which is not generally known to the
+operator. If a plate, coated over the iodine to a rose red, and then
+exposed to strong dry quick or weak bromine water, so that a change of
+color can be seen, then recoated over the iodine twice as long as at
+first coating, it will be found far more sensitive when exposed to the
+light than when it has been recoated over the iodine one-fourth of the
+time of the first coating.
+
+Probably the best accelerating combination is the American compound
+formerly known as “Gurney’s American compound,” or some of the
+combinations of bromide of lime. The first is thought to possess
+perhaps more uniformity in its action than any other combination I have
+ever used.
+
+The plate once coated should be kept excluded from the light by means
+of the plate holder for the camera box.
+
+I will notice one of the principal causes having a tendency to prevent
+the perfect uniformity of chemical action, between the iodine and
+silver; hydrogen, or the moisture in the atmosphere, makes a very
+perceptible barrier. This moisture may arise as the result of the cold,
+from a want of friction in the buffing of the plate, which, coming in
+contact with the warmer air, as a writer on this subject says:
+
+“It is well known that as often as bodies, when cold, are exposed to a
+warmer air, the humidity contained in them is condensed. It is to this
+effect that we must attribute the difficulty experienced in operating
+in most cases.” This is corroborated by the results experienced by our
+operators. So it is seen that the plate should be of a temperature
+above that of the atmosphere. Mr. Gurney submits his plates to a gentle
+heat from a spirit lamp just before exposing them to the vapor of
+iodine. Experience has convinced me that a plate heated to about 80
+deg. before being exposed to iodine will present a far better defined
+image than a plate at a temperature of 50 deg. I account for this by
+noticing that, at a higher temperature, the plate throws off any larger
+crystals that might otherwise be deposited, receiving only the finer,
+thus producing a more perfect chemical combination of iodide of silver.
+I would call the attention of the operator to this point, as presenting
+something of interest, and which may direct in a way of accelerating
+the future operations.
+
+That the presence of a film of moisture over the plate is a preventive
+of uniform chemical action, may be readily understood from the fact
+that iodine is almost insoluble in water, requiring seven thousand
+parts of water to dissolve one of iodine, or one grain to a gallon of
+water. Yet its affinities for silver and other substances are so
+powerful as to prevent its existing in an insulated state, hence we can
+account for the frequent occurrence of a plate presenting parts of an
+image over its surface. It is quite evident that those parts of plate’s
+surface covered with moisture are nothing like as sensitive to the
+iodine as those parts perfectly free.
+
+Exposure of the plate in the Camera, and Position.—The time of exposure
+necessary to produce an image upon the Daguerreotype plate, can only be
+determined by experiment, and requires a liberality of judgment to be
+exercised on the part of the operator. The constant variation of the
+light renders it impossible to lay down any exact rule upon this point.
+Light is not alone to be considered; the amount of coating exercises a
+deviating influence, also the subjects to be represented are not
+equally photogenic, some requiring much longer time of exposure than
+others. This may be easily observed by exposing the plate at the same
+time to a plaster bust and a piece of black velvet, the first being a
+much stronger reflector of light than the latter: the time necessary to
+produce a well developed image of the velvet being about six times
+longer than that required to produce an equally defined image of
+plaster. The manner of judging correctly of the time is by the
+appearance of impression after it has been developed by the mercurial
+vapors. Should it present a deep blue or black appearance it is
+solarized or over-timed. This sometimes is to an extent, that a perfect
+negative is formed, the white being represented black, and the dark
+light.
+
+An object requiring the particular care and attention of the operator
+is the proper focus. It is not unfrequently the complaint of sitters
+that their hands are represented as being magnified and greatly out of
+proportion with the general figure. This is the case also with the nose
+and eyes, but in a less degree. As this cannot be wholly remedied, it
+is desirous to come as near as possible, and in order to do this, it is
+necessary to present the figure in such a position as to bring it as
+nearly as possible upon the same plane by making all parts nearly at
+equal distance from the lenses. This must be done by the sitter
+inclining the head and bust formed to a natural, easy position, and
+placing the hands closely to the body, thus preserving a propel
+proportion, and giving a lively familiarity to the general impression.
+It is not an uncommon fault among our less experienced operators to
+give a front view of the face of nearly every individual, regardless of
+any particular form, and this is often insisted upon by the sitter,[2]
+who seems to think the truth of the picture exists principally in the
+eyes staring the beholder full in the face.
+
+ [2] I might here picture some curious scenes experienced by our
+ operators Every one is familiar with a certain class of our community
+ whose ideas of the importance of a free and easy position of the body
+ are too closely confined with stays, attention to toilet, tightly
+ fitting dress coats and the like, to admit of being represented as if
+ nature had endowed them with least possible power of flexibility. To
+ such we would suggest the following, to be well learned and retained
+ in the mind while presenting themselves before the Daguerreotype
+ camera:
+
+“The experience of one who has often been Daguerreotyped, is, to let
+the operator have his own way.”
+
+Nothing, in many instances, can be more out of place in a Daguerreotype
+portrait than this, for let a man with a thin, long,
+defeated-politician-face, be represented by a directly front view, we
+have, to all appearances, increased the width of the face to such an
+extent as to reveal it flat and broad, losing the characteristic point
+by which it would be the most readily recognized. The method we should
+adopt in taking the likeness of such an individual as above, would be
+to turn the face from the camera, so as to present the end of the nose
+and the prominence of the cheek bone equally distant from the lenses,
+and then focusing on the corner of the eye towards the nose, we cannot
+in many cases, fail to produce an image with the lips, chin, hair, eyes
+and forehead in the minutest possible definition.
+
+It should be the study of every operator to notice the effect of the
+lights and shades while arranging the sitter, and at the same time be
+very particular to give ease in the position.
+
+No matter how successful the chemical effect may have been, should the
+image appear stiff and monument-like, all is lost. “In the masterpiece,
+grace and elegance must be combined.”
+
+I will here use the words of another, which are very true:
+
+“So great is the difference in many faces, when inspected in opposite
+directions, that one of the two views, however accurately taken, would
+not communicate the likeness—it not being, the usually observed
+characteristic form. When the right view of the head is obtained, it is
+first necessary to consider the size of the plate it is to be taken on,
+so as to form an idea of the proportion the head should bear to it. The
+mind must arrange these points before we commence, or we shall find
+everything, too large or too small for the happy proportion of the
+picture, and the conveying of a just notion of the stature. The work
+will have to be done over, and time sacrificed, if this is not attended
+to. The adjustment of the head to the size of the plate (as seen from
+the margin of the mat), is not to be taught: everyone must bring
+himself, by scrutinizing practice, to mathematical accuracy; for
+something will be discovered in every face which can be surmounted only
+by experience.
+
+“The eye nearest the camera, in a three-quarter-face, is placed in the
+middle of the breadth of the plate; the chin, in a person of middle
+stature, in the middle of the length, and higher according to the
+proportional height of the person.”
+
+In regard to the proper elevation of the camera, it may be here stated
+that I have found it best in taking portraits where the hands are
+introduced, to place the camera at about equal height with the eyes of
+the sitter, in order to bring the face and hands equi-distant from the
+tube. It will be found, if the above be followed, that by attaching a
+string to the camera tube, and making a semi-circle, that the face and
+hands of the sitter will occupy a corresponding distance, and the
+consequence is that the impression will appear without the hands being
+magnified. It has been found that a person with a freckly face can have
+as fine, fair, and clear an impression as the most perfect complexion;
+this may be done by the subject rubbing the face until it is very red.
+The effect is to lessen the contrast, by giving the freckles and skin
+the same color and the photogenic intensity of the red and yellow being
+nearly the same, an impression can be produced perfectly clear.
+
+When a child is to be taken, and there are doubts of its keeping still,
+the operation may be accelerated by placing it nearer the window
+bringing the screen nearer, and placing a white muslin cloth over the
+head; this will enable you to work in one third of the usual time.
+Should the person move, or the plate become exposed to the light, it
+may be restored to its original sensitiveness by placing it over the
+quick, one or two seconds.
+
+Developing the Daguerreotype.—After the plate has been submitted to the
+operation of the light, the image is still invisible. It requires to be
+exposed to the vapors of heated mercury. It is not absolutely necessary
+to apply artificial heat to the mercury to develop the image, for fair
+proofs have been produced by placing a plate over the bath at the
+ordinary temperature of the atmosphere. This plan, however, requires a
+long time and cannot be adopted in practice, even if it were advisable.
+The time more usually required in developing the image over the
+mercurial vapors, is about two minutes, and the temperature is raised
+to a point necessary to produce the desired effect in that time. This
+point varies as indicated by different scales, but for the ordinary
+scales it is not far from 90 deg. cen.
+
+The mercury bath is accompanied with a centigrade thermometer, by which
+the heat is regulated. Those furnished by the manufacturers are not
+always correct, and it requires some experience to find the proper
+degree on the scale.
+
+I would here remark that it is advisable, when placing the spirit lamp
+under the bath, to so arrange it that the position of applied heat
+should always be on the same point, viz., should the heat be directly
+under the bulb containing the thermometer it would raise the mercury in
+the tube to the point marked, and the temperature of that in the bath
+would be far below what it should be; hence it is (where time is
+followed for developing) that many failures occur. This is observed
+more readily in the large baths made of thick iron, particularly upon
+first heating. In practice I apply the heat as nearly as possible
+between the centre of the bottom of the bath and the bulb containing
+the mercury tube. It is advisable to keep the lamp lighted under the
+bath from the time of commencing in the morning to the close of
+business at night. By this means you have a uniformity of action, that
+cannot be otherwise obtained.
+
+It is well known to the experienced Daguerreotypist, that different
+atmospheres have a decided effect upon the mercury in developing the
+Daguerreotype. It will require a greater degree of heat for one
+atmosphere than for another. Experience alone determines this little
+difference.
+
+In summer, on cloudy and stormy days, mercurial vapors rise more
+readily and quickly than in the temperature of autumn or winter. From
+60 degrees upwards towards the boiling point (660 deg.), the vapors of
+mercury rise in greater abundance and collect in larger globules on
+cold surfaces.
+
+For various reasons I prefer a high temperature and short exposure. It
+accelerates the process. It renders the lights of the picture more
+strong and clear, while the deep shades are more intense. It gives a
+finer lustre to the drapery. The solarized portions also are very
+seldom blue, especially after gilding. If heated too high, however, the
+light parts become of a dead, chalky white, and the shadows are injured
+by numerous little globules of mercury deposited over them. Just the
+right quantity of mercury leaves the impression of a transparent,
+pearly white tone, which improves in the highest degree in gilding. To
+mercurialize with exactness is a nice point. If there is reason to
+suspect having timed rather short in the camera, reduce the time over
+mercury in a corresponding proportion. A dark impression will be ruined
+by the quantity of mercury which would only improve a light one.
+
+If practicable, it is most expedient that the plate be submitted to the
+action of mercury immediately on coming from the camera. I have
+frequently, however, carried plates for miles in the plate-holders and
+after exposing in the camera, brought them back to expose to mercury,
+and obtained fair proofs; but for the reason before given, it is
+advisable to carry along the bath, and bring out the impression on the
+spot.
+
+It is sometimes the practice of inexperienced operators to take the
+plate off the bath and examine the impression by solar light. This plan
+should be abandoned, as it is almost sure to produce a dense blue film
+over the shadows.
+
+This I am led to believe is occasioned by the action of light on the
+yet sensitive portions of the plate, and made to appear only by
+subsequent exposure to mercury, being equivalent to solarization.
+
+There has been little said by our professors upon the subject of the
+position of the plates while exposed to the mercurial vapour. Mr. Hunt,
+in referring to this subject, says: “Daguerre himself laid much stress
+upon the necessity of exposing the plate to the mercury at an angle of
+about 45 deg.. This, perhaps, is the most convenient position as it
+enables the operator to view the plate distinctly, and watch the
+development of the design; but beyond this, I am satisfied there exists
+no real necessity for angular position. Both horizontally and
+vertically, I have often produced equally effective Daguerreotypes.” I
+presume from the last sentence of Mr. Hunt, that he has confined his
+experiments to the smaller sized plates. Hence he may not have thought
+of the effect of the vertical exposure of a large plate.
+
+In America this is a subject of no little importance. When an
+impression is to be developed upon a plate fifteen by seventeen inches,
+were we to use an angle of about 45 deg., it would be found to make a
+perceptible difference in the appearance of the image. By examining the
+wood tops of our baths as formerly made, it will be found that there is
+a great variation in the distance from the mercury to the different
+portions of the plate. By measuring one of these tops for the size
+plate above mentioned, I find the distance to the nearest point between
+the mercury and the plate, to be thirteen, and the middle point
+sixteen, and the furthest point twenty-one and a half inches: by this
+we see that one point of the plate is eight and a half inches further
+from the mercury than the nearest point; even this is not the variation
+there would necessarily be, were we to adopt the angle of 45 deg. as
+urged by Daguerre.
+
+Among our principal professors, the bevel top will not be found in use
+where the large plates are used. Should any one feel desirous to test
+more minutely the effect produced by a bevel top bath, I would suggest
+to them to place a frame, so constructed as to hold three sixth size
+plates, and fit it to the top of the bath, and so arrange it with
+openings that the plates may be placed, one at the nearest point of the
+mercury, the second midway, and the third to the greatest distance, and
+by placing the plates over at one and the same time, the experimenter
+will be enabled to judge if there exists a difference in the
+developing. In speaking of the above, reference is had to baths to the
+ordinary heights used by operators.
+
+We will now proceed to examine the effect produced by mercurial vapor
+upon the plate at different lengths of exposure. In some investigations
+which I have made upon the appearance of the Daguerreotype impressions
+when developed over mercury at 90 deg. C. (194 deg. F.), the following
+was the result. Plates, coated and exposed to light in our usual manner
+of operating, produced on exposure of
+
+1/2 minute, whole impression, deep blue.
+
+1 minute, ashy and flat; no shadows; linen, deep blue.
+
+1 1/2 minute, coarse and spongy; shadows, muddy; drapery, dirty reddish
+brown.
+
+2 minutes, shallow or watery; shadows, yellowish; drapery, brown.
+
+2 1/4 minutes, soft; face, scarcely white; shadows, neutral; drapery,
+fine dark brown linen somewhat blue.
+
+2 1/2 minutes, clear and pearly; shadows, clear and positive, of a
+purple tint; drapery, jet black, with the dark shades slightly frosted
+with mercury.
+
+2 3/4 to 3 minutes, hard and chalky; shadows, harsh; drapery,
+roughened, and misty with excess of mercury.
+
+The foregoing results will be found general.
+
+There are numerous opinions among our operators in regard to the
+quantity of mercury necessary for a bath. As regards this, I need only
+say, similar results occur when two pounds or two ounces are used, but
+the quantity generally employed is about a quarter of a pound. I am of
+the opinion that one ounce will answer as well as a larger quantity. I
+know of no better proof in favor of a small quantity than that
+presented in the following incident. Several years since, an operator
+(Mr. Senter, of Auburn, N.Y.) of my acquaintance, was requested to go
+several miles to take a Daguerreotype portrait of a deceased person. He
+packed up his apparatus and proceeded over a rough road for some
+distance to the house where he was to take the portrait, and arranging
+his apparatus, with all the expedition which the occasion required,
+after having everything in usual order (as was supposed), he proceeded
+and took some ten or twelve very superior impressions. They were fine,
+clear, and well developed. After taking the number ordered, he
+proceeded to repack his apparatus, and to his surprise, when he took up
+the bottle he carried the mercury in, he found it still filled, and
+none in the bath, except only such particles as had adhered to the
+sides, after dusting and being jolted for several miles over the rough
+road. From this it will be seen that a very little mercury will suffice
+to develop fine proofs. I saw some of the impressions referred to
+above, and they were certainly well developed, and very superior
+specimens of our art.
+
+Removing the Coating.—After the impression has been developed over the
+mercurial vapor, the next step is to remove the sensitive coating. For
+this purpose the following solution is used:
+
+Put about two ounces of hyposulphite of soda in a pint of water, which
+should always be filtered before using. A convenient way of doing this
+is to have two bottles, and a large funnel with a sponge pressed into
+the neck of it; or, what is better, some filtering paper folded in it.
+The solution in one bottle, the funnel is placed in the other, and the
+picture held over it; when the solution is poured on the plate, it runs
+from it into the filter, and is always ready for use.
+
+It is best that the washing be done immediately on the plate coming
+from the mercury bath. If allowed to stand long with the coating on, it
+assumes a very dark tint—as the operation of the light continues,
+though less active than while exposed in the camera, and destroys that
+brightness which would otherwise have been obtained. It is preferable
+to wash and gild a picture without it first being dried; yet when there
+are doubts of its giving satisfaction, there would sometimes be a
+saving by drying and getting the decision of the subject before
+gilding, as this last injures the plate for another impression. First,
+light your spirit-lamp, then with your plyers take the plate by the
+lower right-hand corner, holding it in such a manner that the plyers
+will form in a line with the upper left-hand corner; pour on, slowly,
+the hyposulphite solution, slightly agitating the plate, until all the
+coating is dissolved off; then rinse off with clean water, and if it is
+not to be gilded, dry by holding the plate perpendicular with the
+bottom left-hand corner lowest, and applying the blaze of the
+spirit-lamp to the back, at the same time blowing gently downward on
+the face of the plate.
+
+The hyposulphite solution should be often filtered through a sponge,
+and it will answer for a great number of washings. Yet it is observed
+that the mercury collects in this solution in small globules; these
+often come in contact with the plate, causing white spots, which spoil
+the impression. They should be guarded against, and the solution
+renewed. Again, in order to prevent streaks or scum on the surface of
+the plate, it is necessary that the coating should be removed with a
+good degree of uniformity. I find in practice that the hyposulphite of
+soda in our market varies much as regards strength, and consequently
+the rule to be adopted is to make a solution of sufficient strength to
+remove the coating in about ten seconds. I am aware that it may be said
+that this strong solution would have a tendency to injure the
+impression by destroying in a measure the sharpness of outline. To meet
+this, it need only to be said that the preventive is, to not let the
+solution rest on the surface of the plate for a longer time than is
+absolutely necessary, and then it should be drenched copiously with
+water; hence a chemical action upon the image is prevented and the
+general operation facilitated. This plan is adopted by our first
+operators with the greatest success.
+
+If the operator should allow the hyposulphite solution to run over the
+plate unevenly, it is quite likely that white or blue streaks would
+result. These it is impossible to remove without injury to the
+impression. Some, in order to prevent this, breathe over the surface,
+thus moistening it and putting it in a condition to receive the
+solution with greater uniformity. The plate should be well washed with
+water before gilding.
+
+Gilding, or Fixing the Image.—The next process to be given is that for
+fixing the image on the plate. This is done by precipitating a thin
+film of gold over the surface and is productive of the most brilliant
+effect when prepared immediately after the plate has been washed with
+water after the application of the hyposulphite solution, and before
+the plate has been allowed to dry. When, however, the plate has been
+dried and allowed to stand for any time, before gilding, the
+hyposulphite wash should be applied as at first, in order to destroy
+any chemical coating that may have been formed on exposure of the plate
+to the air. For gilding the larger plates, we have a gilding stand so
+constructed that the plate can be put on a perfect level. In practice,
+I prefer holding the plate with nippers, fastened at one corner. Hold
+the plate in the same manner as in removing the coating; pour on the
+gilding, newly filtered, until the surface is wholly covered, and with
+the blaze of the spirit lamp, at least three inches high, apply it to
+the back of the plate, moving it about, that the surface may be heated
+with as much uniformity as possible. Continuing this operation, the
+surface will generally become covered with small yellow bubbles which
+soon disappear, leaving the image clear and distinct.
+
+It is advisable to make use of a lamp having a sufficiently strong
+flame to produce the effect in a few minutes. If after a first heating,
+it is found that the impression can admit of a greater degree of
+intensity, it might be heated anew; but that is seldom necessary, and
+often by trying to do too, well, the operator, if he persists in
+heating certain parts of the plate, may find the liquid dry up just
+above the flame, and inevitably cause a stain; [3] or else the blacks
+are covered with a film, or even the coating of gold may suddenly
+exfoliate, when small particles are detached from the plate. The
+impression is then entirely spoiled, but the plate may be re-polished.
+
+ [3] This can be remedied, however, if it is immediately washed over
+ with the same solution that is on the plate, so that the surface shall
+ not become cool; continue for a short time to apply the lamp under,
+ and agitate the plate slightly, and it will soon be free from all
+ imperfections and give a fine clear tone.
+
+It is not unfrequent that the surface assumes a dark, cloudy
+appearance. This is generally the best sign that the gilding will bring
+out the impression with the greatest degree of distinctness. Soon, the
+clouds gradually begin to disappear, and, “like a thing of life” stands
+forth the image, clothed with all the brilliancy and clearness that the
+combined efforts of nature and art can produce. When in the operator’s
+judgment the operation has arrived at the highest state of perfection,
+rinse suddenly, with an abundance of clean water, and dry as before
+described.
+
+When an impression is dark, the gilding process may be longer
+continued; but when light, it should be gilded quickly, as lengthening
+the time tends to bleach the impression and make it too white. The
+cause of this appears to be, that with a moderate heat the chlorine is
+merely set free from the gold, and remaining in the solution, instead
+of being driven off, with its powerful bleaching, properties, it
+immediately acts upon the shades of the picture. A dark impression can
+thus, by a low heat, long-continued, be made quite light. To procure
+the best effect, then, heat suddenly with a large blaze, and judging it
+to be at the maximum, cool as suddenly as possible.
+
+When the hyposulphite of gold is used instead of the chloride, a less
+heat should be employed.
+
+Coloring Daguerreotypes.—Of all the so-called improvements in the
+Daguerreotype, the coloring is the least worthy of notice. Yet the
+operator is often, in fact most generally, called upon to hide an
+excellent specimen under paint. I can conceive of nothing more perfect
+in a Daguerreotype than a finely-developed image, with clearness of
+lights and shadows, possessing the lively tone resulting from good
+gilding. Such pictures, however, are not always had, and then color may
+perform the part of hiding the imperfections. We present the following
+method as given in Willat’s Manual:
+
+“Daguerreotype portraits are now commonly met with beautifully colored;
+but the coloring is a process requiring great care and judgment, and
+many good pictures are spoiled in fruitless experiments. Several
+different methods of coloring have been proposed. The simplest mode
+appears to be that of using dry colors prepared in the following
+manner: A little of the color required, very finely ground, is thrown
+into a glass containing water, in which a few grains of gum arabic have
+been dissolved. After standing a few moments, the mixture may be passed
+through bibulous paper, and the residue perfectly dried for use. The
+principal colors used are Carmine, Chrome Yellow, Burnt Sienna,
+Ultramarine and White; boxes fitted with sets of colors properly
+prepared, may be obtained of the dealers, and include Carmine, White,
+Lilac, Sky Blue, Pink, Yellow, Flesh color, Orange, Brown, Purple,
+Light Green, Dark Green and Blue. With a few colors, however, all the
+rest may be made thus: Orange, by Yellow and Red; Purple, with Blue and
+Red; Green, Blue and Yellow; Brown, with Umber, Carmine and Lamp Black;
+Scarlet, Carmine and Light Red. While it is true that a little color
+may relieve the dark metallic look of some Daguerreotypes, it must not
+be concealed that the covering of the fine delicate outline and
+exquisite gradations of tone of a good picture with such a coating, is
+barbarous and unartistic.
+
+“The prevaling taste is, however, decidedly for colored proofs, and the
+following directions will assist the amateur in ministering to this
+perverted taste, should he be so inclined. The coloring should commence
+with the face, and the flesh tint must be stippled on (not rubbed) with
+a small camel’s-hair brush, beginning from the centre of the cheek,
+taking great care not to go over the outline of the face, and also not
+to have too much color in the brush; the eyes and eyebrows must not be
+touched with color. After the flesh color is applied, take a piece of
+very soft cotton and pass it very gently backwards and forwards over
+the face, so as to soften down the color, and then apply the carmine to
+give the required tint. For men, the darker tints should predominate,
+and for women the warmer. Very light hair may be improved by a slight
+tint of brown, or yellow and brown, according to the color. In coloring
+the drapery, the same care must be used. No rules can be laid down for
+all the different colors required, and the amateur had better obtain
+the assistance or advice of some one accustomed to the use of colors. A
+little white with a dash of blue or a little silver, will improve white
+linen, lace, etc. The jewelry may be touched with gold or silver from
+the shells, moistened with distilled water, and laid on with a
+fine-pointed sable-hair brush.
+
+“Brilliants may be represented by picking the plate with the point of a
+pin or knife.”
+
+
+
+
+CHAPTER II.
+
+MISCELLANEOUS.
+
+
+Coloring Back Grounds—Transparent ditto—Gilding Dissolvent Solution for
+removing Specks—Solarized Impression—To Purify Water—Cleaning
+Mercury—Adhesive Paper—Black Stain for Apparatus—Sealing Wax for
+Bottles—Rouge—Rotten Stone—Potassa Solution—Hyposulphite
+Solution—Substitute for do.—Gilding Solution—Solution for increasing
+the Brilliancy of the Daguerreotype—Bleaching Solution;—Cold
+Gilding—Neutralizing Agents—Buff Dryer—Keeping Buffs in order—Cleaning
+Buckskins—Reflector for taking Views.
+
+To Color Back-grounds—To obtain a properly colored back ground is a
+matter of no little importance to the Daguerreotype operator. I had
+nearly exhausted all patience, and tried the skill of painters to
+obtain a back-ground that would be suitable to my purpose; but all to
+no avail. At last I adopted the following method, and at a cost of
+coloring of twenty-five cents, can now produce a back-ground far more
+valuable than those which had cost five dollars before.
+
+Take common earth paint, such as is used in painting roofs; mix this
+with water to about the consistency of cream; then to four quarts of
+this mixture add about one pint of glue water (common glue dissolved in
+water, also about as thick as cream). This last will cause the paint to
+adhere to the cloth, to which it is applied with a common white-wash
+brush. By applying the brush on the coating while it is wet, it may be
+so blended that not a line can be seen, and a perfectly smooth color of
+any shade can be obtained. The shade of color I use is a light
+reddish-brown. Tripoli, rotten-stone, or any earthy matter, may be
+applied in the same manner.
+
+Transparent or Invisible Back-ground.—I give this as originally
+published in my System of Photography, 1849:
+
+“Take a large woollen blanket with long nap, the longer and rougher it
+is the finer will be the effect produced; stretch it on a frame of
+sufficient size, and suspend the frame at the centre of the upper end
+by a string fastened to a nail in the ceiling, from three to five feet
+back of the sitter. Having arranged this, fasten another string to the
+side of the frame, and while the operation is going on in the camera,
+swing the back-ground from right to left, continuing this during the
+whole time of sitting, and you have a clear “transparent” back-ground,
+which throws the image out in bold relief, and renders the surface of
+the plate invisible. If equalled at all it is only by atmospheric
+back-ground. I consider it to be the best ever known, and think it
+needs but to be tried to afford satisfactory proof that it is so.
+Although used by few before, since the first edition of this work at
+least two thirds of the operators have adopted its use; for any one can
+at once understand the principle and the effect which it produces.”
+
+It may be added that a motion imparted to to any back-ground where
+softness is desired, produces an excellent effect.
+
+Gilding Dissolvent.—To one quart of muriatic acid add as much oxide of
+iron (common iron rust) as it will dissolve in two days. This may be
+done by putting in the oxide in excess. It should be frequently shook,
+and when wanted for bottling it should be allowed to stand in order to
+settle. When this is done the solution may be poured off, and reduced
+by adding to it an equal quantity of water; then it is ready for use.
+This constitutes a gilding dissolvent now in our market.
+
+Solution for Removing Specks.—There is probably no one cause of
+complaint so general as “what makes those black specks?” There are
+several causes which produce them, and probably the most general are
+dust, rouge, or a spray of moisture on the plate. It this be the case,
+there is no solution which can remove them, as they have prevented a
+chemical action with the silver, and their removal would only expose
+the surface of the plate which in itself would afford a contrast with
+the impression. Another and less dangerous source of these specks is
+organic matter contained in the solution employed in dissolving the
+chemicals, or the water in washing. Much of the hyposulphite of soda in
+market contains a sulphuret, which, coming in contact with the silver
+surface, immediately causes oxidation. Such spots, as well also as most
+all others found on the plate after it has been exposed in the camera,
+can be removed by the following, solution: To one ounce of water add a
+piece of cyanide of potassium the size of a pea; filter the solution
+and apply by pouring it on the surface of the plate. In all cases the
+plate should first be wet with water. Apply a gentle heat, and soon the
+spots disappear, leaving the impression clear and free from all organic
+matter.
+
+In the absence of cyanide of potassium, a solution of pure hyposulphite
+of soda will answer as a fair substitute.
+
+To Redeem, a Solarized Impression.—The Daguerreotype plate, prepared in
+the ordinary manner, should be exposed in the camera a sufficient time
+to solarize the impression. Then, before it be exposed to the vapor of
+mercury, expose it for a very brief period to the vapor of either
+chlorine, bromine or iodine. Then expose over mercury, as usual. I have
+produced singularly interesting results by this process.
+
+To Purify Water.—Filter the water well, and then add about three drops
+of nitric acid to the pint. This can be used as absolutely pure water,
+but I would recommend the use of distilled water as preferable.
+
+Cleaning Mercury.—Make a small bag of chamois skin, pour in the
+mercury, and squeeze it through the leather. Repeat this several times,
+and filter by means of a funnel made of paper, with a very small
+aperture, through which it will escape and leave the particles of dust,
+or other substances, in the paper. A paper with a pinhole through it
+will answer as well, and it is less difficult to make.
+
+Adhesive Paper.—Take gum arabic, four ounces, put it in a wide-mouthed
+bottle and pour on water about one-third above the gum. Add half ounce
+of isinglass, or fish glue, and a small piece of loaf sugar. Let all
+dissolve, and spread over French letter paper, with a brush or piece of
+sponge. If once spreading is not enough, perform the same operation a
+second time.
+
+Black Stain for Apparatus.—Dissolve gum shellac in alcohol, or procure
+shellac varnish at the druggists’, stir in lampblack, and apply with a
+sponge or bit of rag. This will adhere to metal, as well as wood, and
+is used for the inside of camera, tubes, etc.
+
+Sealing Wax for Bottles.—Melt together six parts rosin and one beeswax,
+and add a small quantity of lampblack; or, if red is preferable, add
+red lead. Common white wax is best, as most chemicals act less upon it.
+
+When bottles containing bromine are to be sealed, it is well to grease
+the stopper. This, however, only when the bottle is in frequent use,
+for if it were to be sent by any conveyance it would be likely to fly
+out.
+
+Rouge.—The method employed by Lord Ross is probably unsurpassed in the
+production of rouge. He has given his process as follows:
+
+“I prepare the peroxide of iron by precipitation with water of ammonia,
+from a pure dilute solution of sulphate of iron; the precipitate is
+washed, pressed in a screw press till nearly dry, and exposed to a heat
+which in the dark appears a dull, low red. The only points of
+importance are, that the sulphate of iron should be pure, that the
+water of ammonia should be decidedly in excess, and that the heat
+should not exceed that I have described. The color will be a bright
+crimson inclining to yellow. I have tried both potash and soda, pure,
+instead of water of ammonia, but after washing with some degree of
+care, a trace of the alkali still remained, and the peroxide was of an
+ochrey color, till overheated, and did not polish properly.”
+
+Care should be observed to apply rouge in a dry state to the surface of
+the plate.
+
+I would remark, that so far as my experience has gone, I consider good
+rouge fully equal to any other polishing, material for the last or
+finishing polishing; consequently I shall not take up my space in
+enumerating any of the great variety that find few advocates.
+
+Why Rouge is to be preferred.—“Because it burnishes better, and because
+it assists in fixing the layer of gold, rendering it less susceptible
+of being removed in scales when heated too much.”
+
+Rotten Stone.—“Purchase the best ground rotten stone of the druggist,
+put a few ounces at a time in a wedgewood or porcelain mortar, with
+plenty of clean rain water. This should have about forty drops of
+nitric acid to the quart. Grind well, and after letting the mortar
+stand two minutes, pour into a third. After remaining undisturbed eight
+minutes, finally pour off into a fourth to settle. Rinse back the
+sediment in the second and third, and grind over with a new batch.
+Repeat the operation till you have all in the fourth vessel. Let this
+stand several hours, and pour off the water very carefully. Set the
+deposit in the sun, or by a stove to dry. When perfectly dry,
+pulverize, and it is ready for use. With a little trouble you will
+obtain in this way a much better article than can generally be bought
+of dealers. For the last washing, alcohol, or a mixture of alcohol and
+water, is preferable.”
+
+Potassa Solution.—The use of a solution of potassa in the preparation
+of the plate was suggested in the early history of the Daguerreotype.
+It was thought to possess some peculiar property for improving the tone
+of the impression. It is used for moistening the rotten stone in
+polishing the plate, and may be prepared by putting about an ounce and
+a half of alcohol in a close bottle, and add half a stick of caustic
+potash. This will soon become of a deep red color. For use, fill your
+small bottle, having a quill in the cork, with alcohol, and add a few
+drops of the above, or enough to change it to a bright orange or
+saffron color.
+
+A Substitute for the Hyposulphite Solution.—M. DAGUERRE recommends the
+use of a solution of salt water for removing the coating off the plate.
+I found this of some service at one time during my travels. My
+hyposulphite bottle got broke and its contents lost, so as only to
+leave enough for preparing gilding. I resorted to the use of salt
+solution, and found it to answer well. Make a saturated solution of
+salt in water. First wash the plate with clear water; then immerse it
+in the saline solution, when it should be agitated, and the coating
+will soon disappear. Another process with a salt solution of half the
+strength of the above is very interesting and effectual. The plate
+having been dipped into cold water, is placed in a solution of common
+salt, of moderate strength; it lies without being acted upon at all;
+but if it be now touched on one corner with a piece of zinc, which has
+been scraped bright, the yellow coat of iodine moves off like a wave
+and disappears. It is a very pretty process. The zinc and silver
+forming together a voltaic pair, with the salt water intervening,
+oxidation of the zinc takes place, and the silver surface commences to
+evolve hydrogen gas; while this is in a nascent condition it decomposes
+the film of iodide of silver, giving rise to the production of
+hydriodic acid, which is very soluble in water, and hence instantly
+removed.
+
+This process, therefore, differs from that with hyposulphite. The
+latter acts by dissolving the iodide of silver, the former by
+decomposing it. It is necessary not to leave the zinc in contact too
+long, or it deposits stains, and in large plates the contact should be
+made at the four corners successively, to avoid this accident.
+
+Gilding Solution.—To one pint of pure rain or distilled water add
+fifteen grains of pure chloride of gold, and to another pint add sixty
+grains of hyposulphite of soda. When dissolved, pour the gold solution
+into the hyposulphite by small quantities, shaking well after each
+addition. The soda solution must not be poured into the gold, as the
+gold would be immediately decomposed, and the solution turn black, and
+be unfit for use.
+
+Some operators add muriate of potash and other substances, but these do
+not possess any advantage except in cases where it is necessary to
+bleach the solarized portions of the impression, and when such is the
+case, chloride of sodium (common salt) is probably as effective and is
+the most convenient. Add about a teaspoonful to two ounces of the
+gilding.
+
+Solution, for Increasing the Brilliancy of the Daguerreotype.—This
+solution will have the effect to thoroughly cleanse the surface of the
+gilded plate and excite a powerful influence on the general character
+of the impression. To a solution of three ounces of water, in which is
+dissolved a quarter of an ounce of cyanide of potassium, add one
+teaspoonful of a solution containing six ounces of water and half an
+ounce of each pure carbonate of potash, alum, common salt, gallic acid,
+sulphate of copper, and purified borax. While the plate is wet, pour on
+a little, and heat it with a powerful blaze. The effect will be quickly
+produced, in from three to fifteen seconds. Rinse and dry, as in the
+gilding.
+
+Bleaching Solution.—Make a saturated solution of muriate of ammonia
+(sal ammoniac) in pure water, and filter through paper. Reduce with an
+equal quantity of water when used. When the linen or any other portion
+of the impression is badly solarized, after removing the coating, rinse
+with water; then pour this upon the surface in the same manner as the
+gilding solution. If the solarization be very deep, apply the lamp
+beneath, and warm the plate a trifle. Now pour off, and, without
+rinsing, apply the gilding. The whole operation must be quickly
+performed, or the chlorine soon attacks the shades of the picture. When
+properly done, however, the solarized parts are restored to a clear,
+transparent white.
+
+Electro, or Cold Gilding.—This process I have adopted, and it produces
+exceedingly beautiful impressions for the stereoscope, adding a great
+charm to the pleasing effect of that instrument. It also possesses a
+pretty and curious effect on views. It is easy of trial, and may be
+used by dissolving one gramme of chloride of gold in half a litre of
+ordinary water, and thirty grammes of hyposulphite of soda in another
+half litre of similar water; then pour the solution of chloride of gold
+into that of soda, by little and little, agitating it exactly as in M.
+Fizeau’s preparation, of which there is but a variation.
+
+When you wish to use it, pour some into a plate, or any other vessel of
+the same kind, sufficient to cover the proof; then, after having added
+to it a drop of ammonia, immerse the plate in it as soon as you take it
+out of the mercury-box, after having wiped its back and edges, and
+agitate the mixture quickly from right to left, so as to dissolve
+rapidly the coating of iodide of silver as usual. As soon as the plate
+appears white, cease all rapid motion, but continue to give it a slight
+undulating one; for if it were allowed to remain still for only a few
+minutes, the proof would be clouded. By little and little, the surface
+of the plate takes a yellow tint, which darkens more and more,
+approaching to bistre. You stop therefore, at the color you wish; and
+when the proof has been washed and dried, in the manner previously
+explained, it will be found to be fixed, without any stain, with a
+limpid surface, and an extraordinary warm tone. If you were to augment
+the proportions of the ammonia or chloride of gold, the operation would
+progress much quicker, but then the middle of the proof would be always
+much clearer than towards the border. The mixture may be used several
+times without being renewed. It does not, however, give such a
+beautiful color to the impression as when it is newly prepared. By
+communicating to the vessel containing the solution a continual motion,
+the impression, when once immersed, will be fixed. During that time,
+and while attending to anything else, watch its color; and at the end
+of ten minutes or a quarter of an hour, take it out of the bath and dry
+it.
+
+Agent for Neutralizing Bromine, Chlorine, and Iodine Vapors.—Aqua
+ammonia, sprinkled about the chemical or coating room, will soon
+neutralize all the vapor in the atmosphere of either chlorine, bromine,
+or iodine. No operator should be without, at least, a six-ounce bottle
+filled with ammonia. A little of its vapor about the camera-box has a
+decided and happy effect. Burnt coffee, pulverized, has also the
+property of destroying the vapors of the above chemicals, as also
+almost any other agent employed about the Daguerreotype room. Its
+deodorizing properties are such that if brought in contact with air
+filled with the odor of decomposing meat, it will instantly destroy all
+disagreeable smell. It can easily be used in the Daguerreotype room by
+placing a little of the raw bean, finely pulverized, on an old plate,
+and roasting it over the spirit-lamp.
+
+Buff Dryer.—There are various methods for keeping buffs dry and free
+from dust. Some place a sheet of iron against the wall at an angle
+sufficient to put a lamp between it and the wall, and then let the buff
+rest against the top of the sheet. By this method the buff is for its
+full length close to the heated iron, and at the same time exposed to
+the heated atmosphere and any dust that may be free. I would recommend
+some arrangement by which the buff would be inclosed. I have found the
+following to answer the purpose well, which is a box of sheet iron
+twenty inches long, eight wide and five high, with one end left open
+and the other closed; the cover is made of the same material, with the
+edges bent over to go on and off. There are several wires running
+through the centre of the sides, which it is necessary to cover with
+cloth or paper to absorb all the moisture that may be made by applying
+the heat, and the buffs are put in and taken out at the open end. In
+order that the heat may be as nearly uniform as possible, an iron bar
+one inch wide, eighteen inches long and one half inch thick, is so bent
+that the centre is one quarter inch from the bottom of the box, and
+that at least two inches of each end come in contact with the bottom;
+this being riveted on the bottom, and a lamp with a small blaze applied
+to the centre of the bar of iron. This will constitute one of the best
+and cheapest buff dryers in use. It may be suspended from the wall by
+placing wires around it, or it may stand upon legs. Perhaps a more
+convenient plan is to place it under the workbench in a similar
+position to a drawer. One precaution is necessary: when first heating
+the dryer, apply but a very gentle heat. This will prevent an
+accumulation of moisture, which would otherwise pass off in steam,
+coming in contact with the buff, thus causing a dampness. Another
+caution: never have the temperature of the air in the heater more than
+ten degrees above that which surrounds it.
+
+When wheels are used, they should be encased in a sheet iron or wood
+case. All those made for our market are provided in this respect.
+
+Keeping Buffs in Order.—This is one of the most important objects to
+arrest the attention of the operator. Every buff is more or less liable
+to get out of order by dust falling upon or coming in contact with the
+polishing powder employed in cleaning the plate. The edge of every
+plate should be thoroughly wiped and freed from any material that may
+adhere while cleaning. I have adopted the following method, which
+proves highly successful:
+
+Rub the buff leather, holding the face down, with the sharp edge of a
+pair of shears or a piece of glass. This brings out any portion of the
+skin which may have become matted from any moisture, and also takes out
+any substance imbedded in it, and prevents it from scratching. Then,
+with a stiff brush, rub the buff well, and it will be found to work
+well. This same process employ on wheels and hand buffs every morning,
+or oftener, as occasion requires.
+
+Preparing Buffs.—Two of these are necessary. That part of the stick to
+be covered should be about eighteen or twenty inches long, and three
+wide, and made crowning on the face from one end to the other, about
+one half inch. Before covering, these are to be padded with two or
+three thicknesses of Canton flannel. The buff should not be too hard,
+but padded with flannel, so that by drawing it over the plate, it may
+touch across the surface. The only proper material for buffs is
+prepared buckskin; and if prepared in a proper manner, this needs
+nothing but to be tacked upon the stick. There are several varieties of
+wheels employed; the one most generally adopted is Lewis’ patent, which
+consists of several varieties of wheels. Any operator can make a
+suitable wheel on the same plan of a turning lathe.
+
+To Clean Buckskins.—When the operator is compelled to purchase an
+unprepared buckskin, the following is a good process for cleaning it:
+There is always in the buckskin leather that is purchased, more or less
+of an oily matter, which is acquired in its preparation, sometimes even
+amounting, to a third of its weight. The following is the mode of
+ridding it of this noxious ingredient: Dissolve, in about six or seven
+quarts of filtered water, about five ounces of potash; when dissolved,
+wash with the solution an ordinary buckskin; when it has been well
+stirred in the liquid, the water becomes very soapy, owing to the
+combination of the potash with the oily matters contained in the skin.
+Throw away this solution and use some fresh water without potash and
+rather tepid; change it several times until it remains quite limpid.
+Then gently stretch the skin to dry in an airy shaded place. When
+thoroughly dried, rub it well between the hands. It thus becomes very
+pliant and velvet-like.
+
+Reflectors for Taking Views.—There have been excellent cameras
+introduced for taking views, but the time of exposure, which is
+increased in proportion to the focal length, is considered an
+objection; consequently many adhere to the old plan of using the
+speculum, or rather, substitute a mirror. I now have one which I have
+used for several years and find it equal to any article of the kind
+have ever tried. One is easily made by a tin man, at a trifling
+expense. Procure a piece of best plate looking-glass, two and a half by
+five inches for a quarter, or four by eight for a half-sized camera;
+put a piece of pasteboard of the same size on the back, to protect the
+silvering, and stick around the edge in the same manner as in putting
+up a picture. Take a sheet of tin for the large size, or a half sheet
+for the other; place the glass crosswise in the centre; bend the ends
+of the tin over the edge of the glass and turn them back so as to form
+a groove to hold the glass, and still allow it to slide out and in.
+These ends of the tin must be turned out flaring, that they may not
+reflect in the glass.
+
+Have a tin band about an inch wide made to fit close on the end of the
+camera tube; place it on, and taking the tin containing the glass,
+bring it to an angle of forty-five degrees with the tube, extending
+nearly the whole length of the glass in front of the lenses; lap the
+loose ends of the tin on each side of the tin rim, and having your
+camera turned on the side to throw the view lengthwise, arrange the
+exact angle by examining the image on the ground-glass. When you have
+it exactly right, hold it while it is soldered fast to the band. Take
+out your glass and stain the tin black, to prevent reflection.
+
+
+
+
+CHAPTER III.
+
+CHEMICALS.
+
+
+Bromine and its Compounds—Iodine and its Compounds—Chlorine and its
+compounds—Cyanide of Potassium—Hyposulphite of Soda—Hyposulphite of
+Gold—Nitric Acid—Nitro-Muriatic Acid—Hydrochloric Acid—Hydrofluoric
+Acid—Sulphuric Acid—Accelerating Substances—Liquid Sensitives—Dry
+Sensitives, etc., etc.
+
+BROMINE.
+
+An article so extensively used in the practice of the Daguerreotypic
+art as Bromine, is deserving of especial attention, and accordingly
+every person should endeavor to make himself familiar with its
+properties and applications.
+
+History.—This element was discovered in 1826 by M. Balard, in the
+mother-liquor, or residue of the evaporation of sea-water. It is named
+from its offensive odor (bromos, bad odor). In nature it is found in
+sea-water combined with alkaline bases, and in the waters of many
+saline springs and inland seas. The salt springs of Ohio abound in the
+compounds of bromine, and it is found in the waters of the Dead Sea.
+The only use which has been made of bromine in the arts is in the
+practice of photography. It is also used in medicine In a chemical
+point of view it is very interesting, from its similarity in
+properties, and the parallelism of its compounds to chlorine and
+iodine.
+
+Dr. D. Alter, of Freeport, Pa., is the only American manufacturer, and
+furnishes all of the “American Bromine.” Yet we understand much
+purporting to be of German manufacture is prepared from that made in
+Freeport. This is done by individuals in this city, who get well paid
+for the deception.
+
+For the successful application of bromine as an accelerating agent, we
+are indebted to Mr. John Goddard of London, who at the time was
+associated with Mr. John Johnson, now a resident of this city.
+
+Preparation.—The mother-liquor containing bromides is treated with a
+current of chlorine gas, which decomposes these salts, setting the
+bromine free, which at once colors the liquid to a reddish brown color.
+Ether is added and shaken with the liquid, until all the bromine is
+taken up by the ether, which acquires a fine red color and separates
+from the saline liquid.
+
+{74}
+
+Solution of caustic potash is then added to the ethereal solution,
+forming bromide of potassium and bromate of potash. This solution is
+evaporated to dryness, and the salts being collected are heated in a
+glass retort with sulphuric acid and a little oxide of manganese. The
+bromine is distilled, and is condensed in a cooled receiver, into a red
+liquid.
+
+Properties.—Bromine somewhat resembles chlorine in its odor, but is
+more offensive. At common temperatures it is a very volatile liquid, of
+a deep red color, and with a specific gravity of 3, being one of the
+heaviest fluids known. Sulphuric acid floats on its surface, and is
+used to prevent its escape. At zero it freezes into a brittle solid. A
+few drops in a large flask will fill the whole vessel when slightly
+warmed, with blood red vapors, which have a density of nearly 6.00, air
+being one. It is a non-conductor of electricity, and suffers no change
+of properties from heat, or any other of the imponderable agents. It
+dissolves slightly in water, forming a bleaching solution.
+
+Chloride of Bromine.—This as an accelerating agent is by many
+considered superior {75} to the other Bromide combinations. It can be
+readily prepared by passing a current of chlorine through a vessel
+containing bromine. A mixture of two parts muriatic acid and one of
+black oxide of manganese, should be put into a flask having a bent tube
+to conduct the chlorine vapor into the bromine in another vessel. This
+last vessel should also be supplied with a bent tube for conducting the
+combined vapors with a third vessel or receiver. On the application of
+the heat from a spirit lamp to the bottom of the flask, a current of
+chlorine gas will be disengaged, and pass into the bromine, when it
+readily combines, and gives off a vapor, which, when condensed in the
+third vessel, forms a volatile yellowish-red liquid. It is best, even
+at ordinary temperature, to place the receiver in an ice bath. For
+manner of using, see farther on, under head of Accelerators.
+
+Bromides.—A bromide treated with oil of vitriol, disengages
+chlorohyadic acid; but vapors of bromine are constantly disengaged, at
+the same time imparting a brown color to the gas. If the bromide be
+treated with a mixture of sulphuric acid, and peroxide of manganese,
+bromide is only disengaged. A solution of a bromide gives, with of
+nitrate {76} silver, a light yellowish white precipitate of bromide of
+silver, which is insoluble in an excess of acid, and readily dissolves
+in ammonia. The precipitated bromide is colored by light like the
+chloride, but is immediately tinged brown, while the chloride assumes
+at first a violet hue. The bromides, in solution, are readily
+decomposed and chloride being set free, colors the liquid brown.
+
+In the whole range of heliographic chemicals there is probably not
+another collection less understood and being so productive of
+interesting investigation as the bromides.
+
+Bromide of Iodine.—M. de Valicours furnishes us with the best method
+for preparing this mixture:
+
+“Into a bottle of the capacity of about two ounces, pour thirty or
+forty drops of bromine, the precise quantity not being of importance.
+Then add, grain by grain, as much iodine as the bromine will dissolve
+till quite saturated. This point is ascertained when some grains of the
+iodine remain undissolved. They may remain in the bottle, as they will
+not interfere with the success of the preparation.
+
+“The bromide of iodine thus prepared, from its occupying so small a
+space, can very easily be carried, but in this state it is much too
+concentrated to be used. When it is to be employed, pour a small
+quantity, say fifteen drops, by means of a dropping-tube, into a bottle
+containing about half an ounce of filtered river water. It will easily
+be understood that the bromide of iodine can be used with a greater or
+less quantity of water without altering the proportion which exists
+between the bromine and iodine.”
+
+This article forms a very good dry accelerator, and is by some persons
+thought superior to all others, as it works with great uniformity, and
+is less liable to scum the plate in coating at high temperatures, or
+when the thermometer indicates a heat above 60 deg.
+
+Bromide of Potassium—Is prepared by mixing bromine and a solution of
+pure potass together, and evaporating to dryness; it crystallizes in
+small cubes, and dissolves readily in water. This agent is extensively
+employed in the paper and glass processes.
+
+Bromide of Lime. This the principal accelerator used in the American
+practice, and is the best of all dry combinations at present employed.
+There are many reasons why the dry is advantageous; these are too
+familiar to repeat.
+
+“The bromide of lime may be produced by allowing bromine vapor to act
+upon hydrate of lime for some hours. The most convenient method of
+doing this is to place some of the hydrate at the bottom of the flask,
+and then put some bromine into a glass capsule supported a little above
+the lime. As heat is developed during the combination, it is better to
+place the lower part of the flask in water at the temperature of about
+50 deg. Fah.; the lime gradually assumes a beautiful scarlet color, and
+acquires an appearance very similar to that of the red iodide of
+mercury. The chloro-iodide of lime may be formed in the same manner; it
+has a deep brown color. Both these compounds, when the vapor arising
+from them is not too intense, have an odor analogous to that of
+bleaching powder, and quite distinguishable from chlorine, bromine, or
+iodine alone.”
+
+Farther on, I have given, in connection with accelerators, a process I
+adopt, which is far less tedious and equally reliable.
+
+Bromide of Silver—May be formed by pouring an alkaline bromide into a
+solution of nitrate of silver, in the shape of a white, slightly
+yellowish precipitate, which is insoluble in water and nitric acid, but
+readily dissolves in ammonia and the alkaline hyposulphites. Chlorine
+easily decomposes bromide of silver, and transforms it into chloride.
+
+M. Biot has expressed his opinion, that it is not possible to find any
+substance more sensitive to light than the bromide of silver. This is
+true to a certain extent, but in combination with deoxidizing agents,
+other preparations have a decided superiority over the pure bromide of
+silver.
+
+Bromide of Gold—Is readily prepared by adding a little bromide to the
+brown gold of the assayers, and allowing it to remain some time under
+water, or assisting its action by a gentle heat. It forms a salt of a
+bright crimson color, but in its general properties is precisely
+similar to the chloride used in gilding.
+
+Bromide of Magnesia—Is prepared in the same manner as bromide of lime.
+
+This mixture is particularly adapted for hot climates, and is used in
+this country by some few who regard its use as a valuable secret.
+
+Bromide of Starch.—This preparation is much used, but not alone. It is
+combined with lime by putting about one part in measure of starch to
+four of lime. It is prepared by adding bromine to finely pulverized
+starch, in the same manner as bromide of lime. (See Accelerators.)
+
+Experiments with Bromine.—Place in a very flaring wine glass a few
+drops (say ten) of bromine, then place a small piece of phosphorus
+about one-twentieth of an inch in diameter. Place the latter on the end
+of a stick from five to ten feet in length. So place it that the
+phosphorus can be dropped into the glass, and in an instant combustion
+giving a loud report will be the result.
+
+b. Expose a daguerreotype plate to the vapor of bromine, it assumes a
+leaden-grey color, which, blackens by light very readily. Exposing this
+to mercury will not produce any decided action upon the lights. Immerse
+it in the solution of the muriate of soda, and the parts unacted upon
+by light becomes a jet black, while the parts on which the light has
+acted will be dissolved off, leaving a clean coating of silver. This
+will be a most decided black picture on a white ground.
+
+c. Expose an impressioned plate, that has been sufficient time in the
+camera to become solarized, to the vapors of bromine, and the
+impression will be fully developed and exhibit no signs of
+solarization. The exposure over the bromine most be very brief.
+Chlorine or iodine will produce the same result. The latter is
+preferable.
+
+Again, should the impressioned plate be exposed too long over the vapor
+of bromine, the impression would be rendered wholly insensitive to the
+mercurial vapor. Hence this method is resorted to for restoring the
+sensibility of the plate when there is reason to believe that the
+impression would not be a desirable one; as, for example, if a likeness
+of a child be wanted, and it had moved before the plate had been
+sufficiently long exposed in the camera, the plate may be restored to
+its original sensitiveness by re-coating over bromine, as above, thus
+saving the time and labor of re-preparing the plate for the chemicals.
+
+d. If by accident (we would not advise a trial to any extent of this),
+you should inhale a quantity of the vapor of bromine, immediately
+inhale the vapor of aqua ammonia, as this neutralizes the dangerous
+effect of the bromine vapor. Every operator should be provided with a
+bottle of ammonia, as a little sprinkled about the chemical room soon
+disinfects it of all iodine or bromine vapor, and also tends to
+facilitate the operation in the camera.
+
+IODINE.
+
+History of Iodine.—This is one of the simple chemical bodies which was
+discovered in 1812 by M. Courtois, of Paris, a manufacturer of
+saltpetre, who found it in the mother-water of that salt. Its
+properties were first studied into by M. Gay Lussac. It partakes much
+of the nature of chlorine and bromine. Its affinity for other
+substances is so powerful as to prevent it from existing in an isolated
+state. It occurs combined with potassium and sodium in many mineral
+waters, such as the brine spring of Ashby-de-la-Zouche, and other
+strongly saline springs. This combination exists sparingly in
+sea-water, abundantly in many species of fucus or sea-weed, and in the
+kelp made from them. It is an ingredient in the Salt Licks, saline, and
+brine springs of this country, especially of those in the valley of the
+Mississippi. It is sparingly found in fresh-water plants, as well also
+in coal, and in combination with numerous other bodies.
+
+Fermented liquors contain iodine; wine, cider, and perry are more
+iodureted than the average of fresh waters. Milk is richer in iodine
+than wine; independently of the soil, with which it varies, the
+proportion of iodine in milk is in the inverse ratio of the abundance
+of that secretion. Eggs (not the shell) contain much iodine. A fowl’s
+egg weighing 50 gr. contains more iodine than a quart of cow’s milk.
+Iodine exists in arable land. It is abundant in sulphur, iron, and
+manganese ores, and sulphuret of mercury: but rare in gypsum, chalk,
+calcareous and silicious earths. Any attempt to extract iodine
+economically should be made with the plants of the ferro-iodureted
+fresh waters. Most of the bodies regarded by the therapeutists as
+pectoral and anti-scrofulous are rich in iodine.
+
+It is probably to the application of this body that we owe the
+discovery of the daguerreotype. There is no record of the precise date
+when Daguerre commenced experimenting with iodine, but by the published
+correspondence between him and M. Neipce, his partner, it was previous
+to 1833. There is no doubt, however, that the first successful
+application was made in 1838, as the discovery was reported to the
+world early in January, 1839.
+
+Preparation.—Iodine is mostly prepared from kelp, or the half vitrified
+ashes of seaweed, prepared by the inhabitants of the western islands,
+and the northern shores of Scotland and Ireland. It is treated with
+water, which washes out all the soluble salts, and the filtered
+solution is evaporated until nearly all the carbonate of soda and other
+saline matters have crystallized out. The remaining liquor, which
+contains the iodine, is mixed with successive portions of sulphuric
+acid in a leaden retort, and after standing some days to allow the
+sulphureted hydrogen, etc., to escape, peroxide of manganese is added,
+and the whole gently heated. Iodine distills over in a purple vapor,
+and is condensed in a receiver, or in a series of two-necked globes.
+
+Properties.—Iodine is solid at the ordinary temperature, presenting the
+appearance of dark-grey or purple spangles, possessing a high degree of
+metallic lustre. It somewhat resembles plumbago, with which it is
+sometimes diluted, particularly when it is fine. Operators should
+endeavor to secure the larger crystals. It melts at 224.6 deg., forming
+a brown or nearly black liquid. It boils at about 356 deg., and emits a
+very deep violet colored vapor. It gives off a very appreciable vapor,
+sufficient for all purposes of forming the iodide of silver on the
+daguerreotype plate, at a temperature of 45 deg. or even lower. Iodine
+crystallizes readily. Every operator has found upon the side of the jar
+in his coating-box, perfectly regular crystals, deposited there by
+sublimation.
+
+Water dissolves but a small proportion of iodine, requiring 7000 parts
+of water to dissolve one of iodine, {85} or one grain to the gallon of
+water. Alcohol and ether dissolve it freely, as does a solution of
+nitrate or hydrochlorate of ammonia and of iodides.
+
+The density of solid iodine is 4.95; that of its vapor 8.716. It
+greatly resembles chlorine and bromine in its combinations, but its
+affinities are weaker. It does not destroy the majority of organic
+substances, and vegetable colors generally resist its action. It
+combines with several organic substances, imparting to them peculiar
+colors. It colors the skin brown, but the stain soon disappears.
+
+Chloride of Iodine—Is formed by passing chlorine into a bottle
+containing some iodine. This can be readily done by pouring one ounce
+and a half of muriatic acid upon a quarter of an ounce of powdered
+black oxide of manganese, and heat it gradually in a flask, to which is
+adapted a bent glass tube. This tube must connect with the bottle
+containing the iodine, and the yellowish-green gas disengaged will
+readily combine with the iodine, forming a deep red liquid, and the
+operation is complete. The use of chloride of iodine will be referred
+to in connection with the Accelerators.
+
+{86}
+
+Iodides.—The iodide treated with the oil of vitriol, instantly produces
+a considerable deposit of iodine; and if the mixture be heated, intense
+violent vapors are disengaged. The reaction is due to the decomposition
+of oil of vitriol by iodohydric acid, water and sulphurous acid being
+formed, and iodine set free. The iodides in solution are decomposed by
+chlorine, iodine being precipitated, the smallest quantity of which in
+solution is instantly detected by its imparting to starch an intensely
+blue color.
+
+Iodide of Potassium.[4]—This compound is easily made in the following
+manner: Subject to a moderate heat a mixture of 100 parts of iodine, 75
+of carbonate of potash, 30 of iron filings, and 120 parts of water.
+This mass must be thoroughly dried and then heated to redness; the
+resulting reddish powder is to be washed with water, and the solution
+obtained filtered, and evaporated to dryness. It is found that 100
+parts of iodine yield 135 parts of very white, but slightly alkaline,
+iodide of potassium.
+
+ [4] I shall present the preparation of only a few iodides, and such as
+ are more intimately connected with the Daguerreotype.
+
+Experiment.—On projecting dry pulverized iodide of potassium into fused
+anhydrous phosphoric acid, a violent disengagement of iodine takes
+place, attended by a transient ignition; fused hydrate of phosphoric
+acid liberates iodine abundantly from iodide of potassium; this
+reaction is accompanied by the phenomenon of flame and formation of a
+considerable quantity of hydriodic acid.
+
+Iodide of Mercury.—For the preparation of iodide of mercury, Dublanc
+recommends to cover 100 grms. of mercury with 1 kilogrm. of alcohol, to
+add 124 grms. of iodine gradually in portions of ten grms., and
+agitating between each fresh addition, until the alcohol becomes
+colorless again. After the addition of the last 4 grms. the alcohol
+remains colored, the whole of the mercury having become converted into
+iodide. The resulting preparation is washed with alcohol; it is
+crystalline and of a hyacinth color.
+
+Iodide of Silver.—This compound is formed upon every plate upon which a
+Daguerreotype is produced. The vapor of iodine coming in contact with
+the silver surface, forms an iodide which is peculiarly sensitive to
+light.
+
+The various colors produced are owing to the thickness of the coating,
+and the maximum sensibility of the coating, as generally adopted, is
+when it assumes a deep yellow, or slightly tinged with rose color.
+
+This compound is largely employed in most photographic processes on
+paper, and may be easily prepared by the following formula: By adding
+iodide of potassium to a solution of nitrate of silver, a
+yellowish-white precipitate of iodide of silver is obtained, which is
+insoluble in water, slightly soluble in nitric acid, and soluble in a
+small degree in ammonia, which properties seem easily to distinguish it
+from the chloride and bromide of silver. Chlorine decomposes it and
+sets the iodine free, and chlorohydric acid converts it into a
+chloride. It fuses below a red heat. Although the effect of light on
+the iodide is less rapid than on the chloride, the former sooner
+turning black, assuming a brown tinge; but when in connection with
+gallic acid and the ferrocyanate of potash, it forms two of the most
+sensitive processes on paper.
+
+Iodide of silver dissolves easily in a solution of iodide of potassium,
+and the liquid deposits in evaporation crystals of a double iodide.
+
+Iodide of Gold.—If a solution of potassium be added to a solution of
+chloride of gold, a precipitate of iodide of gold takes place, soluble
+in an excess of the precipitate. A little free potash should be added
+to combine with any iodide that may chance to be set free by the
+chloride of gold.
+
+Iodide of Lime is prepared by adding iodine to hydrate of lime (which
+will be referred to farther on) until the mixture assumes a light
+yellow shade, when wanted for combinations with accelerators, or to a
+dark brown when employed for the first coating. This latter mixture has
+been sold in our market under the name of “Iodide of Brome.”
+
+Iodide of Bromine.—(See page 76.)
+
+Experiments with Iodine.—Place a plate which has been exposed in the
+camera over the vapor of iodine for a very brief period, and it will
+present the appearance of the impression having been solarized.
+
+b. Upon a Daguerreotype plate, from which an impression has been
+effaced by rubbing or otherwise, the picture may be made to reappear by
+merely coating it over with iodine.
+
+c. Place in a vessel a little water, into which put the smallest
+possible quantity of free iodine and add a little starch, and the
+liquid will instantly assume a blue color. Advantage is taken of this
+fact in the laboratory to detect the presence of iodine in liquids. The
+starch should be dissolved in boiling water and allowed to cool. There
+are numerous other interesting experiments that can be performed by the
+aid of iodine, but it is unnecessary here to consume more space.
+
+CHLORINE.
+
+History.—The Swedish chemist, Scheele, in 1774, while examining the
+action of hydrochloric acid on peroxide of manganese, first noticed
+this element. He called it dephlogisticated muriatic acid. It was
+afterwards, by the French nomenclaturists, termed oxygenated muriatic
+acid, conceiving it to be a compound of oxygen and muriatic acid. This
+view of its notice was corrected by Sir H. Davy (in 1809), who gave it
+the present name. In 1840-41, this gas vas employed for accelerating
+the operation of light upon the iodized Daguerreotype plate. John
+Goddard, Wolcott & Johnson, Claudet, Draper, Morse and others, were
+among the first made acquainted with its use. Count Rumford, Ritter,
+Scheele, Seebert and others, experimented with chlorine in regard to
+its effect when exposed to the action of light in combination with
+silver. In 1845, M. Edward Becquerel announced that he had “been
+successful in obtaining, by the agency of solar radiations, distinct
+impressions, of the colors of nature.”
+
+On the 4th of March, 1851, Neipce, St. Victor, a former partner of
+DAGUERRE, announced that he had produced “all the colors by using a
+bath of bichloride of copper, and that a similar phenomenon occurs with
+all salts of copper, mixed with chlorine.”
+
+Preparation.—This is easily accomplished by putting about two parts of
+hydrochloric (muriatic) acid on one of powdered black oxide of
+manganese, and heating it gradually in a flask or retort, to which may
+be adapted a bent glass tube. A yellowish-green gas is disengaged,
+which being conducted through the glass tube to the bottom of a bottle,
+can readily be collected, being much heavier than the air, displaces it
+completely and the bottle is filled (which can be seen by the green
+color); a greased stopper is tightly fitted to it, and another bottle
+may be substituted.
+
+In all experiments with chlorine, care should be taken not to inhale
+the gas!
+
+Properties.—Chlorine is a greenish-yellow gas (whence its name, from
+chloros, green), with a powerful and suffocating odor, and is wholly
+irrespirable. Even when much diluted with air, it produces the most
+annoying irritation of the throat, with stricture of the chest and a
+severe cough, which continues for hours, with the discharge of much
+thick mucus. The attempt to breathe the undiluted gas would be fatal;
+yet, in a very small quantity, and dissolved in water, it is used with
+benefit by patients suffering under pulmonary consumption.
+
+Under a pressure of about four atmospheres, it becomes a limpid fluid
+of a fine yellow color, which does not freeze at zero, and is not a
+conductor of electricity. It immediately returns to the gaseous state
+with effervescence on removing the pressure.
+
+Water recently boiled will absorb, if cold, about twice its bulk of
+chlorine gas, acquiring its color and characteristic properties. The
+moist gas, exposed to a cold of 32 deg., yields beautiful yellow
+crystals, which are a definite compound of one equivalent of chlorine
+and ten of water. If these crystals are hermetically sealed up in a
+glass tube, they will, on melting, exert such a pressure as to liquefy
+a portion of the gas, which is distinctly seen as a yellow fluid, not
+miscible with the water which is present. Chlorine is one of the
+heaviest of the gases, its density being 2.47, and 100 cubic inches
+weighing 76.5 grains.
+
+Chlorine Water.—This combination, which is used in conducting M.
+Neipce’s process, can be readily prepared by conducting the gas into a
+bottle containing distilled water. One part water dissolves two parts
+of chlorine.
+
+Chlorides.—The metallic chlorides are nearly all soluble in water; that
+of silver and protochloride of mercury being the only exceptions. A
+metallic chloride, treated with oil of vitriol, disengages chlorohydric
+acid. Heated with a mixture of peroxide of manganese and sulphuric
+acid, chlorine is given off, which is easily recognized by its odor and
+other physical properties.
+
+The chlorides dissolve in water; give with nitrate of silver, a white
+precipitate, even in highly diluted solutions, becoming violet colored
+and finally black when exposed to the light. The rapidity of the change
+of color is proportioned to the intensity of the light. It is insoluble
+in nitric acid, but readily soluble in ammonia; it fuses without
+decomposition, forming, when cold, a tough, horny mass, and is reduced
+by hydrogen and by fusion with carbonate of soda, or with resin.
+
+Chloride of Bromine. (See page 74.)
+
+Chloride of Iodine. (See page 85.)
+
+Chloride of potassium.—or (Muriate of Potassa).—Dissolve half an ounce
+of carbonate of potassa in water, and neutralize with muriatic acid.
+Upon concentrating the solutions, cubic crystals will be obtained,
+having a taste similar to common salt. They consist of potassium and
+chloride, and when dissolved in water they may be regarded as muriate
+of potassa.
+
+Chloride of Lime.—Mix half an ounce of slacked lime (hydrate of lime)
+with six ounces of water, and conduct into this milk of lime, with
+frequent agitation, as much chlorine gas as will evolve from two ounces
+of muriatic acid and half an ounce of black oxide of manganese. The
+liquid clarifies by standing; may be regarded as a solution of chloride
+of lime, and must be protected from the air and light. It may also be
+made without putting in the water with the hydrate of lime, by merely
+passing the chlorine into the hydrate of lime. This last is by some
+used in preparations for accelerating the operation of taking
+Daguerreotypes, but when used for this purpose it is in small
+quantities.
+
+Chloride of Calcium.—To one part of water add two parts of muriatic
+acid, and add pieces of common chalk until effervescence ceases; then
+filter through cotton cloth and evaporate it by placing it in all
+earthen or porcelain dish, over a slow fire, to the consistency of a
+syrup. When cooling, large prismatic crystals of chloride of calcium
+are formed. These must be quickly dried by pressing between folds of
+blotting paper and kept carefully excluded from the air, as it readily
+attracts hydrogen. For most daguerreotype purposes, the syrup may be at
+once evaporated to dryness. This is frequently placed in the iodine
+coating box for the purpose of keeping the atmosphere dry. It is so
+easily made that every operator can provide himself with it in a short
+time, and at little expense.
+
+Chloride of Gold.—Is prepared by dissolving gold in aqua regia, a
+composition of one part of nitric to two parts of muriatic acid. Gold
+foil is the best for our purposes; coin, however, answers, in most
+cases, for the daguerreotype operator, as the alloy, being so slight is
+not noticed in the gilding process. When the latter is used, it will
+facilitate the operation to beat it out, forming a thin sheet, and then
+cutting in small strips. Where purity is required, foil is better. The
+gold is placed in three or four times its own weight of the above
+acids. For this purpose, an evaporating dish is best (a common saucer
+will do); a moderate heat may be applied to favor the action. The
+mixture should be stirred often with a glass rod; care should be
+observed not to apply too much heat, for at a temperature of about 300
+deg. the chlorine would be expelled and leave a metallic precipitate,
+which would require re-dissolving. Acid may at any time be added if
+necessary to dissolve the gold, but it is advisable to add as little
+excess as possible, as it would require more time to evaporate. After
+all the gold has dissolved, and the liquid assumes a deep red color,
+the solution should be allowed to cool, being stirred nearly all the
+time. This salt is of a reddish-brown color. It is rarely we find in
+our market good chloride of gold, as common, salt is used for the bulk;
+and when the bottles are labelled “15 grains,” “20 grains,” nine-tenths
+do not in reality contain exceeding five grains of chloride of gold.
+The salt is mixed with the above solution when it is cooling, and gives
+bright yellow crystals, which some of our uninformed operators conceive
+to be the best quality.
+
+Chloride of Silver.—(Oxide of Silver.)—Take any quantity of silver coin
+or other silver, roll or hammer it thin; cut in small pieces. This in
+order to save time. Put the silver in a glass or earthen vessel
+(Florence flask is best); pour in nitric acid and water, about three
+parts of the former to one of the latter. The operation of cutting up
+the silver may be facilitated by applying a gentle heat. This blue
+solution consists of oxide of silver and oxide of copper, both combined
+with nitric acid. Should the operator wish a pure solution of silver,
+which, however, is not always used, he may obtain it in the following
+manner:
+
+To separate the two metals contained in the above solution from each
+other, put some bright copper coins into the solution and set it aside
+in a warm place for three or four days, occasionally giving it a
+circular motion. The separated laminae are pure silver, which is to be
+digested with ammonia until it ceases to be colored blue. The silver,
+after being washed and dried, is again dissolved in nitric acid, and
+the liquid, diluted with water, is kept as solution, of silver.
+
+Either of the above solutions (the one of oxide of silver and copper,
+and the pure silver solution) may be prepared for use by putting them
+in a bottle, with a quantity of water, and adding common fine salt, you
+obtain a white curdy precipitate of chloride of silver. No matter how
+much salt is used, provided enough be added to throw down all the
+chloride of silver. This solution should be well agitated and then
+allowed to stand for a few minutes; thus the white precipitate is in
+the bottom of the bottle. When the water has become clear, pour it off
+with care, leaving the sediment behind, then add a fresh quantity of
+clean water, shake, let settle, and pour off as before. Repeat the same
+for several times, and the excess of salt will disappear, leaving the
+white precipitate, which may be drained of the water and dried in the
+dark, and kept free from light and air.
+
+CYANIDE OF POTASSIUM.
+
+Cyanide of Potassium.—This important article is worthy the undivided
+attention of every Daguerreotypist. I here give Mr. Smee’s process for
+its preparation. This is from that author’s work entitled, “Electro
+Metallurgy,” American edition:
+
+“The cyanide of potassium, so often alluded to while treating of the
+metallo-cyanides, may be formed in several ways. It may be obtained by
+heating to a dull redness the yellow ferrocyanate of potash, in a
+covered vessel, filtering and rapidly evaporating it. The objection to
+this method, however, is that without great care the whole of the
+ferrocyanate is not decomposed, a circumstance which much reduces its
+value for electro-metallurgy. By boiling, however, the ignited residue
+with spirits of wine this difficulty is said to be overcome, as the
+ferrocyanate is absolutely insoluble in that menstruum, while the
+cyanuret, at that heat, freely dissolves, and is as easily re-deposited
+on cooling.
+
+“There is, however, a much better process by which this salt may be
+formed, viz. by simply transmitting hydrocyanic acid through potassium.
+Although the modes of making this acid are very numerous, there is but
+one which is likely to be employed on a very large scale, and that is
+its formation from the yellow ferrocyanate by means of sulphuric acid.
+This process is performed as follows: any given weight of the yellow
+salt is taken and dissolved in about five times its weight of water;
+this is placed in a retort, or some such analogous vessel, to which is
+then added a quantity of strong sulphuric acid, twice the weight of the
+salt, and diluted with three or four times its quantity of water. A
+pipe is carried from the neck of the retort to the receiving bottle,
+which should be kept as cool as possible.
+
+“For small operations, those invaluable vessels, Florence flasks,
+answer well: a bent tube being connected at one end to its month, the
+other passing into the second vessel; heat should be cautiously applied
+by means of an Argand lamp, a little vessel of sand being placed under
+the flask, which helps the acid to decompose the salt. Prussic acid is
+then generated and passes through the tube to the recipient vessel,
+which is to be charged with liquor potassae.
+
+“When the potash is saturated, the operation is completed. The Germans
+recommend a strong, alcoholic solution of potassa to be used in the
+second vessel, for in this case, the hydrocyanic or prussic acid
+combines with the potassa, forming a hydrocyanate of potassa, or, the
+water being abstracted, the cyanuret of potassium, which spontaneously
+precipitates, on the saturation of the fluid, the cyanuret, being
+insoluble in strong alcohol. The ferrocyanate of potash may be
+considered as containing three equivalents of hydrocyanic acid, two of
+potash and one of iron; but, unfortunately, we can only obtain half the
+acid from the salt, owing to the formation of a compound during its
+decomposition which resists the action of the acid. The decomposition
+of this salt taking 2 equivalents or 426 grains (to avoid fractions)
+would afford 3 equivalents or 81 grains of hydrocyanic, or prussic
+acid, capable of forming 198 grains of cyanuret of potassium, while in
+the retort there would remain 384 grains or 3 equivalents of bisulphate
+of potash, and 1 equivalent or 174 grains of a peculiar compound, said
+to contain 3 equivalents of cyanogen, 1 of potassium, and one of iron
+(Pereira). It is manifest that, but for this later compound, we might
+double the quantity of hydrocyanic acid from the yellow salt.”
+
+The decomposition just described is the one usually received; but too
+much reliance must not be placed on its accuracy, for the analysis of
+the several compounds is too difficult for the results to be fully
+admitted. The residue left in the retort speedily turns to one of the
+blues, identical with, or allied to, Prussian blue. This is at best a
+disagreeable process to conduct, for the hydrocyanic acid formed
+adheres so strongly to the glass, that, instead of being freely given
+off, bubbles are evolved suddenly with such explosive violence as
+occasionally to crack the vessel. This may be remedied as far as
+possible by the insertion of plenty of waste pieces of platinum—if
+platinized, so much the better, as that facilitates the escape of the
+gas. The heat should be applied to every part of the vessel, and the
+flame should not be allowed to play upon one single part alone. Large
+commercial operations are performed in green glass or stone-ware
+retorts.
+
+“Now for one word of advice to the tyro: Remember that you are working
+with prussic acid; therefore, never conduct the process in a room, the
+fumes being quite as poisonous as the solution of the acid itself;
+moreover, have always a bottle of ammonia or chlorine by your side,
+that should you have chanced to inhale more than is pleasant, it will
+be instantly at hand to counteract any bad effects. It is stated by
+Pereira, that a little sulphuric acid or hydroferrocyanic acid passes
+to the outer vessel, but probably the amount would be of no consequence
+for electro-metallurgy, otherwise, it might be as well to use a
+Woulfe’s apparatus, and discard the salt formed in the first vessel. To
+the large manufacturer it may be worth considering whether some other
+metallo-cyanuret, formed in a similar manner to the ferrocyanuret,
+might not be more advantageously employed, because the residue of the
+process last described contains a large quantity of cyanogen which the
+acid is unable to set free.
+
+“There are other modes of procuring prussic acid, besides the one which
+has been so tediously described; but these are found to be more
+expensive. The only one which I shall now notice is the process by
+which it is obtained from bicyanide of mercury. The bicyanide of
+mercury itself is formed when peroxide of mercury is digested with
+Prussian blue, the peroxide of mercury abstracting the whole of the
+cyanogen from the blue, and leaving the oxides of iron at the bottom of
+the vessel. The solution may be evaporated to dryness, and one part of
+the salt dissolved in six of water; one part of muriatic acid, sp. gr.
+1.15, is then added, and the solution distilled, when the whole of the
+hydrocyanic acid passes over, and by being conducted into a solution of
+potassa, as in the former process, forms cyanuret of potassium. This
+process, though easier than the first described, is rather given as a
+resource under peculiar circumstances than as one to be adopted by the
+large manufacturer. The expense is the only objection, but in a small
+quantity this cannot be a consideration.
+
+“In giving this very rough outline of the general mode of forming
+salts, the minutiae necessary for chemical work have altogether been
+avoided, and those parts alone are entered upon which are more
+immediately necessary for the electro metallurgist to know and practice
+for himself. This will account for the long description of the cyanuret
+of potassium, while the preparation of the equally important and even
+more used acids, the sulphuric, muriatic, etc., commonly found in
+commerce, are altogether neglected.
+
+“In using solutions of cyanide of potassium, the workman should not
+immerse his arms into them, otherwise it occasionally happens that the
+solution produces very troublesome eruptions over the skin.”
+
+HYPOSULPHITE OF SODA.
+
+Hyposulphite of Soda.—This salt forms one of the important chemicals
+for the Daguerreotype operator. Its application to this art is of an
+interesting nature. It is used to dissolve the sensitive salt of silver
+which remains unchanged during the exposure in the camera. It has the
+property of readily dissolving the chloride, bromide and iodide of
+silver. It should be pure and free from sulphuret of sodium; should
+this last be present, it will cause brown spots of sulphurated silver
+upon the Daguerreotype impression. This annoyance is a great source of
+complaint from many operators, and ever will be, so long as it is
+prepared by men who have no reputation to lose, and whose eyes are
+blinded by the “Almighty Dollar.”
+
+A good article may be prepared as follows:
+
+“Mix one pound of finely pulverized carbonate of soda with ten ounces
+of flowers of sulphur, and heat the mixture slowly in a porcelain dish
+till the sulphur melts. Stir the fused mass, so as to expose all its
+parts freely to the atmosphere, whereby it passes from the state of a
+sulphuret, by the absorption of atmospheric oxygen, into that of a
+sulphite, with the phenomenon of very slight incandescence. Dissolve in
+water, filter the solution, and boil it immediately along with flowers
+of sulphur. The filtered concentrated saline liquid will afford, on
+cooling, a large quantity of pure and beautiful crystals of
+hyposulphite of soda.”
+
+Hyposulphite of Gold.—This compound salt is by a few considered
+preferable to the chloride of gold, but our experience has induced us
+to use the latter, believing we are enabled to produce a more brilliant
+and warm-toned impression with it. When the hyposulphite of gold is
+used in gilding, it requires less heat and a longer application, as
+there is some danger of producing a glossy scum over some parts of the
+surface of the plate. I prepare this salt as follows:
+
+Dissolve one part chloride of gold and four parts hyposulphite of soda
+in equal quantities of distilled water: pour the gold into the
+hyposulphite solution, in the same manner as in mixing the gilding
+solution; let it stand until it becomes limpid; filter and evaporate to
+dryness. Re-dissolve and add a few grains of burnt alum.
+
+After standing a few hours, filter and evaporate again. If not
+sufficiently pure, repeat the crystallization until it is so. For
+gilding, dissolve in water and use in the same manner as the common
+gilding solution.
+
+N.B.—The four following mixtures were employed in Neipce’s process in
+his earliest experiments:
+
+Aqueous Solution of Bichloride of Mercury.—Eight grains of bichloride
+of mercury in 10,000 grains of distilled water.
+
+Solution of Cyanide of Mercury.—A flask of distilled water is saturated
+with cyanide of mercury, and a certain quantity is decanted, which is
+diluted with an equal quantity of distilled water.
+
+Acidulated White Oil of Petroleum.—This oil is acidulated by mixing
+with it one tenth of pure nitric acid, leaving it for at least 48
+hours, occasionally agitating the flask. The oil, which is acidulated,
+and which then powerfully reddens litmus paper, is decanted. It is also
+a little colored, but remains very limpid.
+
+Solution of Chloride of Gold and Platinum.—In order not to multiply the
+solutions, take the ordinary chloride of gold, used for fixing the
+impressions, and which is composed of 1 gramme of chloride of gold and
+50 grains of hyposulphate of soda, to a quart of distilled water.
+
+With respect to chloride of platinum, 4 grains must be dissolved in 3
+quarts of distilled water; these two solutions are mixed in equal
+quantities.
+
+Acids.—I shall not go into the preparations of the various acids
+employed in the Daguerreotype. This would be useless to the operator,
+as there are few, if any, that it would be advisable to prepare. It is
+only necessary for the experimenter to be made acquainted with their
+properties, and this in order to prevent any haphazard experiments,
+which are too common among operators. Any person who may be desirous to
+try an experiment, should first study the agents he wishes to employ.
+By so doing much time and money will be saved; while the searcher after
+new discoveries would rarely become vexed on account of his own
+ignorance, or be obliged to avail himself of the experience of others
+in any department of science.
+
+Nitric Acid—Exists in combination with the bases, potash, soda, lime,
+magnesia, in both the mineral and vegetable kingdoms, and is never
+found insoluble. It has the same constituents as common air, but in
+different proportions. The strongest nitric acid contains in every
+pound, two and a quarter ounces of water. Pure nitric acid is
+colorless, with a specific gravity of 1.5, and boiling at 248 deg.. It
+is a most powerful oxidizing agent, and is decomposed with more or less
+rapidity, by almost all the metals, to which it yields a portion of its
+oxygen.
+
+The nitric acid of commerce, is generally the article used by the
+Daguerreotypist. This usually contains some chlorine and sulphuric
+acid. It is obtained by the distillation of saltpetre with sulphuric
+acid. It is employed in the Daguerreotype process for dissolving
+silver, preparing chloride or oxide, nitrate of silver, [the former
+used in galvanizing,] and in combination with muriatic acid for
+preparing chloride of gold, used in gilding. It is also used by some
+for preparing the plate.
+
+Acidulated Solution.—This solution is used for cleaning the surface of
+the Daguerreotype plate. It has the property of softening the silver,
+and bringing it to a state in which it is very susceptible of being
+either oxidized or iodized, hence it contributes to increase the
+sensibility of the plate. The proportions are to one drop of acid add
+from 15 to 20 drops of water, or make the solution about like sharp
+vinegar to the taste.
+
+Nitro-Muriatic Acid.—Aqua Regia is a compound menstruum invented by the
+alchemists for dissolving gold. It is composed of colorless nitric acid
+(aqua-fortis) and ordinary muriatic acid; the mixture is yellow, and
+acquires the power of dissolving gold and platinum. These materials are
+not properly oxidized; it nearly causes their combination with
+chlorine, which is in the Muriatic acid.
+
+Hydrochloric Acid (Muriatic Acid).—This acid forms a valuable addition
+to the chemicals employed by the practical Daguerreotypist. This acid
+is formed by acting upon common salt (which is chloride of sodium) by
+concentrated sulphuric acid. The water of the acid is decomposed, and
+its hydrogen combines with the chloride of the salt to form muriatic
+acid, and this unites with the sulphuric acid to form sulphate of soda;
+60 parts of common salt and 49 parts of concentrated sulphuric acid,
+afford, by this mutual action, 37 parts of muriatic acid and 72 parts
+of sulphate of soda. The muriatic acid of commerce has usually a
+yellowish tinge, but when chemically pure it is colorless. The former
+is commonly contaminated with sulphurous acid, sulphuric acid,
+chlorine, iron, and sometimes with arsenic.
+
+Muriatic acid, from the fact of the presence of the chlorine, is used
+in the Daguerreotype process for dissolving gold, and in combination
+with various accelerators. Its presence can be detected by ammonia. A
+strip of paper dipped in this and waved to and fro will emit a thick
+white smoke if the acid vapor be in the atmosphere. The ammonia
+neutralizes the acid fumes. By reversing the experiment we can
+determine whether vapor of ammonia be in the air, and also deprive
+these suffocating and dangerous gases of their injurious properties,
+and remove them from the air. Every Daguerreotype operator should be
+furnished with, at least, a six ounce bottle of aqua ammonia. Its
+operation is very nearly the same on bromine and iodine vapor.
+
+Hydrofluoric Acid (Fluorohydric Acid).—This acid is used to form some
+of the most volatile and sensitive compounds employed in the
+Daguerreotype. It is one of the most dangerous bodies to experiment
+with: it is volatile and corrosive, giving off dense white fumes in the
+air. It combines with water with great heat. At 32 deg. it condenses
+into a colorless fluid, with a density 1.069. It is obtained from
+decomposition of fluorspar by strong sulphuric acid. It readily
+dissolves the silica in glass, and consequently cannot be kept in a
+vessel of that material. It is prepared and kept in lead. It is
+employed in accelerators on account of its fluorine.
+
+One small drop on the tongue of a dog causes death. The operator who
+wishes to use it should pour some of the liquid for which he intends it
+into a graduate, or other vessel, and then add the desired quantity of
+acid. If by accident any of the spray should fall upon the skin, it
+should at once be copiously drenched with water.
+
+Sulphuric Acid.—There are two sorts of this acid: one is an oily,
+fuming liquid; this is made in Nordhausen, in Saxony, and is commonly
+called “Nordhausen sulphuric acid,” or oil of vitriol. The other which
+is the kind used in connection with the Daguerreotype, is common
+sulphuric acid. It is somewhat thinner, and when undiluted is not
+fuming. This acid may be obtained in a solid and dry state, called
+anhydrous sulphuric acid.
+
+The common sulphuric acid is made by burning sulphur, which forms
+sulphurous acid. To convert this into sulphuric acid and gain more
+oxygen, nitric acid, which is rich in that body, is added. It forms a
+limpid, colorless fluid, of a specific gravity of 1.8. It boils at 620
+deg.; it freezes at 15 deg. It is acrid and caustic, and intensely acid
+in all its characters, even when largely diluted.
+
+Its attraction for basis is such that it separates or expels all other
+acids, more or less perfectly, from their combinations. Its affinity
+for water is such that it rapidly absorbs it from the atmosphere, and
+when mixed with water much heat is evolved. It acts energetically upon
+animal and vegetable substances, and is a poisonous, dangerous
+substance to get on the skin. It is a powerful oxidizing agent; hence
+its use in the galvanic battery, for which purpose it is mostly used by
+the Daguerreotypist. The fumes of this being so much more offensive
+than nitric acid, the latter is sometimes used. It is also employed in
+some of the more sensitive accelerators.
+
+ACCELERATING SUBSTANCES.
+
+Remarks on the Accelerating substances Used in the Daguerreotype.—I
+have now arrived at a point in this work, where the eye of the
+Daguerreotype public will intently search for something new. This
+search will prove in vain, at least so far as regards those who have
+enjoyed and embraced the opportunities for studying the principles of
+our art. Every experienced operator has in a degree become familiar
+with the mechanical uses of all the agents employed, while I fear but
+few understand the properties, and laws governing those properties,
+which are so indispensable to produce an image impressed upon the
+silver surface.
+
+There are three substances which form the bases for producing a
+Daguerreotype; silver, iodine and bromine. Each forms a separate body
+which is indispensable to the operators success as the art is now
+practiced in America. With these three, compounds of great variety are
+formed.
+
+The silver surface is first thoroughly cleaned and freed from all
+organic matter, then exposed to vapor of iodine, producing an iodide of
+silver. The plate upon which is this salt, is again exposed to the
+vapor of bromine, forming a bromo-iodide of silver, a salt also.
+
+As most of the various accelerators are compounds of bromine, with
+either chlorine or fluorine combination, they partake somewhat of the
+nature of these latter, giving results which can be detected by the
+experienced operator. Thus muriatic acid is added for its chlorine,
+which can generally be detected by the impression produced, being of a
+light, soft, mellow tone, and in most cases presenting a brilliant
+black to that colored drapery. Those who wish to experiment with agents
+for accelerating substances, should first study to well understand
+their peculiar nature and properties; as well, also, to endeavor to
+find out what will be the probable changes they undergo in combination
+as an accelerator. This should be done before making the experiments.
+From the foregoing it will be seen that numerous compounds are formed
+from the same basis, and, consequently, it would be a waste of time and
+a useless appropriation to devote more of our space than is necessary
+to give the principal and most reliable combination.
+
+In America, the words “Quick” and “Quick Stuff,” are more generally
+used for and instead of the more proper names, “Sensitives,” or
+“Accelerators,” etc. As it has by use become common, I frequently use
+it in this work.
+
+Liquid Accelerator, No. 1.—This mixture was used by me in 1849, and is
+given as it appeared in my “System of Photography,” published at the
+above date:
+
+Take pure rain or distilled water, one quart, filter through paper into
+a ground stopper bottle, and add, for warm weather, one and a half
+ounce chloride of iodine; or for cold, one ounce; then add one ounce
+bromine, and shake well. Now with care not to allow the vapor to
+escape, add drop by drop, thirty drops of aqua ammonia, shaking well at
+each drop. Care must be taken not to add more at a time, as it evokes
+too much heat. This mixed, in equal proportions with John Roach’s
+quick, forms an excellent chemical combination. For this purpose, take
+one and a half ounce of each, to which add ten ounces water, for warm
+weather, or from six to seven for cold. Pour the whole into a large
+box, and it will work from two to four months. I am now using (1849)
+one charged as above which has been in constant use for three months,
+and works uniformly well. The above is right for half or full size
+boxes, but half of it would be sufficient for a quarter size box.
+
+Coat to the first shade of rose over iodine, change to a deep rosy red
+over quick, and black about one tenth the first.
+
+I would not now recommend the addition of “John Roach’s quick,” as I
+believe equally good results can be produced without it. This liquid is
+now used by many, and is very good for taking views.
+
+Lime Water Quick.—This mixture is more used at present than all the
+other liquids ever introduced. It produced the most uniform results,
+giving the fine soft tone so characteristic in pictures produces from
+accelerators containing chlorine. To one quart of lime water (this can
+be had of any druggist) add one and a half ounce of pulverized alum.
+This should be shook at intervals for twenty—four hours; then add one
+ounce of chloride of iodine and three fourths ounce of bromine.
+
+Lime Water.—This is easily prepared by putting lime into water, say a
+piece of quick-lime about the size of an egg into one quart of water.
+This should be shook occasionally for two or three days and allowed to
+settle, when the water can be poured off and used.
+
+Use.—To one part of quick add six parts of water; coat to a light
+yellow over the iodine, to a rose color over the quick, and recoat
+about one tenth. The above coating may be increased or diminished, it
+matters not, so that there is not too much, and the proper proportions
+are preserved. Some add to the above a small quantity of magnesia, say
+about a teaspoonful to the quart of liquid.
+
+Liquid Accelerator, No. 2.—The following was for a long time used by
+one of the first houses in the United States, and probably was one of
+the first liquids ever used. It produces a fine-toned picture, but is
+not considered as sure as the lime water quick:
+
+Take rain water one quart, add pulverized alum until it is a little
+sour to the taste, and a small piece, say one half inch square, of
+magnesia. Filter through paper, and add chloride of iodine one half
+ounce, bromine sufficient to take it up, which is a little less than
+half an ounce.
+
+Charge with one of quick to six of water; coat over iodine to a soft
+yellow, nearly, but not quite, bordering on a rose; over quick to a
+dark purple, or steel, and back one sixth to one tenth.
+
+Wolcott’s American Mixture.—Van Loan Quick.—This mixture was first
+formed and used by T. Wolcott & Johnson and gained great celebrity for
+its productions. I have now a bottle hermetically sealed that contains
+about a half ounce of this mixture prepared in 1841 by John Johnson,
+now a resident of this city, and the former partner of Mr. Wolcott. The
+preparation of this mixture, as furnished by Mr. Johnson himself, is
+given as follows:
+
+“One part of bromine, eight parts of nitric acid, sixteen parts of
+muriatic acid, water one hundred parts. This mixture should be allowed
+to stand for several days; it improves by age.
+
+“Use.—A few drops say, 6 to 12, of this mixture, should be put into
+about 6 or 8 ounces of water; it will require frequent replenishing by
+the addition of a few more drops. The plate should be coated over the
+dry iodine to a red just bordering on a slate, and then exposed to the
+mixture only sufficiently long to change the color. If this is not done
+in less than six seconds it is not strong enough. Re-coat over the
+iodine full one fourth as long as first coating.”
+
+This exceedingly volatile compound is difficult to control from its
+instability; it is but little used. The impressions successfully
+produced by this mixture are very brilliant, and possess a pleasing
+peculiarity.
+
+DRY SENSITIVES.
+
+Hydrate of Lime.—The operation by which water is combined with lime is
+called slaking. Take a piece of quick lime, common lime used in mortar,
+and immerse it in warm water for about fifteen seconds; then place it
+in an iron or tin vessel. It will soon begin to swell, evolving a great
+deal of heat and emitting steam, and soon falls into a fine powder,
+hydrate of lime. This should be well stirred and allowed to cool, and
+then bottled in order to prevent it from giving off the hydrate and
+recovering the carbonic acid from the atmosphere. The last is
+detrimental to its use with bromine, and is one cause of the complaint
+that “it will not take bromine.” The hydrate of lime should, not be
+dried over a heat, as has been supposed by many, for in that case the
+hydrogen is expelled and it returns to a carbonate. It is advisable to
+cool it in a damp place like a ground cellar. Much of the lime in our
+market will not, except it be quite damp, combine with the bromine.
+This is owing to impurities. Nothing is equal to oyster-shell lime,
+which I use altogether.
+
+Bromide of Lime.—In preparing large quantities of this, we adopt the
+following method: Fill a four-quart bottle about two-thirds full of
+hydrate of lime; pour into this about one or two ounces of bromine;
+then shake well, add more of the bromine, shake well and let it stand
+for a few hours, adding sufficient bromine to give it a fine red color.
+It is better when kept in the large bottles, as it forms a more perfect
+combination: in other words it improves by age.
+
+Use.—Coat over the iodine to a rose red and then over this mixture to a
+purple or slate; recoat over the first about one fourth as long as
+first coating.
+
+Gurneys American Compound.—Of this compound there are two combinations,
+one for use, when the temperature of the atmosphere is above 65 or 70
+deg., and the other at a lower temperature. The first is called No. 1,
+the second No. 2.
+
+No. 1 is prepared by placing hydrate of lime in a bottle, say to three
+quarts of the hydrate of lime, add one ounce of pulverized burnt alum,
+and as much chloride of lime as can be put on a quarter of a dollar,
+and from 15 to 30 grains of dry pulverized iodine, or enough to change
+the color of the hydrate of lime, to the slightest possible tinge of
+yellow. There had better be less than carry the color to a deeper
+shade. The object of using the iodine is to form a compound with
+bromine that is not so volatile as the bromine itself. No matter how
+little iodine is combined with the bromine, the vapors possess their
+relative proportion; hence, only enough iodine to prevent “flaring,” or
+as it is often termed a “scum-coating,” is used. The iodine should be
+thoroughly combined with the lime, which will take about one or two
+days. Should add bromine the same as in bromide of lime, until the
+compound assumes a light red color.
+
+No. 2 is prepared in the same manner as No. 1, except the addition of
+the iodine, which is omitted.
+
+Use.—No. 1. Coat over the iodine to a bright yellow color, then over
+the compound, No. 1, to red color, recoat over iodine, about one sixth
+as long, as the time occupied in first coating.
+
+No. 2. Coat over iodine same as above, except recoat over the iodine
+about one fourth to one half as long as first coating.
+
+Dry Quick, No. 1.—Bromide of Lime and Starch.—The following compound
+forms an excellent accelerator, and is used by many. It is claimed for
+this preparation, that it will hold the bromine longer than others
+where starch is not employed. As regards this claim we do not think it
+can be substantiated. Our experience in practice has led us to the
+conclusion that there is no great difference as respects durability,
+but there is some little difference as regards the tone of the
+impressions produced by its use.
+
+To one quart of hydrate of lime add one quart of finely pulverized
+starch. To this mixture add bromine, until it assumes a deep yellow or
+pink color.
+
+Starch may be added to any of the dry mixtures.
+
+Use.—Coat over the iodine to a deep yellow, then over this quick to a
+red color, recoat about one sixth of the time of first coating.
+
+I will here again remark, that the exact color of the coating is not
+essentially provided a proper proportion is preserved.
+
+I have never seen it stated, though it be a fact worthy of note, that a
+proportionate time for coating over the iodine and accelerator, will
+not answer. For example: if a plate exposed to the vapor of iodine be
+perfectly coated in sixteen seconds, and then exposed to an
+accelerator, (not having iodine in its combination) receives its
+coating in four seconds, it will be found that a proper proportionate
+coating cannot be preserved by adopting, a proportion of time, but on
+the contrary, the time will diminish; for exposure over the
+accelerator, as in the above example, if it be desired to coat the
+plate with twice as much iodine as in the above example, the time would
+be, over iodine thirty-two seconds, and over the accelerator (to
+possess a proper proportion) from six to seven seconds. Hence it is
+that many inexperienced operators, when wishing to vary their usual
+manner of coating, fail in producing a favorable result. They coat
+calculating a proportion of time when they should not.
+
+Dry Quick, No. 2.—Bromide of Lime and Magnesia.—To one quart of hydrate
+of lime add one quart of magnesia, and mix them well together; add
+bromine same as in preparing bromide of lime; coat the same as over dry
+quick No. 1. This combination produces very uniform results, and is
+worked with much success by beginners.
+
+Chloro-Bromide of Lime.—To the bromide of lime add chloride of bromine
+until the mixture becomes a pale yellow color, resembling sulphur. It
+should be shook well, and enough of the chloride of bromine added to
+bring the compound to a deep blood red color.
+
+Use.—Coat over the iodine to a pink color, and then over the above to a
+red, or just changing the color. It should be remembered that
+accelerators containing chlorine do not admit of a great change of
+color of coating on the plate.
+
+Iodide of Starch.—This mixture can be employed for coating over in warm
+weather, and prevent the flashing resulting at high temperatures. It
+may be used the same as the iodide alone.
+
+To six ounces of finely pulverized starch, add one fourth ounce of dry
+iodine.
+
+Use.—Same as the dry iodine alone.
+
+The same combination may be made with lime, magnesia and other
+substances.
+
+Concentrated Solution of Iodine for First Coating.—It may appear
+strange to some of our old operators that an aqueous solution of iodine
+can be used for coating the plate and forming the iodide of silver. It
+has long been a cry among most operators that it is impossible to
+succeed when the iodine box contains dampness. Now this is a great
+mistake, and we will here state that in all cases where dampness
+appears upon a properly prepared Daguerreotype plate, it is the result
+of a different temperature of the metal from the air which surrounds
+it. Mr. Senter, of Auburn, was the first of our operators who used a
+solution of iodine for coating the plate, and we several years since
+saw his results, which would rival the production of any other
+operator. A concentrated solution of iodine is prepared by putting into
+a common bottle two thimblesful of hyposulphite of soda and a rather
+larger quantity of iodine, so that there may be more than sufficient.
+Add to it about 40 ounces of common water (heated to 60 or 70 degrees),
+by little and little, moving, the bottle to warm it, for fear of
+breaking. After shaking it a short time, the water is rapidly and
+strongly colored. The solution should be poured into a bottle with a
+ground stopper, and when cool used for iodizing.
+
+A solution of sufficient strength can be made by moistening or just
+covering the iodine with water.
+
+Chloride of Iodine as an Accelerator.—This is probably one of the best
+accelerators that can be used for coating the plate for taking views;
+it works too slow, however, to meet the wants of the operating room,
+yet its use was formerly, for a long time, adhered to by some of our
+best professors. In producing views with this, we are successful in
+obtaining well-developed impressions, with a depth of tone and richness
+of appearance not to be met with in the productions of any other
+substances. I give its use as furnished me by an old and experienced
+operator, and published in Humphrey’s Journal, vol. i. p. 180:
+
+“As the process of using chloride of iodine may be of interest to some
+of our subscribers, I take pleasure in giving the following
+manipulation. To one ounce of chloride of iodine add two ounces of
+water; place this mixture in a coating-box, the same as quick stuff;
+coat the plate with dry iodine to a light yellow, or lemon color; then
+bring the coating to a deep pink over the chloride. The plate must be
+recoated over the dry iodine.”
+
+This combination has been very successfully used in one of our most
+extensive establishments in this city, and the superiority of the
+pictures produced by it was considered as an equivalent for the
+additional time required to bring out the impressions.
+
+Chlorine as an Accelerator.—I shall here refer to but a single
+experiment in which I employed chlorine gas for coating the plate. I
+was provided with a retort, the neck of which was fitted to the jar of
+my coating-box, through a hole drilled for its reception. This was
+fitted perfectly tight in my coating-box. I placed some pure undiluted
+bromine water and the agents necessary for producing chlorine gas (in
+small quantity) in the retort. The result was that my first experiment
+produced an impression completely solarized in all its parts by an
+exposure of four seconds of time, which would have required an exposure
+of twenty seconds to produce a perfectly developed impression by the
+usual process.
+
+Another trial immediately produced one of the finest toned impressions
+I ever saw, perfectly developed in one second of time.
+
+My next two or three experiments proved total failures. I was unable to
+produce even a sign of an impression. By accident my retort was broken,
+and not being in a locality convenient to obtain another, my
+experiments were necessarily suspended.
+
+My attention was not called to this subject again for several years,
+when I noticed an account of some similar experiments by F. A. P.
+Barnard and Dr. W. H. Harrington, the latter of whom is now of the firm
+of Dobyns & Harrington, of New Orleans.
+
+From reading this article, I found my own difficulties explained. Too
+much of the chlorine gas was present in my coating jar. I would like to
+see some of our enterprising operators investigate this combination.
+
+It is a singular fact, that the vapors of bromine and chlorine
+combining upon the iodide of silver, produce a more sensitive coating
+than when the two are combined in solution, as in chloride of bromine
+solution. Those having Humphrey’s Journal at hand, can refer to vol. i.
+p. 142.
+
+To use Bromine Water or other Accelerators in Hot Weather.—An excellent
+plan for using bromine water is as follows:
+
+Fill a two-ounce bottle quarter full of it, and then fill the bottle
+with fine sand, which serves to preserve a low temperature; then place
+the bottle in a porous cup, same as used in the battery; fill this also
+with sand, and close the end with plaster of Paris. Place this in a
+coating-box, and it will be found to act with great uniformity and be
+quite permanent.
+
+Bromide of Lime, another accelerator, can be used in the same manner,
+except it is, only necessary, when a solid sensitive is used, to mix it
+with the sand without placing it in a bottle. This method is employed
+with great success by a few, who have regarded it as a secret worth
+keeping.
+
+A Combination, requiring the Use of only One Coating-box.—It is often
+wondered by beginners, why some solution requiring only one coating
+cannot be employed. This can be done, but the results are not so
+satisfactory as when two or more are employed. Such an accelerator may
+be produced by adding alcoholic solution of iodine to a solution of
+chlorate of potash, until the latter will take up no more of the
+former, and to each ounce, by measure of this solution, ten drops of a
+saturated solution of bromide in water are added. The solution of
+chlorate of potash is made by diluting, one part of a saturated
+solution of the salt with ten parts of water. The use of the chlorate
+is simply as a solvent of iodine.
+
+Fats as Accelerators.—The use of fats, oils, or greasy substances, has
+been one of the most emphatic prohibitions about the Daguerreotype
+plate. Yet it has been proved that its presence in a small quantity
+upon the silver surface has the effect of reducing the time of exposure
+in the camera from two-thirds to three-fourths. An application may be
+made as follows: Pour sweet oil, or rub beef or mutton fat, on a common
+buff, which is free from all polishing powders. With this, buff a
+well-cleaned plate, and it will leave a scum, which should be mostly
+removed by using another buff, which should be clean. Coat the plate in
+the usual manner, and the result will be a great reduction in the time
+of exposure in the camera. The impression produced upon a plate so
+prepared presents, when coming from the vapor of mercury, a grey,
+scummy appearance, which, on the application of heat in gilding, does
+not improve; hence its use is not generally adopted.
+
+We have instituted some investigations upon this subject, and in the
+present volume, we shall not refer to it further. Those wishing to
+learn more fully the effect of light upon organic substances will find
+Robert Hunt’s “Researches on Light” an invaluable work.
+
+
+
+
+CHAPTER IV.
+
+LIGHT AND OPTICS.
+
+
+Light—Optics—Solar Spectrum—Decomposition of Light—Light, Heat, and
+Actinism—Blue Paper and Color for the Walls of the Operating
+Room—Proportions of Light, Heat, and Actinism composing a
+Sunbeam—Refraction—Reflection—Lenses—Copying Spherical
+Aberration—Chromatic Aberration.
+
+It is advisable that persons engaging in the Daguerreotype art should
+have at least a little knowledge of the general principles of light and
+optics. It is not the author’s design here to give a full treatise on
+these subjects, but he only briefly refers to the matter, giving a few
+facts.
+
+It has been well observed by an able writer, that it is impossible to
+trace the path of a sunbeam through our atmosphere without feeling a
+desire to know its nature, by what power it traverses the immensity of
+space, and the various modifications it undergoes at the surfaces and
+interior of terrestrial substances.
+
+Light is white and colorless, as long as it does not come in contact
+with matter. When in apposition with any body, it suffers variable
+degrees of decomposition, resulting in color, as by reflection,
+dispersion, refraction, and unequal absorption.
+
+To Sir I. Newton the world is indebted for proving the compound nature
+of a ray of white light emitted from the sun. The object of this work
+is not to engage in an extended theory upon the subject of light, but
+to recur only to some points of more particular interest to the
+photographic operator.
+
+The decomposition of a beam of light can be noticed by exposing it to a
+prism. If, in a dark room, a beam of light be admitted through a small
+hole in a shutter, it will form a white round spot upon the place where
+it falls. If a triangular prism of glass be placed on the inside of the
+dark room, so that the beam of light falls upon it, it no longer has
+the same direction, nor does it form a round spot, but an oblong
+painted image of seven colors—red, orange, yellow, green, blue, indigo,
+and violet. This is called the solar spectrum, and will be readily
+understood by reference to the accompanying diagram, Fig. 1.
+
+{133}
+
+To those who are unacquainted with the theory of light (and for their
+benefit this chapter is given), it may be a matter of wonder how a beam
+of light can be divided.
+
+[Illustration: Fig. 1]
+
+This can be understood when I say, that white light is a bundle of
+colored rays united together, and when so incorporated, they are
+colorless; but in passing through the prism the bond of union is
+severed, and the colored rays come out singly and separately, because
+each ray has a certain amount of refracting (bending) power, peculiar
+to itself. These rays always hold the same relation to each other, as
+may be seen by comparing every spectrum or rainbow; there is never any
+confusion or misplacement.
+
+There are various other means of decomposing {134} white light besides
+the prism, of which one of the principal and most interesting to the
+Daguerreotypist is by reflection from colored bodies. If a beam of
+white light falls upon a white surface, it is reflected without change;
+but if it falls upon a red surface, only the red ray is reflected: so
+also with yellow and other colors. The ray which is reflected
+corresponds with the color of the object. It is this reflected
+decomposed light which prevents the beautifully-colored image we see
+upon the ground glass in our cameras.
+
+[Illustration: Fig. 2]
+
+A sunbeam may be capable of three divisions—LIGHT, HEAT, and ACTINISM;
+the last causes all the chemical changes, and is the acting power upon
+surfaces prepared to receive the photographic image. The accompanying
+illustration, Fig. 2, will readily bring to the mind of the reader the
+relation of these one to another, and their intensities in the
+different parts of a decomposed sunbeam.
+
+The various points of the solar spectrum are represented in the order
+in which they occur between A, and B, this exhibits the limits of the
+Newtonian spectrum, corresponding with Fig. 1. Sir John Herschel and
+Seebeck have shown that there exists, beyond the violet, a faint violet
+light, or rather a lavender to b, to which gradually becomes colorless;
+similarly, red light exists beyond the assigned limits of the red ray
+to a. The greatest amount of actinic power is shown at E opposite the
+violet; hence this color “exerts” the greatest amount of influence in
+the formation of the photographic image.
+
+(Blue paper and blue color have been somewhat extensively used by our
+Daguerreotype operators in their operating rooms and skylights, in
+order to facilitate the operation in the camera. I fancy, however, that
+this plan cannot be productive of as much good as thought by some, from
+the fact, that the light falling upon the subject, and then reflected
+into the camera, is, coming through colorless glass, not affected by
+such rays as may be reflected from the walls of the operating room; and
+even if it were so, I conceive that it would be injurious, by
+destroying the harmony of shadows which might otherwise occur.) The
+greatest amount of white light is at C; the yellow contains less of the
+chemical power than any other portion of the solar spectrum. It has
+been found that the most intense heat is at the extreme red, b.
+
+Artificial lights differ in their color; the white light of burning
+charcoal, which is the principal light from candles, oil and gas,
+contains three rays—red, yellow, and blue. The dazzling light emitted
+from lime intensely heated, known as the Drummond light, gives the
+colors of the prism almost as bright as the solar spectrum.
+
+If we expose a prepared Daguerreotype plate or sensitive paper to the
+solar spectrum, it will be observed that the luminous power (the
+yellow) occupies but a small space compared with the influence of heat
+and chemical power. R. Hunt, in his Researches on Light, has presented
+the following remarks upon the accompanying illustration:
+
+[Illustration: Fig. 3]
+
+“If the linear measure, or the diameter of a circle which shall include
+the luminous rays, is 25, that of the calorific spectrum will be 42.10,
+and of the chemical spectrum 55.10. Such a series of circles may well
+be used to represent a beam from the sun, which may be regarded as an
+atom of Light, surrounded with an invisible atmosphere of Heat, and
+another still more extended, which possesses the remarkable property of
+producing chemical and molecular change.
+
+A ray of light, in passing obliquely through any medium of uniform
+density, does not change its course; but if it should pass into a
+denser body, it would turn from a straight line, pursue a less oblique
+direction, and in a line nearer to a perpendicular to the surface of
+that body. Water exerts a stronger refracting power than air; and if a
+ray of light fall upon a body of this fluid its course is changed, as
+may be seen by reference to Fig. 4.
+
+[Illustration: Fig. 4]
+
+It is observed that it proceeds in a less oblique direction (towards
+the dotted line), and, on passing on through, leaves the liquid,
+proceeding in a line parallel to that at which it entered. It should be
+observed that at the surface of bodies the refractive power is exerted,
+and that the light proceeds in a straight line until leaving the body.
+The refraction is more or less, and in all cases in proportion as the
+rays fall more or less obliquely on the refracting surface. It is this
+law of optics which has given rise to the lenses in our camera tubes,
+by which means we are enabled to secure a well-delineated
+representation of any object we choose to picture.
+
+When a ray of light passes from one medium to another, and through that
+into the first again, if the two refractions be equal, and in opposite
+directions, no sensible effect will be produced.
+
+The reader may readily comprehend the phenomena of refraction, by means
+of light passing through lenses of different curves, by reference to
+the following diagrams:—
+
+[Illustration: Fig. 5, 6, 7]
+
+Fig 5 represents a double-convex lens, Fig. 6 a double-concave, and
+Fig. 7 a concavo-convex or meniscus. By these it is seen that a
+double-convex lens tends to condense the rays of light to a focus, a
+double-concave to scatter them, and a concavo-convex combines both
+powers.
+
+If parallel rays of light fall upon a double-convex lens, D D, Fig. 8,
+they will be refracted (excepting such as pass directly through the
+centre) to a point termed the principal focus.
+
+[Illustration: Fig. 8]
+
+The lines A B C represent parallel rays which pass through the lens, D
+D, and meet at F; this point being the principal focus, its distance
+from the lens is called the focal length. Those rays of light which are
+traversing a parallel course, when they enter the lens are brought to a
+focus nearer the lens than others. Hence the difficulty the operator
+sometimes experiences by not being able to “obtain a focus,” when he
+wishes to secure a picture of some very distant objects; he does not
+get his ground glass near enough to the lenses. Again, the rays from an
+object near by may be termed diverging rays. This will be better
+comprehended by reference to Fig. 9, where it will be seen that the
+dotted lines, representing parallel rays, meet nearer the lenses than
+those from the point A. The closer the object is to the lenses, the
+greater will be the divergence. This rule is applicable to copying. Did
+we wish to copy a 1/6 size Daguerreotype on a 1/16 size plate, we
+should place it in such a position to the lenses at A that the focus
+would be at F, where the image would be represented at about the proper
+size. Now, if we should wish to copy the 1/6 size picture, and produce
+another of exactly the same dimensions, we have only to bring it nearer
+to the lenses, so that the lens D E shall be equi-distant from the
+picture and the focus, i. e. from A to B. The reason of this is, that
+the distance of the picture from the lens, in the last copy, is less
+than the other, and the divergence has increased, throwing, the focus
+further from the lens.”
+
+[Illustration: Fig. 9]
+
+These remarks have been introduced here as being important for those
+who may not understand the principles of enlarging or reducing pictures
+in copying.
+
+I would remark that the points F and A, in Fig. 9, are termed
+“conjugate foci.”
+
+If we hold a double-convex lens opposite any object, we find that an
+inverted image of that object will be formed on a paper held behind it.
+To illustrate this more clearly, I will refer to the following woodcut:
+
+[Illustration: Fig. 10]
+
+“If A B C is an object placed before a convex lens, L L, every point of
+it will send forth rays in all directions; but, for the sake of
+simplicity, suppose only three points to give out rays, one at the top,
+one at the middle, and one at the bottom; the whole of the rays then
+that proceed from the point A, and fall on the lens L L, will be
+refracted and form an image somewhere on the line A G E, which is drawn
+direct through the centre of the lens; consequently the focus E,
+produced by the convergence of the rays proceding from A, must form an
+image of A, only in a different relative position; the middle point of
+C being in a direct line with the axis of the lens, will have its image
+formed on the axis F, and the rays proceeding from the point B will
+form an image at D; so that by imagining luminous objects to be made up
+of all infinite number of radiating points and the rays from each
+individual point, although falling on the whole surface of the lens, to
+converge again and form a focus or representation of that point from
+which the rays first emerged, it will be very easy to comprehend how
+images are formed, and the cause of those images being reversed.
+
+“It must also be evident, that in the two triangles A G B and D G E,
+that E D, the length of the image, must be to A B, the length of the
+object, as G D, the distance of the image, is to G B, the distance of
+the object from the lens.
+
+It will be observed that in the last cut the image produced by the lens
+is curved. Now, it would be impossible to produce a well-defined image
+from the centre to the edge upon a plain surface; the outer edges would
+be misty, indistinct, or crayon-like. The centre of the image might be
+represented clear and sharp on the ground glass, yet this would be far
+from the case in regard to the outer portions. This is called spherical
+aberration, and to it is due the want of distinctness which is
+frequently noticed around the edges of pictures taken in the camera. To
+secure a camera with a flat, sharp, field, should be the object of
+every operator; and, in a measure, this constitutes the great
+difference in cameras manufactured in this country.
+
+Spherical aberration is overcome by proper care in the formation of the
+lens: “It can be shown upon mathematical data that a lens similar to
+that given in the following diagram—one surface of which is a section
+of an ellipse, and the other of a circle struck from the furthest of
+the two foci of that ellipse—produces no aberration.
+
+“At the earliest period of the employment of the camera obscura, a
+double-convex lens was used to produce the image; but this form was
+soon abandoned, on account of the spherical aberration so caused.
+Lenses for the photographic camera are now always ground of a
+concavo-convex form, or meniscus, which corresponds more nearly to the
+accompanying diagram.”
+
+[Illustration: Fig. 11]
+
+Chromatic Aberration is another difficulty that opticians have to
+contend with in the manufacturing of lenses. It will be remembered,
+that in a former page (133) a beam of light is decomposed by passing
+through a glass prism giving seven distinct colors—red, orange, yellow,
+green, blue, indigo and violet.
+
+Now, as has been said before, the dissimilar rays having an unequal
+degree of refrangibility, it will be impossible to obtain a focus by
+the light passing through a double-convex lens without its being
+fringed with color. Its effect will be readily understood by reference
+to the accompanying cut.
+
+[Illustration: Fig. 8]
+
+If L L be a double convex-lens, and R R R parallel rays of white light,
+composed of the seven colored rays, each having a different index of
+refraction, they cannot be refracted to one and the same point; the red
+rays, being the least refrangible, will be bent to r, and the violet
+rays, being the most refrangible, to v: the distance v r constitutes
+the chromatic aberration, and the circle, of which the diameter is a l,
+the place or point of mean refraction, and is called the circle of
+least aberration. If the rays of the sun are refracted by means of a
+lens, and the image received on a screen placed between C and o, so as
+to cut the cone L a l L, a luminous circle will be formed on the paper,
+only surrounded by a red border, because it is produced by a section of
+the cone L a l L, of which the external rays L a L l, are red; if the
+screen be moved to the other side of o, the luminous circle will be
+bordered with violet, because it will be a section of the cone M a M l,
+of which the exterior rays are violet. To avoid the influence of
+spherical aberration, and to render the phenomena of coloration more
+evident, let an opaque disc be placed over the central portion of the
+lens, so as to allow the rays only to pass which are at the edge of the
+glass; a violet image of the sun will then be seen at v, red at r, and,
+finally, images of all the colors of the spectrum in the intermediate
+space; consequently, the general image will not only be confused, but
+clothed with prismatic colors.”
+
+To overcome the difficulty arising from the chromatic aberration, the
+optician has only to employ a combination of lenses of opposite focal
+length, and cut from glass possessing different refrangible powers, so
+that the rays of light passing through the one are strongly refracted,
+and in the other are bent asunder again, reproducing white light.
+
+To the photographer one of the most important features, requiring his
+particular attention, is, that he be provided with a good lens. By the
+remarks given in the preceding pages, he will be enabled, in a measure,
+to judge of some of the difficulties to which he is occasionally
+subjected. We have in this country but two or three individuals who are
+giving their attention to the manufacture of lenses, and their
+construction is such, that they are quite free from the spherical or
+chromatic aberration.
+
+
+
+
+CHAPTER V.
+
+
+To make Plates for the Daguerreotype—Determining the Time of Exposure
+in the Camera—Instantaneous Process for Producing
+Daguerreotype—Galvanizing the Daguerreotype Plate—Silvering
+Solution—Daguerreotype without Mercury—Management of Chemicals—Hints
+and Cautions—Electrotyping—Crayon Daguerreotypes—Illuminated
+Daguerreotypes—Natural Colors in Heliography—Multiplying Daguerreotypes
+on one Plate—Deposit in Gilding—Practical Hints on the Daguerreotype.
+
+TO MAKE PLATES FOR THE DAGUERREOTYPE.
+
+I do not give the method employed by our regular plate manufacturers;
+this is not important, as the operator could not possibly profit by it
+from the fact of the great expense of manufacturing. The following will
+be found practical:
+
+Procure a well planished copper plate of the required size, and well
+polish it, first with pumice stone and water, then with snake stone,
+jewelers’ rouge. Plates can be purchased in a high state of preparation
+from the engravers. Having prepared the copper-plate, well rub it with
+salt and water, and then with the silvering powder. No kind answers
+better than that used by clock-makers to silver their dial-plates. It
+is composed of one part of well washed chloride of silver, five parts
+of cream of tartar, and four parts of table salt. This powder must be
+kept in a dark vessel, and in a dry place. For a plate six inches by
+five, as much of this composition as can be taken up on a shilling is
+sufficient. It is to be laid in the centre of the copper, and the
+figures being wetted, to be quickly rubbed over every part of the
+plate, adding occasionally a little damp salt. The copper being covered
+with the silvering is to be speedily well washed in water, in which a
+little soda is dissolved, and as soon as the surface is of a fine
+silvery whiteness, it is to be dried with a very clean warm cloth. In
+this state the plates may be kept for use. The first process is to
+expose the plate to the heat of a spirit flame, until the silvered
+surface becomes of a well-defined golden-yellow color; then, when the
+plate is cold, take a piece of cotton, dipped in very dilute nitric
+acid, and rub lightly over it until the white hue is restored, and dry
+it with very soft clean cloths. A weak solution of the hydriodate of
+potash, in which a small portion of iodine is dissolved, is now passed
+over the plate with a wide camel’s hair brush. The silver is thus
+converted, over its surface, into an ioduret of silver; and in this
+state it is exposed to light, which blackens it. When dry, it is to be
+again polished, either with dilute acid or a solution of carbonate of
+soda, and afterwards with dry cotton, and the smallest possible portion
+of prepared chalk: by this means a surface of the highest polish is
+produced. The rationale of this process is, in the first place, the
+heat applied dries off any adhering acid, and effects more perfect
+union between the copper and silver, so as to enable it to bear the
+subsequent processes. The first yellow surface appears to be an oxide
+of silver with, possibly, a minute quantity of copper in combination,
+which being removed leaves a surface chemically pure.
+
+Another Method.—The best and simplest mode with which we are acquainted
+is to divide an earthenware vessel with a diaphragm: one side should be
+filled with a very dilute solution of sulphuric acid, and the other
+with either a solution of ferroprussiate of potash, or muriate of soda,
+saturated with chloride of silver. The copper plate, varnished on one
+side, is united, by means of a copper wire, with a plate of zinc. The
+zinc plate being immersed in the acid, and the copper in the salt, a
+weak electric current is generated, which precipitates the silver in a
+very uniform manner over the entire surface.
+
+Another Method.—A piece of brass or of polished copper, brass is
+preferred, is perfectly planished and its surface made perfectly clean.
+A solution of nitrate of silver, so weak that the silver is
+precipitated slowly, and a brownish color, on the brass, is laid
+uniformly over it, “at least three times,” with a camel’s hair pencil.
+After each application of the nitrate, the plate should be rubbed
+gently in one direction, with moistened bitartrate of potassa, applied
+with buff. This coat of silver receives a fine polish from peroxide of
+iron and buff. Proofs are said to have been taken on it, comparable
+with those obtained on French plates.
+
+M. SOLIEL’S PROCESS FOR DETERMINING THE TIME OF EXPOSURE IN THE CAMERA.
+
+M. Soliel has proposed the use of the chloride of silver to determine
+the time required to produce a good impression on the iodated plate in
+the camera. His method is to fix at the bottom of a tube, blackened
+within, a piece of card, on which chloride of silver, mixed with gum or
+dextrine, is spread. The tube thus disposed is turned from the side of
+the object of which we wish to take the image, and the time that the
+chloride of silver takes to become of a greyish slate color will be the
+time required for the light of the camera to produce a good effect on
+the iodated silver.
+
+INSTANTANEOUS PROCESS FOR PROCURING DAGUERREOTYPES.
+
+The following method of producing Daguerreotypes has by some been named
+as above. Most experienced operators have been long acquainted with the
+effect of the vapor of ammonia upon the chemically coated plate. I will
+here insert Mr. W. H. Hewett’s plan of proceeding. This gentleman, in
+referring to it (published in 1845), says:
+
+“This improvement consists in using the vapor of ammonia, as an object
+to accelerate the action of light upon the plate. The effect is
+produced upon a simple iodized plate, but still more upon a plate
+prepared in the ordinary way, with both iodine and bromine. By this
+means, the author obtained impressions instantaneously in the sunshine,
+and in five to ten seconds in a moderate light; and he hopes to be able
+to take moving objects. It can be applied by exposing the prepared
+plate over a surface of water, to which a few drops of ammonia have
+been added (sufficient to make it smell of ammonia); or the vapor can
+be introduced into the camera during the action. In fact, the presence
+of ammonia, in the operating-room, appears to have a good effect, as it
+also neutralizes the vapors of iodine and bromine that may be floating
+about, and which are so detrimental to the influences of light upon the
+plate.”
+
+GALVANIZING THE DAGUERREOTYPE PLATE.
+
+In consideration of the importance of galvanized plates, I shall
+endeavor to give as plain and concise a manner of manipulation as
+possible. For some time it was a question among the operators
+generally, as to the beneficial result of electrotyping, the
+Daguerreotype plate, but for a few years past our first operators have
+found it a fact, that a well electro-silvered surface is the best for
+producing a portrait by the Daguerreotype.
+
+From my own experiments, I have found that a plate, by being
+galvanized, can be rendered more sensitive to the operation of the
+light in proportion of one to five, viz.: if a plate as furnished by
+the market, be cleaned, polished, coated and exposed in the camera, if
+the required time to freely develop an impression be ten seconds, a
+similar plate prepared in like manner and galvanized, will produce an
+equally well-defined image in eight seconds. In connection with this
+subject, there is one fact worthy of notice; a plate with a very heavy
+coating of pure silver, will not produce an equally developed image, as
+a plate with a thinner coating, hence the thin coating, providing it
+entirely covers the surface, is the best, and is the one most to be
+desired. The experiment is plain and simple. Let the slate receive a
+heavy or thick coating by the electrotype, then polish, coat, expose in
+the usual manner, and the result will be a flat, ashy, indistinct
+impression; when, on the other hand, the thin coating will produce a
+bright, clear and distinct image, with all the details delineated.
+
+The style of battery best for the purpose has been, and now is, a
+question of dispute among operators; some preferring the Daniell
+battery to Smee’s. Some claim the superiority of the first from its
+uniformity of action; others, of the latter, for its strength. I
+consider either good, and for the inexperienced would prefer the
+Daniell. This is more simple in its construction, while it has
+certainty in action. The more skillful electrotyper would prefer
+Smee’s, and this is the one most generally in use. I would remark that
+the plan of galvanizing plates should be followed by every operator,
+and when once thoroughly tested, no one will abandon it.
+
+SILVERING SOLUTION.
+
+To any desired quantity of chloride of silver in water add, little by
+little, cyanide of potassium, shaking well at each addition, until all
+the cyanide is dissolved. Continue this operation, and add the cyanide,
+until all the precipitate is taken up and held in solution.
+
+This solution is now ready for the plate-cup. Enough water may be added
+to cover any sized plate when held perpendicular in the cup. The
+strength of the solution may be kept up by occasionally adding the
+chloride of silver and cyanide of potassium. There should alway be a
+very little excess of the cyanide.
+
+The plate should be well cleaned and buffed, and the solution well
+stirred before it is immersed. Care should be observed to keep the
+solution clean, and allow no particle of dust to come in contact with
+the surface of the plate. The plate is now to be attached to the pole
+of the battery.
+
+After remaining a short time, it assumes a blue color; take it out,
+rinse freely with pure water, then dry with a spirit lamp, and it is
+ready for buffing. Buff and coat in the usual manner. Some operators
+are in the practice of immersing the plate in the solution and buffing
+twice. This additional silvering is no improvement wherever there has
+been a proper first coating.
+
+Sometimes the operator is troubled with streaks or scum on the plate.
+This may arise from three causes, all of which experience must teach
+the experimenter to avoid; first, too great an excess of cyanide in the
+solution; second, a lack of silver; third, the current too strong.
+Another annoyance arises from the solution being dirty and the dirt
+collecting on the surface. When this is the case, the dirt is sure to
+come in contact with the surface of the plate as it is plunged into the
+solution, and the result is a scum that it is difficult to dispose of.
+This can be prevented only by frequent filtering. One thing should
+always be borne in mind in electrotyping Daguerreotype plates—that in
+order to secure a perfectly coated surface, the plate should be
+perfectly cleaned. In this point, many who have tried the electrotype
+process have failed, attributing their ill success to other than the
+proper cause.
+
+DAGUERREOTYPES WITHOUT MERCURY.
+
+The following process possesses some interest, and is worthy a trial
+from operators. M. Natterer, of Vienna, discovered a process for
+obtaining proofs on iodized plates with the chloride of sulphur,
+without the use of mercury. A plate of silver is iodized in the usual
+manner, and then placed on the top of a vessel six or eight inches
+high, having at the bottom, in a small cup, a few drops of chloride of
+sulphur; it should remain exposed to the action of the vapor until the
+sombre yellow color is changed to a red, after which it is brought to a
+focus in the camera, where it is exposed to the light in the camera,
+for about the time necessary to produce an ordinary daguerreotype. The
+plate is then taken out and examined in the camera by the light of a
+candle. It often occurs that no trace of the image is as yet
+perceptible, but if the plate is heated by placing over a spirit lamp
+the unprepared side, or if left for some time in the dark, or, lastly,
+if exposed only a few seconds to a weak, dimmed light, the positive
+picture then appears with all its shades. Of these three modes of
+bringing out the image, the second is superior to the others.
+
+MANAGEMENT OF CHEMICALS.
+
+It is necessary, first of all, to know that you have a chemical which
+is capable of producing good results when in skillful hands. For this
+reason it is best to prepare your own quick, after some formula which
+is known to be good. Those quick-stuffs which contain chloride of
+iodine are noted for their depth of tone while they probably operate
+with less uniformity than those which are destitute of it. For
+operating under ordinary circumstances, especially with an inferior
+light, probably no accelerator is more quick and sure than Wolcott’s.
+It also produces a very fine, white pleasing picture, though lacking
+that depth of impression so much to be desired. The dry quick operates
+with surety, and its use is simple and easy, producing an impression
+much like Wolcott’s. For those having a good and permanent light,
+however, we would recommend a chemical giving more body to the
+impression.
+
+There is a class of accelerators called sensitives, claiming to work in
+from three to ten seconds, which, however, will be found very little,
+if any, more sensitive than this. We frequently work it with the
+ordinary coating in twelve and fifteen seconds. The manner in which the
+sensitives are worked is by coating very light. In this way, a flat,
+shallow picture is obtained in a few seconds; and the same can be done
+with any of the more volatile quicks.
+
+It is a fact not generally known, that a plate coated in a light
+chemical room is more sensitive than when coated in darkness. By
+admitting a free, uniform light, and exposing the plate to it a few
+seconds after coating, then timing short in the camera, a very light,
+clear impression is obtained. The time in the camera is reduced in
+proportion to the previous action of light. The shades, of course, are
+destroyed, and the tone injured; still, for taking children, we have
+succeeded better by this method than by the use of “sensitives.” The
+discovery of this principle was accidental, while operating where the
+direct ray s of the sun, entering the window just before sunset, fell
+on the curtain of our dark room, rendering it very light within.
+
+The selection of iodine is not unimportant. Reject, at once, that which
+has anything like a dull, black, greasy appearance; and select that
+which is in beautiful large crystalline scales, of a purple color, and
+brilliant steel lustre.
+
+Solarization, and general blueness of all the light parts of the
+picture, were formerly great obstacles to success, though now scarcely
+thought of by first-class artists. Beginners in the art, however, are
+still apt to meet with this difficulty. It is occasioned by dampness in
+the iodine box, which causes the plate to become coated with a
+hydro-iodide of silver, instead of the iodide. The remedy is in drying
+your iodine. If in summer, you can open your box and set it in sunshine
+a few minutes; or if in winter, set it under a stove a short time. The
+true method, however, is to dry it by means of the chloride of calcium.
+It has such a remarkable affinity for water, that a small fragment
+placed in the open air, even in the dryest weather, soon becomes
+dissolved.
+
+Take one or two ounces of this chemical, heat it in the drying bath, or
+in a hot stove, to perfect dryness; place it in a small glass toy dish,
+or large watch crystal, and set it in the centre of your iodine box.
+Take this out and heat to dryness every morning. Adopt this process,
+and with your mercury at a high temperature, you will never be troubled
+with blue pictures.
+
+Young operators are apt to impute all want of success in operating to
+their chemicals, even though the cause is quite as likely to be
+elsewhere. Failure is quite likely to occur from dampness in the buffs,
+or in the polish; it is therefore necessary to be constantly on the
+guard in this quarter. With a view to this, always scrape your buffs
+with a dull knife, or with one blade of your shears, the first thing in
+the morning, and after brushing them thoroughly, dry them, either in
+the sun, by a stove, or in the buff-dryer. It is equally important that
+the polish and the brush should be kept dry.
+
+Want of success may arise from vapors of iodine or bromine in the
+camera box, mercury bath, or even in the buffs. It is incredible how
+small a quantity of these vapors will affect the effect of light when
+coming in contact with the plate, after or during the exposure in the
+camera. It is therefore necessary to be cautious not to mix chemicals,
+nor open your boxes or bottles in your room, but take them out to do
+it. Never hurry the operation through from lack of confidence in the
+result. The fact of anything being out of order, forms no excuse for
+slighting the process. If unsuccessful, do not pursue the same course
+every trial, but vary with a view to detect the cause of the
+difficulty.
+
+In case of a long series of failures, institute a regular course of
+investigation, after this manner, commencing where the trouble is most
+likely to occur:
+
+1. Are the plates well cleaned?
+
+2. Is the iodine dry? If the impressions come out blue, you may rest
+assured it is not. Take out the iodine, wipe and dry the box, and dry
+the calcium.
+
+3. Is the quick battery of the right strength? If dry, it must change
+the plate in from six to fifteen seconds. If any of the chloride of
+iodine class, it may vary from five seconds to a minute. Begin by
+coating light, and increase on each trial, observing the effect. If the
+light side of the picture seems loth to come out, and shows no contrast
+with the dark side, it is to be inferred that your battery is too
+strong, and must be reduced with water or set out in the open air for a
+few minutes, with the lid off. If working an old battery, never renew
+very strong, or it will work dark and heavy. A battery, to work well,
+should be gradually losing strength, but never gaining. An old battery,
+however, may be quickened up and made to work well for some time, by
+adding five of six drops of sulphuric acid, repeating the quantity as
+often as necessary, providing always that acid be not used in
+manufacturing the quick.
+
+4. Have the plates lost their sensitiveness by being many times exposed
+to mercury? Clean and burn them; but if French plates, burn light, or
+you spoil them.
+
+5. Are the buff s dry and clean? Examine the plate critically after
+buffing to detect any appearance of scum or film on the surface. If so,
+the longer you buff the more it shows. Scrape and dry the buffs
+thoroughly.
+
+6. Is the mercury free from scum and dirt? If not, filter. Is it also
+far enough from the coating boxes? Should be at least three feet, and
+kept covered.
+
+7. Is the mercury sufficiently heated? This is important. Long
+exposure, however, will answer the same purpose.
+
+8. Are your lenses clean, and in proper place?
+
+9. Are the tablets in focus with the ground-glass? If you can attribute
+the failure to none of these, mix a new box of some other kind of
+quick, say the dry, for instance. If you fail in the same manner here,
+take time, wash your buffs, overhaul all the chemicals, and start anew.
+Do not be discouraged.
+
+There is no day so dark but that the sun will shine again. We will
+close with this brief summary of advice:
+
+Clean your plates. Keep everything dry. Keep the mercury hot. Follow
+these instructions carefully, and you must succeed.
+
+HINTS AND CAUTIONS.
+
+First of all, cleanliness should be observed. When there is dust or
+dirt about your room, particularly about the work-bench, failures will
+be frequent; for the smallest particles of rotten-stone, when allowed
+to come in contact with the buffs, will produce scratches on the
+surface of the plate, which very much injures the operation, and often
+causes failures.
+
+Dust flying about the room is injurious, if allowed to fall on the
+plate, either before or after it has been coated, as it causes black
+spots which cannot be removed.
+
+The polished plate should not be allowed to come in contact with a
+strong current of air, for it tends to oxidize the surface. Breathing
+on the surface should also be avoided, for the same reason.
+
+The plate should, in all cases, be buffed immediately before using, and
+not allowed to stand any length of time. It should be held with the
+polished face downward.
+
+It is always best that the plate should be of the same temperature of
+the atmosphere in the room.
+
+Keep the camera and mercury-bath perfectly free from the vapors of
+iodine and bromine; for the presence of the slightest degree of either
+of the above will injure the impression in no small degree. As a
+preventive, let the camera be exposed to the sun or fire for a few
+minutes in the morning.
+
+Filter your mercury often, to keep the surface free from film and dust.
+
+The hyposulphite solution should be filtered through sponge every time
+it is used.
+
+The direct rays of light must not enter the camera in conjunction with
+those reflected from the object; or the picture will be veiled, and the
+color of the plate changed to a thick green.
+
+If the plate be iodized only to a light-yellow, the result might be of
+a bluish or grey tinge: and this is generally the case, when the quick
+is new and strong, and there is an excess of it on the plate, and yet
+not enough to form the bromide iodide of silver; in which case it would
+wholly spoil the impression.
+
+Your iodine will be found to operate more successfully, when the time
+required for coating the plate does not fall short of fifteen seconds,
+or exceed one minute.
+
+Too quick coating can be avoided by using less iodine in your box. In
+the summer months, when the weather is 80 deg. and over, one quarter of
+an ounce, or even less, will work to advantage.
+
+ELECTROTYPING.
+
+I am indebted to Mr. J. H. Fitzgibbons for the following process, which
+he employed in producing the excellent specimens he exhibited at the
+Crystal Palace:
+
+“I shall endeavor to lay down in as comprehensive a manner as possible
+the method by which I have been enabled to produce the most
+satisfactory results. I use a Smee’s battery (another kind will do).
+After filling the cell, of common size, nearly full with water; add
+about quarter of an ounce of sulphuric acid. Mix this well, and let it
+stand for about three hours, or until the action of the battery becomes
+weak, when it is in order to work with a very uniform action. Put one
+pound of sulphate of copper in one quart of water; stir it until the
+sulphate of copper is all dissolved, and then add one half ounce of
+sulphuric acid and a quarter of an ounce of nitric acid. This solution,
+well mixed, should be filtered, and it is ready for use. It is very
+important that the solution should be kept clean, clear, and free from
+all foreign substance. The above quantity of this solution will be
+found sufficient for electrotyping a dozen of the sixth-size plates.
+When it is required to be strengthened, it is only necessary to add a
+little of the sulphate of copper.
+
+“With the battery prepared as above, and the solution of sulphate of
+copper in a vessel of proper dimensions to receive your plate, connect
+the galvanic current, and immerse the impressioned plate, letting it
+remain until a thin film of copper has been formed, then the battery
+can be strengthened, and the impression will be of sufficient thickness
+to be removed in from eight to twelve hours. An old Daguerreotype plate
+attached to the opposite pole of the battery (copper side towards the
+face of the plate to be electrotyped), will answer the same purpose as
+the silver-plate.
+
+“The great difficulty in taking an electrotype impression, and
+preserving the original, has been attributed to the battery being too
+powerful. I am led to believe from practice that the principal
+difficulty has been in the Daguerreotype plate itself, for if we use an
+impression that has been taken but a few days, and taken in the usual
+way, we will find it difficult to succeed without spoiling both the
+copy and original, and so also with an old impression.
+
+“I have found the most certain method to be as follows:—Coat the
+Daguerreotype plate as usual, except use less of the accelerators, the
+proportion of iodine coating being greater, of course the time of
+exposure in the camera will be lengthened. Mercurialize it at about a
+temperature requiring to develop the image, from six to eight minutes,
+at least. Gilding the Daguerreotype has much to do towards producing a
+good electrotype copy. This should be done by applying a little heat,
+and gilding very slowly, giving a coating of gold with the greatest
+possible uniformity. By this method, I have been enabled to produce any
+number of proofs. I have produced a dozen from one impression, and it
+remains as perfect as when first taken.
+
+“By a little judgment and care the operator will be enabled to produce
+the electrotype copy of the Daguerreotype plate without any difficulty.
+The electrotype copy should be immediately put under a glass and sealed
+in the same manner as the ordinary Daguerreotype.”
+
+CRAYON DAGUERREOTYPES.
+
+This process is patented in the United States, by J. A. Whipple, of
+Boston, and of course no honorable person will use it for his own
+benefit without purchasing a right.
+
+A white back-ground is generally employed, the object being to blur the
+lower portion of the plate, leaving the head of the subject in relief.
+Every Daguerreotypist is familiar with the fact that a motion of any
+body between the camera and the sitter will cause a “blur.” Cut a piece
+of thin paper and scallop it, making a semicircle. This is kept
+straight by means of a wire frame, and it is to be moved in front of
+the lower part of the body of the sitter during the time of exposure of
+the plate in the camera. Develop over mercury as usual, and the result
+will be a crayon Daguerreotype.
+
+Another method is to have a wheel with a hole cut through it of a
+diameter of about 12 inches. This hole is so cut as to leave teeth
+resembling those of a large saw. This wheel is so arranged that it can
+be turned around, which should be done during the time of exposure in
+the camera. It must be placed between the camera and the sitter, and at
+such a distance from the camera as to allow such proportion of the body
+of the sitter be seen upon the ground-glass as is desired. It will be
+readily seen that by turning this wheel during the operation will
+produce the same result as the paper being moved in the other method.
+The teeth make the “blur.” The side of the wheel towards the camera may
+be black, by which means the result will be a dark instead of a light
+border.
+
+ILLUMINATED DAGUERREOTYPES.
+
+This process is also patented, and the remarks on the preceding subject
+will apply in this case. The plate is prepared and exposed as in the
+usual method of the Daguerreotype. A white back-ground is employed. Let
+the head of the sitter come in the middle of the plate, and before
+exposing it to the vapors of mercury, put a small mat or diaphragm,
+having a small hole through it, over or directly on the surface of the
+plate. This diaphragm should be bevelled, and the bevel should be
+towards the surface of the plate; this, in order to prevent too sharp a
+line on the impression. It will be readily seen that if an impressioned
+plate so covered is placed over the mercury, it will be developed on
+such portions only as are exposed. The principle is so familiar that
+further explanations are unnecessary.
+
+NATURAL COLORS IN HELIOGRAPHY.
+
+This subject is worthy the attention of every operator. The following
+process is so plain and easy of trial that any Daguerreotypist can try
+it. This is as given by Mr. James Campbell, and was published in
+Humphrey’s Journal of the Daguerreotype and Photographic Arts, vol. 5,
+page 11. Mr. Campbell has done much to further the process announced by
+M. Neipce, and his experiments have proved highly successful.
+
+The following is submitted as worthy of trial:
+
+“The proper preparation of the chloridated plate, to enable it to
+receive colored impressions is an object of the first importance to
+those wishing to experiment on it, and consequently requires particular
+notice. The plate may be prepared by making it the positive pole of a
+battery, and letting it at the same time be immersed in chlorine water.
+The negative pole should be a slip of platinum. All the colors may be
+produced from a plate so prepared if the chlorine and water are in the
+right proportions; but generally one color or the other predominates,
+according to the amount of chlorine in the liquid. By adding the
+chlorides of strontian, uranium, potassium, sodium, iron, or copper to
+the liquid, various effects may be produced, and these bodies will be
+found to produce the same color on the plate that their flame gives to
+alcohol.
+
+“The honor of this discovery is due to M. Neipce. Copper gives a
+variegated flame; hence many colors may be impressed on a plate
+prepared with a solution of its chloride.
+
+“M. Neipce recommends a solution of the mixed chlorides of copper and
+iron, and it is with these, that I have been most successful. As the
+chlorides of copper and iron are not much used in the arts, they are
+not generally found for sale in the shops; and it may be well to
+furnish those not much versed in chemistry with an easy method of
+preparing them.
+
+“They may be made directly from either metal by dissolving it in
+hydrochloric acid; but they may be formed by a cheaper method, and by
+which also the acid fumes are avoided.
+
+“Sulphate of iron or copper, or both together, may be dissolved in
+water and then neutralized with common crude potash, or its carbonate
+or bicarbonate—known commonly as pearl ash and saleratus. If either of
+the latter be used, there will be formed sulphate of potash and a
+carbonate of the metal used, and there will also be a considerable
+effervescence of carbonic acid, which will, if care is not taken, cause
+the mixture to run over the vessel. After the copper or iron salt is
+neutralized, which is known by its ceasing to effervesce, the carbonate
+of the metal will settle slowly, and will at first nearly fill the
+vessel. The supernatant fluid, which is sulphate of potash in solution,
+may now be carefully poured off, and its place filled with water; this
+operation should be repeated several times until the water which passes
+off is tasteless. The carbonate of the metal rapidly changes to an
+oxide by contact with the air, and it will generally be found, when it
+is sufficiently washed, that it is at least half oxide. On adding
+hydrochloric acid cautiously to the mixture, a chloric of the metal
+will be formed, and carbonic acid will be evolved from the remaining
+carbonate. The chloride formed is soluble; but as there are two
+chlorides of these metals, and we wish to produce the one which
+contains the most chlorine, it is best to add the acid cautiously until
+the solution is decidedly acid. After filtering the solution, it is fit
+for use; and it should be preserved in well-stoppered bottles. The
+water used should be rain or distilled water.
+
+“About one part of the mixed chlorides should be used to three or four
+of water.
+
+“The battery may be either Smee’s, Daniell’s, or Grove’s; if of either
+of the former, it should be of two series; if of the latter, one cup is
+sufficient.
+
+“The plate on being immersed in the liquid, almost instantly takes a
+violet color. It should be allowed to remain from two to five minutes,
+according to the strength of the battery, and until it becomes nearly
+black. It should now be carefully washed, and afterwards heated over a
+spirit lamp until it takes a cherry-red color, and it is then ready for
+exposure in the camera. Before speaking of exposing the plate, it may
+be well to speak of some difficulties which the inexperienced operator
+may find in preparing it. If the battery is not in good order, and a
+sufficient current is not passed through the solution, the plate will
+become coated—and apparently almost as well as when the battery is
+working well—but on exposure it will give a negative picture, and but
+little colored; while if the battery is in good order, the impression
+is invariably positive.
+
+“Sometimes on heating the plate after washing, the surface is covered
+with spots or assumes a variegated appearance. This indicates that the
+solution is impure, or that the plate have not been thoroughly washed
+and are still contaminated with the soluble chlorides which are
+contained in the solution.
+
+“From the fact that the plate if prepared with positive electricity
+gives a positive picture, while it prepared otherwise it gives a
+negative, it is evident that electricity plays an important part in
+this process. The same is true to some extent with the compounds formed
+with iodine, bromine, and fluorine.
+
+“On heating the plate, the brown coating of chloride melts into a
+translucent enamel, and the heat should be withdrawn when a cherry-red
+color is produced. It the heat is continued longer, the plate assumes a
+lighter color, and becomes less sensitive; and the enamel will finally
+scale off. To produce a picture by the ordinary process of M. Neipce,
+unaccelerated, it should be exposed for from three to five hours to
+sunlight in the camera, though pictures may be procured by contact, in
+from fifteen to thirty minutes.”
+
+MULTIPLYING DAGUERREOTYPES ON ONE PLATE.
+
+I have produced some interesting specimens of the Daguerreotypic art,
+by exposing in the camera only a portion of the sensitive plate to the
+action of light. When on the exposed portion an image is formed, then
+taking the tablet into the dark room, change ends and expose the
+sensitive portion, and produce another image, developing as usual. This
+plan is adapted for taking likenesses for lockets. Two images can be
+presented as sitting side by side, by covering half the plate with
+black paper, and exposing as before. In this manner we have been
+enabled to surprise persons by exhibiting their portrait on the same
+plate with a stranger’s. Daguerreotypists must be cautious in
+practicing this, as it might not be agreeable to the parties whose
+likenesses are together, by the above process. It is impossible to
+produce an impression without a line being seen where the edge of the
+paper prevented the operation of the light.
+
+I have recently seen a fine specimen produced by another plan, which
+far exceeds the above, there being no line, or any peculiarity denoting
+two exposures. The specimen referred to, was a gentleman represented on
+one plate by two full length portraits. This was produced by using a
+black velvet for the background. The plate was exposed sufficient time
+to produce one impression, and then the gentleman assumed another
+position, and is repeated as looking at himself. From the fact that the
+time required to develop black velvet being so much longer than that
+for producing a portrait, we are enabled to produce the above
+interesting results.
+
+DEPOSIT IN GILDING.
+
+Regarding specks from bad water, I would remark that gilding should be
+made only with distilled water. Thus made, it produces very little
+deposit, even by long keeping. It therefore preserves its original
+strength, and works with great uniformity.
+
+Every grain of deposit contains at least 7-10 its weight of gold,
+easily discoverable by the blowpipe. Such gilding is continually
+deteriorating, which with good chloride and distilled water may be
+prevented. Distilled water should also be used for the hyposulphite.
+and for cleaning plates. Any good, clear water may be afterwards used
+for washing off, with equally good results. I am very rarely troubled
+with specs, and deem this as the main reason.
+
+With a portable still attached to a cooking stove, I obtain half a
+gallon of water per hour, and with very little trouble. A small tin
+retort or still connected with a Leibig’s condenser, would not add much
+to the “traps” of the travelling operator, and save him many a
+disreputable specimen.—T. J. BAILEY.—Humphrey’s Journal.
+
+PRACTICAL HINTS ON THE DAGUERREOTYPE.
+
+The following is from Humphrey’s Journal, vol. 5, and from the pen of
+Dr. WM. HARRINGTON, one of the most able writers upon the subject of
+the Daguerreotype in this country:
+
+THE CAUSE OF THE DIFFICULTY THAT SOMETIMES OCCURS TO PREVENT THE
+PRODUCTION OF A CLEAR IMPRESSION UPON A DAGUERREOTYPE PLATE.
+
+Beyond all doubt this is traceable to dampness. Truly this is not a new
+thought; but where does this dampness come from? How does it originate,
+and where is it located? Generally it has been referred to a point
+entirely remote from its real location.
+
+This dampness exists particularly upon the surface of the plate; is
+obviously derived immediately from the atmosphere; and is owing to a
+certain relative temperature of the plate with the hygrometric
+condition of the atmosphere.
+
+Whenever this relation exists between the plate and atmosphere, a
+precipitation of moisture takes place upon the surface of the plate,
+which render all efforts at polishing impracticable. This interference
+is not confined to the buffing operation alone, but sometimes is
+discoverable even in the ordinary process of scouring. Every one at all
+experienced in this art will remember that it is not always an easy
+matter for him, by scouring, to bring his plate to the desired lustre.
+All his efforts become unavailing; the more he rubs, the duller the
+surface of his plate appears; and although he renews his cotton
+repeatedly, still he is obliged to content himself with an
+unsatisfactory finish.
+
+This relative condition is not confined to any particular season of the
+year, nor to any certain thermometric temperature; but may occur in
+summer as well as in winter; the weather being warm or cold, wet or
+dry, clear or cloudy, raining or shining. Under any of these
+circumstances, if the relation of the plate and atmosphere be such as
+to invite upon the plate a precipitation of humidity from the
+atmosphere, the prospect of producing a clear impression is quite
+problematical.
+
+It is reasonable to expect this occurrence from the fact that metal is
+a good radiator, and radiation reduces the temperature of a metallic
+body below that of the atmosphere. Consequently, if this relative
+condition happens, the result will be as I have stated.
+
+Bodies may be colder than the atmosphere and yet derive no moisture
+from it; while at the same time the driest atmosphere is not devoid of
+moisture, but will part with it under certain conditions.
+
+Assuming for granted that this relative condition between the plate and
+atmosphere, disposing the former to receive the humidity of the latter,
+constitutes the great obstacle the operator has to contend with in
+producing, a clear proof upon the plate, the remedy naturally suggests
+itself, and is very simple. It consists in merely heating the plate
+above the temperature of the atmosphere, previous to polishing, and
+retaining that temperature during the operation. Various measures might
+be devised to effect the desired object; one of which consists of a
+sheet-iron box, heated from the inside by a spirit-lamp, upon the top
+of which are to be kept the plates ready to undergo the process of
+being polished; the blocks of the swing or any other vice; or the iron
+bed belonging to Lewis’s vice.
+
+In cold weather, when it is necessary to keep a fire in the preparation
+room, all of the above may be so arranged in the vicinity of the fire
+as to receive the requisite degree of heat for the purpose specified.
+
+This part of the subject, however, is left entirely for the ingenuity
+of the operator. No matter by hat means he accomplishes the object; all
+that is required is to heat the plate above the temperature of the
+atmosphere and retain that heat during the process of polishing.
+
+Since the adoption of this method, in connection with my partner, T. J.
+Dobyns, even in this humid climate of ours, when everything in the room
+is dripping with moisture, it has been attended with invariable
+success.
+
+CHOICE OF PLATES, ETC.
+
+In the great catalogue of complaints made by operators, none is more
+common than that alleged against the quality of plates in general use.
+Although the greatest diversity of opinion exists upon this subject,
+nevertheless the plates of every manufactory share in this universal
+condemnation.
+
+To be sure it cannot be denied but that this necessary article of
+utility in the photographic art has undergone a sad deterioration in
+quality owing to the increasing demand and great reduction in price—the
+plates of the present day being by no means so heavily coated with
+silver as formerly—but the complaint alluded to is not predicated so
+much upon the thinness of silver as upon a mysterious something which
+has conferred upon the plates the epithet of not good.
+
+That this complaint is in a great measure groundless appears evident
+from the fact that while, with the same brand of plates one operator
+can work successfully, another encounters the greatest difficulty;
+while one is able to produce beautifully clear and altogether
+satisfactory results, the other labors under the troublesome annoyance
+of innumerable specks, large dark insensitive patches and brown
+map-like portions, together with divers other blemishes, sufficient to
+prevent him from obtaining anything like a tolerable impression.
+
+From this wide difference in the results of the two operators using
+identically the same article, it is but reasonable to conclude that the
+complaint is founded in error; while the inference is no more than
+just, that the fault may be traced to a want of practical skill on the
+part of the complaining operator himself; rather than to the inferior
+quality of the plates.
+
+The question, then, whether the plates are unfit for use, or whether
+those who pronounce them so understand how to use them, appears to be
+satisfactorily answered. It therefore becomes a matter worthy of
+investigation, to ascertain what superior judgment and skill one
+operator possesses over another which enable him to work successfully a
+quality of plate, pronounced by the other entirely useless.
+
+Suppose we make a critical examination of one of the repudiated plates.
+From its external appearance we have little hesitation in pronouncing
+it to be French; indeed, this presumption is strongly corroborated by
+the fact that it is ornamented upon one of its corners with a brand to
+designate the manufactory from which it emanated.
+
+Upon close inspection we cannot fail to notice a striking peculiarity
+upon the surface; the roughness is very remarkable; the planishing
+hammer has left amazingly visible indications of its busy work. One
+would suppose the manufacturer intended the surface of the plate to
+represent the undulations of the sea, instead of that smooth and level
+character so strongly recommended by M. Daguerre.
+
+Such a plate necessarily requires at the hand of the operator
+considerable labor before the surface is in a proper condition to
+receive a suitable polish from the buffer. The least reflection in the
+world should teach any one that so long as the undulatory character
+continues upon the surface of the plate, it is in a very imperfect
+condition for buffing, because the buffer cannot touch every point
+equally; the elevated portions alone receiving a high degree of polish
+while the depressed portion, from their roughness acting as nuclei,
+gather dust, rouge, and other foreign bodies, so detrimental to
+sensitiveness. The secret of the superior judgment and skill of one
+operator over another, is intimately connected with this point: his
+success depends very much upon the first process of cleaning the plate.
+
+Let us examine the manipulation of the complaining operator. He takes
+one of these plates and gives it a careful scouring with rotten-stone
+and alcohol or any other liquid preferred for this part of the
+operation—that is, he gives it what he terms a careful scouring—very
+gently indeed because, from the frequent trials he is in the habit of
+making in the camera, he fears he will rub the silver entirely away
+before he succeeds in obtaining a good impression. The dark patches,
+specks, and granular appearance resulting entirely from the unevenness
+of the surface of the plate, look like copper to him, and he is
+surprised that he should have rubbed away the silver so soon,
+particularly by such delicate handling.
+
+The judgment and experience of the successful operator, however, teach
+him that scouring injures a plate less than buffing. He knows that
+unless the hammer marks be obliterated, he cannot by the buffer produce
+a surface of uniform polish and sensitiveness, without which a fair
+proof is extremely doubtful; he knows that the time employed in the
+preliminary operation of cleaning the plate properly is economy.
+
+There is a style of French plates in the market, denominated heavy,
+which are truly excellent, if properly managed. Much patience, however,
+is required to remove the marks of the hammer; but with tripoli and
+alcohol the surface is readily cut down, and the plate is then
+susceptible of a beautiful black lustre by polishing with the buffer.
+The complaining operator could not succeed by his own method with one
+of the plates; he would encounter all manner of clouds and other
+unaccountable phenomena; he would imagine this plate entirely worn out
+before it was half cleaned, and soon fix in his own estimation the
+reputation of the heavy plate.
+
+In making a choice of plates, therefore, it would appear to be a matter
+of perfect indifference with an experienced operator what kind he would
+use, except so far only as the labor required in cleaning them was to
+be taken into consideration.
+
+The distinction between a scale plate, a Scovill No. 1, S. F., heavy A,
+star, crescent, eagle, or any other brand, consists in the superior
+finish of some, and the thinness of the silver in the cheaper
+qualities.
+
+Consequently, let the complaining operator but employ the diligence
+inculcated in this article, to clean his plate thoroughly, so as to
+bring it to a perfectly even and level surface, and he will seldom be
+troubled with specks, clouds, dark patches, and the host of other
+obstacles which heretofore have tormented him.
+
+
+
+
+CHAPTER VI.
+
+AN ACCOUNT OF WOLCOTT AND JOHNSON’S EARLY EXPERIMENTS, IN THE
+DAGUERREOTYPE. BY JOHN JOHNSON.
+
+
+[From Humphrey’s Journal, vol. ii 1851]
+
+As a general thing, however perfect any invention may be deemed by the
+inventor or discoverer, it falls to the lot of most, to be the subject
+of improvement and advancement, and especially is this the case with
+those new projects in science which open an untrodden field to the view
+of the artisan. Such has been, in an eminent degree, the case with the
+discovery first announced to the world by Mons. Jean Jaques Claude
+Daguerre, of Paris, in the year 1839, and which excited unbounded
+astonishment, curiosity and surprise. It may be questioned had any
+other than Daguerre himself discovered a like beautiful combination,
+whether the world would have been favored with details exhibiting so
+much care, patience and perseverance as the Daguerreotype on its
+introduction. Shortly after, these details reached the United States,
+by Professor S. F. B. Morse, of New York, who was, at the time of the
+discovery, residing in Paris. By this announcement, the whole
+scientific corps was set in operation, many repeating the experiments,
+following carefully the directions pointed out by Daguerre, as being
+necessary to success. Among the number in the United States, was
+Alexander S. Wolcott (since deceased) and myself; both of this city. On
+the morning of the 6th day of October, 1839, I took to A. Wolcott’s
+residence, a full description of Daguerre’s discovery, he being at the
+time engaged in the department of Mechanical Dentistry, on some work
+requiring his immediate attention, the work being promised at 2 P.M.
+that day; having, therefore, no opportunity to read the description for
+himself (a thing he was accustomed to do at all times, when
+investigating any subject). I read to him the paper, and proposed to
+him that if he would plan a camera (a matter he was fully acquainted
+with, both theoretically and practically), I would obtain the materials
+as specified by Daguerre. This being agreed to, I departed for the
+purpose, and on my return to his shop, he handed me the sketch of a
+camera box, without at all explaining in what manner the lens was to be
+mounted. This I also undertook to procure. After 2, P.M., he had more
+leisure, when he proceeded to complete the camera, introducing for that
+purpose a reflector in the back of the box, and also to affix a plate
+holder on the inside, with a slide to obtain the focus on the plate,
+prepared after the manner of Daguerre. While Mr. Wolcott was engaged
+with the camera, I busied myself in polishing the silver plate, or
+rather silver plated copper; but ere reaching the end preparatory to
+iodizing, I found I had nearly or quite removed the silver surface from
+off the plate, and that being the best piece of sliver-plated copper to
+be found, the first remedy at hand that suggested itself, was a
+burnisher, and a few strips were quickly burnished and polished.
+Meantime, the camera being finished, Mr. Wolcott, after reading for
+himself Daguerre’s method of iodizing, prepared two plates, and placing
+them in the camera, guessed at the required time they should remain
+exposed to the action of the light; after mercurializing each in turn,
+and removing the iodized surface with a solution of common salt two
+successful impressions were obtained, each unlike the other!
+Considerable surprise was excited by this result, for each plate was
+managed precisely like the other. On referring to Daguerre, no
+explanation was found for this strange result; time, however, revealed
+to us that one picture was positive, and the other negative. On this
+subject I shall have much to say during the progress of the work.
+Investigating, the cause of this difference occupied the remainder of
+that day. However, another attempt was agreed upon, and the
+instruments, plates, etc., prepared and taken up into an attic room, in
+a position most favorable for light. Having duly arranged the camera, I
+sat for five minutes, and the result was a profile miniature (a
+miniature in reality,) or a plate not quite three-eighths of an inch
+square. Thus, with much deliberation and study, passed the first day in
+Daguerreotype—little dreaming or knowing into what a labyrinth such a
+beginning was hastening us.
+
+[Description of apparatus represented on pages 192 and 199:]
+
+A.—The Box—about 4 inches long by about 2 outside diameter. B.—The
+Reflector soldered to a brass screw, and mounted in the rear of the
+box.
+c.—The slide to regulate the focus to the plate holder. d.—The standard
+to the plate holder screwed to the slide. f.—The plate-holder frame
+having two small ledges, * *, for the plate to rest upon.
+
+{192}
+
+g.—The plate resting upon the ledge., * *, and kept against the frame
+by the spring h. The plates used were about 3/8 of an inch square.
+A.—The window with the sashes removed.
+
+B and C (p. 199) are large looking-glasses mounted as plain reflectors,
+the lower one C having rotary motion upon the saddle, resting upon the
+sill of the window in order to direct the rays of the sun upon the
+reflector B, at any hour of the day—the vertical motion of the
+reflector C being necessary, the sun varying in altitude so much during
+the hours most favorable to the production of portraits. The reflector
+C was {193} kept up to the required position by the handle lever,
+upright post and bolts. Reflector B was hinged at its upper end at the
+top of the window frame, the only motion being necessary was that which
+would reflect upon the sitter the incident rays from reflector C—the
+reflector B being kept at the required angle by the connecting lever m,
+etc. Suitable back-grounds were placed behind the sitter.
+
+[Illustration: Fig. 12]
+
+The reflector B and C, had frequently to be renewed, the heat of the
+sun soon destroying their brilliance or power of reflecting, light,
+before renewing them, however, we resorted to the springing of them, by
+which means their power was increased for a period.
+
+The camera or reflecting apparatus, invented by Mr. Wolcott, was, from
+the nature of the case, better adapted at that day to the taking of
+portraits from life, than any other instruments. After carefully
+examining the camera described by Daguerre, and the time stated as
+necessary to produce action for an image, it became evident to the mind
+of Mr. Wolcott at once, that more light could be obtained (as the field
+of view required was not large) by employing a reflector of short focus
+and wide aperture, than from a lens arrangement, owing to spherical
+aberration and other causes. Many experiments having been tried with
+the small instrument figured (p. 199), a reflector for taking portraits
+from life was determined on, having eight inches diameter, with twelve
+inches focal distance for parallel rays; this was to admit plates of
+two inches wide by two and a half long Mr. Wolcott having on hand
+reflectors of the right diameter, for Newtonian telescopes, of eight
+feet focal distance, resolved (as it was a matter of experiment) to
+grind down or increase the curve for the focal distance before
+named—this required time. In the mean time, many plans were pursued for
+making good plates, and the means of finishing, them. As the completion
+of the large reflector drew to a close, our mutual friend, Henry Fitz,
+Jr., returned from England, whither he had been on a visit, and when he
+heard what we were about, kindly offered his assistance; he being well
+versed in optics, and having been before engaged with Mr. Wolcott, in
+that and other business is offer was gladly accepted—Mr. Wolcott
+himself having frequent engagement; to fill as operator in the details
+of mechanical dentistry. Thus, by the aid of Mr. Fitz, the reflector
+was polished, and experiments soon after tried on plates of two by tow
+and a half inches, with tolerable success. Illness on my part quite
+suspended further trial for nearly four weeks.
+
+On my recovery, early in January, 1840, our experiments were again
+resumed with improved results, so much so as to induce Mr. Wolcott and
+myself to entertain serious thoughts of making a business of the taking
+of likenesses from life, intending to use the reflecting apparatus
+invented by Mr. Wolcott, and for which he obtained Letters Patent, on
+the 8th day of May, 1840. Up to January 1st, 1840, all experiments had
+been tried on an economical scale, and the apparatus then made, was
+unfit for public exhibition; we resolved to make the instruments as
+perfect as possible while they were in progress of manufacture.
+Experiments were made upon mediums for protecting the eyes from the
+direct light of the sun, and also upon the best form and material for a
+back-ground to the likenesses. The length of time required for a
+“sitting,” even with the reflecting apparatus, was such as to render
+the operation anything but pleasant. Expedients were ever ready in the
+hands of Wolcott: blue glass was tried and abandoned in consequence of
+being, at that time, unable to procure a piece of uniform density and
+surface: afterwards a series of thin muslin screens secured to wire
+frames were prepared as a substitute for blue glass. The objections to
+these screens, however, were serious, inasmuch as a multiplication of
+them became necessary to lessen the intensity of the light sufficiently
+for due protection to the eyes, without which, the likenesses, other
+than profiles, were very unpleasant to look upon. Most of the
+portraits, then of necessity were profiles formed upon back-grounds,
+the lighter parts relieved upon black, and the darker parts upon light
+ground; the back-ground proper being of light colored material with
+black velvet so disposed upon the light ground, this being placed
+sufficiently far from the sitter, to produce harmony of effect when
+viewed in the field of the camera. Other difficulties presented
+themselves seriously to the working of the discovery of Daguerre, to
+portrait taking—one of which was the necessity for a constant and
+nearly horizontal light, that the shaded portions of the portrait
+should not be too hard, and yet, at the same time, be sufficiently well
+developed without the “high light” of the picture becoming overdone,
+solarized or destroyed. In almost all the early specimens of the
+Daguerreotype, extremes of light and shade presented themselves, much
+to the annoyance of the early operators, and seriously objectionable
+were such portraits. To overcome this difficulty, Mr. Wolcott mounted,
+with suitable joints, upon the top of his camera, a large looking-glass
+or plane reflector, in such a manner that the light of the sun (as a
+strong light was absolutely necessary), when falling upon the glass
+could be directed upon the person in an almost horizontal direction.
+
+Early in February, 1840, Mr. Johnson, Sen., (since deceased) sailed for
+Europe with a few specimen likenesses taken with the instruments
+completed as above, with the intention of patenting the invention. On
+his arrival a joint arrangement was effected with Mr. Richard Beard, of
+London, in patenting and working the invention in England. Up to
+February, 1840, but few friends had been made acquainted with the
+progress of the art in the hands of Mr. Wolcott and myself. From time
+to time reports reached us from various sources of the success of
+others, and specimens of landscapes, etc., were exhibited at Dr. James
+R. Chilton’s laboratory, in Broadway, much to the gratification of the
+numerous visitors and anxious expectants for this most wonderful
+discovery. Dr. Chilton, Professor J. J. Mapes, Professor J. W. Draper.
+Professor S. F. B. Morse, all of this city; Mr. Cornelius, Dr. Goddard
+and others of Philadelphia; Mr. Southworth, Professor Plumbe, and
+numerous others were early in the field; all, however, using the same
+description of camera as that of Daguerre, with modification for light,
+either by enlargement by lens and aperture for light, or by shortening
+the focal distance.
+
+At a conversational meeting of the Mechanics’ Institute, Professor J.
+J. Mapes being present, a question was asked if any one present could
+give information relative to portraiture from life by the
+Daguerreotype. Mr. Kells, a friend of Mr. Wolcott and a scientific and
+practical man (since deceased), at once marked out upon the
+black-board, the whole as contrived by Mr. Wolcott. This gave publicity
+to the invention of Mr. Wolcott. Shortly after, Professor Mapes, Dr.
+Chilton, and many others, sat for their portraits, and were highly
+gratified. Professor Morse also came and proposed to Mr. Wolcott to
+join him in the working of the invention, etc.
+
+From this time much interest was manifested by our friends in our
+progress. Rooms were obtained in the Granite Buildings, corner of
+Broadway and Chambers street, and fitted for business. The rooms being
+small, it was soon found impracticable to use the arrangement of
+looking-glass, as previously spoken of; a new plan became necessary, to
+introduce which, the sashes were removed, {199} and two large
+looking-glasses were mounted in proper frames, thus:—
+
+[Illustration: Fig. 13]
+
+Just in front, and between the sitter and {200} the reflector, upon a
+proper stand, were used those paper muslin screen before described;
+also screens of tissue paper. These screens, however, when they were
+used, required so much time for a sitting, that some other medium, as a
+protection to the eyes, became absolutely necessary. The most plausible
+thing that suggested itself was blue glass; but, as this could not be
+found, numerous were the expedients proposed by the friends of the art,
+who from time to time visited our rooms. At the suggestion of Professor
+Mapes (who is ever ready to assist those in perplexity), a trough of
+plate glass s, about twenty-eight inches square in the clear, and from
+three to four inches thick, was filled with a solution of ammonia
+sulphate of copper, and mounted on the frame as in the sketch, which,
+for a time, answered extremely well; soon, however, decomposition of
+this solution became apparent from the increased length of time
+required for a sitting, although to the eye of an observer, no visible
+cause for such long sittings could be pointed out. Professor Mapes
+being appealed to, suggested that to the above solution a little acid
+be added which acted like a charm—shortening the time for a sitting
+from six, eight, or ten minutes to that of about one. Decomposition,
+however, would go on by the action of light and heat through the
+solution. New solutions were tried, when the whole were finally
+abandoned as being, too uncertain and troublesome. (The reflecting
+apparatus R, was placed upon the stand as in the sketch, with a wedge
+for elevating the camera, between it and the table, to obtain the image
+properly upon the plate.) A quantity of blue window glass was next
+obtained, and holes drilled through the corners of it, and several
+sheets were wired together to increase the size, and, when complete,
+was suspended from the ceiling in its proper place, and so arranged
+that when a person was sitting, this sheet of glass could be moved to
+and from, the object of which was to prevent shadows on the face of the
+sitter produced from the uneven surface of the glass. This latter
+contrivance was used until a perfect plate of glass was procured.
+
+The number of persons desirous of obtaining, their miniatures, induced
+many to entertain the idea of establishing themselves in the Art as a
+profession, and numerous were the applications for information; many
+persons paying for their portraits solely with the view of seeing the
+manner of our manipulations, in order that they might obtain
+information to carry on likeness-taking as a business.
+
+The reflecting camera being a very troublesome instrument to make, and
+difficulties besetting us from every source, but little attention could
+be given to teaching others; and, indeed, as the facts seemed to be at
+this time, we knew but little of the necessary manipulations ourselves.
+In course of time, several established themselves. The first one, after
+ourselves, who worked the discovery of Daguerre for portrait taking in
+this city, was a Mr. Prosch; followed soon after by many others, in
+almost all cases copying the reflecting arrangement for light, as
+figured above, many using it even after we had long abandoned that
+arrangement for a better one.
+
+Innumerable obstacles to the rapid advance of the daguerreotype,
+presented themselves almost hourly, much to the annoyance of ourselves,
+and those dependent upon our movements for their advancement. Among the
+most difficult problems of the day, was the procuring of good plates.
+Messrs. Corduran & Co. were among the first to supply the trade; at
+that early day, however, it was a very rare thing, to be able to
+procure an even perfect surface, from the fact that a pure surface of
+silver could scarcely be obtained, the manufacturers deeming it too
+much trouble to prepare silver plated copper with pure silver—the
+result was, that in attempting to polish perfectly such plated metal as
+could be procured, the plates would become cloudy, or colored in spots,
+from the fact of having more or less alloy, according as more or less
+of the silver surface was removed in polishing the plate fit for an
+impression. To explain more clearly, it was the practice of most silver
+platers to use an alloy for silver-plating. In the reduction of the
+ingot to sheet metal, annealing has to be resorted to, and acid pickles
+to remove oxides, etc. The number of times the plated metal is exposed
+to heat and acid in its reduction to the required thickness, produces a
+surface of pure silver. The most of this surface is, however, so rough
+as to be with difficulty polished, without in places removing entirely
+this pellicle of pure metal, and exposing a polished surface of the
+alloy used in plating. Whenever such metal was used, very unsightly
+stains or spots frequently disfigured the portraits. The portrait, or
+portion of it, developed upon the pure silver, being much lighter or
+whiter than that developed upon the alloy; it therefore appeared that
+the purer the silver, the more sensitive the plate became. Accordingly,
+we directed Messrs. Scovills, of Connecticut, to prepare a roll of
+silver-plated metal, with pure silver; it fortunately proved to be a
+good article, but, unfortunately, a pound of this metal (early in 1840)
+cost the round sum of $9. Like descriptions of metal, the same
+gentlemen would be glad to furnish, at this time, for $4. Soon after
+this, some samples of English plated metal, of a very superior quality,
+came to our possession, and relieved us from the toil of making and
+plating one plate at a time, an expedient we were compelled to resort
+to, to command material to meet the pressing demands for portraits.
+
+Having it now in our power to obtain good plated metal, a more rapid
+mode of polishing than that recommended by Daguerre was attempted as
+follows:
+
+This metal was cut to the desired size, and having a pair of “hand
+rolls” at hand, each plate, with its silvered side placed next to the
+highly polished surface of a steel die, was passed and repassed through
+the rolls many times, by which process a very smooth, perfect surface
+was obtained. The plates were then annealed, and a number of plates
+thus prepared were fastened to the bottom of a box a few inches deep a
+foot wide, and eighteen inches long; this box was placed upon a table
+and attached to a rod connected to the face plate of a lathe, a few
+inches from its centre, so as to give the box a reciprocating motion. A
+quantity of emery was now strewn over the plates, and the lathe set in
+motion. The action produced wag a friction or rubbing of the emery over
+the surface of the plates.
+
+When continued for some time, a greyish polish was the result. Linseed,
+when used in the same manner, gave us better hope of success, and the
+next step resorted to was to build a wheel and suspend it after the
+manner of a grindstone. The plates being secured to the inner side of
+the wheel or case, and as this case revolved, the seeds would
+constantly keep to the lower level, and their sliding over the surface
+of the plates would polish or burnish their surfaces. This, with the
+former, was soon abandoned; rounded shots of silver placed in the same
+wheel were found not to perform the polishing so well as linseed.
+Buff-wheels of leather with rotten-stone and oil, proved to be far
+superior to all other contrivances; and, subsequently, at the
+suggestion of Professor Draper, velvet was used in lieu of buff
+leather, and soon superseded all other substances, both for lathe and
+hand-buffs, and I would add, for the benefit of new beginners that
+those who are familiar with its use, prefer cotton velvet. The only
+requisite necessary is, that the buffs made of cotton velvet should be
+kept dry and warm.
+
+The greater number of operators, with whose practice I am familiar,
+use, for polishing plates, prepared tripoli, imported from France, or
+Browne’s rotten-stone. The former of these articles is very
+objectionable, inasmuch as there is no positive certainty of being
+enabled to procure or make the article of uniform grit—the nature of
+the substance rendering, it impossible to reduce it to varying degrees
+of evenness, by the well known process of washing, for that purpose,
+and the burning of rotten-stone changes its chemical nature somewhat,
+at the same time rendering, this invaluable article harsh and gritty.
+And especially, no reliance can be placed upon burned rotten stone if
+purchased from those who do not give very great attention and care to
+its preparation; and the same remarks apply to rouge.
+
+The best article for polishing Daguerreotype plates is rotten-stone,
+such as can be procured in any town, prepared after the following
+manner: Procure, say half a dozen wide-mouthed bottles, of suitable
+dimensions, numbering each from one to six. Put into No. 1 about half a
+pound of rotten-stone, and nearly fill the bottle with water. Then,
+with a proper stick or spatule, mix well the rotten-stone and water;
+after which, let No. 1 rest for, say one minute, then carefully pour
+off into bottle No. 2 (or, what would be better, draw off by a syphon)
+as much of the floating particles of rotten-stone as is suspended in
+the water. Again fill bottle No. 1 with water, agitate it as before,
+and decant it to bottle No. 2, care being taken to draw off only the
+suspended particles of rotten-stone.
+
+When a sufficient quantity of washings from bottle No. 1 is collected
+into bottle No. 2, a similar process must be gone through, as above
+stated, for No. 1; the difference being in the care required, and in
+the time allowed between the stirring or mixing the rotten-stone and
+water. The floating particles of rotten-stone, after four minutes’
+subsiding, will be found fine enough for the finest Daguerreotype
+polishing required.
+
+A quantity of such washings may be collected in a large bottle, and
+allowed to stand a few hours, when all the rotten-stone will have
+settled. The water may be poured off and the rotten-stone put into an
+evaporating dish, and while being dried, must be constantly stirred to
+obtain an impalpable powder.
+
+Further washings may in like manner be resorted to for finer qualities
+of rotten-stone. In my practice, I have used the articles at two and
+four minutes’ settling, and occasionally have prepared it after
+standing for eight minutes. So fine a quality as this, however, is
+seldom required. In using, rotten-stone, I mix with it, for polishing,
+fine olive oil, until I obtain a thin paste—and the best of all methods
+for polishing (well planished) Daguerreotype plates, is one like that
+used for glass by lens polishers; that is, by using a disc or
+buff-wheel, and having, a suitable holder by which to secure the plate,
+and then by pressing the plate against the revolving buff, well
+saturated with the mixed oil and rotten-stone, a very good surface is
+obtained. A quantity of plates may be prepared in this way, and all the
+adhering oil, etc., may be removed by a clean hand, or lathe buff,
+after which each plate must be heated to the point necessary to burn
+off the remaining oil great care being required not to overheat the
+plate. A very slight excess of temperature will at once destroy all the
+polish previously obtained. The test for ascertaining the right
+temperature is at hand; the adhering oil will be driven from the plate
+in the form of smoke when the right temperature is reached. The moment
+the smoke ceases to rise from the plate, the heat must be removed, and
+the plate quickly cooled upon a piece of iron.
+
+A quantity of plates thus prepared may be kept on hand for any required
+time, and the labor of one minute, with a lathe or hand-buff with dry
+charcoal, or rather, prepared lampblack, will perfectly polish the
+surface ready for indexing, etc. This lampblack also requires some care
+in preparing. Take a small-size crucible, properly temper it by a slow
+fire, that it may not be cracked after which, fill it with common
+lampblack, cover it over with a piece of soap-stone, and again replace
+it in the fire. Build a good hard coal fire around it continue the heat
+for two or three hours, being careful not to raise the cover till the
+crucible be quite cold. Pulverize when using it. It is very desirable
+to keep this lampblack dry and warm. Some operators use much rouge I
+would recommend the above in preference; but those who feel that they
+cannot dispense with the use of rouge, had better try a large addition
+of prepared lampblack to a small one of rouge, as this latter article,
+unless great pains be taken in its preparation, will adhere and work
+itself into the body of the surface, so that it cannot be removed
+therefrom; and I have seen many specimens of Daguerreotype very much
+injured in effect from this rouge tint disseminated throughout their
+shaded features, at the same time that the whole general effect of such
+pictures is that of a want of life. It is true that with the use of
+rouge a very high degree of polish may be obtained, but probably not
+higher than can be produced with many other substances of a less
+objectionable nature.
+
+From the announcement of the discovery by Daguerre to the beginning of
+the year 1840, I am not aware of any attempt to lessen the time for the
+action of an image, or an impression, other than that of the reflecting
+camera invented by Mr. Wolcott. Early, however, in 1840, Mr. Wolcott
+was desirous to be enabled to further shorten the time for a sitting,
+and having some knowledge of bromine and its action, by request, Dr.
+Chilton prepared a small quantity; but Mr. Wolcott did not succeed very
+well with it, he having invariably used too much in combination with
+iodine to produce that sensitive coating now well known to the
+profession. Professor Morse, of this city, Dr. Goddard, of
+Philadelphia, and others, in the years 1840 and 1841, were acquainted
+with the use of bromine. N. Griffing, of this city, or myself, used
+with tolerable success, iodine in large excess to nitric acid and
+water; and, subsequently, to nitro muriatic acid (which reacted and
+formed a peculiar chloride of iodine); this latter combination proved
+to be preferable to simple iodine, at the same time somewhat more
+sensitive, and was used by me in this city up to the time of my leaving
+for London (October 1, 1840). On arriving in London, I instituted a
+series of experiments in the various chemical combinations, solely with
+the view to be enabled to obtain more speedily a portrait than it was
+practicable to do with any known chemicals at that date. The high
+latitude, and the winter season of the year rendering but a feeble
+light at best, the greater the necessity for a more sensitive chemical
+preparation to the shortening the time for a sitting. Near the
+beginning of the year 1841, I discovered and practically applied,
+chloride of iodine to great advantage, and, as far as memory serves me,
+I believe the first used in this country was some made and shipped,
+Messrs. Harnden & Co., from London, to Mr. Wolcott, in New York.
+
+About the same time, Mr. John Goddard, of London (who was associated
+with myself), discovered a rather valuable combination of chemicals,
+consisting of a mixture of iodine, bromine, iodus, and iodic acid, and
+a proper combination of those bodies gave an action somewhat more
+sensitive than chloride of iodine—but the “high lights” of the
+portraits would become solarized or overdone, more frequently with this
+combination than with the chloride of iodine. Throughout the year 1841,
+I used, with great success, chloride of iodine, applied as one
+coating—occasionally in conjunction with Mr. Wolcott, attempting the
+use of iodine, bromine, and chlorine, and at times with more or less
+success. The difficulty of exactly combining, the three elements above
+mentioned, in order to produce a certainty of result with harmony of
+effect, was the work of many months, with great labor and study, the
+slightest modification requiring a long, series of practical
+experiments, a single change consuming, frequently, an entire day in
+instituting comparisons, etc., etc.
+
+Early in the year, 1842, I discovered a combination of chemicals (now
+known in London as “Wolcott’s Mixture,” in hermetically sealed bulbs)
+of exceeding uniform character, very sensitive to the action of light,
+and specimens produced in 1842-3, with this combination, will bear
+comparison with the best specimens produced at this late date.
+
+About the same time, I discovered that however much overdone a
+Daguerreotype might be, the means were at hand to save or redeem it. It
+has long, since been known to operators, that if a plate be exposed to
+light after being coated, unless it be again coated, a clear and
+distinct picture could not be obtained upon the same plate without
+first repolishing and recoating the same, care being taken that no
+light fall upon the prepared surface. To prevent solarization, coat a
+plate as usual, expose to the action of light any required time
+(according to circumstances), say from quarter to one half more time
+than would be required in the ordinary method of procedure; observe,
+before putting the plate in the mercury box, place it over the vapor of
+iodine, bromine, or chlorine, etc. (carefully excluding the light), for
+a very brief period, great care being required to have the selected
+vapor very much diluted with air, in order to success. Many experiments
+will be required ere arriving at satisfactory results. Specimens now
+unknown to general operators, for harmony of effect, have been, and may
+again be produced by the method pointed out above. I have found the
+best general effect, and the most certain result to follow from the use
+of the vapor of chlorine—but this requires more than ordinary care. I
+would, therefore, recommend the use of iodine. Thus: to a few grains of
+iodine, add an ounce of warm water (which will become tinged with
+iodine); when cold, to half a pint of pure water in a new and clean
+coating box, put, of the above, fifty drops; stir and mix well this
+small quantity of iodine in with the water; in ten minutes this box
+will be ready for use. Great care and judgment will be required in the
+application of this vapor to the plate; if the plate remain over the
+vapor too long, the developed picture will have a faint and misty
+appearance; if not exposed long enough, the “high light” will be
+solarized. I have great hope of the ultimate use of this process, as it
+is the only means yet discovered to be enabled to secure specimens of
+extremes of light and shade, yet producing harmony of effect; and I
+would call the attention of the profession to the fact, that a plate
+may be exposed to the action of light for any length of time (a
+thousand times longer than required to act for the lesser quantity of
+mercury to deposit itself, or that amount necessary to form a perfect
+specimen), and be restored by the application of any of the vapors
+above mentioned, remarking that for extremes for solarization, denser
+vapors will be required. Much remains to be done with this discovery to
+the application of the Daguerreotype.
+
+HUMPHREY’S JOURNAL OF THE DAGUERREOTYPE & PHOTOGRAPHIC ARTS.
+
+The above-named publication is well known as the best and most valuable
+one devoted to the Photographic Science in this country. Humphrey’s
+Journal made its appearance November 1st, 1850, and consequently is the
+first and oldest serial offered to the Photographic world.
+
+The art of producing Portraits and Landscapes by means of Light, has
+recently taken a new and enlivening impulse, which will in all
+probability lead to important and interesting results. No practical
+Daguerreotypist, Photographer, or amateur, should be without the means
+at hand for securing all of the information upon this subject. Each
+should be ready to receive and apply the improvements as they may be
+developed. In order to accomplish this, it is a matter of great
+importance to the Practitioner or Experimenter that he should have a
+reliable medium through which he can obtain information. In what source
+can the inquirer better place his confidence than in a regular Journal,
+whose editor is literally a practical person, and familiar with the
+manipulations necessary for producing Portraits upon “Daguerreotype
+Plates,” and upon glass and paper? Such is the conductor of Humphrey’s
+Journal.
+
+This Journal is published once every two weeks, and contains all the
+improvements relating to the Art, and is the only American Journal
+whose editor is practically acquainted with the process for producing
+Daguerreotypes, Ambrotypes, and Photographs. The first No. of Vol. X.
+is dated May 1st, 1858. The terms (Two Dollars per annum) are trifling
+compared with the vast amount of information furnished.
+
+AMBROTYPES.—Humphrey’s Journal contains everything novel which appears
+upon this subject, and has already presented more new, important, and
+original matter than can be found in any other place.
+
+Many are the letters we have received during the term of the last
+volume, in which the writer has stated that a single number of
+Humphrey’s Journal has contained information of more value to him than
+“several times the amount paid for the entire volume.”
+
+Our resources have grown up around us, and our facilities for
+procuring, as well as distributing, all such facts and improvements as
+will benefit as well as instruct all who have the progress of the Art
+at heart, are as ample as they can well be made.
+
+The future volumes will be abundantly furnished with original writings
+from persons of standing in the scientific world; and the practical
+Photographer will here find a full account of such improvements as may
+from time to time develop themselves.
+
+From the editor’s long practical experience in the Heliographic
+Science, he will be enabled to present the subject in a plain, clear,
+and concise manner.
+
+Read what the Editors say of Humphrey’s Journal:—
+
+“We have received a copy of a valuable Journal (Humphrey’s) published
+in New York, which has reached the 18th number of Vol. VI.... We now
+have the pleasure of quoting from our trans-atlantic
+coadjutor.”—Liverpool Photographic Jour.
+
+“Humphrey’s Journal is practical as well as scientific in
+character.”—American Journal of Science and Arts.
+
+“It treats the subject knowingly and with force.”—New York Tribune.
+
+“It is both a popular and interesting publication.”—Mechanics’
+Magazine.
+
+“It is highly useful to all who practice ‘shadow catching.’”—Ohio State
+Journal.
+
+“The work is neatly gotten up, and contains many interesting varieties
+in this new field of science.”—Times.
+
+“It should be hailed and encouraged, not only by Daguerreotypists
+themselves, but by every lover of Science and Art.”—The Democrat.
+
+“We cannot too strongly urge all artists, and those persons who feel an
+interest in the Heliographic Arts and Sciences, to take a copy of the
+work.”—Sentinel.
+
+“It is indicative of talent worthy of the important Art it is designed
+to elevate.”—American.
+
+“This Art is entitled to its own organ, which could not have fallen
+into better hands than those of the editor of ‘Humphrey’s
+Journal.’”—Transcript.
+
+“It is a scientific work of interest and usefulness.”—Star of the
+North.
+
+“This Journal answers many points heretofore regarded as
+inexplicable.”—Hudson River Chronicle.
+
+“It is rich with interest.”—North American.
+
+“It contains all the ‘Improvements.’”—Delta.
+
+“It teaches us how to take our own portraits.”—Bee.
+
+“It will cultivate a taste for Daguerreotypes.”—Commercial Advertiser.
+
+“It should be in the hands of all.”—Reveille.
+
+“It is the Daguerreotypist’s friend.”—London News.
+
+“It should be found in every library.”—Evening Journal.
+
+From some of our Subscribers
+
+“Humphrey’s Journal has been the means of saving much time and money,
+for by its instruction I have been enabled to produce some of the
+finest Paper Pictures I have ever seen.” W. P.
+
+“Don’t fail to send me the Journal, for I would not be without it for
+five times the amount of subscription. It is the only publication I can
+depend upon.” A. G. R.
+
+“Your treatment of the humbugs and humbugging members of the
+profession, is of the most valuable importance to us practical
+Daguerreans. Go on. God speed! Here is the amount for the renewal of my
+subscription.” E. F. S.
+
+“How can any Operator afford to be without it?” L. L. H.
+
+“Here are five dollars: send me Humphrey’s Journal to this amount. I
+will not be without it.” M. S.
+
+“It is my best friend.” J. E. W.
+
+We might quote like commendatory extracts enough to more than ten times
+fill this page.
+
+Humphrey’s Journal contains 16 octavo pages of reading matter.
+
+TERMS.
+
+One copy per annum, in advance . . . . . . $2 00
+Three copies, do. do. . . . . . . $5 00
+Six copies, do. do. . . . . . . $9 00
+
+The thousands who read it cannot be induced to remain without it. All
+who desire to keep up with the improvements should subscribe for a
+copy.
+
+Subscription price Two Dollars per year.
+
+Don’t fail to become a subscriber. Address
+ S. D. HUMPHREY Office, 37 Lispenard Street, NEW YORK.
+
+THE PRACTICAL MANUAL OF THE COLLODION PROCESS. BY S. D. HUMPHREY.
+THIRD EDITION
+
+This Edition contains all the Improvements in the Art made public up to
+the day of publication, and gives complete Practical Instructions for
+making Collodion Positives or Ambrotypes, Collodion Negatives,
+Printing, etc., etc. The quick, great and unprecedented sale of the
+first and second editions demonstrates, more than the strongest
+language could possibly do, the extraordinary and increasing popularity
+of this work. The Third Edition contains two hundred and sixteen 12mo.
+pages, of a larger size and in smaller type than either of the
+preceding editions, and is illustrated with numerous wood-cuts. It is
+intended to be the best practical work extant; substantially bound in
+cloth, price One Dollar; forwarded by mail (postage prepaid). Address
+
+S. D. HUMPHREY, New York
+
+A GUIDE TO PHOTOGRAPHY,
+
+Containing simple and concise directions for obtaining Views,
+Portraits, etc., by the chemical agency of Light, by W. H.
+Thornthwaite, author of “Photogenic Manipulations,” etc. Illustrated
+with numerous wood-cuts. The Book contains more than one hundred 12mo
+pages, bound in board, and is sold at twenty-five cents per copy, or
+five copies for one dollar. Address
+
+S. D. HUMPHREY, New York
+
+HOLMES, BOOTH & HAYDENS, MANUFACTURERS OF DAGUERREOTYPE CASES, PLATES,
+CAMERAS, MATTINGS, PRESERVERS, ETC., ETC.
+
+MANUFACTURERS AND IMPORTERS OF EVERY VARIETY OF AMBROTYPE, AND
+PHOTOGRAPHIC GOODS,
+
+Of the Best and most approved Quality.
+
+ESPECIAL ATTENTION GIVEN TO THE FURNISHING OF EVERY ARTICLE USED IN THE
+PRACTICE OF THE DAGUERREOTYPE
+
+Depot 81 Chambers and 63 Reade St., New York.
+
+Manufactory at Waterbury, Conn.
+
+HOLMES, BOOTH & HAYDENS’ CAMERAS
+
+From 1/4 to the Mammoth size. These CAMERAS are of the most superior
+make, and all subjected to the most thorough test before being offered
+for sale.
+
+VIEW CAMERAS, made expressly for taking views: an entirely new article.
+
+DAGUERREOTYPE PLATES, OF EVERY VARIETY, AND WE WOULD CALL PARTICULAR
+ATTENTION TO THE
+
+Wreath, and H. B. & H. Eagle 40 Plates, AS HAVING NO EQUALS IN THE
+MARKET.
+
+SOLE AGENTS FOR THE CELEBRATED H. B. AND N. P. FRENCH PLATES.
+
+Always on hand a complete assortment of Ambrotype and Photographic
+goods.
+
+SOLE AGENTS FOR THE Patent solid glass corner Plate Holders.
+
+All orders will receive prompt attention, and be forwarded with
+dispatch.
+
+HOLMES, BOOTH & HAYDENS, 81 Chambers, and 63 Reade St. New York.
+
+SCOVILL MANUFACTURING CO.
+
+MANUFACTURER OF DAGUERREOTYPE PLATES, MATTINGS, PRESERVERS, CASES,
+APPARATUS, etc., etc.
+
+Importers and Dealers in every description of Daguerreotype,
+Photographic, AND AMBROTYPE GOODS,
+
+The SCOVILL MANUFACTURING COMPANY flatter themselves that an experience
+of nearly twenty years in the business and the most extensive variety
+of the above Goods in the United States, entitle them to the
+continuance of orders for the Domestic and Foreign trade, which will
+receive the most careful attention.
+
+Park Building, New York. Entrances—36 Park Row, 4 Beekman, and 141
+Nassau Street.
+
+SCOVILL MANUFACTURING CO.
+
+Would call especial attention to their large variety of
+
+CASES,
+
+Embracing many Fancy Styles made only by themselves, and to which they
+are constantly adding New Designs.
+
+Union Cases, Of all sizes, with Riveted Hinges. AGENTS FOR THE SALE OF
+C. C. HARRISON’S CAMERAS,
+
+with improvements, which we are now prepared to sell at reduced prices,
+and warranted to give better satisfaction than ever before
+DAGUERREOTYPE PLATES, H. B.—N. P.—Star and other brands PLATE GLASS,
+embracing three-quarters white: Crown and all other varieties. We would
+call particular attention to our Black Glass, made expressly for
+Ambrotypes.
+
+CHEMICALS, for the Daguerreotype and Photographic Art. Iodized and
+Plain COLLODION. Gun Cotton, etc., etc. Tagliabue’s Collodiometres and
+Actino-Hydrometres, for testing Chemicals.
+
+APPARATUS OF EVERY VARIETY.
+
+Gutta Percha, Porcelain, and Glassware of all kinds used in the Art.
+
+A large assortment of Gilt Frames always on hand and made to order.
+
+Ambrotype Shields, with solid corners of a new style.
+
+All orders will meet with prompt attention
+
+SCOVILL MANUFACTURING CO., PARK BUILDINGM New York 36 Park Row, 4
+Beckman, and 141 Nassau Street.
+
+HARDWICH’S PHOTOGRAPHIC CHEMISTRY AMERICAN EDITION.
+
+A MANUAL of PHOTOGRAPHIC CHEMISTRY,
+ INCLUDING THE PRACTICE OF THE COLLODION PROCESS.
+
+BY
+
+T. FREDERICK HARDWICH,
+
+LECTURER ON PHOTOGRAPHY IN KINGS COLLEGE, LONDON; LATE DEMONSTRATOR OF
+CHEMISTRY IN KING’S COLLEGE.
+
+Last Edition,
+
+The above is the title of this new and valuable work. It is too well
+known to need any further comment in this place. This volume contains
+nearly 300 large duodecimo pages, bound in red cloth, $1.00. Copies to
+be forwarded by mail, $1.18, postage pre-paid.
+
+S. D. HUMPHREY, Photographic Book Publisher, 37 LISPENARD
+STREET, NEW YORK,
+
+N.B. Postage stamps taken.
+
+
+
+
+End of the Project Gutenberg EBook of American Handbook of the Daguerrotype, by Samuel D. Humphrey
+
+*** END OF THIS PROJECT GUTENBERG EBOOK AMERICAN HANDBOOK OF THE DAGUERROTYPE ***
+
+***** This file should be named 167-0.txt or 167-0.zip *****
+This and all associated files of various formats will be found in:
+ http://www.gutenberg.org/1/6/167/
+
+Produced by Gregory Walker, for the Digital Daguerreian Archive Project.
+
+Updated editions will replace the previous one--the old editions will
+be renamed.
+
+Creating the works from print editions not protected by U.S. copyright
+law means that no one owns a United States copyright in these works,
+so the Foundation (and you!) can copy and distribute it in the United
+States without permission and without paying copyright
+royalties. Special rules, set forth in the General Terms of Use part
+of this license, apply to copying and distributing Project
+Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm
+concept and trademark. Project Gutenberg is a registered trademark,
+and may not be used if you charge for the eBooks, unless you receive
+specific permission. If you do not charge anything for copies of this
+eBook, complying with the rules is very easy. You may use this eBook
+for nearly any purpose such as creation of derivative works, reports,
+performances and research. They may be modified and printed and given
+away--you may do practically ANYTHING in the United States with eBooks
+not protected by U.S. copyright law. Redistribution is subject to the
+trademark license, especially commercial redistribution.
+
+START: FULL LICENSE
+
+THE FULL PROJECT GUTENBERG LICENSE
+PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK
+
+To protect the Project Gutenberg-tm mission of promoting the free
+distribution of electronic works, by using or distributing this work
+(or any other work associated in any way with the phrase "Project
+Gutenberg"), you agree to comply with all the terms of the Full
+Project Gutenberg-tm License available with this file or online at
+www.gutenberg.org/license.
+
+Section 1. General Terms of Use and Redistributing Project
+Gutenberg-tm electronic works
+
+1.A. By reading or using any part of this Project Gutenberg-tm
+electronic work, you indicate that you have read, understand, agree to
+and accept all the terms of this license and intellectual property
+(trademark/copyright) agreement. If you do not agree to abide by all
+the terms of this agreement, you must cease using and return or
+destroy all copies of Project Gutenberg-tm electronic works in your
+possession. If you paid a fee for obtaining a copy of or access to a
+Project Gutenberg-tm electronic work and you do not agree to be bound
+by the terms of this agreement, you may obtain a refund from the
+person or entity to whom you paid the fee as set forth in paragraph
+1.E.8.
+
+1.B. "Project Gutenberg" is a registered trademark. It may only be
+used on or associated in any way with an electronic work by people who
+agree to be bound by the terms of this agreement. There are a few
+things that you can do with most Project Gutenberg-tm electronic works
+even without complying with the full terms of this agreement. See
+paragraph 1.C below. There are a lot of things you can do with Project
+Gutenberg-tm electronic works if you follow the terms of this
+agreement and help preserve free future access to Project Gutenberg-tm
+electronic works. See paragraph 1.E below.
+
+1.C. The Project Gutenberg Literary Archive Foundation ("the
+Foundation" or PGLAF), owns a compilation copyright in the collection
+of Project Gutenberg-tm electronic works. Nearly all the individual
+works in the collection are in the public domain in the United
+States. If an individual work is unprotected by copyright law in the
+United States and you are located in the United States, we do not
+claim a right to prevent you from copying, distributing, performing,
+displaying or creating derivative works based on the work as long as
+all references to Project Gutenberg are removed. Of course, we hope
+that you will support the Project Gutenberg-tm mission of promoting
+free access to electronic works by freely sharing Project Gutenberg-tm
+works in compliance with the terms of this agreement for keeping the
+Project Gutenberg-tm name associated with the work. You can easily
+comply with the terms of this agreement by keeping this work in the
+same format with its attached full Project Gutenberg-tm License when
+you share it without charge with others.
+
+1.D. The copyright laws of the place where you are located also govern
+what you can do with this work. Copyright laws in most countries are
+in a constant state of change. If you are outside the United States,
+check the laws of your country in addition to the terms of this
+agreement before downloading, copying, displaying, performing,
+distributing or creating derivative works based on this work or any
+other Project Gutenberg-tm work. The Foundation makes no
+representations concerning the copyright status of any work in any
+country outside the United States.
+
+1.E. Unless you have removed all references to Project Gutenberg:
+
+1.E.1. The following sentence, with active links to, or other
+immediate access to, the full Project Gutenberg-tm License must appear
+prominently whenever any copy of a Project Gutenberg-tm work (any work
+on which the phrase "Project Gutenberg" appears, or with which the
+phrase "Project Gutenberg" is associated) is accessed, displayed,
+performed, viewed, copied or distributed:
+
+ This eBook is for the use of anyone anywhere in the United States and
+ most other parts of the world at no cost and with almost no
+ restrictions whatsoever. You may copy it, give it away or re-use it
+ under the terms of the Project Gutenberg License included with this
+ eBook or online at www.gutenberg.org. If you are not located in the
+ United States, you'll have to check the laws of the country where you
+ are located before using this ebook.
+
+1.E.2. If an individual Project Gutenberg-tm electronic work is
+derived from texts not protected by U.S. copyright law (does not
+contain a notice indicating that it is posted with permission of the
+copyright holder), the work can be copied and distributed to anyone in
+the United States without paying any fees or charges. If you are
+redistributing or providing access to a work with the phrase "Project
+Gutenberg" associated with or appearing on the work, you must comply
+either with the requirements of paragraphs 1.E.1 through 1.E.7 or
+obtain permission for the use of the work and the Project Gutenberg-tm
+trademark as set forth in paragraphs 1.E.8 or 1.E.9.
+
+1.E.3. If an individual Project Gutenberg-tm electronic work is posted
+with the permission of the copyright holder, your use and distribution
+must comply with both paragraphs 1.E.1 through 1.E.7 and any
+additional terms imposed by the copyright holder. Additional terms
+will be linked to the Project Gutenberg-tm License for all works
+posted with the permission of the copyright holder found at the
+beginning of this work.
+
+1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm
+License terms from this work, or any files containing a part of this
+work or any other work associated with Project Gutenberg-tm.
+
+1.E.5. Do not copy, display, perform, distribute or redistribute this
+electronic work, or any part of this electronic work, without
+prominently displaying the sentence set forth in paragraph 1.E.1 with
+active links or immediate access to the full terms of the Project
+Gutenberg-tm License.
+
+1.E.6. You may convert to and distribute this work in any binary,
+compressed, marked up, nonproprietary or proprietary form, including
+any word processing or hypertext form. However, if you provide access
+to or distribute copies of a Project Gutenberg-tm work in a format
+other than "Plain Vanilla ASCII" or other format used in the official
+version posted on the official Project Gutenberg-tm web site
+(www.gutenberg.org), you must, at no additional cost, fee or expense
+to the user, provide a copy, a means of exporting a copy, or a means
+of obtaining a copy upon request, of the work in its original "Plain
+Vanilla ASCII" or other form. Any alternate format must include the
+full Project Gutenberg-tm License as specified in paragraph 1.E.1.
+
+1.E.7. Do not charge a fee for access to, viewing, displaying,
+performing, copying or distributing any Project Gutenberg-tm works
+unless you comply with paragraph 1.E.8 or 1.E.9.
+
+1.E.8. You may charge a reasonable fee for copies of or providing
+access to or distributing Project Gutenberg-tm electronic works
+provided that
+
+* You pay a royalty fee of 20% of the gross profits you derive from
+ the use of Project Gutenberg-tm works calculated using the method
+ you already use to calculate your applicable taxes. The fee is owed
+ to the owner of the Project Gutenberg-tm trademark, but he has
+ agreed to donate royalties under this paragraph to the Project
+ Gutenberg Literary Archive Foundation. Royalty payments must be paid
+ within 60 days following each date on which you prepare (or are
+ legally required to prepare) your periodic tax returns. Royalty
+ payments should be clearly marked as such and sent to the Project
+ Gutenberg Literary Archive Foundation at the address specified in
+ Section 4, "Information about donations to the Project Gutenberg
+ Literary Archive Foundation."
+
+* You provide a full refund of any money paid by a user who notifies
+ you in writing (or by e-mail) within 30 days of receipt that s/he
+ does not agree to the terms of the full Project Gutenberg-tm
+ License. You must require such a user to return or destroy all
+ copies of the works possessed in a physical medium and discontinue
+ all use of and all access to other copies of Project Gutenberg-tm
+ works.
+
+* You provide, in accordance with paragraph 1.F.3, a full refund of
+ any money paid for a work or a replacement copy, if a defect in the
+ electronic work is discovered and reported to you within 90 days of
+ receipt of the work.
+
+* You comply with all other terms of this agreement for free
+ distribution of Project Gutenberg-tm works.
+
+1.E.9. If you wish to charge a fee or distribute a Project
+Gutenberg-tm electronic work or group of works on different terms than
+are set forth in this agreement, you must obtain permission in writing
+from both the Project Gutenberg Literary Archive Foundation and The
+Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm
+trademark. Contact the Foundation as set forth in Section 3 below.
+
+1.F.
+
+1.F.1. Project Gutenberg volunteers and employees expend considerable
+effort to identify, do copyright research on, transcribe and proofread
+works not protected by U.S. copyright law in creating the Project
+Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm
+electronic works, and the medium on which they may be stored, may
+contain "Defects," such as, but not limited to, incomplete, inaccurate
+or corrupt data, transcription errors, a copyright or other
+intellectual property infringement, a defective or damaged disk or
+other medium, a computer virus, or computer codes that damage or
+cannot be read by your equipment.
+
+1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right
+of Replacement or Refund" described in paragraph 1.F.3, the Project
+Gutenberg Literary Archive Foundation, the owner of the Project
+Gutenberg-tm trademark, and any other party distributing a Project
+Gutenberg-tm electronic work under this agreement, disclaim all
+liability to you for damages, costs and expenses, including legal
+fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT
+LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE
+PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE
+TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE
+LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR
+INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH
+DAMAGE.
+
+1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a
+defect in this electronic work within 90 days of receiving it, you can
+receive a refund of the money (if any) you paid for it by sending a
+written explanation to the person you received the work from. If you
+received the work on a physical medium, you must return the medium
+with your written explanation. The person or entity that provided you
+with the defective work may elect to provide a replacement copy in
+lieu of a refund. If you received the work electronically, the person
+or entity providing it to you may choose to give you a second
+opportunity to receive the work electronically in lieu of a refund. If
+the second copy is also defective, you may demand a refund in writing
+without further opportunities to fix the problem.
+
+1.F.4. Except for the limited right of replacement or refund set forth
+in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO
+OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.
+
+1.F.5. Some states do not allow disclaimers of certain implied
+warranties or the exclusion or limitation of certain types of
+damages. If any disclaimer or limitation set forth in this agreement
+violates the law of the state applicable to this agreement, the
+agreement shall be interpreted to make the maximum disclaimer or
+limitation permitted by the applicable state law. The invalidity or
+unenforceability of any provision of this agreement shall not void the
+remaining provisions.
+
+1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the
+trademark owner, any agent or employee of the Foundation, anyone
+providing copies of Project Gutenberg-tm electronic works in
+accordance with this agreement, and any volunteers associated with the
+production, promotion and distribution of Project Gutenberg-tm
+electronic works, harmless from all liability, costs and expenses,
+including legal fees, that arise directly or indirectly from any of
+the following which you do or cause to occur: (a) distribution of this
+or any Project Gutenberg-tm work, (b) alteration, modification, or
+additions or deletions to any Project Gutenberg-tm work, and (c) any
+Defect you cause.
+
+Section 2. Information about the Mission of Project Gutenberg-tm
+
+Project Gutenberg-tm is synonymous with the free distribution of
+electronic works in formats readable by the widest variety of
+computers including obsolete, old, middle-aged and new computers. It
+exists because of the efforts of hundreds of volunteers and donations
+from people in all walks of life.
+
+Volunteers and financial support to provide volunteers with the
+assistance they need are critical to reaching Project Gutenberg-tm's
+goals and ensuring that the Project Gutenberg-tm collection will
+remain freely available for generations to come. In 2001, the Project
+Gutenberg Literary Archive Foundation was created to provide a secure
+and permanent future for Project Gutenberg-tm and future
+generations. To learn more about the Project Gutenberg Literary
+Archive Foundation and how your efforts and donations can help, see
+Sections 3 and 4 and the Foundation information page at
+www.gutenberg.org
+
+
+
+Section 3. Information about the Project Gutenberg Literary Archive Foundation
+
+The Project Gutenberg Literary Archive Foundation is a non profit
+501(c)(3) educational corporation organized under the laws of the
+state of Mississippi and granted tax exempt status by the Internal
+Revenue Service. The Foundation's EIN or federal tax identification
+number is 64-6221541. Contributions to the Project Gutenberg Literary
+Archive Foundation are tax deductible to the full extent permitted by
+U.S. federal laws and your state's laws.
+
+The Foundation's principal office is in Fairbanks, Alaska, with the
+mailing address: PO Box 750175, Fairbanks, AK 99775, but its
+volunteers and employees are scattered throughout numerous
+locations. Its business office is located at 809 North 1500 West, Salt
+Lake City, UT 84116, (801) 596-1887. Email contact links and up to
+date contact information can be found at the Foundation's web site and
+official page at www.gutenberg.org/contact
+
+For additional contact information:
+
+ Dr. Gregory B. Newby
+ Chief Executive and Director
+ gbnewby@pglaf.org
+
+Section 4. Information about Donations to the Project Gutenberg
+Literary Archive Foundation
+
+Project Gutenberg-tm depends upon and cannot survive without wide
+spread public support and donations to carry out its mission of
+increasing the number of public domain and licensed works that can be
+freely distributed in machine readable form accessible by the widest
+array of equipment including outdated equipment. Many small donations
+($1 to $5,000) are particularly important to maintaining tax exempt
+status with the IRS.
+
+The Foundation is committed to complying with the laws regulating
+charities and charitable donations in all 50 states of the United
+States. Compliance requirements are not uniform and it takes a
+considerable effort, much paperwork and many fees to meet and keep up
+with these requirements. We do not solicit donations in locations
+where we have not received written confirmation of compliance. To SEND
+DONATIONS or determine the status of compliance for any particular
+state visit www.gutenberg.org/donate
+
+While we cannot and do not solicit contributions from states where we
+have not met the solicitation requirements, we know of no prohibition
+against accepting unsolicited donations from donors in such states who
+approach us with offers to donate.
+
+International donations are gratefully accepted, but we cannot make
+any statements concerning tax treatment of donations received from
+outside the United States. U.S. laws alone swamp our small staff.
+
+Please check the Project Gutenberg Web pages for current donation
+methods and addresses. Donations are accepted in a number of other
+ways including checks, online payments and credit card donations. To
+donate, please visit: www.gutenberg.org/donate
+
+Section 5. General Information About Project Gutenberg-tm electronic works.
+
+Professor Michael S. Hart was the originator of the Project
+Gutenberg-tm concept of a library of electronic works that could be
+freely shared with anyone. For forty years, he produced and
+distributed Project Gutenberg-tm eBooks with only a loose network of
+volunteer support.
+
+Project Gutenberg-tm eBooks are often created from several printed
+editions, all of which are confirmed as not protected by copyright in
+the U.S. unless a copyright notice is included. Thus, we do not
+necessarily keep eBooks in compliance with any particular paper
+edition.
+
+Most people start at our Web site which has the main PG search
+facility: www.gutenberg.org
+
+This Web site includes information about Project Gutenberg-tm,
+including how to make donations to the Project Gutenberg Literary
+Archive Foundation, how to help produce our new eBooks, and how to
+subscribe to our email newsletter to hear about new eBooks.
+
+
diff --git a/167-0.zip b/167-0.zip
new file mode 100644
index 0000000..9a2deb4
--- /dev/null
+++ b/167-0.zip
Binary files differ
diff --git a/167-h.zip b/167-h.zip
new file mode 100644
index 0000000..97ff3fb
--- /dev/null
+++ b/167-h.zip
Binary files differ
diff --git a/167-h/167-h.htm b/167-h/167-h.htm
new file mode 100644
index 0000000..fc4afb5
--- /dev/null
+++ b/167-h/167-h.htm
@@ -0,0 +1,6195 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
+"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+<head>
+<meta http-equiv="content-type" content="text/html; charset=utf-8" />
+<meta http-equiv="Content-Style-Type" content="text/css" />
+<title>The Project Gutenberg E-text of American Handbook of the Daguerrotype, by Samuel D. Humphrey.</title>
+
+<style type="text/css">
+
+body { margin-right: 10%;
+ margin-left: 10%;
+ text-align: justify }
+
+h1, h2, h3, h4, h5 {text-align: center; font-style: normal; font-weight:
+normal; line-height: 1.5; margin-top: .5em; margin-bottom: .5em;}
+
+h1 {font-size: 300%;
+ margin-top: 0.6em;
+ margin-bottom: 0.6em;
+ letter-spacing: 0.12em;
+ word-spacing: 0.2em;
+ text-indent: 0em;}
+h2 {font-size: 150%; margin-top: 2em; margin-bottom: 1em;}
+h3 {font-size: 150%; margin-top: 2em;}
+h4 {font-size: 120%;}
+h5 {font-size: 110%;}
+
+p {text-indent: 1em;
+ margin-top: 0.25em;
+ margin-bottom: 0.25em; }
+
+p.letter {text-indent: 0%;
+ margin-left: 10%;
+ margin-right: 10%;
+ margin-top: 1em;
+ margin-bottom: 1em; }
+
+p.noindent {text-indent: 0% }
+
+p.footnote {font-size: 90%;
+ text-indent: 0%;
+ margin-left: 10%;
+ margin-right: 10%;
+ margin-top: 1em;
+ margin-bottom: 1em; }
+
+sup { vertical-align: top; font-size: 0.6em; }
+
+p.transnote {font-size: small ;
+ text-indent: 0% ;
+ margin-left: 0% ;
+ margin-right: 0% }
+
+div.fig { display:block;
+ margin:0 auto;
+ text-align:center;
+ margin-top: 1em;
+ margin-bottom: 1em;}
+
+a:link {color:blue; text-decoration:none}
+a:visited {color:blue; text-decoration:none}
+a:hover {color:red}
+
+</style>
+</head>
+<body>
+
+<pre>
+The Project Gutenberg EBook of American Handbook of the Daguerrotype, by Samuel D. Humphrey
+
+This eBook is for the use of anyone anywhere in the United States and most
+other parts of the world at no cost and with almost no restrictions
+whatsoever. You may copy it, give it away or re-use it under the terms of
+the Project Gutenberg License included with this eBook or online at
+www.gutenberg.org. If you are not located in the United States, you'll have
+to check the laws of the country where you are located before using this ebook.
+
+Title: American Handbook of the Daguerrotype
+
+Author: Samuel D. Humphrey
+
+Release Date: September, 1994 [EBook #167]
+[Most recently updated: July 3, 2020]
+
+Language: English
+
+Character set encoding: UTF-8
+
+*** START OF THIS PROJECT GUTENBERG EBOOK AMERICAN HANDBOOK OF THE DAGUERROTYPE ***
+
+
+
+
+Produced by Gregory Walker, for the Digital Daguerreian Archive Project.
+
+
+
+
+
+
+</pre>
+
+<div class="fig" style="width:100%;">
+<img src="images/titlepage.gif" width="462" height="700" alt="[Illustration]" />
+</div>
+
+<p class="transnote">
+This etext was created by Gregory Walker, Austin, Texas, for the Digital
+Daguerreian Archive Project. <br /><br /> Page numbers explicitly referred to in
+the text are marked at their beginning by &ldquo;[page ##]&rdquo; on a separate line.
+I hope this etext inspires a wider interest in the origins of photography and
+in the modern practice of the Daguerreian Art.
+</p>
+
+<p class="transnote">
+[Updater&rsquo;s note: In this version, the above page numbering convention has
+been replaced by &ldquo;{##}&rdquo; sequences placed in line with the surrounding
+text.]
+</p>
+
+<h1>
+AMERICAN HAND BOOK <br /> OF THE <br /> DAGUERREOTYPE
+</h1>
+
+<h3>
+GIVING <br /> THE MOST APPROVED AND CONVENIENT <br /> METHODS FOR PREPARING
+THE CHEMICALS, AND <br /> THE COMBINATIONS USED IN THE ART.
+</h3>
+
+<h3>
+CONTAINING THE <br /> DAGUERREOTYPE, ELECTROTYPE, <br /> AND VARIOUS OTHER
+PROCESSES EMPLOYED IN TAKING <br /> HELIOGRAPHIC IMPRESSIONS.
+</h3>
+
+<p>
+<br /><br />
+</p>
+
+<h2>
+BY S. D. HUMPHREY
+</h2>
+
+<p>
+<br /><br />
+</p>
+
+<h4>
+FIFTH EDITION
+</h4>
+<p>
+<br /><br />
+</p>
+
+<h4>
+NEW YORK: <br /> PUBLISHED BY S. D. HUMPHREY <br /> 37 LISPENARD STREET
+<br /> 1858
+</h4>
+
+<h5>
+Entered, according to Act of Congress, in the year 1858, <br /> by S. D.
+HUMPHREY, In the Clerk&rsquo;s Office of the District Court <br /> of the
+Southern District of New York.
+</h5>
+
+<h3>
+To J. GURNEY, WHOSE PROFESSIONAL SKILL, SCIENTIFIC ACCURACY, <br /> AND
+ENERGETIC PERSEVERANCE, HAVE WON FOR HIM UNIVERSAL ESTEEM, <br /> THIS WORK
+IS MOST RESPECTFULLY INSCRIBED.
+</h3>
+
+<p>
+<br /><br /><br />
+</p>
+
+<h2>PREFACE.</h2>
+
+<p>
+There is not an Amateur or practical Daguerreotypist, who has not felt the
+want of a manual&mdash;Hand Book, giving concise and reliable information for
+the processes, and preparations of the Agents employed in his practice.
+</p>
+
+<p>
+Since portraits by the Daguerreotype are at this time believed to be more
+durable than any other style of &ldquo;Sun-drawing,&rdquo; the author has hit upon the
+present as being an appropriate time for the introduction of the Fifth
+Edition of this work. The earlier edition having a long since been wholly;
+exhausted, the one now before you is presented.
+</p>
+
+<p>
+The endeavor has been to point out the readiest and most approved Methods
+of Operation, and condense in its pages; as much practical information as
+its limits will admit. An extended Preface is unnecessary, since the aim
+and scope of this work are sufficiently indicated by the title.
+</p>
+
+<p class="noindent">
+S. D. HUMPHREY NEW YORK, 1858.
+</p>
+
+<p>
+<br /><br /><br />
+</p>
+
+<h2>
+CONTENTS
+</h2>
+
+<p>
+<a href="#chap01">CHAPTER I.</a>
+</p>
+
+<p class="noindent">
+Polishing the Daguerreotype Plate&mdash;Buffing the Plate&mdash;Coating the
+Plate&mdash;Exposure of the Plate in the Camera&mdash;Position Developing the
+Daguerreotype&mdash;Exposure to Mercury&mdash;Removing the Coating&mdash;Gilding or
+fixing the Image&mdash;Coloring Daguerreotype, . . . . . 18
+</p>
+
+<p>
+<a href="#chap02">CHAPTER II.</a>
+</p>
+
+<p class="noindent">
+Coloring Back Grounds&mdash;Transparent ditto&mdash;Gilding Dissolvent&mdash;Solution for
+removing Specks&mdash;Solarized Impression&mdash;To Purify Water&mdash;Cleaning
+Mercury&mdash;Adhesive Paper&mdash;Black Stain for Apparatus&mdash;Sealing Wax for
+Bottles&mdash;Rouge&mdash;Rotten Stone&mdash;Potassa Solution&mdash;Hyposulphite
+Solution&mdash;Substitute for do.&mdash;Gilding Solution&mdash;Solution for increasing
+the Brilliancy of the Daguerreotype&mdash;Bleaching Solution;&mdash;Cold
+Gilding&mdash;Neutralizing Agents&mdash;Buff Dryer&mdash;Keeping Buffs in order&mdash;Cleaning
+Buckskins&mdash;Reflector for taking Views, . . . . 52
+</p>
+
+<p>
+<a href="#chap03">CHAPTER III.</a>
+</p>
+
+<p class="noindent">
+Bromine and its Compounds&mdash;Iodine and its Compounds&mdash;Chlorine and its
+Compounds&mdash;Cyanide of Potassium&mdash;Hyposulphite of Soda&mdash;Hyphosulphite of
+Gold&mdash;Nitric Acid&mdash;Nitro-Muriatic Acid&mdash;Hydrochloric Acid&mdash;Hydrofluoric
+Acid&mdash;Sulphuric Acid&mdash;Accelerating Substances&mdash;Liquid Sensitives&mdash;Dry
+Sensitives, etc., etc., . . . . . 72
+</p>
+
+<p>
+<a href="#chap04">CHAPTER IV.</a>
+</p>
+
+<p class="noindent">
+Light&mdash;Optics&mdash;Solar Spectrum&mdash;Decomposition of Light&mdash;Light, Heat, and
+Actinism&mdash;Blue Paper and Color for the Walls of the Operating
+Room&mdash;Proportions of Light, Heat and Actinism composing a
+Sunbeam&mdash;Refraction&mdash;Reflection&mdash;Lenses&mdash;Copying Spherical
+Aberration&mdash;Chromatic Aberration, . . . 131
+</p>
+
+<p>
+<a href="#chap05">CHAPTER V.</a>
+</p>
+
+<p class="noindent">
+To make Plates for the Daguerreotype&mdash;Determining the Time of Exposure in
+the Camera&mdash;Instantaneous Process for Producing Daguerreotype&mdash;Galvanizing
+the Daguerreotype Plate&mdash;Silvering Solution&mdash;Daguerreotype without
+Mercury&mdash;Management of Chemicals&mdash;Hints and
+Cautions&mdash;Electrotyping&mdash;Crayon Daguerreotypes&mdash;Illuminated
+Daguerreotypes&mdash;Natural Colors in Heliography&mdash;Multiplying Daguerreotypes
+on one Plate&mdash;Deposit in Gilding&mdash;Practical Hints on the Daguerreotype, .
+. . 149
+</p>
+
+<p>
+<a href="#chap06">CHAPTER VI.</a>
+</p>
+
+<p class="noindent">
+An Account of Wolcott and Johnson&rsquo;s Early experiments in the
+Daguerreotype, . . . 188
+</p>
+
+<p>
+<br /><br /><br />
+</p>
+
+<h1>
+AMERICAN HAND-BOOK of THE DAGUERREOTYPE.
+</h1>
+
+<h2><a name="chap01"></a>CHAPTER I.</h2>
+
+<p class="letter">
+Polishing the Daguerreotype Plate&mdash;Buffing the Plate&mdash;Coating the
+Plate&mdash;Exposure of the Plate in the Camera&mdash;Position&mdash;Developing the
+Daguerreotype&mdash;Exposure to Mercury&mdash;Removing the Coating&mdash;Gilding or
+fixing the Image&mdash;Coloring Daguerreotype.
+</p>
+
+<p>
+Polishing the Daguerreotype Plate.&mdash;I shall endeavor to present to the
+reader the process I have found productive of good and satisfactory
+results, presenting the same in a clear and concise manner, so that any
+one, by following the various manipulations given, will be enabled to
+succeed. If there is any one part of the process in Daguerreotype in which
+operators fail more than all others, it is in not properly preparing the
+plate. It has truly been said that it would take a volume to describe all
+the methods that have been suggested for polishing the plate.
+</p>
+
+<p>
+I shall confine myself to the following description, which has been
+successfully practised, also most generally adopted by our operators, and
+I believe equal, if not superior to any other method, yet at the same time
+it is not of so much importance what particular method is employed, so
+that it be thoroughly and skillfully carried out.
+</p>
+
+<p>
+There is a general tendency with beginners to slight this operation; hence
+the necessity of adopting a system which precludes the possibility of
+doing so. During many years&rsquo; study and practice in the art, I have tried
+numerous methods and substances for the better accomplishment of the end
+in view, and have finally settled upon the following, as being (so far as
+experience allows me to Judge) the modus operandi, best suited to all
+circumstances; under no condition would I approve of a method less
+rigorous or precise.
+</p>
+
+<p>
+The operator being provided with a bottle of finely prepared rotten stone,
+cover the mouth of the bottle with a piece of thick paper, this perforated with
+a pin so that the rotten stone can be dusted on the plate. Fasten the plate on
+the holder, take the rotten stone (Becker&rsquo;s can always be depended upon),
+and dust on lightly until the surface is freely covered; now drop on the
+plate&rsquo;s surface a few drops of an alcoholic solution.<a href="#fn-1" name="fnref-1" id="fnref-1"><sup>[1]</sup></a>
+</p>
+
+<p class="footnote">
+<a name="fn-1" id="fn-1"></a> <a href="#fnref-1">[1]</a>
+This solution is composed of equal parts of alcohol and water, for the summer,
+and in winter three parts alcohol to one of water; a few drops of potassa
+solution may be added, and is known to have a decided effect upon the plate.
+</p>
+
+<p>
+Take a patch of Canton flannel; in order to prevent the moisture from the
+hand it should have a thick, firm texture: with this rub the plate in
+circles across, then back covering one-half of the former row of circles
+in each crossing until you have gone over the plate and back to the point
+of beginning, occupying at least half a minute in the operation, for a
+small plate, and so in proportion for the other sizes.
+</p>
+
+<p>
+Care should be observed to keep the patch wet with the alcoholic solution
+forming a paste on the surface of the plate; the motion of the hand should
+be brisk and free, not hurried, and the pressure about equal to that of a
+pound weight. When the cotton is disposed to adhere to the plate, and slip
+from under the finger, spread the fore and middle fingers a little apart,
+then pressing down, bring them together in such a manner as to form a fold
+in the cloth between them, by which means you will hold it perfectly
+secure.
+</p>
+
+<p>
+Avoid wetting the fingers, and should they perspire, wipe them often, as
+the moisture penetrating the cotton and coming in contact with the plate,
+would cause streaks it would be difficult to remove. I will here remark
+that many operators use much more cotton flannel than there is need of. I
+have found in my experience that a single patch, about one and half inch
+square, will be better for cleaning a number of plates than a new piece
+for every plate. This is the case for the wet, and for the dryrubbing two
+or three pieces will be found to answer. Thus with four or five cloths a
+dozen plates may be prepared.
+</p>
+
+<p>
+Some operators use prepared cotton, and think it more convenient than the
+flannel. This may be had prepared free from seeds and in a very perfect
+state, if wished.
+</p>
+
+<p>
+In going over the plate, great care should be observed, in touching its
+surface as equally as possible. The greatest care should be taken neither
+to touch the plate with the fingers, nor that part of the cotton flannel
+which is to come in contact with its surface; take a clean piece of
+flannel by one corner, snap it smartly to free it from dust and loose
+fibres, lay it face-side upward, dust on a little fine rotten stone; with
+this, polish around, or across, or in circles, lightly and briskly,
+passing gradually over the whole surface of the plate, as was done before
+with the wet. The plate should now exhibit a bright, clear, uniform
+surface, with a strong metallic lustre, perfectly free from any appearance
+of film; if not, the last polished should be continued until the effect is
+obtained, and when once obtained, the plate is ready for buffing.
+</p>
+
+<p>
+Buffing the Plate.&mdash;There are a variety of ways and means employed in this
+part of the operation. Some choose wheels, and others prefer the ordinary
+hand-buff. I have been unable to detect any peculiar advantage in the use
+of the wheel except in the facility of the operation; no doubt, however,
+but there is a saving of time, particularly in the preparation of the
+larger plates. For general use, we have not seen a wheel better adapted
+for this purpose than the one patented by Messrs. Lewis.
+</p>
+
+<p>
+It is generally well to use a hand-buff before placing the plate on the
+wheel; this is in order to prevent, as far as possible, the dust or other
+substance that may be on the surface of the plate from coming in contact
+with the cover of the wheel. I will here follow out the use of the
+hand-buffs (two are necessary) as they are mostly used.
+</p>
+
+<p>
+In the morning, before using the buffs, brush both as clean as possible,
+in order to free them from dust; then with the blade of a pair of shears,
+held perpendicular, rub the buffs from end to end; then knock them both
+together in order to free them from all dust or other substances,
+occasionally exposing them to the sun or to the fire.
+</p>
+
+<p>
+With one of the buffs (reserving the finest and softest for the last
+operation), powder its face with fine rouge and brush off slightly,
+leaving only the finest particles in it. Every operator should have two
+plate-holders; one for cleaning and one for buffing the plate; for when
+using only one, the rotten stone is liable to get on the buff and scratch
+the plate.
+</p>
+
+<p>
+Rest the fingers of the left hand on the back of the buff, near the
+farther end, with about the same pressure as in cleaning, while with the
+right you bear on the handle to correspond, and give the buff a free,
+easy, horizontal motion, passing it very nearly the whole length over the
+plate each time. Continue this operation in such a manner that the plate
+will on all parts of its surface have received an equal amount of polish.
+This buff once well filled with polish, add but little after, say a small
+quantity once in two or three plates. The polish as well as the buffs must
+be kept perfectly dry.
+</p>
+
+<p>
+The second buff should always be in the best order, and if this is the
+case, but little polish after the first need be used. Much depends upon
+the last finish of the surface of the plate, and as a fine impression is
+desired in the same ratio, the operator must exercise care and skill in
+this operation. Some buff the smaller plates on the hands, by resting them
+on the fingers in such a manner that the buff cannot touch them; some by
+holding the edges with thumb and little finger, with the remaining fingers
+under, or on the back; and others buff on the holder. When this last
+method is adopted, it requires the greatest caution to prevent the dust
+from getting on the buff. The holder should be wiped clean.
+</p>
+
+<p>
+The plate frequently slips off or around, and the buff comes in contact
+with the bed of the holder. When, however, the operator is so unfortunate
+as to meet with this mishap, the utmost care must be observed in
+thoroughly cleaning the buff cover before further buffing. In this last
+buffing it may be continued as before, except without the application of
+polish powder to the last buff. Examine the surface occasionally, and buff
+more lightly towards the close of the operation, using at last the mere
+weight of the buff. This last buffing should occupy as long a time as the
+first.
+</p>
+
+<p>
+The point to be aimed at is, the production of a surface of such exquisite
+polish as to be itself invisible, like the surface of a mirror. The secret
+of producing pictures discernible in any light, lies in this: the more
+dark, deep and mirror-like the surface of the plate, the more nearly do we
+approach to perfection.
+</p>
+
+<p>
+In all cases, very light and long continued buffing is productive of the
+greater success, since by that means a more perfect polish can be
+obtained.
+</p>
+
+<p>
+The question is often asked, why is it that the plates receive the coating
+so unevenly? I will answer by saying that it may arise from two causes:
+the first and most general cause is that those parts of the plate&rsquo;s
+surface which will receive the heaviest coating have been more thoroughly
+polished, and the consequence is that it is more sensitive to the chemical
+operation; second, and might perhaps be considered a part of the first,
+the heat of the plate may not be equal in all its parts; this may arise
+from the heat caused by the friction in buffing. It is a well known fact,
+with which every observing practitioner is familiar, that a silver plate
+at a temperature of 45 deg. or less, exposed to the vapors of iodine, is
+less sensitive and takes a longer time to coat, than when it is at a
+temperature of 60 deg. or more.
+</p>
+
+<p>
+Whenever a view is to be taken, or any impression which requires the plate
+to be turned on the side, it should be buffed in the other direction, so
+that the marks will always be horizontal, when the picture is in position.
+With the finest possible polish, the plate is ready for the coating box.
+</p>
+
+<p>
+The question is often asked by operators, what is the state of the plate
+when polished and allowed to stand for a time before using? To meet this
+point we hare only to consider the silver and the power acting upon it.
+Pure atmosphere does not act upon silver; but we do not have this about in
+our operating rooms, as it is more or less charged with sulphurated
+hydrogen, which soon tarnishes the surface of the plate with a film of
+brown sulphurate. It is this that sometimes causes the specks which appear
+on finishing the impression, and are a great annoyance. Hence we see that
+the plate should be buffed just before receiving the vapor of iodine. Mr
+Hunt gives his opinion of the use of diluted nitric acid as the best
+solution for freeing, the surface of the plate; he says:
+</p>
+
+<p>
+&ldquo;Numerous experiments on plated copper, pure silver plates, and on
+silvered glass and paper, have convinced me that the first operation of
+polishing with nitric acid, etc., is essential to the production of the
+most sensitive surface. All who will take the trouble to examine the
+subject, will soon be convinced that the acid softens the silver, bringing
+it to a state in which it is extremely susceptible of being either
+oxydized or iodized, according as the circumstances may occur of its
+exposure to the atmosphere or the iodine.&rdquo;
+</p>
+
+<p>
+I cannot see the objection to this solution; not, however, in general use.
+Our operators do not find it of sufficient importance to the success of
+their pictures to accept it, the alcoholic solution being in its nature
+less objectionable.
+</p>
+
+<p>
+I will say here, that a plate submitted to only an ordinary polish is
+found to contain numberless minute particles of the powder made use of.
+Should the same plate be buffed for a long time, the polish will nearly
+all disappear, leaving the cavities in the surface free for the action of
+agents employed in subsequent operation. For this reason, I find that
+great amount of polishing powder should not be applied to the last buff,
+and it is obvious that three buffs can be employed to adventure; the two
+last should not receive any polishing materials. I have examined a plate
+that was considered to possess a fine finish, and similar had produced
+good impressions; these same plates, when subjected to a long and light
+buffing, would present a surface no finer in appearance to the naked eye;
+but upon exposure to the solar radiation, would produce a well-defined
+image in one fourth less time than the plate without the extra buffing.
+</p>
+
+<p>
+Coating the Plate.&mdash;For this purpose our mechanics and artists have
+provided a simple apparatus called a coating-box, which is so arranged as
+to be perfectly tight, retaining the vapor of the iodine or accelerators,
+and at the same time allowing, by means of a slide, the exposure of the
+plate to these vapors. They can readily be obtained by application to any
+dealer, all of whom can furnish them.
+</p>
+
+<p>
+The principal difficulty in coating the plate, is that of preserving the
+exact proportion between the quantity of iodine and bromine, or quick. It
+is here necessary to say, that hardly any two persons see alike the same
+degree of color, so as to be enabled to judge correctly the exact tint, i.
+e. what one might describe as light rose red, might appear to another as
+bright or cherry red; consequently, the only rule for the student in
+Daguerreotype, is to study what appears to him to be the particular tint
+or shade required to aid him to produce the desired result. Practise has
+proved that but a slight variation in the chemical coating, of the
+Daguerreotype plate will very materially affect the final result.
+</p>
+
+<p>
+The operator will proportion the coating of iodine and bromine or
+accelerators according to the strength and composition of the latter.
+</p>
+
+<p>
+Experience proves that the common impressions, iodized to a rather light
+yellow gold tint, and brought by the bromine to a very light, rose color,
+have their whites very intense, and their deep shades very black. It is
+also known that if you employ a thicker coating of iodine and apply upon
+it a proportionate tint of bromine, so as to obtain a deep rose tint,
+delineations will be less marked, and the image have a softer tone. This
+effect has been obvious to everyone who has practised the art. Thus I may
+observe that the light coatings produce strong contrast of light and
+shade, and that this contrast grows gradually less, until in the very
+heavy coating it almost wholly disappears. From this it will readily be
+perceived that the middle shades are the ones to be desired for
+representing the harmonious blending of the lights and shades.
+</p>
+
+<p>
+Then, if we examine, with respect to strength, or depth of tone, and
+sharpness of impression, we see that the light coating, produces a very
+sharp but shallow impression; while the other extreme gives a deep but
+very dull one. Here, then, are still better reasons for avoiding either
+extreme. The changes through which the plate passes in coating may be
+considered a yellow straw color or dark orange yellow, a rose color more
+or less dark in tint, or red violet, steel blue or indigo, and lastly
+green. After attaining this latter color, the plate resumes a light yellow
+tint, and continues to pass successively a second time, with very few
+exceptions, through all the shades above mentioned.
+</p>
+
+<p>
+I will here present some excellent remarks upon this subject by Mr.
+Finley. This gentleman says:
+</p>
+
+<p>
+&ldquo;It is well known to all who have given much attention to the subject,
+that an excess of iodine gives the light portions of objects with peculiar
+strength and clearness, while the darker parts are retarded, as it were,
+and not brought out by that length of exposure which suffices for the
+former. Hence, statuary, monuments, and all objects of like character,
+were remarkably well delineated by the original process of Daguerre; the
+plate being coated with iodine alone. An excess of bromine, to a certain
+degree, has the opposite effect; the white portions of the impression
+appearing of a dull, leaden hue, while those which should be black, or
+dark, appear quite light. This being the case, I conclude there must be a
+point between the two extremes where light and dark objects will be in
+photogenic equilibrium. The great object, therefore, is to maintain, as
+nearly as possible, a perfect balance between the two elements entering
+into union to form the sensitive coating of the plate, in order that the
+lights and shades be truly and faithfully represented, and that all
+objects, whether light or dark, be made to appear so far conformable to
+nature, as is consistent with the difference in the photogenic energy of
+the different colored rays of light. It is this nicely-balanced
+combination which ensures, in the highest degree, a union of the essential
+qualities of a fine Daguerreotype, viz., clearness and strength, with
+softness and purity of tone.
+</p>
+
+<p>
+&ldquo;So far as I know, it is the universal practice of operators to judge of
+the proportion of iodine and bromine in coating the plate, by two
+standards of color the one fixed upon for the iodine, the other for the
+additional coating of bromine. Now I maintain that these alone form a very
+fallacious standard; first, because the color appears to the eye either
+lighter or darker, according as there is more or less light by which we
+inspect the coating; and secondly, because if it occur that we are
+deceived in obtaining the exact tint for the first coating, we are worse
+misled in obtaining the second, for if the iodine coating be too light,
+then an undue proportion of bromine is used in order to bring it to the
+second standard, and vice versa.&rdquo;
+</p>
+
+<p>
+The iodine box should be kept clean and dry. The plate immediately after
+the last buffing, should be placed over the iodine, and the coating will
+depend upon the character of the tone of the impression desired. Coating
+over dry iodine to an orange color, then over the accelerator, to a light
+rose, and back over iodine one sixth as long as first coating, will
+produce a fine, soft tone, and is the coating generally used for most
+accelerators. The plate iodized to a dark orange yellow, or tinged
+slightly with incipient rose color, coated over the accelerator to a deep
+rose red, then back over iodine one-tenth as long as at first coating,
+gives a clear, strong, bold, deep impression.
+</p>
+
+<p>
+I will here state a singular fact, which is not generally known to the
+operator. If a plate, coated over the iodine to a rose red, and then
+exposed to strong dry quick or weak bromine water, so that a change of
+color can be seen, then recoated over the iodine twice as long as at first
+coating, it will be found far more sensitive when exposed to the light
+than when it has been recoated over the iodine one-fourth of the time of
+the first coating.
+</p>
+
+<p>
+Probably the best accelerating combination is the American compound
+formerly known as &ldquo;Gurney&rsquo;s American compound,&rdquo; or some of the
+combinations of bromide of lime. The first is thought to possess perhaps
+more uniformity in its action than any other combination I have ever used.
+</p>
+
+<p>
+The plate once coated should be kept excluded from the light by means of
+the plate holder for the camera box.
+</p>
+
+<p>
+I will notice one of the principal causes having a tendency to prevent the
+perfect uniformity of chemical action, between the iodine and silver;
+hydrogen, or the moisture in the atmosphere, makes a very perceptible
+barrier. This moisture may arise as the result of the cold, from a want of
+friction in the buffing of the plate, which, coming in contact with the
+warmer air, as a writer on this subject says:
+</p>
+
+<p>
+&ldquo;It is well known that as often as bodies, when cold, are exposed to a
+warmer air, the humidity contained in them is condensed. It is to this
+effect that we must attribute the difficulty experienced in operating in
+most cases.&rdquo; This is corroborated by the results experienced by our
+operators. So it is seen that the plate should be of a temperature above
+that of the atmosphere. Mr. Gurney submits his plates to a gentle heat
+from a spirit lamp just before exposing them to the vapor of iodine.
+Experience has convinced me that a plate heated to about 80 deg. before
+being exposed to iodine will present a far better defined image than a
+plate at a temperature of 50 deg. I account for this by noticing that, at
+a higher temperature, the plate throws off any larger crystals that might
+otherwise be deposited, receiving only the finer, thus producing a more
+perfect chemical combination of iodide of silver. I would call the
+attention of the operator to this point, as presenting something of
+interest, and which may direct in a way of accelerating the future
+operations.
+</p>
+
+<p>
+That the presence of a film of moisture over the plate is a preventive of
+uniform chemical action, may be readily understood from the fact that
+iodine is almost insoluble in water, requiring seven thousand parts of
+water to dissolve one of iodine, or one grain to a gallon of water. Yet
+its affinities for silver and other substances are so powerful as to
+prevent its existing in an insulated state, hence we can account for the
+frequent occurrence of a plate presenting parts of an image over its
+surface. It is quite evident that those parts of plate&rsquo;s surface covered
+with moisture are nothing like as sensitive to the iodine as those parts
+perfectly free.
+</p>
+
+<p>
+Exposure of the plate in the Camera, and Position.&mdash;The time of exposure
+necessary to produce an image upon the Daguerreotype plate, can only be
+determined by experiment, and requires a liberality of judgment to be
+exercised on the part of the operator. The constant variation of the light
+renders it impossible to lay down any exact rule upon this point. Light is
+not alone to be considered; the amount of coating exercises a deviating
+influence, also the subjects to be represented are not equally photogenic,
+some requiring much longer time of exposure than others. This may be
+easily observed by exposing the plate at the same time to a plaster bust
+and a piece of black velvet, the first being a much stronger reflector of
+light than the latter: the time necessary to produce a well developed
+image of the velvet being about six times longer than that required to
+produce an equally defined image of plaster. The manner of judging
+correctly of the time is by the appearance of impression after it has been
+developed by the mercurial vapors. Should it present a deep blue or black
+appearance it is solarized or over-timed. This sometimes is to an extent,
+that a perfect negative is formed, the white being represented black, and
+the dark light.
+</p>
+
+<p>
+An object requiring the particular care and attention of the operator is the
+proper focus. It is not unfrequently the complaint of sitters that their hands
+are represented as being magnified and greatly out of proportion with the
+general figure. This is the case also with the nose and eyes, but in a less
+degree. As this cannot be wholly remedied, it is desirous to come as near as
+possible, and in order to do this, it is necessary to present the figure in
+such a position as to bring it as nearly as possible upon the same plane by
+making all parts nearly at equal distance from the lenses. This must be done by
+the sitter inclining the head and bust formed to a natural, easy position, and
+placing the hands closely to the body, thus preserving a propel proportion, and
+giving a lively familiarity to the general impression. It is not an uncommon
+fault among our less experienced operators to give a front view of the face of
+nearly every individual, regardless of any particular form, and this is often
+insisted upon by the sitter,<a href="#fn-2" name="fnref-2" id="fnref-2"><sup>[2]</sup></a>
+who seems to think the truth of the picture exists principally in the eyes
+staring the beholder full in the face.
+</p>
+
+<p class="footnote">
+<a name="fn-2" id="fn-2"></a> <a href="#fnref-2">[2]</a>
+I might here picture some curious scenes experienced by our operators Every one
+is familiar with a certain class of our community whose ideas of the importance
+of a free and easy position of the body are too closely confined with stays,
+attention to toilet, tightly fitting dress coats and the like, to admit of
+being represented as if nature had endowed them with least possible power of
+flexibility. To such we would suggest the following, to be well learned and
+retained in the mind while presenting themselves before the Daguerreotype
+camera:
+</p>
+
+<p>
+&ldquo;The experience of one who has often been Daguerreotyped, is, to let the
+operator have his own way.&rdquo;
+</p>
+
+<p>
+Nothing, in many instances, can be more out of place in a Daguerreotype
+portrait than this, for let a man with a thin, long,
+defeated-politician-face, be represented by a directly front view, we
+have, to all appearances, increased the width of the face to such an
+extent as to reveal it flat and broad, losing the characteristic point by
+which it would be the most readily recognized. The method we should adopt
+in taking the likeness of such an individual as above, would be to turn
+the face from the camera, so as to present the end of the nose and the
+prominence of the cheek bone equally distant from the lenses, and then
+focusing on the corner of the eye towards the nose, we cannot in many
+cases, fail to produce an image with the lips, chin, hair, eyes and
+forehead in the minutest possible definition.
+</p>
+
+<p>
+It should be the study of every operator to notice the effect of the
+lights and shades while arranging the sitter, and at the same time be very
+particular to give ease in the position.
+</p>
+
+<p>
+No matter how successful the chemical effect may have been, should the
+image appear stiff and monument-like, all is lost. &ldquo;In the masterpiece,
+grace and elegance must be combined.&rdquo;
+</p>
+
+<p>
+I will here use the words of another, which are very true:
+</p>
+
+<p>
+&ldquo;So great is the difference in many faces, when inspected in opposite
+directions, that one of the two views, however accurately taken, would not
+communicate the likeness&mdash;it not being, the usually observed
+characteristic form. When the right view of the head is obtained, it is
+first necessary to consider the size of the plate it is to be taken on, so
+as to form an idea of the proportion the head should bear to it. The mind
+must arrange these points before we commence, or we shall find everything,
+too large or too small for the happy proportion of the picture, and the
+conveying of a just notion of the stature. The work will have to be done
+over, and time sacrificed, if this is not attended to. The adjustment of
+the head to the size of the plate (as seen from the margin of the mat), is
+not to be taught: everyone must bring himself, by scrutinizing practice,
+to mathematical accuracy; for something will be discovered in every face
+which can be surmounted only by experience.
+</p>
+
+<p>
+&ldquo;The eye nearest the camera, in a three-quarter-face, is placed in the
+middle of the breadth of the plate; the chin, in a person of middle
+stature, in the middle of the length, and higher according to the
+proportional height of the person.&rdquo;
+</p>
+
+<p>
+In regard to the proper elevation of the camera, it may be here stated
+that I have found it best in taking portraits where the hands are
+introduced, to place the camera at about equal height with the eyes of the
+sitter, in order to bring the face and hands equi-distant from the tube.
+It will be found, if the above be followed, that by attaching a string to
+the camera tube, and making a semi-circle, that the face and hands of the
+sitter will occupy a corresponding distance, and the consequence is that
+the impression will appear without the hands being magnified. It has been
+found that a person with a freckly face can have as fine, fair, and clear
+an impression as the most perfect complexion; this may be done by the
+subject rubbing the face until it is very red. The effect is to lessen the
+contrast, by giving the freckles and skin the same color and the
+photogenic intensity of the red and yellow being nearly the same, an
+impression can be produced perfectly clear.
+</p>
+
+<p>
+When a child is to be taken, and there are doubts of its keeping still,
+the operation may be accelerated by placing it nearer the window bringing
+the screen nearer, and placing a white muslin cloth over the head; this
+will enable you to work in one third of the usual time. Should the person
+move, or the plate become exposed to the light, it may be restored to its
+original sensitiveness by placing it over the quick, one or two seconds.
+</p>
+
+<p>
+Developing the Daguerreotype.&mdash;After the plate has been submitted to the
+operation of the light, the image is still invisible. It requires to be
+exposed to the vapors of heated mercury. It is not absolutely necessary to
+apply artificial heat to the mercury to develop the image, for fair proofs
+have been produced by placing a plate over the bath at the ordinary
+temperature of the atmosphere. This plan, however, requires a long time
+and cannot be adopted in practice, even if it were advisable. The time
+more usually required in developing the image over the mercurial vapors,
+is about two minutes, and the temperature is raised to a point necessary
+to produce the desired effect in that time. This point varies as indicated
+by different scales, but for the ordinary scales it is not far from 90
+deg. cen.
+</p>
+
+<p>
+The mercury bath is accompanied with a centigrade thermometer, by which
+the heat is regulated. Those furnished by the manufacturers are not always
+correct, and it requires some experience to find the proper degree on the
+scale.
+</p>
+
+<p>
+I would here remark that it is advisable, when placing the spirit lamp
+under the bath, to so arrange it that the position of applied heat should
+always be on the same point, viz., should the heat be directly under the
+bulb containing the thermometer it would raise the mercury in the tube to
+the point marked, and the temperature of that in the bath would be far
+below what it should be; hence it is (where time is followed for
+developing) that many failures occur. This is observed more readily in the
+large baths made of thick iron, particularly upon first heating. In
+practice I apply the heat as nearly as possible between the centre of the
+bottom of the bath and the bulb containing the mercury tube. It is
+advisable to keep the lamp lighted under the bath from the time of
+commencing in the morning to the close of business at night. By this means
+you have a uniformity of action, that cannot be otherwise obtained.
+</p>
+
+<p>
+It is well known to the experienced Daguerreotypist, that different
+atmospheres have a decided effect upon the mercury in developing the
+Daguerreotype. It will require a greater degree of heat for one atmosphere
+than for another. Experience alone determines this little difference.
+</p>
+
+<p>
+In summer, on cloudy and stormy days, mercurial vapors rise more readily
+and quickly than in the temperature of autumn or winter. From 60 degrees
+upwards towards the boiling point (660 deg.), the vapors of mercury rise
+in greater abundance and collect in larger globules on cold surfaces.
+</p>
+
+<p>
+For various reasons I prefer a high temperature and short exposure. It
+accelerates the process. It renders the lights of the picture more strong
+and clear, while the deep shades are more intense. It gives a finer lustre
+to the drapery. The solarized portions also are very seldom blue,
+especially after gilding. If heated too high, however, the light parts
+become of a dead, chalky white, and the shadows are injured by numerous
+little globules of mercury deposited over them. Just the right quantity of
+mercury leaves the impression of a transparent, pearly white tone, which
+improves in the highest degree in gilding. To mercurialize with exactness
+is a nice point. If there is reason to suspect having timed rather short
+in the camera, reduce the time over mercury in a corresponding proportion.
+A dark impression will be ruined by the quantity of mercury which would
+only improve a light one.
+</p>
+
+<p>
+If practicable, it is most expedient that the plate be submitted to the
+action of mercury immediately on coming from the camera. I have
+frequently, however, carried plates for miles in the plate-holders and
+after exposing in the camera, brought them back to expose to mercury, and
+obtained fair proofs; but for the reason before given, it is advisable to
+carry along the bath, and bring out the impression on the spot.
+</p>
+
+<p>
+It is sometimes the practice of inexperienced operators to take the plate
+off the bath and examine the impression by solar light. This plan should
+be abandoned, as it is almost sure to produce a dense blue film over the
+shadows.
+</p>
+
+<p>
+This I am led to believe is occasioned by the action of light on the yet
+sensitive portions of the plate, and made to appear only by subsequent
+exposure to mercury, being equivalent to solarization.
+</p>
+
+<p>
+There has been little said by our professors upon the subject of the
+position of the plates while exposed to the mercurial vapour. Mr. Hunt, in
+referring to this subject, says: &ldquo;Daguerre himself laid much stress upon
+the necessity of exposing the plate to the mercury at an angle of about 45
+deg.. This, perhaps, is the most convenient position as it enables the
+operator to view the plate distinctly, and watch the development of the
+design; but beyond this, I am satisfied there exists no real necessity for
+angular position. Both horizontally and vertically, I have often produced
+equally effective Daguerreotypes.&rdquo; I presume from the last sentence of Mr.
+Hunt, that he has confined his experiments to the smaller sized plates.
+Hence he may not have thought of the effect of the vertical exposure of a
+large plate.
+</p>
+
+<p>
+In America this is a subject of no little importance. When an impression
+is to be developed upon a plate fifteen by seventeen inches, were we to
+use an angle of about 45 deg., it would be found to make a perceptible
+difference in the appearance of the image. By examining the wood tops of
+our baths as formerly made, it will be found that there is a great
+variation in the distance from the mercury to the different portions of
+the plate. By measuring one of these tops for the size plate above
+mentioned, I find the distance to the nearest point between the mercury
+and the plate, to be thirteen, and the middle point sixteen, and the
+furthest point twenty-one and a half inches: by this we see that one point
+of the plate is eight and a half inches further from the mercury than the
+nearest point; even this is not the variation there would necessarily be,
+were we to adopt the angle of 45 deg. as urged by Daguerre.
+</p>
+
+<p>
+Among our principal professors, the bevel top will not be found in use
+where the large plates are used. Should any one feel desirous to test more
+minutely the effect produced by a bevel top bath, I would suggest to them
+to place a frame, so constructed as to hold three sixth size plates, and
+fit it to the top of the bath, and so arrange it with openings that the
+plates may be placed, one at the nearest point of the mercury, the second
+midway, and the third to the greatest distance, and by placing the plates
+over at one and the same time, the experimenter will be enabled to judge
+if there exists a difference in the developing. In speaking of the above,
+reference is had to baths to the ordinary heights used by operators.
+</p>
+
+<p>
+We will now proceed to examine the effect produced by mercurial vapor upon
+the plate at different lengths of exposure. In some investigations which I
+have made upon the appearance of the Daguerreotype impressions when
+developed over mercury at 90 deg. C. (194 deg. F.), the following was the
+result. Plates, coated and exposed to light in our usual manner of
+operating, produced on exposure of
+</p>
+
+<p>
+1/2 minute, whole impression, deep blue.
+</p>
+
+<p>
+1 minute, ashy and flat; no shadows; linen, deep blue.
+</p>
+
+<p>
+1 1/2 minute, coarse and spongy; shadows, muddy; drapery, dirty reddish
+brown.
+</p>
+
+<p>
+2 minutes, shallow or watery; shadows, yellowish; drapery, brown.
+</p>
+
+<p>
+2 1/4 minutes, soft; face, scarcely white; shadows, neutral; drapery, fine
+dark brown linen somewhat blue.
+</p>
+
+<p>
+2 1/2 minutes, clear and pearly; shadows, clear and positive, of a purple
+tint; drapery, jet black, with the dark shades slightly frosted with
+mercury.
+</p>
+
+<p>
+2 3/4 to 3 minutes, hard and chalky; shadows, harsh; drapery, roughened,
+and misty with excess of mercury.
+</p>
+
+<p>
+The foregoing results will be found general.
+</p>
+
+<p>
+There are numerous opinions among our operators in regard to the quantity
+of mercury necessary for a bath. As regards this, I need only say, similar
+results occur when two pounds or two ounces are used, but the quantity
+generally employed is about a quarter of a pound. I am of the opinion that
+one ounce will answer as well as a larger quantity. I know of no better
+proof in favor of a small quantity than that presented in the following
+incident. Several years since, an operator (Mr. Senter, of Auburn, N.Y.)
+of my acquaintance, was requested to go several miles to take a
+Daguerreotype portrait of a deceased person. He packed up his apparatus
+and proceeded over a rough road for some distance to the house where he
+was to take the portrait, and arranging his apparatus, with all the
+expedition which the occasion required, after having everything in usual
+order (as was supposed), he proceeded and took some ten or twelve very
+superior impressions. They were fine, clear, and well developed. After
+taking the number ordered, he proceeded to repack his apparatus, and to
+his surprise, when he took up the bottle he carried the mercury in, he
+found it still filled, and none in the bath, except only such particles as
+had adhered to the sides, after dusting and being jolted for several miles
+over the rough road. From this it will be seen that a very little mercury
+will suffice to develop fine proofs. I saw some of the impressions
+referred to above, and they were certainly well developed, and very
+superior specimens of our art.
+</p>
+
+<p>
+Removing the Coating.&mdash;After the impression has been developed over the
+mercurial vapor, the next step is to remove the sensitive coating. For
+this purpose the following solution is used:
+</p>
+
+<p>
+Put about two ounces of hyposulphite of soda in a pint of water, which
+should always be filtered before using. A convenient way of doing this is
+to have two bottles, and a large funnel with a sponge pressed into the
+neck of it; or, what is better, some filtering paper folded in it. The
+solution in one bottle, the funnel is placed in the other, and the picture
+held over it; when the solution is poured on the plate, it runs from it
+into the filter, and is always ready for use.
+</p>
+
+<p>
+It is best that the washing be done immediately on the plate coming from
+the mercury bath. If allowed to stand long with the coating on, it assumes
+a very dark tint&mdash;as the operation of the light continues, though less
+active than while exposed in the camera, and destroys that brightness
+which would otherwise have been obtained. It is preferable to wash and
+gild a picture without it first being dried; yet when there are doubts of
+its giving satisfaction, there would sometimes be a saving by drying and
+getting the decision of the subject before gilding, as this last injures
+the plate for another impression. First, light your spirit-lamp, then with
+your plyers take the plate by the lower right-hand corner, holding it in
+such a manner that the plyers will form in a line with the upper left-hand
+corner; pour on, slowly, the hyposulphite solution, slightly agitating the
+plate, until all the coating is dissolved off; then rinse off with clean
+water, and if it is not to be gilded, dry by holding the plate
+perpendicular with the bottom left-hand corner lowest, and applying the
+blaze of the spirit-lamp to the back, at the same time blowing gently
+downward on the face of the plate.
+</p>
+
+<p>
+The hyposulphite solution should be often filtered through a sponge, and
+it will answer for a great number of washings. Yet it is observed that the
+mercury collects in this solution in small globules; these often come in
+contact with the plate, causing white spots, which spoil the impression.
+They should be guarded against, and the solution renewed. Again, in order
+to prevent streaks or scum on the surface of the plate, it is necessary
+that the coating should be removed with a good degree of uniformity. I
+find in practice that the hyposulphite of soda in our market varies much
+as regards strength, and consequently the rule to be adopted is to make a
+solution of sufficient strength to remove the coating in about ten
+seconds. I am aware that it may be said that this strong solution would
+have a tendency to injure the impression by destroying in a measure the
+sharpness of outline. To meet this, it need only to be said that the
+preventive is, to not let the solution rest on the surface of the plate
+for a longer time than is absolutely necessary, and then it should be
+drenched copiously with water; hence a chemical action upon the image is
+prevented and the general operation facilitated. This plan is adopted by
+our first operators with the greatest success.
+</p>
+
+<p>
+If the operator should allow the hyposulphite solution to run over the
+plate unevenly, it is quite likely that white or blue streaks would
+result. These it is impossible to remove without injury to the impression.
+Some, in order to prevent this, breathe over the surface, thus moistening
+it and putting it in a condition to receive the solution with greater
+uniformity. The plate should be well washed with water before gilding.
+</p>
+
+<p>
+Gilding, or Fixing the Image.&mdash;The next process to be given is that for
+fixing the image on the plate. This is done by precipitating a thin film
+of gold over the surface and is productive of the most brilliant effect
+when prepared immediately after the plate has been washed with water after
+the application of the hyposulphite solution, and before the plate has
+been allowed to dry. When, however, the plate has been dried and allowed
+to stand for any time, before gilding, the hyposulphite wash should be
+applied as at first, in order to destroy any chemical coating that may
+have been formed on exposure of the plate to the air. For gilding the
+larger plates, we have a gilding stand so constructed that the plate can
+be put on a perfect level. In practice, I prefer holding the plate with
+nippers, fastened at one corner. Hold the plate in the same manner as in
+removing the coating; pour on the gilding, newly filtered, until the
+surface is wholly covered, and with the blaze of the spirit lamp, at least
+three inches high, apply it to the back of the plate, moving it about,
+that the surface may be heated with as much uniformity as possible.
+Continuing this operation, the surface will generally become covered with
+small yellow bubbles which soon disappear, leaving the image clear and
+distinct.
+</p>
+
+<p>
+It is advisable to make use of a lamp having a sufficiently strong flame to
+produce the effect in a few minutes. If after a first heating, it is found that
+the impression can admit of a greater degree of intensity, it might be heated
+anew; but that is seldom necessary, and often by trying to do too, well, the
+operator, if he persists in heating certain parts of the plate, may find the
+liquid dry up just above the flame, and inevitably cause a stain;
+<a href="#fn-3" name="fnref-3" id="fnref-3"><sup>[3]</sup></a> or else the
+blacks are covered with a film, or even the coating of gold may suddenly
+exfoliate, when small particles are detached from the plate. The impression is
+then entirely spoiled, but the plate may be re-polished.
+</p>
+
+<p class="footnote">
+<a name="fn-3" id="fn-3"></a> <a href="#fnref-3">[3]</a>
+This can be remedied, however, if it is immediately washed over with the same
+solution that is on the plate, so that the surface shall not become cool;
+continue for a short time to apply the lamp under, and agitate the plate
+slightly, and it will soon be free from all imperfections and give a fine clear
+tone.
+</p>
+
+<p>
+It is not unfrequent that the surface assumes a dark, cloudy appearance.
+This is generally the best sign that the gilding will bring out the
+impression with the greatest degree of distinctness. Soon, the clouds
+gradually begin to disappear, and, &ldquo;like a thing of life&rdquo; stands forth the
+image, clothed with all the brilliancy and clearness that the combined
+efforts of nature and art can produce. When in the operator&rsquo;s judgment the
+operation has arrived at the highest state of perfection, rinse suddenly,
+with an abundance of clean water, and dry as before described.
+</p>
+
+<p>
+When an impression is dark, the gilding process may be longer continued;
+but when light, it should be gilded quickly, as lengthening the time tends
+to bleach the impression and make it too white. The cause of this appears
+to be, that with a moderate heat the chlorine is merely set free from the
+gold, and remaining in the solution, instead of being driven off, with its
+powerful bleaching, properties, it immediately acts upon the shades of the
+picture. A dark impression can thus, by a low heat, long-continued, be
+made quite light. To procure the best effect, then, heat suddenly with a
+large blaze, and judging it to be at the maximum, cool as suddenly as
+possible.
+</p>
+
+<p>
+When the hyposulphite of gold is used instead of the chloride, a less heat
+should be employed.
+</p>
+
+<p>
+Coloring Daguerreotypes.&mdash;Of all the so-called improvements in the
+Daguerreotype, the coloring is the least worthy of notice. Yet the
+operator is often, in fact most generally, called upon to hide an
+excellent specimen under paint. I can conceive of nothing more perfect in
+a Daguerreotype than a finely-developed image, with clearness of lights
+and shadows, possessing the lively tone resulting from good gilding. Such
+pictures, however, are not always had, and then color may perform the part
+of hiding the imperfections. We present the following method as given in
+Willat&rsquo;s Manual:
+</p>
+
+<p>
+&ldquo;Daguerreotype portraits are now commonly met with beautifully colored;
+but the coloring is a process requiring great care and judgment, and many
+good pictures are spoiled in fruitless experiments. Several different
+methods of coloring have been proposed. The simplest mode appears to be
+that of using dry colors prepared in the following manner: A little of the
+color required, very finely ground, is thrown into a glass containing
+water, in which a few grains of gum arabic have been dissolved. After
+standing a few moments, the mixture may be passed through bibulous paper,
+and the residue perfectly dried for use. The principal colors used are
+Carmine, Chrome Yellow, Burnt Sienna, Ultramarine and White; boxes fitted
+with sets of colors properly prepared, may be obtained of the dealers, and
+include Carmine, White, Lilac, Sky Blue, Pink, Yellow, Flesh color,
+Orange, Brown, Purple, Light Green, Dark Green and Blue. With a few
+colors, however, all the rest may be made thus: Orange, by Yellow and Red;
+Purple, with Blue and Red; Green, Blue and Yellow; Brown, with Umber,
+Carmine and Lamp Black; Scarlet, Carmine and Light Red. While it is true
+that a little color may relieve the dark metallic look of some
+Daguerreotypes, it must not be concealed that the covering of the fine
+delicate outline and exquisite gradations of tone of a good picture with
+such a coating, is barbarous and unartistic.
+</p>
+
+<p>
+&ldquo;The prevaling taste is, however, decidedly for colored proofs, and the
+following directions will assist the amateur in ministering to this
+perverted taste, should he be so inclined. The coloring should commence
+with the face, and the flesh tint must be stippled on (not rubbed) with a
+small camel&rsquo;s-hair brush, beginning from the centre of the cheek, taking
+great care not to go over the outline of the face, and also not to have
+too much color in the brush; the eyes and eyebrows must not be touched
+with color. After the flesh color is applied, take a piece of very soft
+cotton and pass it very gently backwards and forwards over the face, so as
+to soften down the color, and then apply the carmine to give the required
+tint. For men, the darker tints should predominate, and for women the
+warmer. Very light hair may be improved by a slight tint of brown, or
+yellow and brown, according to the color. In coloring the drapery, the
+same care must be used. No rules can be laid down for all the different
+colors required, and the amateur had better obtain the assistance or
+advice of some one accustomed to the use of colors. A little white with a
+dash of blue or a little silver, will improve white linen, lace, etc. The
+jewelry may be touched with gold or silver from the shells, moistened with
+distilled water, and laid on with a fine-pointed sable-hair brush.
+</p>
+
+<p>
+&ldquo;Brilliants may be represented by picking the plate with the point of a
+pin or knife.&rdquo;
+</p>
+
+<h2><a name="chap02"></a>CHAPTER II.</h2>
+
+<h3>
+MISCELLANEOUS.
+</h3>
+
+<p class="letter">
+Coloring Back Grounds&mdash;Transparent ditto&mdash;Gilding Dissolvent Solution for
+removing Specks&mdash;Solarized Impression&mdash;To Purify Water&mdash;Cleaning
+Mercury&mdash;Adhesive Paper&mdash;Black Stain for Apparatus&mdash;Sealing Wax for
+Bottles&mdash;Rouge&mdash;Rotten Stone&mdash;Potassa Solution&mdash;Hyposulphite
+Solution&mdash;Substitute for do.&mdash;Gilding Solution&mdash;Solution for increasing
+the Brilliancy of the Daguerreotype&mdash;Bleaching Solution;&mdash;Cold
+Gilding&mdash;Neutralizing Agents&mdash;Buff Dryer&mdash;Keeping Buffs in order&mdash;Cleaning
+Buckskins&mdash;Reflector for taking Views.
+</p>
+
+<p>
+To Color Back-grounds&mdash;To obtain a properly colored back ground is a
+matter of no little importance to the Daguerreotype operator. I had nearly
+exhausted all patience, and tried the skill of painters to obtain a
+back-ground that would be suitable to my purpose; but all to no avail. At
+last I adopted the following method, and at a cost of coloring of
+twenty-five cents, can now produce a back-ground far more valuable than
+those which had cost five dollars before.
+</p>
+
+<p>
+Take common earth paint, such as is used in painting roofs; mix this with
+water to about the consistency of cream; then to four quarts of this
+mixture add about one pint of glue water (common glue dissolved in water,
+also about as thick as cream). This last will cause the paint to adhere to
+the cloth, to which it is applied with a common white-wash brush. By
+applying the brush on the coating while it is wet, it may be so blended
+that not a line can be seen, and a perfectly smooth color of any shade can
+be obtained. The shade of color I use is a light reddish-brown. Tripoli,
+rotten-stone, or any earthy matter, may be applied in the same manner.
+</p>
+
+<p>
+Transparent or Invisible Back-ground.&mdash;I give this as originally published
+in my System of Photography, 1849:
+</p>
+
+<p>
+&ldquo;Take a large woollen blanket with long nap, the longer and rougher it is
+the finer will be the effect produced; stretch it on a frame of sufficient
+size, and suspend the frame at the centre of the upper end by a string
+fastened to a nail in the ceiling, from three to five feet back of the
+sitter. Having arranged this, fasten another string to the side of the
+frame, and while the operation is going on in the camera, swing the
+back-ground from right to left, continuing this during the whole time of
+sitting, and you have a clear &ldquo;transparent&rdquo; back-ground, which throws the
+image out in bold relief, and renders the surface of the plate invisible.
+If equalled at all it is only by atmospheric back-ground. I consider it to
+be the best ever known, and think it needs but to be tried to afford
+satisfactory proof that it is so. Although used by few before, since the
+first edition of this work at least two thirds of the operators have
+adopted its use; for any one can at once understand the principle and the
+effect which it produces.&rdquo;
+</p>
+
+<p>
+It may be added that a motion imparted to to any back-ground where
+softness is desired, produces an excellent effect.
+</p>
+
+<p>
+Gilding Dissolvent.&mdash;To one quart of muriatic acid add as much oxide of
+iron (common iron rust) as it will dissolve in two days. This may be done
+by putting in the oxide in excess. It should be frequently shook, and when
+wanted for bottling it should be allowed to stand in order to settle. When
+this is done the solution may be poured off, and reduced by adding to it
+an equal quantity of water; then it is ready for use. This constitutes a
+gilding dissolvent now in our market.
+</p>
+
+<p>
+Solution for Removing Specks.&mdash;There is probably no one cause of complaint
+so general as &ldquo;what makes those black specks?&rdquo; There are several causes
+which produce them, and probably the most general are dust, rouge, or a
+spray of moisture on the plate. It this be the case, there is no solution
+which can remove them, as they have prevented a chemical action with the
+silver, and their removal would only expose the surface of the plate which
+in itself would afford a contrast with the impression. Another and less
+dangerous source of these specks is organic matter contained in the
+solution employed in dissolving the chemicals, or the water in washing.
+Much of the hyposulphite of soda in market contains a sulphuret, which,
+coming in contact with the silver surface, immediately causes oxidation.
+Such spots, as well also as most all others found on the plate after it
+has been exposed in the camera, can be removed by the following, solution:
+To one ounce of water add a piece of cyanide of potassium the size of a
+pea; filter the solution and apply by pouring it on the surface of the
+plate. In all cases the plate should first be wet with water. Apply a
+gentle heat, and soon the spots disappear, leaving the impression clear
+and free from all organic matter.
+</p>
+
+<p>
+In the absence of cyanide of potassium, a solution of pure hyposulphite of
+soda will answer as a fair substitute.
+</p>
+
+<p>
+To Redeem, a Solarized Impression.&mdash;The Daguerreotype plate, prepared in
+the ordinary manner, should be exposed in the camera a sufficient time to
+solarize the impression. Then, before it be exposed to the vapor of
+mercury, expose it for a very brief period to the vapor of either
+chlorine, bromine or iodine. Then expose over mercury, as usual. I have
+produced singularly interesting results by this process.
+</p>
+
+<p>
+To Purify Water.&mdash;Filter the water well, and then add about three drops of
+nitric acid to the pint. This can be used as absolutely pure water, but I
+would recommend the use of distilled water as preferable.
+</p>
+
+<p>
+Cleaning Mercury.&mdash;Make a small bag of chamois skin, pour in the mercury,
+and squeeze it through the leather. Repeat this several times, and filter
+by means of a funnel made of paper, with a very small aperture, through
+which it will escape and leave the particles of dust, or other substances,
+in the paper. A paper with a pinhole through it will answer as well, and
+it is less difficult to make.
+</p>
+
+<p>
+Adhesive Paper.&mdash;Take gum arabic, four ounces, put it in a wide-mouthed
+bottle and pour on water about one-third above the gum. Add half ounce of
+isinglass, or fish glue, and a small piece of loaf sugar. Let all
+dissolve, and spread over French letter paper, with a brush or piece of
+sponge. If once spreading is not enough, perform the same operation a
+second time.
+</p>
+
+<p>
+Black Stain for Apparatus.&mdash;Dissolve gum shellac in alcohol, or procure
+shellac varnish at the druggists&rsquo;, stir in lampblack, and apply with a
+sponge or bit of rag. This will adhere to metal, as well as wood, and is
+used for the inside of camera, tubes, etc.
+</p>
+
+<p>
+Sealing Wax for Bottles.&mdash;Melt together six parts rosin and one beeswax,
+and add a small quantity of lampblack; or, if red is preferable, add red
+lead. Common white wax is best, as most chemicals act less upon it.
+</p>
+
+<p>
+When bottles containing bromine are to be sealed, it is well to grease the
+stopper. This, however, only when the bottle is in frequent use, for if it
+were to be sent by any conveyance it would be likely to fly out.
+</p>
+
+<p>
+Rouge.&mdash;The method employed by Lord Ross is probably unsurpassed in the
+production of rouge. He has given his process as follows:
+</p>
+
+<p>
+&ldquo;I prepare the peroxide of iron by precipitation with water of ammonia,
+from a pure dilute solution of sulphate of iron; the precipitate is
+washed, pressed in a screw press till nearly dry, and exposed to a heat
+which in the dark appears a dull, low red. The only points of importance
+are, that the sulphate of iron should be pure, that the water of ammonia
+should be decidedly in excess, and that the heat should not exceed that I
+have described. The color will be a bright crimson inclining to yellow. I
+have tried both potash and soda, pure, instead of water of ammonia, but
+after washing with some degree of care, a trace of the alkali still
+remained, and the peroxide was of an ochrey color, till overheated, and
+did not polish properly.&rdquo;
+</p>
+
+<p>
+Care should be observed to apply rouge in a dry state to the surface of
+the plate.
+</p>
+
+<p>
+I would remark, that so far as my experience has gone, I consider good
+rouge fully equal to any other polishing, material for the last or
+finishing polishing; consequently I shall not take up my space in
+enumerating any of the great variety that find few advocates.
+</p>
+
+<p>
+Why Rouge is to be preferred.&mdash;&ldquo;Because it burnishes better, and because
+it assists in fixing the layer of gold, rendering it less susceptible of
+being removed in scales when heated too much.&rdquo;
+</p>
+
+<p>
+Rotten Stone.&mdash;&ldquo;Purchase the best ground rotten stone of the druggist, put
+a few ounces at a time in a wedgewood or porcelain mortar, with plenty of
+clean rain water. This should have about forty drops of nitric acid to the
+quart. Grind well, and after letting the mortar stand two minutes, pour
+into a third. After remaining undisturbed eight minutes, finally pour off
+into a fourth to settle. Rinse back the sediment in the second and third,
+and grind over with a new batch. Repeat the operation till you have all in
+the fourth vessel. Let this stand several hours, and pour off the water
+very carefully. Set the deposit in the sun, or by a stove to dry. When
+perfectly dry, pulverize, and it is ready for use. With a little trouble
+you will obtain in this way a much better article than can generally be
+bought of dealers. For the last washing, alcohol, or a mixture of alcohol
+and water, is preferable.&rdquo;
+</p>
+
+<p>
+Potassa Solution.&mdash;The use of a solution of potassa in the preparation of
+the plate was suggested in the early history of the Daguerreotype. It was
+thought to possess some peculiar property for improving the tone of the
+impression. It is used for moistening the rotten stone in polishing the
+plate, and may be prepared by putting about an ounce and a half of alcohol
+in a close bottle, and add half a stick of caustic potash. This will soon
+become of a deep red color. For use, fill your small bottle, having a
+quill in the cork, with alcohol, and add a few drops of the above, or
+enough to change it to a bright orange or saffron color.
+</p>
+
+<p>
+A Substitute for the Hyposulphite Solution.&mdash;M. DAGUERRE recommends the
+use of a solution of salt water for removing the coating off the plate. I
+found this of some service at one time during my travels. My hyposulphite
+bottle got broke and its contents lost, so as only to leave enough for
+preparing gilding. I resorted to the use of salt solution, and found it to
+answer well. Make a saturated solution of salt in water. First wash the
+plate with clear water; then immerse it in the saline solution, when it
+should be agitated, and the coating will soon disappear. Another process
+with a salt solution of half the strength of the above is very interesting
+and effectual. The plate having been dipped into cold water, is placed in
+a solution of common salt, of moderate strength; it lies without being
+acted upon at all; but if it be now touched on one corner with a piece of
+zinc, which has been scraped bright, the yellow coat of iodine moves off
+like a wave and disappears. It is a very pretty process. The zinc and
+silver forming together a voltaic pair, with the salt water intervening,
+oxidation of the zinc takes place, and the silver surface commences to
+evolve hydrogen gas; while this is in a nascent condition it decomposes
+the film of iodide of silver, giving rise to the production of hydriodic
+acid, which is very soluble in water, and hence instantly removed.
+</p>
+
+<p>
+This process, therefore, differs from that with hyposulphite. The latter
+acts by dissolving the iodide of silver, the former by decomposing it. It
+is necessary not to leave the zinc in contact too long, or it deposits
+stains, and in large plates the contact should be made at the four corners
+successively, to avoid this accident.
+</p>
+
+<p>
+Gilding Solution.&mdash;To one pint of pure rain or distilled water add fifteen
+grains of pure chloride of gold, and to another pint add sixty grains of
+hyposulphite of soda. When dissolved, pour the gold solution into the
+hyposulphite by small quantities, shaking well after each addition. The
+soda solution must not be poured into the gold, as the gold would be
+immediately decomposed, and the solution turn black, and be unfit for use.
+</p>
+
+<p>
+Some operators add muriate of potash and other substances, but these do
+not possess any advantage except in cases where it is necessary to bleach
+the solarized portions of the impression, and when such is the case,
+chloride of sodium (common salt) is probably as effective and is the most
+convenient. Add about a teaspoonful to two ounces of the gilding.
+</p>
+
+<p>
+Solution, for Increasing the Brilliancy of the Daguerreotype.&mdash;This
+solution will have the effect to thoroughly cleanse the surface of the
+gilded plate and excite a powerful influence on the general character of
+the impression. To a solution of three ounces of water, in which is
+dissolved a quarter of an ounce of cyanide of potassium, add one
+teaspoonful of a solution containing six ounces of water and half an ounce
+of each pure carbonate of potash, alum, common salt, gallic acid, sulphate
+of copper, and purified borax. While the plate is wet, pour on a little,
+and heat it with a powerful blaze. The effect will be quickly produced, in
+from three to fifteen seconds. Rinse and dry, as in the gilding.
+</p>
+
+<p>
+Bleaching Solution.&mdash;Make a saturated solution of muriate of ammonia (sal
+ammoniac) in pure water, and filter through paper. Reduce with an equal
+quantity of water when used. When the linen or any other portion of the
+impression is badly solarized, after removing the coating, rinse with
+water; then pour this upon the surface in the same manner as the gilding
+solution. If the solarization be very deep, apply the lamp beneath, and
+warm the plate a trifle. Now pour off, and, without rinsing, apply the
+gilding. The whole operation must be quickly performed, or the chlorine
+soon attacks the shades of the picture. When properly done, however, the
+solarized parts are restored to a clear, transparent white.
+</p>
+
+<p>
+Electro, or Cold Gilding.&mdash;This process I have adopted, and it produces
+exceedingly beautiful impressions for the stereoscope, adding a great
+charm to the pleasing effect of that instrument. It also possesses a
+pretty and curious effect on views. It is easy of trial, and may be used
+by dissolving one gramme of chloride of gold in half a litre of ordinary
+water, and thirty grammes of hyposulphite of soda in another half litre of
+similar water; then pour the solution of chloride of gold into that of
+soda, by little and little, agitating it exactly as in M. Fizeau&rsquo;s
+preparation, of which there is but a variation.
+</p>
+
+<p>
+When you wish to use it, pour some into a plate, or any other vessel of
+the same kind, sufficient to cover the proof; then, after having added to
+it a drop of ammonia, immerse the plate in it as soon as you take it out
+of the mercury-box, after having wiped its back and edges, and agitate the
+mixture quickly from right to left, so as to dissolve rapidly the coating
+of iodide of silver as usual. As soon as the plate appears white, cease
+all rapid motion, but continue to give it a slight undulating one; for if
+it were allowed to remain still for only a few minutes, the proof would be
+clouded. By little and little, the surface of the plate takes a yellow
+tint, which darkens more and more, approaching to bistre. You stop
+therefore, at the color you wish; and when the proof has been washed and
+dried, in the manner previously explained, it will be found to be fixed,
+without any stain, with a limpid surface, and an extraordinary warm tone.
+If you were to augment the proportions of the ammonia or chloride of gold,
+the operation would progress much quicker, but then the middle of the
+proof would be always much clearer than towards the border. The mixture
+may be used several times without being renewed. It does not, however,
+give such a beautiful color to the impression as when it is newly
+prepared. By communicating to the vessel containing the solution a
+continual motion, the impression, when once immersed, will be fixed.
+During that time, and while attending to anything else, watch its color;
+and at the end of ten minutes or a quarter of an hour, take it out of the
+bath and dry it.
+</p>
+
+<p>
+Agent for Neutralizing Bromine, Chlorine, and Iodine Vapors.&mdash;Aqua
+ammonia, sprinkled about the chemical or coating room, will soon
+neutralize all the vapor in the atmosphere of either chlorine, bromine, or
+iodine. No operator should be without, at least, a six-ounce bottle filled
+with ammonia. A little of its vapor about the camera-box has a decided and
+happy effect. Burnt coffee, pulverized, has also the property of
+destroying the vapors of the above chemicals, as also almost any other
+agent employed about the Daguerreotype room. Its deodorizing properties
+are such that if brought in contact with air filled with the odor of
+decomposing meat, it will instantly destroy all disagreeable smell. It can
+easily be used in the Daguerreotype room by placing a little of the raw
+bean, finely pulverized, on an old plate, and roasting it over the
+spirit-lamp.
+</p>
+
+<p>
+Buff Dryer.&mdash;There are various methods for keeping buffs dry and free from
+dust. Some place a sheet of iron against the wall at an angle sufficient
+to put a lamp between it and the wall, and then let the buff rest against
+the top of the sheet. By this method the buff is for its full length close
+to the heated iron, and at the same time exposed to the heated atmosphere
+and any dust that may be free. I would recommend some arrangement by which
+the buff would be inclosed. I have found the following to answer the
+purpose well, which is a box of sheet iron twenty inches long, eight wide
+and five high, with one end left open and the other closed; the cover is
+made of the same material, with the edges bent over to go on and off.
+There are several wires running through the centre of the sides, which it
+is necessary to cover with cloth or paper to absorb all the moisture that
+may be made by applying the heat, and the buffs are put in and taken out
+at the open end. In order that the heat may be as nearly uniform as
+possible, an iron bar one inch wide, eighteen inches long and one half
+inch thick, is so bent that the centre is one quarter inch from the bottom
+of the box, and that at least two inches of each end come in contact with
+the bottom; this being riveted on the bottom, and a lamp with a small
+blaze applied to the centre of the bar of iron. This will constitute one
+of the best and cheapest buff dryers in use. It may be suspended from the
+wall by placing wires around it, or it may stand upon legs. Perhaps a more
+convenient plan is to place it under the workbench in a similar position
+to a drawer. One precaution is necessary: when first heating the dryer,
+apply but a very gentle heat. This will prevent an accumulation of
+moisture, which would otherwise pass off in steam, coming in contact with
+the buff, thus causing a dampness. Another caution: never have the
+temperature of the air in the heater more than ten degrees above that
+which surrounds it.
+</p>
+
+<p>
+When wheels are used, they should be encased in a sheet iron or wood case.
+All those made for our market are provided in this respect.
+</p>
+
+<p>
+Keeping Buffs in Order.&mdash;This is one of the most important objects to
+arrest the attention of the operator. Every buff is more or less liable to
+get out of order by dust falling upon or coming in contact with the
+polishing powder employed in cleaning the plate. The edge of every plate
+should be thoroughly wiped and freed from any material that may adhere
+while cleaning. I have adopted the following method, which proves highly
+successful:
+</p>
+
+<p>
+Rub the buff leather, holding the face down, with the sharp edge of a pair
+of shears or a piece of glass. This brings out any portion of the skin
+which may have become matted from any moisture, and also takes out any
+substance imbedded in it, and prevents it from scratching. Then, with a
+stiff brush, rub the buff well, and it will be found to work well. This
+same process employ on wheels and hand buffs every morning, or oftener, as
+occasion requires.
+</p>
+
+<p>
+Preparing Buffs.&mdash;Two of these are necessary. That part of the stick to be
+covered should be about eighteen or twenty inches long, and three wide,
+and made crowning on the face from one end to the other, about one half
+inch. Before covering, these are to be padded with two or three
+thicknesses of Canton flannel. The buff should not be too hard, but padded
+with flannel, so that by drawing it over the plate, it may touch across
+the surface. The only proper material for buffs is prepared buckskin; and
+if prepared in a proper manner, this needs nothing but to be tacked upon
+the stick. There are several varieties of wheels employed; the one most
+generally adopted is Lewis&rsquo; patent, which consists of several varieties of
+wheels. Any operator can make a suitable wheel on the same plan of a
+turning lathe.
+</p>
+
+<p>
+To Clean Buckskins.&mdash;When the operator is compelled to purchase an
+unprepared buckskin, the following is a good process for cleaning it:
+There is always in the buckskin leather that is purchased, more or less of
+an oily matter, which is acquired in its preparation, sometimes even
+amounting, to a third of its weight. The following is the mode of ridding
+it of this noxious ingredient: Dissolve, in about six or seven quarts of
+filtered water, about five ounces of potash; when dissolved, wash with the
+solution an ordinary buckskin; when it has been well stirred in the
+liquid, the water becomes very soapy, owing to the combination of the
+potash with the oily matters contained in the skin. Throw away this
+solution and use some fresh water without potash and rather tepid; change
+it several times until it remains quite limpid. Then gently stretch the
+skin to dry in an airy shaded place. When thoroughly dried, rub it well
+between the hands. It thus becomes very pliant and velvet-like.
+</p>
+
+<p>
+Reflectors for Taking Views.&mdash;There have been excellent cameras introduced
+for taking views, but the time of exposure, which is increased in
+proportion to the focal length, is considered an objection; consequently
+many adhere to the old plan of using the speculum, or rather, substitute a
+mirror. I now have one which I have used for several years and find it
+equal to any article of the kind have ever tried. One is easily made by a
+tin man, at a trifling expense. Procure a piece of best plate
+looking-glass, two and a half by five inches for a quarter, or four by
+eight for a half-sized camera; put a piece of pasteboard of the same size
+on the back, to protect the silvering, and stick around the edge in the
+same manner as in putting up a picture. Take a sheet of tin for the large
+size, or a half sheet for the other; place the glass crosswise in the
+centre; bend the ends of the tin over the edge of the glass and turn them
+back so as to form a groove to hold the glass, and still allow it to slide
+out and in. These ends of the tin must be turned out flaring, that they
+may not reflect in the glass.
+</p>
+
+<p>
+Have a tin band about an inch wide made to fit close on the end of the
+camera tube; place it on, and taking the tin containing the glass, bring
+it to an angle of forty-five degrees with the tube, extending nearly the
+whole length of the glass in front of the lenses; lap the loose ends of
+the tin on each side of the tin rim, and having your camera turned on the
+side to throw the view lengthwise, arrange the exact angle by examining
+the image on the ground-glass. When you have it exactly right, hold it
+while it is soldered fast to the band. Take out your glass and stain the
+tin black, to prevent reflection.
+</p>
+
+<h2><a name="chap03"></a>CHAPTER III.</h2>
+
+<h3>
+CHEMICALS.
+</h3>
+
+<p class="letter">
+Bromine and its Compounds&mdash;Iodine and its Compounds&mdash;Chlorine and its
+compounds&mdash;Cyanide of Potassium&mdash;Hyposulphite of Soda&mdash;Hyposulphite of
+Gold&mdash;Nitric Acid&mdash;Nitro-Muriatic Acid&mdash;Hydrochloric Acid&mdash;Hydrofluoric
+Acid&mdash;Sulphuric Acid&mdash;Accelerating Substances&mdash;Liquid Sensitives&mdash;Dry
+Sensitives, etc., etc.
+</p>
+
+<h3>
+BROMINE.
+</h3>
+
+<p>
+An article so extensively used in the practice of the Daguerreotypic art
+as Bromine, is deserving of especial attention, and accordingly every
+person should endeavor to make himself familiar with its properties and
+applications.
+</p>
+
+<p>
+History.&mdash;This element was discovered in 1826 by M. Balard, in the
+mother-liquor, or residue of the evaporation of sea-water. It is named
+from its offensive odor (bromos, bad odor). In nature it is found in
+sea-water combined with alkaline bases, and in the waters of many saline
+springs and inland seas. The salt springs of Ohio abound in the compounds
+of bromine, and it is found in the waters of the Dead Sea. The only use
+which has been made of bromine in the arts is in the practice of
+photography. It is also used in medicine In a chemical point of view it is
+very interesting, from its similarity in properties, and the parallelism
+of its compounds to chlorine and iodine.
+</p>
+
+<p>
+Dr. D. Alter, of Freeport, Pa., is the only American manufacturer, and
+furnishes all of the &ldquo;American Bromine.&rdquo; Yet we understand much purporting
+to be of German manufacture is prepared from that made in Freeport. This
+is done by individuals in this city, who get well paid for the deception.
+</p>
+
+<p>
+For the successful application of bromine as an accelerating agent, we are
+indebted to Mr. John Goddard of London, who at the time was associated
+with Mr. John Johnson, now a resident of this city.
+</p>
+
+<p>
+Preparation.&mdash;The mother-liquor containing bromides is treated with a
+current of chlorine gas, which decomposes these salts, setting the bromine
+free, which at once colors the liquid to a reddish brown color. Ether is
+added and shaken with the liquid, until all the bromine is taken up by the
+ether, which acquires a fine red color and separates from the saline
+liquid.
+</p>
+
+<p class="noindent">
+{74}
+</p>
+
+<p>
+Solution of caustic potash is then added to the ethereal solution, forming
+bromide of potassium and bromate of potash. This solution is evaporated to
+dryness, and the salts being collected are heated in a glass retort with
+sulphuric acid and a little oxide of manganese. The bromine is distilled,
+and is condensed in a cooled receiver, into a red liquid.
+</p>
+
+<p>
+Properties.&mdash;Bromine somewhat resembles chlorine in its odor, but is more
+offensive. At common temperatures it is a very volatile liquid, of a deep
+red color, and with a specific gravity of 3, being one of the heaviest
+fluids known. Sulphuric acid floats on its surface, and is used to prevent
+its escape. At zero it freezes into a brittle solid. A few drops in a
+large flask will fill the whole vessel when slightly warmed, with blood
+red vapors, which have a density of nearly 6.00, air being one. It is a
+non-conductor of electricity, and suffers no change of properties from
+heat, or any other of the imponderable agents. It dissolves slightly in
+water, forming a bleaching solution.
+</p>
+
+<p>
+Chloride of Bromine.&mdash;This as an accelerating agent is by many considered
+superior {75} to the other Bromide combinations. It can be readily
+prepared by passing a current of chlorine through a vessel containing
+bromine. A mixture of two parts muriatic acid and one of black oxide of
+manganese, should be put into a flask having a bent tube to conduct the
+chlorine vapor into the bromine in another vessel. This last vessel should
+also be supplied with a bent tube for conducting the combined vapors with
+a third vessel or receiver. On the application of the heat from a spirit
+lamp to the bottom of the flask, a current of chlorine gas will be
+disengaged, and pass into the bromine, when it readily combines, and gives
+off a vapor, which, when condensed in the third vessel, forms a volatile
+yellowish-red liquid. It is best, even at ordinary temperature, to place
+the receiver in an ice bath. For manner of using, see farther on, under
+head of Accelerators.
+</p>
+
+<p>
+Bromides.&mdash;A bromide treated with oil of vitriol, disengages chlorohyadic
+acid; but vapors of bromine are constantly disengaged, at the same time
+imparting a brown color to the gas. If the bromide be treated with a
+mixture of sulphuric acid, and peroxide of manganese, bromide is only
+disengaged. A solution of a bromide gives, with of nitrate {76} silver, a
+light yellowish white precipitate of bromide of silver, which is insoluble
+in an excess of acid, and readily dissolves in ammonia. The precipitated
+bromide is colored by light like the chloride, but is immediately tinged
+brown, while the chloride assumes at first a violet hue. The bromides, in
+solution, are readily decomposed and chloride being set free, colors the
+liquid brown.
+</p>
+
+<p>
+In the whole range of heliographic chemicals there is probably not another
+collection less understood and being so productive of interesting
+investigation as the bromides.
+</p>
+
+<p>
+Bromide of Iodine.&mdash;M. de Valicours furnishes us with the best method for
+preparing this mixture:
+</p>
+
+<p>
+&ldquo;Into a bottle of the capacity of about two ounces, pour thirty or forty
+drops of bromine, the precise quantity not being of importance. Then add,
+grain by grain, as much iodine as the bromine will dissolve till quite
+saturated. This point is ascertained when some grains of the iodine remain
+undissolved. They may remain in the bottle, as they will not interfere
+with the success of the preparation.
+</p>
+
+<p>
+&ldquo;The bromide of iodine thus prepared, from its occupying so small a space,
+can very easily be carried, but in this state it is much too concentrated
+to be used. When it is to be employed, pour a small quantity, say fifteen
+drops, by means of a dropping-tube, into a bottle containing about half an
+ounce of filtered river water. It will easily be understood that the
+bromide of iodine can be used with a greater or less quantity of water
+without altering the proportion which exists between the bromine and
+iodine.&rdquo;
+</p>
+
+<p>
+This article forms a very good dry accelerator, and is by some persons
+thought superior to all others, as it works with great uniformity, and is
+less liable to scum the plate in coating at high temperatures, or when the
+thermometer indicates a heat above 60 deg.
+</p>
+
+<p>
+Bromide of Potassium&mdash;Is prepared by mixing bromine and a solution of pure
+potass together, and evaporating to dryness; it crystallizes in small
+cubes, and dissolves readily in water. This agent is extensively employed
+in the paper and glass processes.
+</p>
+
+<p>
+Bromide of Lime. This the principal accelerator used in the American
+practice, and is the best of all dry combinations at present employed.
+There are many reasons why the dry is advantageous; these are too familiar
+to repeat.
+</p>
+
+<p>
+&ldquo;The bromide of lime may be produced by allowing bromine vapor to act upon
+hydrate of lime for some hours. The most convenient method of doing this
+is to place some of the hydrate at the bottom of the flask, and then put
+some bromine into a glass capsule supported a little above the lime. As
+heat is developed during the combination, it is better to place the lower
+part of the flask in water at the temperature of about 50 deg. Fah.; the
+lime gradually assumes a beautiful scarlet color, and acquires an
+appearance very similar to that of the red iodide of mercury. The
+chloro-iodide of lime may be formed in the same manner; it has a deep
+brown color. Both these compounds, when the vapor arising from them is not
+too intense, have an odor analogous to that of bleaching powder, and quite
+distinguishable from chlorine, bromine, or iodine alone.&rdquo;
+</p>
+
+<p>
+Farther on, I have given, in connection with accelerators, a process I
+adopt, which is far less tedious and equally reliable.
+</p>
+
+<p>
+Bromide of Silver&mdash;May be formed by pouring an alkaline bromide into a
+solution of nitrate of silver, in the shape of a white, slightly yellowish
+precipitate, which is insoluble in water and nitric acid, but readily
+dissolves in ammonia and the alkaline hyposulphites. Chlorine easily
+decomposes bromide of silver, and transforms it into chloride.
+</p>
+
+<p>
+M. Biot has expressed his opinion, that it is not possible to find any
+substance more sensitive to light than the bromide of silver. This is true
+to a certain extent, but in combination with deoxidizing agents, other
+preparations have a decided superiority over the pure bromide of silver.
+</p>
+
+<p>
+Bromide of Gold&mdash;Is readily prepared by adding a little bromide to the
+brown gold of the assayers, and allowing it to remain some time under
+water, or assisting its action by a gentle heat. It forms a salt of a
+bright crimson color, but in its general properties is precisely similar
+to the chloride used in gilding.
+</p>
+
+<p>
+Bromide of Magnesia&mdash;Is prepared in the same manner as bromide of lime.
+</p>
+
+<p>
+This mixture is particularly adapted for hot climates, and is used in this
+country by some few who regard its use as a valuable secret.
+</p>
+
+<p>
+Bromide of Starch.&mdash;This preparation is much used, but not alone. It is
+combined with lime by putting about one part in measure of starch to four
+of lime. It is prepared by adding bromine to finely pulverized starch, in
+the same manner as bromide of lime. (See Accelerators.)
+</p>
+
+<p>
+Experiments with Bromine.&mdash;Place in a very flaring wine glass a few drops
+(say ten) of bromine, then place a small piece of phosphorus about
+one-twentieth of an inch in diameter. Place the latter on the end of a
+stick from five to ten feet in length. So place it that the phosphorus can
+be dropped into the glass, and in an instant combustion giving a loud
+report will be the result.
+</p>
+
+<p>
+b. Expose a daguerreotype plate to the vapor of bromine, it assumes a
+leaden-grey color, which, blackens by light very readily. Exposing this to
+mercury will not produce any decided action upon the lights. Immerse it in
+the solution of the muriate of soda, and the parts unacted upon by light
+becomes a jet black, while the parts on which the light has acted will be
+dissolved off, leaving a clean coating of silver. This will be a most
+decided black picture on a white ground.
+</p>
+
+<p>
+c. Expose an impressioned plate, that has been sufficient time in the
+camera to become solarized, to the vapors of bromine, and the impression
+will be fully developed and exhibit no signs of solarization. The exposure
+over the bromine most be very brief. Chlorine or iodine will produce the
+same result. The latter is preferable.
+</p>
+
+<p>
+Again, should the impressioned plate be exposed too long over the vapor of
+bromine, the impression would be rendered wholly insensitive to the
+mercurial vapor. Hence this method is resorted to for restoring the
+sensibility of the plate when there is reason to believe that the
+impression would not be a desirable one; as, for example, if a likeness of
+a child be wanted, and it had moved before the plate had been sufficiently
+long exposed in the camera, the plate may be restored to its original
+sensitiveness by re-coating over bromine, as above, thus saving the time
+and labor of re-preparing the plate for the chemicals.
+</p>
+
+<p>
+d. If by accident (we would not advise a trial to any extent of this), you
+should inhale a quantity of the vapor of bromine, immediately inhale the
+vapor of aqua ammonia, as this neutralizes the dangerous effect of the
+bromine vapor. Every operator should be provided with a bottle of ammonia,
+as a little sprinkled about the chemical room soon disinfects it of all
+iodine or bromine vapor, and also tends to facilitate the operation in the
+camera.
+</p>
+
+<h3>
+IODINE.
+</h3>
+
+<p>
+History of Iodine.&mdash;This is one of the simple chemical bodies which was
+discovered in 1812 by M. Courtois, of Paris, a manufacturer of saltpetre,
+who found it in the mother-water of that salt. Its properties were first
+studied into by M. Gay Lussac. It partakes much of the nature of chlorine
+and bromine. Its affinity for other substances is so powerful as to
+prevent it from existing in an isolated state. It occurs combined with
+potassium and sodium in many mineral waters, such as the brine spring of
+Ashby-de-la-Zouche, and other strongly saline springs. This combination
+exists sparingly in sea-water, abundantly in many species of fucus or
+sea-weed, and in the kelp made from them. It is an ingredient in the Salt
+Licks, saline, and brine springs of this country, especially of those in
+the valley of the Mississippi. It is sparingly found in fresh-water
+plants, as well also in coal, and in combination with numerous other
+bodies.
+</p>
+
+<p>
+Fermented liquors contain iodine; wine, cider, and perry are more
+iodureted than the average of fresh waters. Milk is richer in iodine than
+wine; independently of the soil, with which it varies, the proportion of
+iodine in milk is in the inverse ratio of the abundance of that secretion.
+Eggs (not the shell) contain much iodine. A fowl&rsquo;s egg weighing 50 gr.
+contains more iodine than a quart of cow&rsquo;s milk. Iodine exists in arable
+land. It is abundant in sulphur, iron, and manganese ores, and sulphuret
+of mercury: but rare in gypsum, chalk, calcareous and silicious earths.
+Any attempt to extract iodine economically should be made with the plants
+of the ferro-iodureted fresh waters. Most of the bodies regarded by the
+therapeutists as pectoral and anti-scrofulous are rich in iodine.
+</p>
+
+<p>
+It is probably to the application of this body that we owe the discovery
+of the daguerreotype. There is no record of the precise date when Daguerre
+commenced experimenting with iodine, but by the published correspondence
+between him and M. Neipce, his partner, it was previous to 1833. There is
+no doubt, however, that the first successful application was made in 1838,
+as the discovery was reported to the world early in January, 1839.
+</p>
+
+<p>
+Preparation.&mdash;Iodine is mostly prepared from kelp, or the half vitrified
+ashes of seaweed, prepared by the inhabitants of the western islands, and
+the northern shores of Scotland and Ireland. It is treated with water,
+which washes out all the soluble salts, and the filtered solution is
+evaporated until nearly all the carbonate of soda and other saline matters
+have crystallized out. The remaining liquor, which contains the iodine, is
+mixed with successive portions of sulphuric acid in a leaden retort, and
+after standing some days to allow the sulphureted hydrogen, etc., to
+escape, peroxide of manganese is added, and the whole gently heated.
+Iodine distills over in a purple vapor, and is condensed in a receiver, or
+in a series of two-necked globes.
+</p>
+
+<p>
+Properties.&mdash;Iodine is solid at the ordinary temperature, presenting the
+appearance of dark-grey or purple spangles, possessing a high degree of
+metallic lustre. It somewhat resembles plumbago, with which it is
+sometimes diluted, particularly when it is fine. Operators should endeavor
+to secure the larger crystals. It melts at 224.6 deg., forming a brown or
+nearly black liquid. It boils at about 356 deg., and emits a very deep
+violet colored vapor. It gives off a very appreciable vapor, sufficient
+for all purposes of forming the iodide of silver on the daguerreotype
+plate, at a temperature of 45 deg. or even lower. Iodine crystallizes
+readily. Every operator has found upon the side of the jar in his
+coating-box, perfectly regular crystals, deposited there by sublimation.
+</p>
+
+<p>
+Water dissolves but a small proportion of iodine, requiring 7000 parts of
+water to dissolve one of iodine, {85} or one grain to the gallon of water.
+Alcohol and ether dissolve it freely, as does a solution of nitrate or
+hydrochlorate of ammonia and of iodides.
+</p>
+
+<p>
+The density of solid iodine is 4.95; that of its vapor 8.716. It greatly
+resembles chlorine and bromine in its combinations, but its affinities are
+weaker. It does not destroy the majority of organic substances, and
+vegetable colors generally resist its action. It combines with several
+organic substances, imparting to them peculiar colors. It colors the skin
+brown, but the stain soon disappears.
+</p>
+
+<p>
+Chloride of Iodine&mdash;Is formed by passing chlorine into a bottle containing
+some iodine. This can be readily done by pouring one ounce and a half of
+muriatic acid upon a quarter of an ounce of powdered black oxide of
+manganese, and heat it gradually in a flask, to which is adapted a bent
+glass tube. This tube must connect with the bottle containing the iodine,
+and the yellowish-green gas disengaged will readily combine with the
+iodine, forming a deep red liquid, and the operation is complete. The use
+of chloride of iodine will be referred to in connection with the
+Accelerators.
+</p>
+
+<p class="noindent">
+{86}
+</p>
+
+<p>
+Iodides.&mdash;The iodide treated with the oil of vitriol, instantly produces a
+considerable deposit of iodine; and if the mixture be heated, intense
+violent vapors are disengaged. The reaction is due to the decomposition of
+oil of vitriol by iodohydric acid, water and sulphurous acid being formed,
+and iodine set free. The iodides in solution are decomposed by chlorine,
+iodine being precipitated, the smallest quantity of which in solution is
+instantly detected by its imparting to starch an intensely blue color.
+</p>
+
+<p>
+Iodide of Potassium.<a href="#fn-4" name="fnref-4" id="fnref-4"><sup>[4]</sup></a>&mdash;This
+compound is easily made in the following manner: Subject to a moderate heat a
+mixture of 100 parts of iodine, 75 of carbonate of potash, 30 of iron filings,
+and 120 parts of water. This mass must be thoroughly dried and then heated to
+redness; the resulting reddish powder is to be washed with water, and the
+solution obtained filtered, and evaporated to dryness. It is found that 100
+parts of iodine yield 135 parts of very white, but slightly alkaline, iodide of
+potassium.
+</p>
+
+<p class="footnote">
+<a name="fn-4" id="fn-4"></a> <a href="#fnref-4">[4]</a>
+I shall present the preparation of only a few iodides, and such as are more
+intimately connected with the Daguerreotype.
+</p>
+
+<p>
+Experiment.&mdash;On projecting dry pulverized iodide of potassium into fused
+anhydrous phosphoric acid, a violent disengagement of iodine takes place,
+attended by a transient ignition; fused hydrate of phosphoric acid
+liberates iodine abundantly from iodide of potassium; this reaction is
+accompanied by the phenomenon of flame and formation of a considerable
+quantity of hydriodic acid.
+</p>
+
+<p>
+Iodide of Mercury.&mdash;For the preparation of iodide of mercury, Dublanc
+recommends to cover 100 grms. of mercury with 1 kilogrm. of alcohol, to
+add 124 grms. of iodine gradually in portions of ten grms., and agitating
+between each fresh addition, until the alcohol becomes colorless again.
+After the addition of the last 4 grms. the alcohol remains colored, the
+whole of the mercury having become converted into iodide. The resulting
+preparation is washed with alcohol; it is crystalline and of a hyacinth
+color.
+</p>
+
+<p>
+Iodide of Silver.&mdash;This compound is formed upon every plate upon which a
+Daguerreotype is produced. The vapor of iodine coming in contact with the
+silver surface, forms an iodide which is peculiarly sensitive to light.
+</p>
+
+<p>
+The various colors produced are owing to the thickness of the coating, and
+the maximum sensibility of the coating, as generally adopted, is when it
+assumes a deep yellow, or slightly tinged with rose color.
+</p>
+
+<p>
+This compound is largely employed in most photographic processes on paper,
+and may be easily prepared by the following formula: By adding iodide of
+potassium to a solution of nitrate of silver, a yellowish-white
+precipitate of iodide of silver is obtained, which is insoluble in water,
+slightly soluble in nitric acid, and soluble in a small degree in ammonia,
+which properties seem easily to distinguish it from the chloride and
+bromide of silver. Chlorine decomposes it and sets the iodine free, and
+chlorohydric acid converts it into a chloride. It fuses below a red heat.
+Although the effect of light on the iodide is less rapid than on the
+chloride, the former sooner turning black, assuming a brown tinge; but
+when in connection with gallic acid and the ferrocyanate of potash, it
+forms two of the most sensitive processes on paper.
+</p>
+
+<p>
+Iodide of silver dissolves easily in a solution of iodide of potassium,
+and the liquid deposits in evaporation crystals of a double iodide.
+</p>
+
+<p>
+Iodide of Gold.&mdash;If a solution of potassium be added to a solution of
+chloride of gold, a precipitate of iodide of gold takes place, soluble in
+an excess of the precipitate. A little free potash should be added to
+combine with any iodide that may chance to be set free by the chloride of
+gold.
+</p>
+
+<p>
+Iodide of Lime is prepared by adding iodine to hydrate of lime (which will
+be referred to farther on) until the mixture assumes a light yellow shade,
+when wanted for combinations with accelerators, or to a dark brown when
+employed for the first coating. This latter mixture has been sold in our
+market under the name of &ldquo;Iodide of Brome.&rdquo;
+</p>
+
+<p>
+Iodide of Bromine.&mdash;(See page 76.)
+</p>
+
+<p>
+Experiments with Iodine.&mdash;Place a plate which has been exposed in the
+camera over the vapor of iodine for a very brief period, and it will
+present the appearance of the impression having been solarized.
+</p>
+
+<p>
+b. Upon a Daguerreotype plate, from which an impression has been effaced
+by rubbing or otherwise, the picture may be made to reappear by merely
+coating it over with iodine.
+</p>
+
+<p>
+c. Place in a vessel a little water, into which put the smallest possible
+quantity of free iodine and add a little starch, and the liquid will
+instantly assume a blue color. Advantage is taken of this fact in the
+laboratory to detect the presence of iodine in liquids. The starch should
+be dissolved in boiling water and allowed to cool. There are numerous
+other interesting experiments that can be performed by the aid of iodine,
+but it is unnecessary here to consume more space.
+</p>
+
+<h3>
+CHLORINE.
+</h3>
+
+<p>
+History.&mdash;The Swedish chemist, Scheele, in 1774, while examining the
+action of hydrochloric acid on peroxide of manganese, first noticed this
+element. He called it dephlogisticated muriatic acid. It was afterwards,
+by the French nomenclaturists, termed oxygenated muriatic acid, conceiving
+it to be a compound of oxygen and muriatic acid. This view of its notice
+was corrected by Sir H. Davy (in 1809), who gave it the present name. In
+1840-41, this gas vas employed for accelerating the operation of light
+upon the iodized Daguerreotype plate. John Goddard, Wolcott &amp; Johnson,
+Claudet, Draper, Morse and others, were among the first made acquainted
+with its use. Count Rumford, Ritter, Scheele, Seebert and others,
+experimented with chlorine in regard to its effect when exposed to the
+action of light in combination with silver. In 1845, M. Edward Becquerel
+announced that he had &ldquo;been successful in obtaining, by the agency of
+solar radiations, distinct impressions, of the colors of nature.&rdquo;
+</p>
+
+<p>
+On the 4th of March, 1851, Neipce, St. Victor, a former partner of
+DAGUERRE, announced that he had produced &ldquo;all the colors by using a bath
+of bichloride of copper, and that a similar phenomenon occurs with all
+salts of copper, mixed with chlorine.&rdquo;
+</p>
+
+<p>
+Preparation.&mdash;This is easily accomplished by putting about two parts of
+hydrochloric (muriatic) acid on one of powdered black oxide of manganese,
+and heating it gradually in a flask or retort, to which may be adapted a
+bent glass tube. A yellowish-green gas is disengaged, which being
+conducted through the glass tube to the bottom of a bottle, can readily be
+collected, being much heavier than the air, displaces it completely and
+the bottle is filled (which can be seen by the green color); a greased
+stopper is tightly fitted to it, and another bottle may be substituted.
+</p>
+
+<p>
+In all experiments with chlorine, care should be taken not to inhale the
+gas!
+</p>
+
+<p>
+Properties.&mdash;Chlorine is a greenish-yellow gas (whence its name, from
+chloros, green), with a powerful and suffocating odor, and is wholly
+irrespirable. Even when much diluted with air, it produces the most
+annoying irritation of the throat, with stricture of the chest and a
+severe cough, which continues for hours, with the discharge of much thick
+mucus. The attempt to breathe the undiluted gas would be fatal; yet, in a
+very small quantity, and dissolved in water, it is used with benefit by
+patients suffering under pulmonary consumption.
+</p>
+
+<p>
+Under a pressure of about four atmospheres, it becomes a limpid fluid of a
+fine yellow color, which does not freeze at zero, and is not a conductor
+of electricity. It immediately returns to the gaseous state with
+effervescence on removing the pressure.
+</p>
+
+<p>
+Water recently boiled will absorb, if cold, about twice its bulk of
+chlorine gas, acquiring its color and characteristic properties. The moist
+gas, exposed to a cold of 32 deg., yields beautiful yellow crystals, which
+are a definite compound of one equivalent of chlorine and ten of water. If
+these crystals are hermetically sealed up in a glass tube, they will, on
+melting, exert such a pressure as to liquefy a portion of the gas, which
+is distinctly seen as a yellow fluid, not miscible with the water which is
+present. Chlorine is one of the heaviest of the gases, its density being
+2.47, and 100 cubic inches weighing 76.5 grains.
+</p>
+
+<p>
+Chlorine Water.&mdash;This combination, which is used in conducting M. Neipce&rsquo;s
+process, can be readily prepared by conducting the gas into a bottle
+containing distilled water. One part water dissolves two parts of
+chlorine.
+</p>
+
+<p>
+Chlorides.&mdash;The metallic chlorides are nearly all soluble in water; that
+of silver and protochloride of mercury being the only exceptions. A
+metallic chloride, treated with oil of vitriol, disengages chlorohydric
+acid. Heated with a mixture of peroxide of manganese and sulphuric acid,
+chlorine is given off, which is easily recognized by its odor and other
+physical properties.
+</p>
+
+<p>
+The chlorides dissolve in water; give with nitrate of silver, a white
+precipitate, even in highly diluted solutions, becoming violet colored and
+finally black when exposed to the light. The rapidity of the change of
+color is proportioned to the intensity of the light. It is insoluble in
+nitric acid, but readily soluble in ammonia; it fuses without
+decomposition, forming, when cold, a tough, horny mass, and is reduced by
+hydrogen and by fusion with carbonate of soda, or with resin.
+</p>
+
+<p>
+Chloride of Bromine. (See page 74.)
+</p>
+
+<p>
+Chloride of Iodine. (See page 85.)
+</p>
+
+<p>
+Chloride of potassium.&mdash;or (Muriate of Potassa).&mdash;Dissolve half an ounce
+of carbonate of potassa in water, and neutralize with muriatic acid. Upon
+concentrating the solutions, cubic crystals will be obtained, having a
+taste similar to common salt. They consist of potassium and chloride, and
+when dissolved in water they may be regarded as muriate of potassa.
+</p>
+
+<p>
+Chloride of Lime.&mdash;Mix half an ounce of slacked lime (hydrate of lime)
+with six ounces of water, and conduct into this milk of lime, with
+frequent agitation, as much chlorine gas as will evolve from two ounces of
+muriatic acid and half an ounce of black oxide of manganese. The liquid
+clarifies by standing; may be regarded as a solution of chloride of lime,
+and must be protected from the air and light. It may also be made without
+putting in the water with the hydrate of lime, by merely passing the
+chlorine into the hydrate of lime. This last is by some used in
+preparations for accelerating the operation of taking Daguerreotypes, but
+when used for this purpose it is in small quantities.
+</p>
+
+<p>
+Chloride of Calcium.&mdash;To one part of water add two parts of muriatic acid,
+and add pieces of common chalk until effervescence ceases; then filter
+through cotton cloth and evaporate it by placing it in all earthen or
+porcelain dish, over a slow fire, to the consistency of a syrup. When
+cooling, large prismatic crystals of chloride of calcium are formed. These
+must be quickly dried by pressing between folds of blotting paper and kept
+carefully excluded from the air, as it readily attracts hydrogen. For most
+daguerreotype purposes, the syrup may be at once evaporated to dryness.
+This is frequently placed in the iodine coating box for the purpose of
+keeping the atmosphere dry. It is so easily made that every operator can
+provide himself with it in a short time, and at little expense.
+</p>
+
+<p>
+Chloride of Gold.&mdash;Is prepared by dissolving gold in aqua regia, a
+composition of one part of nitric to two parts of muriatic acid. Gold foil
+is the best for our purposes; coin, however, answers, in most cases, for
+the daguerreotype operator, as the alloy, being so slight is not noticed
+in the gilding process. When the latter is used, it will facilitate the
+operation to beat it out, forming a thin sheet, and then cutting in small
+strips. Where purity is required, foil is better. The gold is placed in
+three or four times its own weight of the above acids. For this purpose,
+an evaporating dish is best (a common saucer will do); a moderate heat may
+be applied to favor the action. The mixture should be stirred often with a
+glass rod; care should be observed not to apply too much heat, for at a
+temperature of about 300 deg. the chlorine would be expelled and leave a
+metallic precipitate, which would require re-dissolving. Acid may at any
+time be added if necessary to dissolve the gold, but it is advisable to
+add as little excess as possible, as it would require more time to
+evaporate. After all the gold has dissolved, and the liquid assumes a deep
+red color, the solution should be allowed to cool, being stirred nearly
+all the time. This salt is of a reddish-brown color. It is rarely we find
+in our market good chloride of gold, as common, salt is used for the bulk;
+and when the bottles are labelled &ldquo;15 grains,&rdquo; &ldquo;20 grains,&rdquo; nine-tenths do
+not in reality contain exceeding five grains of chloride of gold. The salt
+is mixed with the above solution when it is cooling, and gives bright
+yellow crystals, which some of our uninformed operators conceive to be the
+best quality.
+</p>
+
+<p>
+Chloride of Silver.&mdash;(Oxide of Silver.)&mdash;Take any quantity of silver coin
+or other silver, roll or hammer it thin; cut in small pieces. This in
+order to save time. Put the silver in a glass or earthen vessel (Florence
+flask is best); pour in nitric acid and water, about three parts of the
+former to one of the latter. The operation of cutting up the silver may be
+facilitated by applying a gentle heat. This blue solution consists of
+oxide of silver and oxide of copper, both combined with nitric acid.
+Should the operator wish a pure solution of silver, which, however, is not
+always used, he may obtain it in the following manner:
+</p>
+
+<p>
+To separate the two metals contained in the above solution from each
+other, put some bright copper coins into the solution and set it aside in
+a warm place for three or four days, occasionally giving it a circular
+motion. The separated laminae are pure silver, which is to be digested
+with ammonia until it ceases to be colored blue. The silver, after being
+washed and dried, is again dissolved in nitric acid, and the liquid,
+diluted with water, is kept as solution, of silver.
+</p>
+
+<p>
+Either of the above solutions (the one of oxide of silver and copper, and
+the pure silver solution) may be prepared for use by putting them in a
+bottle, with a quantity of water, and adding common fine salt, you obtain
+a white curdy precipitate of chloride of silver. No matter how much salt
+is used, provided enough be added to throw down all the chloride of
+silver. This solution should be well agitated and then allowed to stand
+for a few minutes; thus the white precipitate is in the bottom of the
+bottle. When the water has become clear, pour it off with care, leaving
+the sediment behind, then add a fresh quantity of clean water, shake, let
+settle, and pour off as before. Repeat the same for several times, and the
+excess of salt will disappear, leaving the white precipitate, which may be
+drained of the water and dried in the dark, and kept free from light and
+air.
+</p>
+
+<h3>
+CYANIDE OF POTASSIUM.
+</h3>
+
+<p>
+Cyanide of Potassium.&mdash;This important article is worthy the undivided
+attention of every Daguerreotypist. I here give Mr. Smee&rsquo;s process for its
+preparation. This is from that author&rsquo;s work entitled, &ldquo;Electro
+Metallurgy,&rdquo; American edition:
+</p>
+
+<p>
+&ldquo;The cyanide of potassium, so often alluded to while treating of the
+metallo-cyanides, may be formed in several ways. It may be obtained by
+heating to a dull redness the yellow ferrocyanate of potash, in a covered
+vessel, filtering and rapidly evaporating it. The objection to this
+method, however, is that without great care the whole of the ferrocyanate
+is not decomposed, a circumstance which much reduces its value for
+electro-metallurgy. By boiling, however, the ignited residue with spirits
+of wine this difficulty is said to be overcome, as the ferrocyanate is
+absolutely insoluble in that menstruum, while the cyanuret, at that heat,
+freely dissolves, and is as easily re-deposited on cooling.
+</p>
+
+<p>
+&ldquo;There is, however, a much better process by which this salt may be
+formed, viz. by simply transmitting hydrocyanic acid through potassium.
+Although the modes of making this acid are very numerous, there is but one
+which is likely to be employed on a very large scale, and that is its
+formation from the yellow ferrocyanate by means of sulphuric acid. This
+process is performed as follows: any given weight of the yellow salt is
+taken and dissolved in about five times its weight of water; this is
+placed in a retort, or some such analogous vessel, to which is then added
+a quantity of strong sulphuric acid, twice the weight of the salt, and
+diluted with three or four times its quantity of water. A pipe is carried
+from the neck of the retort to the receiving bottle, which should be kept
+as cool as possible.
+</p>
+
+<p>
+&ldquo;For small operations, those invaluable vessels, Florence flasks, answer
+well: a bent tube being connected at one end to its month, the other
+passing into the second vessel; heat should be cautiously applied by means
+of an Argand lamp, a little vessel of sand being placed under the flask,
+which helps the acid to decompose the salt. Prussic acid is then generated
+and passes through the tube to the recipient vessel, which is to be
+charged with liquor potassae.
+</p>
+
+<p>
+&ldquo;When the potash is saturated, the operation is completed. The Germans
+recommend a strong, alcoholic solution of potassa to be used in the second
+vessel, for in this case, the hydrocyanic or prussic acid combines with
+the potassa, forming a hydrocyanate of potassa, or, the water being
+abstracted, the cyanuret of potassium, which spontaneously precipitates,
+on the saturation of the fluid, the cyanuret, being insoluble in strong
+alcohol. The ferrocyanate of potash may be considered as containing three
+equivalents of hydrocyanic acid, two of potash and one of iron; but,
+unfortunately, we can only obtain half the acid from the salt, owing to
+the formation of a compound during its decomposition which resists the
+action of the acid. The decomposition of this salt taking 2 equivalents or
+426 grains (to avoid fractions) would afford 3 equivalents or 81 grains of
+hydrocyanic, or prussic acid, capable of forming 198 grains of cyanuret of
+potassium, while in the retort there would remain 384 grains or 3
+equivalents of bisulphate of potash, and 1 equivalent or 174 grains of a
+peculiar compound, said to contain 3 equivalents of cyanogen, 1 of
+potassium, and one of iron (Pereira). It is manifest that, but for this
+later compound, we might double the quantity of hydrocyanic acid from the
+yellow salt.&rdquo;
+</p>
+
+<p>
+The decomposition just described is the one usually received; but too much
+reliance must not be placed on its accuracy, for the analysis of the
+several compounds is too difficult for the results to be fully admitted.
+The residue left in the retort speedily turns to one of the blues,
+identical with, or allied to, Prussian blue. This is at best a
+disagreeable process to conduct, for the hydrocyanic acid formed adheres
+so strongly to the glass, that, instead of being freely given off, bubbles
+are evolved suddenly with such explosive violence as occasionally to crack
+the vessel. This may be remedied as far as possible by the insertion of
+plenty of waste pieces of platinum&mdash;if platinized, so much the better, as
+that facilitates the escape of the gas. The heat should be applied to
+every part of the vessel, and the flame should not be allowed to play upon
+one single part alone. Large commercial operations are performed in green
+glass or stone-ware retorts.
+</p>
+
+<p>
+&ldquo;Now for one word of advice to the tyro: Remember that you are working
+with prussic acid; therefore, never conduct the process in a room, the
+fumes being quite as poisonous as the solution of the acid itself;
+moreover, have always a bottle of ammonia or chlorine by your side, that
+should you have chanced to inhale more than is pleasant, it will be
+instantly at hand to counteract any bad effects. It is stated by Pereira,
+that a little sulphuric acid or hydroferrocyanic acid passes to the outer
+vessel, but probably the amount would be of no consequence for
+electro-metallurgy, otherwise, it might be as well to use a Woulfe&rsquo;s
+apparatus, and discard the salt formed in the first vessel. To the large
+manufacturer it may be worth considering whether some other
+metallo-cyanuret, formed in a similar manner to the ferrocyanuret, might
+not be more advantageously employed, because the residue of the process
+last described contains a large quantity of cyanogen which the acid is
+unable to set free.
+</p>
+
+<p>
+&ldquo;There are other modes of procuring prussic acid, besides the one which
+has been so tediously described; but these are found to be more expensive.
+The only one which I shall now notice is the process by which it is
+obtained from bicyanide of mercury. The bicyanide of mercury itself is
+formed when peroxide of mercury is digested with Prussian blue, the
+peroxide of mercury abstracting the whole of the cyanogen from the blue,
+and leaving the oxides of iron at the bottom of the vessel. The solution
+may be evaporated to dryness, and one part of the salt dissolved in six of
+water; one part of muriatic acid, sp. gr. 1.15, is then added, and the
+solution distilled, when the whole of the hydrocyanic acid passes over,
+and by being conducted into a solution of potassa, as in the former
+process, forms cyanuret of potassium. This process, though easier than the
+first described, is rather given as a resource under peculiar
+circumstances than as one to be adopted by the large manufacturer. The
+expense is the only objection, but in a small quantity this cannot be a
+consideration.
+</p>
+
+<p>
+&ldquo;In giving this very rough outline of the general mode of forming salts,
+the minutiae necessary for chemical work have altogether been avoided, and
+those parts alone are entered upon which are more immediately necessary
+for the electro metallurgist to know and practice for himself. This will
+account for the long description of the cyanuret of potassium, while the
+preparation of the equally important and even more used acids, the
+sulphuric, muriatic, etc., commonly found in commerce, are altogether
+neglected.
+</p>
+
+<p>
+&ldquo;In using solutions of cyanide of potassium, the workman should not
+immerse his arms into them, otherwise it occasionally happens that the
+solution produces very troublesome eruptions over the skin.&rdquo;
+</p>
+
+<h3>
+HYPOSULPHITE OF SODA.
+</h3>
+
+<p>
+Hyposulphite of Soda.&mdash;This salt forms one of the important chemicals for
+the Daguerreotype operator. Its application to this art is of an
+interesting nature. It is used to dissolve the sensitive salt of silver
+which remains unchanged during the exposure in the camera. It has the
+property of readily dissolving the chloride, bromide and iodide of silver.
+It should be pure and free from sulphuret of sodium; should this last be
+present, it will cause brown spots of sulphurated silver upon the
+Daguerreotype impression. This annoyance is a great source of complaint
+from many operators, and ever will be, so long as it is prepared by men
+who have no reputation to lose, and whose eyes are blinded by the
+&ldquo;Almighty Dollar.&rdquo;
+</p>
+
+<p>
+A good article may be prepared as follows:
+</p>
+
+<p>
+&ldquo;Mix one pound of finely pulverized carbonate of soda with ten ounces of
+flowers of sulphur, and heat the mixture slowly in a porcelain dish till
+the sulphur melts. Stir the fused mass, so as to expose all its parts
+freely to the atmosphere, whereby it passes from the state of a sulphuret,
+by the absorption of atmospheric oxygen, into that of a sulphite, with the
+phenomenon of very slight incandescence. Dissolve in water, filter the
+solution, and boil it immediately along with flowers of sulphur. The
+filtered concentrated saline liquid will afford, on cooling, a large
+quantity of pure and beautiful crystals of hyposulphite of soda.&rdquo;
+</p>
+
+<p>
+Hyposulphite of Gold.&mdash;This compound salt is by a few considered
+preferable to the chloride of gold, but our experience has induced us to
+use the latter, believing we are enabled to produce a more brilliant and
+warm-toned impression with it. When the hyposulphite of gold is used in
+gilding, it requires less heat and a longer application, as there is some
+danger of producing a glossy scum over some parts of the surface of the
+plate. I prepare this salt as follows:
+</p>
+
+<p>
+Dissolve one part chloride of gold and four parts hyposulphite of soda in
+equal quantities of distilled water: pour the gold into the hyposulphite
+solution, in the same manner as in mixing the gilding solution; let it
+stand until it becomes limpid; filter and evaporate to dryness.
+Re-dissolve and add a few grains of burnt alum.
+</p>
+
+<p>
+After standing a few hours, filter and evaporate again. If not
+sufficiently pure, repeat the crystallization until it is so. For gilding,
+dissolve in water and use in the same manner as the common gilding
+solution.
+</p>
+
+<p>
+N.B.&mdash;The four following mixtures were employed in Neipce&rsquo;s process in his
+earliest experiments:
+</p>
+
+<p>
+Aqueous Solution of Bichloride of Mercury.&mdash;Eight grains of bichloride of
+mercury in 10,000 grains of distilled water.
+</p>
+
+<p>
+Solution of Cyanide of Mercury.&mdash;A flask of distilled water is saturated
+with cyanide of mercury, and a certain quantity is decanted, which is
+diluted with an equal quantity of distilled water.
+</p>
+
+<p>
+Acidulated White Oil of Petroleum.&mdash;This oil is acidulated by mixing with
+it one tenth of pure nitric acid, leaving it for at least 48 hours,
+occasionally agitating the flask. The oil, which is acidulated, and which
+then powerfully reddens litmus paper, is decanted. It is also a little
+colored, but remains very limpid.
+</p>
+
+<p>
+Solution of Chloride of Gold and Platinum.&mdash;In order not to multiply the
+solutions, take the ordinary chloride of gold, used for fixing the
+impressions, and which is composed of 1 gramme of chloride of gold and 50
+grains of hyposulphate of soda, to a quart of distilled water.
+</p>
+
+<p>
+With respect to chloride of platinum, 4 grains must be dissolved in 3
+quarts of distilled water; these two solutions are mixed in equal
+quantities.
+</p>
+
+<p>
+Acids.&mdash;I shall not go into the preparations of the various acids employed
+in the Daguerreotype. This would be useless to the operator, as there are
+few, if any, that it would be advisable to prepare. It is only necessary
+for the experimenter to be made acquainted with their properties, and this
+in order to prevent any haphazard experiments, which are too common among
+operators. Any person who may be desirous to try an experiment, should
+first study the agents he wishes to employ. By so doing much time and
+money will be saved; while the searcher after new discoveries would rarely
+become vexed on account of his own ignorance, or be obliged to avail
+himself of the experience of others in any department of science.
+</p>
+
+<p>
+Nitric Acid&mdash;Exists in combination with the bases, potash, soda, lime,
+magnesia, in both the mineral and vegetable kingdoms, and is never found
+insoluble. It has the same constituents as common air, but in different
+proportions. The strongest nitric acid contains in every pound, two and a
+quarter ounces of water. Pure nitric acid is colorless, with a specific
+gravity of 1.5, and boiling at 248 deg.. It is a most powerful oxidizing
+agent, and is decomposed with more or less rapidity, by almost all the
+metals, to which it yields a portion of its oxygen.
+</p>
+
+<p>
+The nitric acid of commerce, is generally the article used by the
+Daguerreotypist. This usually contains some chlorine and sulphuric acid.
+It is obtained by the distillation of saltpetre with sulphuric acid. It is
+employed in the Daguerreotype process for dissolving silver, preparing
+chloride or oxide, nitrate of silver, [the former used in galvanizing,]
+and in combination with muriatic acid for preparing chloride of gold, used
+in gilding. It is also used by some for preparing the plate.
+</p>
+
+<p>
+Acidulated Solution.&mdash;This solution is used for cleaning the surface of
+the Daguerreotype plate. It has the property of softening the silver, and
+bringing it to a state in which it is very susceptible of being either
+oxidized or iodized, hence it contributes to increase the sensibility of
+the plate. The proportions are to one drop of acid add from 15 to 20 drops
+of water, or make the solution about like sharp vinegar to the taste.
+</p>
+
+<p>
+Nitro-Muriatic Acid.&mdash;Aqua Regia is a compound menstruum invented by the
+alchemists for dissolving gold. It is composed of colorless nitric acid
+(aqua-fortis) and ordinary muriatic acid; the mixture is yellow, and
+acquires the power of dissolving gold and platinum. These materials are
+not properly oxidized; it nearly causes their combination with chlorine,
+which is in the Muriatic acid.
+</p>
+
+<p>
+Hydrochloric Acid (Muriatic Acid).&mdash;This acid forms a valuable addition to
+the chemicals employed by the practical Daguerreotypist. This acid is
+formed by acting upon common salt (which is chloride of sodium) by
+concentrated sulphuric acid. The water of the acid is decomposed, and its
+hydrogen combines with the chloride of the salt to form muriatic acid, and
+this unites with the sulphuric acid to form sulphate of soda; 60 parts of
+common salt and 49 parts of concentrated sulphuric acid, afford, by this
+mutual action, 37 parts of muriatic acid and 72 parts of sulphate of soda.
+The muriatic acid of commerce has usually a yellowish tinge, but when
+chemically pure it is colorless. The former is commonly contaminated with
+sulphurous acid, sulphuric acid, chlorine, iron, and sometimes with
+arsenic.
+</p>
+
+<p>
+Muriatic acid, from the fact of the presence of the chlorine, is used in
+the Daguerreotype process for dissolving gold, and in combination with
+various accelerators. Its presence can be detected by ammonia. A strip of
+paper dipped in this and waved to and fro will emit a thick white smoke if
+the acid vapor be in the atmosphere. The ammonia neutralizes the acid
+fumes. By reversing the experiment we can determine whether vapor of
+ammonia be in the air, and also deprive these suffocating and dangerous
+gases of their injurious properties, and remove them from the air. Every
+Daguerreotype operator should be furnished with, at least, a six ounce
+bottle of aqua ammonia. Its operation is very nearly the same on bromine
+and iodine vapor.
+</p>
+
+<p>
+Hydrofluoric Acid (Fluorohydric Acid).&mdash;This acid is used to form some of
+the most volatile and sensitive compounds employed in the Daguerreotype.
+It is one of the most dangerous bodies to experiment with: it is volatile
+and corrosive, giving off dense white fumes in the air. It combines with
+water with great heat. At 32 deg. it condenses into a colorless fluid,
+with a density 1.069. It is obtained from decomposition of fluorspar by
+strong sulphuric acid. It readily dissolves the silica in glass, and
+consequently cannot be kept in a vessel of that material. It is prepared
+and kept in lead. It is employed in accelerators on account of its
+fluorine.
+</p>
+
+<p>
+One small drop on the tongue of a dog causes death. The operator who
+wishes to use it should pour some of the liquid for which he intends it
+into a graduate, or other vessel, and then add the desired quantity of
+acid. If by accident any of the spray should fall upon the skin, it should
+at once be copiously drenched with water.
+</p>
+
+<p>
+Sulphuric Acid.&mdash;There are two sorts of this acid: one is an oily, fuming
+liquid; this is made in Nordhausen, in Saxony, and is commonly called
+&ldquo;Nordhausen sulphuric acid,&rdquo; or oil of vitriol. The other which is the
+kind used in connection with the Daguerreotype, is common sulphuric acid.
+It is somewhat thinner, and when undiluted is not fuming. This acid may be
+obtained in a solid and dry state, called anhydrous sulphuric acid.
+</p>
+
+<p>
+The common sulphuric acid is made by burning sulphur, which forms
+sulphurous acid. To convert this into sulphuric acid and gain more oxygen,
+nitric acid, which is rich in that body, is added. It forms a limpid,
+colorless fluid, of a specific gravity of 1.8. It boils at 620 deg.; it
+freezes at 15 deg. It is acrid and caustic, and intensely acid in all its
+characters, even when largely diluted.
+</p>
+
+<p>
+Its attraction for basis is such that it separates or expels all other
+acids, more or less perfectly, from their combinations. Its affinity for
+water is such that it rapidly absorbs it from the atmosphere, and when
+mixed with water much heat is evolved. It acts energetically upon animal
+and vegetable substances, and is a poisonous, dangerous substance to get
+on the skin. It is a powerful oxidizing agent; hence its use in the
+galvanic battery, for which purpose it is mostly used by the
+Daguerreotypist. The fumes of this being so much more offensive than
+nitric acid, the latter is sometimes used. It is also employed in some of
+the more sensitive accelerators.
+</p>
+
+<h3>
+ACCELERATING SUBSTANCES.
+</h3>
+
+<p>
+Remarks on the Accelerating substances Used in the Daguerreotype.&mdash;I have
+now arrived at a point in this work, where the eye of the Daguerreotype
+public will intently search for something new. This search will prove in
+vain, at least so far as regards those who have enjoyed and embraced the
+opportunities for studying the principles of our art. Every experienced
+operator has in a degree become familiar with the mechanical uses of all
+the agents employed, while I fear but few understand the properties, and
+laws governing those properties, which are so indispensable to produce an
+image impressed upon the silver surface.
+</p>
+
+<p>
+There are three substances which form the bases for producing a
+Daguerreotype; silver, iodine and bromine. Each forms a separate body
+which is indispensable to the operators success as the art is now
+practiced in America. With these three, compounds of great variety are
+formed.
+</p>
+
+<p>
+The silver surface is first thoroughly cleaned and freed from all organic
+matter, then exposed to vapor of iodine, producing an iodide of silver.
+The plate upon which is this salt, is again exposed to the vapor of
+bromine, forming a bromo-iodide of silver, a salt also.
+</p>
+
+<p>
+As most of the various accelerators are compounds of bromine, with either
+chlorine or fluorine combination, they partake somewhat of the nature of
+these latter, giving results which can be detected by the experienced
+operator. Thus muriatic acid is added for its chlorine, which can
+generally be detected by the impression produced, being of a light, soft,
+mellow tone, and in most cases presenting a brilliant black to that
+colored drapery. Those who wish to experiment with agents for accelerating
+substances, should first study to well understand their peculiar nature
+and properties; as well, also, to endeavor to find out what will be the
+probable changes they undergo in combination as an accelerator. This
+should be done before making the experiments. From the foregoing it will
+be seen that numerous compounds are formed from the same basis, and,
+consequently, it would be a waste of time and a useless appropriation to
+devote more of our space than is necessary to give the principal and most
+reliable combination.
+</p>
+
+<p>
+In America, the words &ldquo;Quick&rdquo; and &ldquo;Quick Stuff,&rdquo; are more generally used
+for and instead of the more proper names, &ldquo;Sensitives,&rdquo; or &ldquo;Accelerators,&rdquo;
+etc. As it has by use become common, I frequently use it in this work.
+</p>
+
+<p>
+Liquid Accelerator, No. 1.&mdash;This mixture was used by me in 1849, and is
+given as it appeared in my &ldquo;System of Photography,&rdquo; published at the above
+date:
+</p>
+
+<p>
+Take pure rain or distilled water, one quart, filter through paper into a
+ground stopper bottle, and add, for warm weather, one and a half ounce
+chloride of iodine; or for cold, one ounce; then add one ounce bromine,
+and shake well. Now with care not to allow the vapor to escape, add drop
+by drop, thirty drops of aqua ammonia, shaking well at each drop. Care
+must be taken not to add more at a time, as it evokes too much heat. This
+mixed, in equal proportions with John Roach&rsquo;s quick, forms an excellent
+chemical combination. For this purpose, take one and a half ounce of each,
+to which add ten ounces water, for warm weather, or from six to seven for
+cold. Pour the whole into a large box, and it will work from two to four
+months. I am now using (1849) one charged as above which has been in
+constant use for three months, and works uniformly well. The above is
+right for half or full size boxes, but half of it would be sufficient for
+a quarter size box.
+</p>
+
+<p>
+Coat to the first shade of rose over iodine, change to a deep rosy red
+over quick, and black about one tenth the first.
+</p>
+
+<p>
+I would not now recommend the addition of &ldquo;John Roach&rsquo;s quick,&rdquo; as I
+believe equally good results can be produced without it. This liquid is
+now used by many, and is very good for taking views.
+</p>
+
+<p>
+Lime Water Quick.&mdash;This mixture is more used at present than all the other
+liquids ever introduced. It produced the most uniform results, giving the
+fine soft tone so characteristic in pictures produces from accelerators
+containing chlorine. To one quart of lime water (this can be had of any
+druggist) add one and a half ounce of pulverized alum. This should be
+shook at intervals for twenty&mdash;four hours; then add one ounce of chloride
+of iodine and three fourths ounce of bromine.
+</p>
+
+<p>
+Lime Water.&mdash;This is easily prepared by putting lime into water, say a
+piece of quick-lime about the size of an egg into one quart of water. This
+should be shook occasionally for two or three days and allowed to settle,
+when the water can be poured off and used.
+</p>
+
+<p>
+Use.&mdash;To one part of quick add six parts of water; coat to a light yellow
+over the iodine, to a rose color over the quick, and recoat about one
+tenth. The above coating may be increased or diminished, it matters not,
+so that there is not too much, and the proper proportions are preserved.
+Some add to the above a small quantity of magnesia, say about a
+teaspoonful to the quart of liquid.
+</p>
+
+<p>
+Liquid Accelerator, No. 2.&mdash;The following was for a long time used by one
+of the first houses in the United States, and probably was one of the
+first liquids ever used. It produces a fine-toned picture, but is not
+considered as sure as the lime water quick:
+</p>
+
+<p>
+Take rain water one quart, add pulverized alum until it is a little sour
+to the taste, and a small piece, say one half inch square, of magnesia.
+Filter through paper, and add chloride of iodine one half ounce, bromine
+sufficient to take it up, which is a little less than half an ounce.
+</p>
+
+<p>
+Charge with one of quick to six of water; coat over iodine to a soft
+yellow, nearly, but not quite, bordering on a rose; over quick to a dark
+purple, or steel, and back one sixth to one tenth.
+</p>
+
+<p>
+Wolcott&rsquo;s American Mixture.&mdash;Van Loan Quick.&mdash;This mixture was first
+formed and used by T. Wolcott &amp; Johnson and gained great celebrity for
+its productions. I have now a bottle hermetically sealed that contains
+about a half ounce of this mixture prepared in 1841 by John Johnson, now a
+resident of this city, and the former partner of Mr. Wolcott. The
+preparation of this mixture, as furnished by Mr. Johnson himself, is given
+as follows:
+</p>
+
+<p>
+&ldquo;One part of bromine, eight parts of nitric acid, sixteen parts of
+muriatic acid, water one hundred parts. This mixture should be allowed to
+stand for several days; it improves by age.
+</p>
+
+<p>
+&ldquo;Use.&mdash;A few drops say, 6 to 12, of this mixture, should be put into about
+6 or 8 ounces of water; it will require frequent replenishing by the
+addition of a few more drops. The plate should be coated over the dry
+iodine to a red just bordering on a slate, and then exposed to the mixture
+only sufficiently long to change the color. If this is not done in less
+than six seconds it is not strong enough. Re-coat over the iodine full one
+fourth as long as first coating.&rdquo;
+</p>
+
+<p>
+This exceedingly volatile compound is difficult to control from its
+instability; it is but little used. The impressions successfully produced
+by this mixture are very brilliant, and possess a pleasing peculiarity.
+</p>
+
+<h3>
+DRY SENSITIVES.
+</h3>
+
+<p>
+Hydrate of Lime.&mdash;The operation by which water is combined with lime is
+called slaking. Take a piece of quick lime, common lime used in mortar,
+and immerse it in warm water for about fifteen seconds; then place it in
+an iron or tin vessel. It will soon begin to swell, evolving a great deal
+of heat and emitting steam, and soon falls into a fine powder, hydrate of
+lime. This should be well stirred and allowed to cool, and then bottled in
+order to prevent it from giving off the hydrate and recovering the
+carbonic acid from the atmosphere. The last is detrimental to its use with
+bromine, and is one cause of the complaint that &ldquo;it will not take
+bromine.&rdquo; The hydrate of lime should, not be dried over a heat, as has
+been supposed by many, for in that case the hydrogen is expelled and it
+returns to a carbonate. It is advisable to cool it in a damp place like a
+ground cellar. Much of the lime in our market will not, except it be quite
+damp, combine with the bromine. This is owing to impurities. Nothing is
+equal to oyster-shell lime, which I use altogether.
+</p>
+
+<p>
+Bromide of Lime.&mdash;In preparing large quantities of this, we adopt the
+following method: Fill a four-quart bottle about two-thirds full of
+hydrate of lime; pour into this about one or two ounces of bromine; then
+shake well, add more of the bromine, shake well and let it stand for a few
+hours, adding sufficient bromine to give it a fine red color. It is better
+when kept in the large bottles, as it forms a more perfect combination: in
+other words it improves by age.
+</p>
+
+<p>
+Use.&mdash;Coat over the iodine to a rose red and then over this mixture to a
+purple or slate; recoat over the first about one fourth as long as first
+coating.
+</p>
+
+<p>
+Gurneys American Compound.&mdash;Of this compound there are two combinations,
+one for use, when the temperature of the atmosphere is above 65 or 70
+deg., and the other at a lower temperature. The first is called No. 1, the
+second No. 2.
+</p>
+
+<p>
+No. 1 is prepared by placing hydrate of lime in a bottle, say to three
+quarts of the hydrate of lime, add one ounce of pulverized burnt alum, and
+as much chloride of lime as can be put on a quarter of a dollar, and from
+15 to 30 grains of dry pulverized iodine, or enough to change the color of
+the hydrate of lime, to the slightest possible tinge of yellow. There had
+better be less than carry the color to a deeper shade. The object of using
+the iodine is to form a compound with bromine that is not so volatile as
+the bromine itself. No matter how little iodine is combined with the
+bromine, the vapors possess their relative proportion; hence, only enough
+iodine to prevent &ldquo;flaring,&rdquo; or as it is often termed a &ldquo;scum-coating,&rdquo; is
+used. The iodine should be thoroughly combined with the lime, which will
+take about one or two days. Should add bromine the same as in bromide of
+lime, until the compound assumes a light red color.
+</p>
+
+<p>
+No. 2 is prepared in the same manner as No. 1, except the addition of the
+iodine, which is omitted.
+</p>
+
+<p>
+Use.&mdash;No. 1. Coat over the iodine to a bright yellow color, then over the
+compound, No. 1, to red color, recoat over iodine, about one sixth as
+long, as the time occupied in first coating.
+</p>
+
+<p>
+No. 2. Coat over iodine same as above, except recoat over the iodine about
+one fourth to one half as long as first coating.
+</p>
+
+<p>
+Dry Quick, No. 1.&mdash;Bromide of Lime and Starch.&mdash;The following compound
+forms an excellent accelerator, and is used by many. It is claimed for
+this preparation, that it will hold the bromine longer than others where
+starch is not employed. As regards this claim we do not think it can be
+substantiated. Our experience in practice has led us to the conclusion
+that there is no great difference as respects durability, but there is
+some little difference as regards the tone of the impressions produced by
+its use.
+</p>
+
+<p>
+To one quart of hydrate of lime add one quart of finely pulverized starch.
+To this mixture add bromine, until it assumes a deep yellow or pink color.
+</p>
+
+<p>
+Starch may be added to any of the dry mixtures.
+</p>
+
+<p>
+Use.&mdash;Coat over the iodine to a deep yellow, then over this quick to a red
+color, recoat about one sixth of the time of first coating.
+</p>
+
+<p>
+I will here again remark, that the exact color of the coating is not
+essentially provided a proper proportion is preserved.
+</p>
+
+<p>
+I have never seen it stated, though it be a fact worthy of note, that a
+proportionate time for coating over the iodine and accelerator, will not
+answer. For example: if a plate exposed to the vapor of iodine be
+perfectly coated in sixteen seconds, and then exposed to an accelerator,
+(not having iodine in its combination) receives its coating in four
+seconds, it will be found that a proper proportionate coating cannot be
+preserved by adopting, a proportion of time, but on the contrary, the time
+will diminish; for exposure over the accelerator, as in the above example,
+if it be desired to coat the plate with twice as much iodine as in the
+above example, the time would be, over iodine thirty-two seconds, and over
+the accelerator (to possess a proper proportion) from six to seven
+seconds. Hence it is that many inexperienced operators, when wishing to
+vary their usual manner of coating, fail in producing a favorable result.
+They coat calculating a proportion of time when they should not.
+</p>
+
+<p>
+Dry Quick, No. 2.&mdash;Bromide of Lime and Magnesia.&mdash;To one quart of hydrate
+of lime add one quart of magnesia, and mix them well together; add bromine
+same as in preparing bromide of lime; coat the same as over dry quick No.
+1. This combination produces very uniform results, and is worked with much
+success by beginners.
+</p>
+
+<p>
+Chloro-Bromide of Lime.&mdash;To the bromide of lime add chloride of bromine
+until the mixture becomes a pale yellow color, resembling sulphur. It
+should be shook well, and enough of the chloride of bromine added to bring
+the compound to a deep blood red color.
+</p>
+
+<p>
+Use.&mdash;Coat over the iodine to a pink color, and then over the above to a
+red, or just changing the color. It should be remembered that accelerators
+containing chlorine do not admit of a great change of color of coating on
+the plate.
+</p>
+
+<p>
+Iodide of Starch.&mdash;This mixture can be employed for coating over in warm
+weather, and prevent the flashing resulting at high temperatures. It may
+be used the same as the iodide alone.
+</p>
+
+<p>
+To six ounces of finely pulverized starch, add one fourth ounce of dry
+iodine.
+</p>
+
+<p>
+Use.&mdash;Same as the dry iodine alone.
+</p>
+
+<p>
+The same combination may be made with lime, magnesia and other substances.
+</p>
+
+<p>
+Concentrated Solution of Iodine for First Coating.&mdash;It may appear strange
+to some of our old operators that an aqueous solution of iodine can be
+used for coating the plate and forming the iodide of silver. It has long
+been a cry among most operators that it is impossible to succeed when the
+iodine box contains dampness. Now this is a great mistake, and we will
+here state that in all cases where dampness appears upon a properly
+prepared Daguerreotype plate, it is the result of a different temperature
+of the metal from the air which surrounds it. Mr. Senter, of Auburn, was
+the first of our operators who used a solution of iodine for coating the
+plate, and we several years since saw his results, which would rival the
+production of any other operator. A concentrated solution of iodine is
+prepared by putting into a common bottle two thimblesful of hyposulphite
+of soda and a rather larger quantity of iodine, so that there may be more
+than sufficient. Add to it about 40 ounces of common water (heated to 60
+or 70 degrees), by little and little, moving, the bottle to warm it, for
+fear of breaking. After shaking it a short time, the water is rapidly and
+strongly colored. The solution should be poured into a bottle with a
+ground stopper, and when cool used for iodizing.
+</p>
+
+<p>
+A solution of sufficient strength can be made by moistening or just
+covering the iodine with water.
+</p>
+
+<p>
+Chloride of Iodine as an Accelerator.&mdash;This is probably one of the best
+accelerators that can be used for coating the plate for taking views; it
+works too slow, however, to meet the wants of the operating room, yet its
+use was formerly, for a long time, adhered to by some of our best
+professors. In producing views with this, we are successful in obtaining
+well-developed impressions, with a depth of tone and richness of
+appearance not to be met with in the productions of any other substances.
+I give its use as furnished me by an old and experienced operator, and
+published in Humphrey&rsquo;s Journal, vol. i. p. 180:
+</p>
+
+<p>
+&ldquo;As the process of using chloride of iodine may be of interest to some of
+our subscribers, I take pleasure in giving the following manipulation. To
+one ounce of chloride of iodine add two ounces of water; place this
+mixture in a coating-box, the same as quick stuff; coat the plate with dry
+iodine to a light yellow, or lemon color; then bring the coating to a deep
+pink over the chloride. The plate must be recoated over the dry iodine.&rdquo;
+</p>
+
+<p>
+This combination has been very successfully used in one of our most
+extensive establishments in this city, and the superiority of the pictures
+produced by it was considered as an equivalent for the additional time
+required to bring out the impressions.
+</p>
+
+<p>
+Chlorine as an Accelerator.&mdash;I shall here refer to but a single experiment
+in which I employed chlorine gas for coating the plate. I was provided
+with a retort, the neck of which was fitted to the jar of my coating-box,
+through a hole drilled for its reception. This was fitted perfectly tight
+in my coating-box. I placed some pure undiluted bromine water and the
+agents necessary for producing chlorine gas (in small quantity) in the
+retort. The result was that my first experiment produced an impression
+completely solarized in all its parts by an exposure of four seconds of
+time, which would have required an exposure of twenty seconds to produce a
+perfectly developed impression by the usual process.
+</p>
+
+<p>
+Another trial immediately produced one of the finest toned impressions I
+ever saw, perfectly developed in one second of time.
+</p>
+
+<p>
+My next two or three experiments proved total failures. I was unable to
+produce even a sign of an impression. By accident my retort was broken,
+and not being in a locality convenient to obtain another, my experiments
+were necessarily suspended.
+</p>
+
+<p>
+My attention was not called to this subject again for several years, when
+I noticed an account of some similar experiments by F. A. P. Barnard and
+Dr. W. H. Harrington, the latter of whom is now of the firm of Dobyns
+&amp; Harrington, of New Orleans.
+</p>
+
+<p>
+From reading this article, I found my own difficulties explained. Too much
+of the chlorine gas was present in my coating jar. I would like to see
+some of our enterprising operators investigate this combination.
+</p>
+
+<p>
+It is a singular fact, that the vapors of bromine and chlorine combining
+upon the iodide of silver, produce a more sensitive coating than when the
+two are combined in solution, as in chloride of bromine solution. Those
+having Humphrey&rsquo;s Journal at hand, can refer to vol. i. p. 142.
+</p>
+
+<p>
+To use Bromine Water or other Accelerators in Hot Weather.&mdash;An excellent
+plan for using bromine water is as follows:
+</p>
+
+<p>
+Fill a two-ounce bottle quarter full of it, and then fill the bottle with
+fine sand, which serves to preserve a low temperature; then place the
+bottle in a porous cup, same as used in the battery; fill this also with
+sand, and close the end with plaster of Paris. Place this in a
+coating-box, and it will be found to act with great uniformity and be
+quite permanent.
+</p>
+
+<p>
+Bromide of Lime, another accelerator, can be used in the same manner,
+except it is, only necessary, when a solid sensitive is used, to mix it
+with the sand without placing it in a bottle. This method is employed with
+great success by a few, who have regarded it as a secret worth keeping.
+</p>
+
+<p>
+A Combination, requiring the Use of only One Coating-box.&mdash;It is often
+wondered by beginners, why some solution requiring only one coating cannot
+be employed. This can be done, but the results are not so satisfactory as
+when two or more are employed. Such an accelerator may be produced by
+adding alcoholic solution of iodine to a solution of chlorate of potash,
+until the latter will take up no more of the former, and to each ounce, by
+measure of this solution, ten drops of a saturated solution of bromide in
+water are added. The solution of chlorate of potash is made by diluting,
+one part of a saturated solution of the salt with ten parts of water. The
+use of the chlorate is simply as a solvent of iodine.
+</p>
+
+<p>
+Fats as Accelerators.&mdash;The use of fats, oils, or greasy substances, has
+been one of the most emphatic prohibitions about the Daguerreotype plate.
+Yet it has been proved that its presence in a small quantity upon the
+silver surface has the effect of reducing the time of exposure in the
+camera from two-thirds to three-fourths. An application may be made as
+follows: Pour sweet oil, or rub beef or mutton fat, on a common buff,
+which is free from all polishing powders. With this, buff a well-cleaned
+plate, and it will leave a scum, which should be mostly removed by using
+another buff, which should be clean. Coat the plate in the usual manner,
+and the result will be a great reduction in the time of exposure in the
+camera. The impression produced upon a plate so prepared presents, when
+coming from the vapor of mercury, a grey, scummy appearance, which, on the
+application of heat in gilding, does not improve; hence its use is not
+generally adopted.
+</p>
+
+<p>
+We have instituted some investigations upon this subject, and in the
+present volume, we shall not refer to it further. Those wishing to learn
+more fully the effect of light upon organic substances will find Robert
+Hunt&rsquo;s &ldquo;Researches on Light&rdquo; an invaluable work.
+</p>
+
+<h2><a name="chap04"></a>CHAPTER IV.</h2>
+
+<h3>
+LIGHT AND OPTICS.
+</h3>
+
+<p class="letter">
+Light&mdash;Optics&mdash;Solar Spectrum&mdash;Decomposition of Light&mdash;Light, Heat, and
+Actinism&mdash;Blue Paper and Color for the Walls of the Operating
+Room&mdash;Proportions of Light, Heat, and Actinism composing a
+Sunbeam&mdash;Refraction&mdash;Reflection&mdash;Lenses&mdash;Copying Spherical
+Aberration&mdash;Chromatic Aberration.
+</p>
+
+<p>
+It is advisable that persons engaging in the Daguerreotype art should have
+at least a little knowledge of the general principles of light and optics.
+It is not the author&rsquo;s design here to give a full treatise on these
+subjects, but he only briefly refers to the matter, giving a few facts.
+</p>
+
+<p>
+It has been well observed by an able writer, that it is impossible to
+trace the path of a sunbeam through our atmosphere without feeling a
+desire to know its nature, by what power it traverses the immensity of
+space, and the various modifications it undergoes at the surfaces and
+interior of terrestrial substances.
+</p>
+
+<p>
+Light is white and colorless, as long as it does not come in contact with
+matter. When in apposition with any body, it suffers variable degrees of
+decomposition, resulting in color, as by reflection, dispersion,
+refraction, and unequal absorption.
+</p>
+
+<p>
+To Sir I. Newton the world is indebted for proving the compound nature of
+a ray of white light emitted from the sun. The object of this work is not
+to engage in an extended theory upon the subject of light, but to recur
+only to some points of more particular interest to the photographic
+operator.
+</p>
+
+<p>
+The decomposition of a beam of light can be noticed by exposing it to a
+prism. If, in a dark room, a beam of light be admitted through a small
+hole in a shutter, it will form a white round spot upon the place where it
+falls. If a triangular prism of glass be placed on the inside of the dark
+room, so that the beam of light falls upon it, it no longer has the same
+direction, nor does it form a round spot, but an oblong painted image of
+seven colors&mdash;red, orange, yellow, green, blue, indigo, and violet. This
+is called the solar spectrum, and will be readily understood by reference
+to the accompanying diagram, Fig. 1.
+</p>
+
+<p class="noindent">
+{133}
+</p>
+
+<p>
+To those who are unacquainted with the theory of light (and for their
+benefit this chapter is given), it may be a matter of wonder how a beam of
+light can be divided.
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig1.gif" width="545" height="304" alt="[Illustration: Fig. 1]" />
+</div>
+
+<p>
+This can be understood when I say, that white light is a bundle of colored
+rays united together, and when so incorporated, they are colorless; but in
+passing through the prism the bond of union is severed, and the colored
+rays come out singly and separately, because each ray has a certain amount
+of refracting (bending) power, peculiar to itself. These rays always hold
+the same relation to each other, as may be seen by comparing every
+spectrum or rainbow; there is never any confusion or misplacement.
+</p>
+
+<p>
+There are various other means of decomposing {134} white light besides the
+prism, of which one of the principal and most interesting to the
+Daguerreotypist is by reflection from colored bodies. If a beam of white
+light falls upon a white surface, it is reflected without change; but if
+it falls upon a red surface, only the red ray is reflected: so also with
+yellow and other colors. The ray which is reflected corresponds with the
+color of the object. It is this reflected decomposed light which prevents
+the beautifully-colored image we see upon the ground glass in our cameras.
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig2.gif" width="502" height="479" alt="[Illustration: Fig. 2]" />
+</div>
+
+<p>
+A sunbeam may be capable of three divisions&mdash;LIGHT, HEAT, and ACTINISM;
+the last causes all the chemical changes, and is the acting power upon
+surfaces prepared to receive the photographic image. The accompanying
+illustration, Fig. 2, will readily bring to the mind of the reader the
+relation of these one to another, and their intensities in the different
+parts of a decomposed sunbeam.
+</p>
+
+<p>
+The various points of the solar spectrum are represented in the order in
+which they occur between A, and B, this exhibits the limits of the
+Newtonian spectrum, corresponding with Fig. 1. Sir John Herschel and
+Seebeck have shown that there exists, beyond the violet, a faint violet
+light, or rather a lavender to b, to which gradually becomes colorless;
+similarly, red light exists beyond the assigned limits of the red ray to
+a. The greatest amount of actinic power is shown at E opposite the violet;
+hence this color &ldquo;exerts&rdquo; the greatest amount of influence in the
+formation of the photographic image.
+</p>
+
+<p>
+(Blue paper and blue color have been somewhat extensively used by our
+Daguerreotype operators in their operating rooms and skylights, in order
+to facilitate the operation in the camera. I fancy, however, that this
+plan cannot be productive of as much good as thought by some, from the
+fact, that the light falling upon the subject, and then reflected into the
+camera, is, coming through colorless glass, not affected by such rays as
+may be reflected from the walls of the operating room; and even if it were
+so, I conceive that it would be injurious, by destroying the harmony of
+shadows which might otherwise occur.) The greatest amount of white light
+is at C; the yellow contains less of the chemical power than any other
+portion of the solar spectrum. It has been found that the most intense
+heat is at the extreme red, b.
+</p>
+
+<p>
+Artificial lights differ in their color; the white light of burning
+charcoal, which is the principal light from candles, oil and gas, contains
+three rays&mdash;red, yellow, and blue. The dazzling light emitted from lime
+intensely heated, known as the Drummond light, gives the colors of the
+prism almost as bright as the solar spectrum.
+</p>
+
+<p>
+If we expose a prepared Daguerreotype plate or sensitive paper to the
+solar spectrum, it will be observed that the luminous power (the yellow)
+occupies but a small space compared with the influence of heat and
+chemical power. R. Hunt, in his Researches on Light, has presented the
+following remarks upon the accompanying illustration:
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig3.gif" width="548" height="558" alt="[Illustration: Fig. 3]" />
+</div>
+
+<p>
+&ldquo;If the linear measure, or the diameter of a circle which shall include
+the luminous rays, is 25, that of the calorific spectrum will be 42.10,
+and of the chemical spectrum 55.10. Such a series of circles may well be
+used to represent a beam from the sun, which may be regarded as an atom of
+Light, surrounded with an invisible atmosphere of Heat, and another still
+more extended, which possesses the remarkable property of producing
+chemical and molecular change.
+</p>
+
+<p>
+A ray of light, in passing obliquely through any medium of uniform
+density, does not change its course; but if it should pass into a denser
+body, it would turn from a straight line, pursue a less oblique direction,
+and in a line nearer to a perpendicular to the surface of that body. Water
+exerts a stronger refracting power than air; and if a ray of light fall
+upon a body of this fluid its course is changed, as may be seen by
+reference to Fig. 4.
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig4.gif" width="342" height="236" alt="[Illustration: Fig. 4]" />
+</div>
+
+<p>
+It is observed that it proceeds in a less oblique direction (towards the
+dotted line), and, on passing on through, leaves the liquid, proceeding in
+a line parallel to that at which it entered. It should be observed that at
+the surface of bodies the refractive power is exerted, and that the light
+proceeds in a straight line until leaving the body. The refraction is more
+or less, and in all cases in proportion as the rays fall more or less
+obliquely on the refracting surface. It is this law of optics which has
+given rise to the lenses in our camera tubes, by which means we are
+enabled to secure a well-delineated representation of any object we choose
+to picture.
+</p>
+
+<p>
+When a ray of light passes from one medium to another, and through that
+into the first again, if the two refractions be equal, and in opposite
+directions, no sensible effect will be produced.
+</p>
+
+<p>
+The reader may readily comprehend the phenomena of refraction, by means of
+light passing through lenses of different curves, by reference to the
+following diagrams:&mdash;
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig5.gif" width="493" height="270" alt="[Illustration: Fig. 5, 6, 7]" />
+</div>
+
+<p>
+Fig 5 represents a double-convex lens, Fig. 6 a double-concave, and Fig. 7
+a concavo-convex or meniscus. By these it is seen that a double-convex
+lens tends to condense the rays of light to a focus, a double-concave to
+scatter them, and a concavo-convex combines both powers.
+</p>
+
+<p>
+If parallel rays of light fall upon a double-convex lens, D D, Fig. 8,
+they will be refracted (excepting such as pass directly through the
+centre) to a point termed the principal focus.
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig8a.gif" width="362" height="198" alt="[Illustration: Fig. 8]" />
+</div>
+
+<p>
+The lines A B C represent parallel rays which pass through the lens, D D,
+and meet at F; this point being the principal focus, its distance from the
+lens is called the focal length. Those rays of light which are traversing
+a parallel course, when they enter the lens are brought to a focus nearer
+the lens than others. Hence the difficulty the operator sometimes
+experiences by not being able to &ldquo;obtain a focus,&rdquo; when he wishes to
+secure a picture of some very distant objects; he does not get his ground
+glass near enough to the lenses. Again, the rays from an object near by
+may be termed diverging rays. This will be better comprehended by
+reference to Fig. 9, where it will be seen that the dotted lines,
+representing parallel rays, meet nearer the lenses than those from the
+point A. The closer the object is to the lenses, the greater will be the
+divergence. This rule is applicable to copying. Did we wish to copy a 1/6
+size Daguerreotype on a 1/16 size plate, we should place it in such a
+position to the lenses at A that the focus would be at F, where the image
+would be represented at about the proper size. Now, if we should wish to
+copy the 1/6 size picture, and produce another of exactly the same
+dimensions, we have only to bring it nearer to the lenses, so that the
+lens D E shall be equi-distant from the picture and the focus, i. e. from
+A to B. The reason of this is, that the distance of the picture from the
+lens, in the last copy, is less than the other, and the divergence has
+increased, throwing, the focus further from the lens.&rdquo;
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig9.gif" width="538" height="200" alt="[Illustration: Fig. 9]" />
+</div>
+
+<p>
+These remarks have been introduced here as being important for those who
+may not understand the principles of enlarging or reducing pictures in
+copying.
+</p>
+
+<p>
+I would remark that the points F and A, in Fig. 9, are termed &ldquo;conjugate
+foci.&rdquo;
+</p>
+
+<p>
+If we hold a double-convex lens opposite any object, we find that an
+inverted image of that object will be formed on a paper held behind it. To
+illustrate this more clearly, I will refer to the following woodcut:
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig10.gif" width="495" height="280" alt="[Illustration: Fig. 10]" />
+</div>
+
+<p>
+&ldquo;If A B C is an object placed before a convex lens, L L, every point of it
+will send forth rays in all directions; but, for the sake of simplicity,
+suppose only three points to give out rays, one at the top, one at the
+middle, and one at the bottom; the whole of the rays then that proceed
+from the point A, and fall on the lens L L, will be refracted and form an
+image somewhere on the line A G E, which is drawn direct through the
+centre of the lens; consequently the focus E, produced by the convergence
+of the rays proceding from A, must form an image of A, only in a different
+relative position; the middle point of C being in a direct line with the
+axis of the lens, will have its image formed on the axis F, and the rays
+proceeding from the point B will form an image at D; so that by imagining
+luminous objects to be made up of all infinite number of radiating points
+and the rays from each individual point, although falling on the whole
+surface of the lens, to converge again and form a focus or representation
+of that point from which the rays first emerged, it will be very easy to
+comprehend how images are formed, and the cause of those images being
+reversed.
+</p>
+
+<p>
+&ldquo;It must also be evident, that in the two triangles A G B and D G E, that
+E D, the length of the image, must be to A B, the length of the object, as
+G D, the distance of the image, is to G B, the distance of the object from
+the lens.
+</p>
+
+<p>
+It will be observed that in the last cut the image produced by the lens is
+curved. Now, it would be impossible to produce a well-defined image from
+the centre to the edge upon a plain surface; the outer edges would be
+misty, indistinct, or crayon-like. The centre of the image might be
+represented clear and sharp on the ground glass, yet this would be far
+from the case in regard to the outer portions. This is called spherical
+aberration, and to it is due the want of distinctness which is frequently
+noticed around the edges of pictures taken in the camera. To secure a
+camera with a flat, sharp, field, should be the object of every operator;
+and, in a measure, this constitutes the great difference in cameras
+manufactured in this country.
+</p>
+
+<p>
+Spherical aberration is overcome by proper care in the formation of the
+lens: &ldquo;It can be shown upon mathematical data that a lens similar to that
+given in the following diagram&mdash;one surface of which is a section of an
+ellipse, and the other of a circle struck from the furthest of the two
+foci of that ellipse&mdash;produces no aberration.
+</p>
+
+<p>
+&ldquo;At the earliest period of the employment of the camera obscura, a
+double-convex lens was used to produce the image; but this form was soon
+abandoned, on account of the spherical aberration so caused. Lenses for
+the photographic camera are now always ground of a concavo-convex form, or
+meniscus, which corresponds more nearly to the accompanying diagram.&rdquo;
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig11.gif" width="320" height="266" alt="[Illustration: Fig. 11]" />
+</div>
+
+<p>
+Chromatic Aberration is another difficulty that opticians have to contend
+with in the manufacturing of lenses. It will be remembered, that in a
+former page (133) a beam of light is decomposed by passing through a glass
+prism giving seven distinct colors&mdash;red, orange, yellow, green, blue,
+indigo and violet.
+</p>
+
+<p>
+Now, as has been said before, the dissimilar rays having an unequal degree
+of refrangibility, it will be impossible to obtain a focus by the light
+passing through a double-convex lens without its being fringed with color.
+Its effect will be readily understood by reference to the accompanying
+cut.
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig8b.gif" width="410" height="180" alt="[Illustration: Fig. 8]" />
+</div>
+
+<p>
+If L L be a double convex-lens, and R R R parallel rays of white light,
+composed of the seven colored rays, each having a different index of
+refraction, they cannot be refracted to one and the same point; the red
+rays, being the least refrangible, will be bent to r, and the violet rays,
+being the most refrangible, to v: the distance v r constitutes the
+chromatic aberration, and the circle, of which the diameter is a l, the
+place or point of mean refraction, and is called the circle of least
+aberration. If the rays of the sun are refracted by means of a lens, and
+the image received on a screen placed between C and o, so as to cut the
+cone L a l L, a luminous circle will be formed on the paper, only
+surrounded by a red border, because it is produced by a section of the
+cone L a l L, of which the external rays L a L l, are red; if the screen
+be moved to the other side of o, the luminous circle will be bordered with
+violet, because it will be a section of the cone M a M l, of which the
+exterior rays are violet. To avoid the influence of spherical aberration,
+and to render the phenomena of coloration more evident, let an opaque disc
+be placed over the central portion of the lens, so as to allow the rays
+only to pass which are at the edge of the glass; a violet image of the sun
+will then be seen at v, red at r, and, finally, images of all the colors
+of the spectrum in the intermediate space; consequently, the general image
+will not only be confused, but clothed with prismatic colors.&rdquo;
+</p>
+
+<p>
+To overcome the difficulty arising from the chromatic aberration, the
+optician has only to employ a combination of lenses of opposite focal
+length, and cut from glass possessing different refrangible powers, so
+that the rays of light passing through the one are strongly refracted, and
+in the other are bent asunder again, reproducing white light.
+</p>
+
+<p>
+To the photographer one of the most important features, requiring his
+particular attention, is, that he be provided with a good lens. By the
+remarks given in the preceding pages, he will be enabled, in a measure, to
+judge of some of the difficulties to which he is occasionally subjected.
+We have in this country but two or three individuals who are giving their
+attention to the manufacture of lenses, and their construction is such,
+that they are quite free from the spherical or chromatic aberration.
+</p>
+
+<h2><a name="chap05"></a>CHAPTER V.</h2>
+
+<p class="letter">
+To make Plates for the Daguerreotype&mdash;Determining the Time of Exposure in
+the Camera&mdash;Instantaneous Process for Producing Daguerreotype&mdash;Galvanizing
+the Daguerreotype Plate&mdash;Silvering Solution&mdash;Daguerreotype without
+Mercury&mdash;Management of Chemicals&mdash;Hints and
+Cautions&mdash;Electrotyping&mdash;Crayon Daguerreotypes&mdash;Illuminated
+Daguerreotypes&mdash;Natural Colors in Heliography&mdash;Multiplying Daguerreotypes
+on one Plate&mdash;Deposit in Gilding&mdash;Practical Hints on the Daguerreotype.
+</p>
+
+<h3>
+TO MAKE PLATES FOR THE DAGUERREOTYPE.
+</h3>
+
+<p>
+I do not give the method employed by our regular plate manufacturers; this
+is not important, as the operator could not possibly profit by it from the
+fact of the great expense of manufacturing. The following will be found
+practical:
+</p>
+
+<p>
+Procure a well planished copper plate of the required size, and well
+polish it, first with pumice stone and water, then with snake stone,
+jewelers&rsquo; rouge. Plates can be purchased in a high state of preparation
+from the engravers. Having prepared the copper-plate, well rub it with
+salt and water, and then with the silvering powder. No kind answers better
+than that used by clock-makers to silver their dial-plates. It is composed
+of one part of well washed chloride of silver, five parts of cream of
+tartar, and four parts of table salt. This powder must be kept in a dark
+vessel, and in a dry place. For a plate six inches by five, as much of
+this composition as can be taken up on a shilling is sufficient. It is to
+be laid in the centre of the copper, and the figures being wetted, to be
+quickly rubbed over every part of the plate, adding occasionally a little
+damp salt. The copper being covered with the silvering is to be speedily
+well washed in water, in which a little soda is dissolved, and as soon as
+the surface is of a fine silvery whiteness, it is to be dried with a very
+clean warm cloth. In this state the plates may be kept for use. The first
+process is to expose the plate to the heat of a spirit flame, until the
+silvered surface becomes of a well-defined golden-yellow color; then, when
+the plate is cold, take a piece of cotton, dipped in very dilute nitric
+acid, and rub lightly over it until the white hue is restored, and dry it
+with very soft clean cloths. A weak solution of the hydriodate of potash,
+in which a small portion of iodine is dissolved, is now passed over the
+plate with a wide camel&rsquo;s hair brush. The silver is thus converted, over
+its surface, into an ioduret of silver; and in this state it is exposed to
+light, which blackens it. When dry, it is to be again polished, either
+with dilute acid or a solution of carbonate of soda, and afterwards with
+dry cotton, and the smallest possible portion of prepared chalk: by this
+means a surface of the highest polish is produced. The rationale of this
+process is, in the first place, the heat applied dries off any adhering
+acid, and effects more perfect union between the copper and silver, so as
+to enable it to bear the subsequent processes. The first yellow surface
+appears to be an oxide of silver with, possibly, a minute quantity of
+copper in combination, which being removed leaves a surface chemically
+pure.
+</p>
+
+<p>
+Another Method.&mdash;The best and simplest mode with which we are acquainted
+is to divide an earthenware vessel with a diaphragm: one side should be
+filled with a very dilute solution of sulphuric acid, and the other with
+either a solution of ferroprussiate of potash, or muriate of soda,
+saturated with chloride of silver. The copper plate, varnished on one
+side, is united, by means of a copper wire, with a plate of zinc. The zinc
+plate being immersed in the acid, and the copper in the salt, a weak
+electric current is generated, which precipitates the silver in a very
+uniform manner over the entire surface.
+</p>
+
+<p>
+Another Method.&mdash;A piece of brass or of polished copper, brass is
+preferred, is perfectly planished and its surface made perfectly clean. A
+solution of nitrate of silver, so weak that the silver is precipitated
+slowly, and a brownish color, on the brass, is laid uniformly over it, &ldquo;at
+least three times,&rdquo; with a camel&rsquo;s hair pencil. After each application of
+the nitrate, the plate should be rubbed gently in one direction, with
+moistened bitartrate of potassa, applied with buff. This coat of silver
+receives a fine polish from peroxide of iron and buff. Proofs are said to
+have been taken on it, comparable with those obtained on French plates.
+</p>
+
+<h3>
+M. SOLIEL&rsquo;S PROCESS FOR DETERMINING THE TIME OF EXPOSURE IN THE CAMERA.
+</h3>
+
+<p>
+M. Soliel has proposed the use of the chloride of silver to determine the
+time required to produce a good impression on the iodated plate in the
+camera. His method is to fix at the bottom of a tube, blackened within, a
+piece of card, on which chloride of silver, mixed with gum or dextrine, is
+spread. The tube thus disposed is turned from the side of the object of
+which we wish to take the image, and the time that the chloride of silver
+takes to become of a greyish slate color will be the time required for the
+light of the camera to produce a good effect on the iodated silver.
+</p>
+
+<h3>
+INSTANTANEOUS PROCESS FOR PROCURING DAGUERREOTYPES.
+</h3>
+
+<p>
+The following method of producing Daguerreotypes has by some been named as
+above. Most experienced operators have been long acquainted with the
+effect of the vapor of ammonia upon the chemically coated plate. I will
+here insert Mr. W. H. Hewett&rsquo;s plan of proceeding. This gentleman, in
+referring to it (published in 1845), says:
+</p>
+
+<p>
+&ldquo;This improvement consists in using the vapor of ammonia, as an object to
+accelerate the action of light upon the plate. The effect is produced upon
+a simple iodized plate, but still more upon a plate prepared in the
+ordinary way, with both iodine and bromine. By this means, the author
+obtained impressions instantaneously in the sunshine, and in five to ten
+seconds in a moderate light; and he hopes to be able to take moving
+objects. It can be applied by exposing the prepared plate over a surface
+of water, to which a few drops of ammonia have been added (sufficient to
+make it smell of ammonia); or the vapor can be introduced into the camera
+during the action. In fact, the presence of ammonia, in the
+operating-room, appears to have a good effect, as it also neutralizes the
+vapors of iodine and bromine that may be floating about, and which are so
+detrimental to the influences of light upon the plate.&rdquo;
+</p>
+
+<h3>
+GALVANIZING THE DAGUERREOTYPE PLATE.
+</h3>
+
+<p>
+In consideration of the importance of galvanized plates, I shall endeavor
+to give as plain and concise a manner of manipulation as possible. For
+some time it was a question among the operators generally, as to the
+beneficial result of electrotyping, the Daguerreotype plate, but for a few
+years past our first operators have found it a fact, that a well
+electro-silvered surface is the best for producing a portrait by the
+Daguerreotype.
+</p>
+
+<p>
+From my own experiments, I have found that a plate, by being galvanized,
+can be rendered more sensitive to the operation of the light in proportion
+of one to five, viz.: if a plate as furnished by the market, be cleaned,
+polished, coated and exposed in the camera, if the required time to freely
+develop an impression be ten seconds, a similar plate prepared in like
+manner and galvanized, will produce an equally well-defined image in eight
+seconds. In connection with this subject, there is one fact worthy of
+notice; a plate with a very heavy coating of pure silver, will not produce
+an equally developed image, as a plate with a thinner coating, hence the
+thin coating, providing it entirely covers the surface, is the best, and
+is the one most to be desired. The experiment is plain and simple. Let the
+slate receive a heavy or thick coating by the electrotype, then polish,
+coat, expose in the usual manner, and the result will be a flat, ashy,
+indistinct impression; when, on the other hand, the thin coating will
+produce a bright, clear and distinct image, with all the details
+delineated.
+</p>
+
+<p>
+The style of battery best for the purpose has been, and now is, a question
+of dispute among operators; some preferring the Daniell battery to Smee&rsquo;s.
+Some claim the superiority of the first from its uniformity of action;
+others, of the latter, for its strength. I consider either good, and for
+the inexperienced would prefer the Daniell. This is more simple in its
+construction, while it has certainty in action. The more skillful
+electrotyper would prefer Smee&rsquo;s, and this is the one most generally in
+use. I would remark that the plan of galvanizing plates should be followed
+by every operator, and when once thoroughly tested, no one will abandon
+it.
+</p>
+
+<h3>
+SILVERING SOLUTION.
+</h3>
+
+<p>
+To any desired quantity of chloride of silver in water add, little by
+little, cyanide of potassium, shaking well at each addition, until all the
+cyanide is dissolved. Continue this operation, and add the cyanide, until
+all the precipitate is taken up and held in solution.
+</p>
+
+<p>
+This solution is now ready for the plate-cup. Enough water may be added to
+cover any sized plate when held perpendicular in the cup. The strength of
+the solution may be kept up by occasionally adding the chloride of silver
+and cyanide of potassium. There should alway be a very little excess of
+the cyanide.
+</p>
+
+<p>
+The plate should be well cleaned and buffed, and the solution well stirred
+before it is immersed. Care should be observed to keep the solution clean,
+and allow no particle of dust to come in contact with the surface of the
+plate. The plate is now to be attached to the pole of the battery.
+</p>
+
+<p>
+After remaining a short time, it assumes a blue color; take it out, rinse
+freely with pure water, then dry with a spirit lamp, and it is ready for
+buffing. Buff and coat in the usual manner. Some operators are in the
+practice of immersing the plate in the solution and buffing twice. This
+additional silvering is no improvement wherever there has been a proper
+first coating.
+</p>
+
+<p>
+Sometimes the operator is troubled with streaks or scum on the plate. This
+may arise from three causes, all of which experience must teach the
+experimenter to avoid; first, too great an excess of cyanide in the
+solution; second, a lack of silver; third, the current too strong. Another
+annoyance arises from the solution being dirty and the dirt collecting on
+the surface. When this is the case, the dirt is sure to come in contact
+with the surface of the plate as it is plunged into the solution, and the
+result is a scum that it is difficult to dispose of. This can be prevented
+only by frequent filtering. One thing should always be borne in mind in
+electrotyping Daguerreotype plates&mdash;that in order to secure a perfectly
+coated surface, the plate should be perfectly cleaned. In this point, many
+who have tried the electrotype process have failed, attributing their ill
+success to other than the proper cause.
+</p>
+
+<h3>
+DAGUERREOTYPES WITHOUT MERCURY.
+</h3>
+
+<p>
+The following process possesses some interest, and is worthy a trial from
+operators. M. Natterer, of Vienna, discovered a process for obtaining
+proofs on iodized plates with the chloride of sulphur, without the use of
+mercury. A plate of silver is iodized in the usual manner, and then placed
+on the top of a vessel six or eight inches high, having at the bottom, in
+a small cup, a few drops of chloride of sulphur; it should remain exposed
+to the action of the vapor until the sombre yellow color is changed to a
+red, after which it is brought to a focus in the camera, where it is
+exposed to the light in the camera, for about the time necessary to
+produce an ordinary daguerreotype. The plate is then taken out and
+examined in the camera by the light of a candle. It often occurs that no
+trace of the image is as yet perceptible, but if the plate is heated by
+placing over a spirit lamp the unprepared side, or if left for some time
+in the dark, or, lastly, if exposed only a few seconds to a weak, dimmed
+light, the positive picture then appears with all its shades. Of these
+three modes of bringing out the image, the second is superior to the
+others.
+</p>
+
+<h3>
+MANAGEMENT OF CHEMICALS.
+</h3>
+
+<p>
+It is necessary, first of all, to know that you have a chemical which is
+capable of producing good results when in skillful hands. For this reason
+it is best to prepare your own quick, after some formula which is known to
+be good. Those quick-stuffs which contain chloride of iodine are noted for
+their depth of tone while they probably operate with less uniformity than
+those which are destitute of it. For operating under ordinary
+circumstances, especially with an inferior light, probably no accelerator
+is more quick and sure than Wolcott&rsquo;s. It also produces a very fine, white
+pleasing picture, though lacking that depth of impression so much to be
+desired. The dry quick operates with surety, and its use is simple and
+easy, producing an impression much like Wolcott&rsquo;s. For those having a good
+and permanent light, however, we would recommend a chemical giving more
+body to the impression.
+</p>
+
+<p>
+There is a class of accelerators called sensitives, claiming to work in
+from three to ten seconds, which, however, will be found very little, if
+any, more sensitive than this. We frequently work it with the ordinary
+coating in twelve and fifteen seconds. The manner in which the sensitives
+are worked is by coating very light. In this way, a flat, shallow picture
+is obtained in a few seconds; and the same can be done with any of the
+more volatile quicks.
+</p>
+
+<p>
+It is a fact not generally known, that a plate coated in a light chemical
+room is more sensitive than when coated in darkness. By admitting a free,
+uniform light, and exposing the plate to it a few seconds after coating,
+then timing short in the camera, a very light, clear impression is
+obtained. The time in the camera is reduced in proportion to the previous
+action of light. The shades, of course, are destroyed, and the tone
+injured; still, for taking children, we have succeeded better by this
+method than by the use of &ldquo;sensitives.&rdquo; The discovery of this principle
+was accidental, while operating where the direct ray s of the sun,
+entering the window just before sunset, fell on the curtain of our dark
+room, rendering it very light within.
+</p>
+
+<p>
+The selection of iodine is not unimportant. Reject, at once, that which
+has anything like a dull, black, greasy appearance; and select that which
+is in beautiful large crystalline scales, of a purple color, and brilliant
+steel lustre.
+</p>
+
+<p>
+Solarization, and general blueness of all the light parts of the picture,
+were formerly great obstacles to success, though now scarcely thought of
+by first-class artists. Beginners in the art, however, are still apt to
+meet with this difficulty. It is occasioned by dampness in the iodine box,
+which causes the plate to become coated with a hydro-iodide of silver,
+instead of the iodide. The remedy is in drying your iodine. If in summer,
+you can open your box and set it in sunshine a few minutes; or if in
+winter, set it under a stove a short time. The true method, however, is to
+dry it by means of the chloride of calcium. It has such a remarkable
+affinity for water, that a small fragment placed in the open air, even in
+the dryest weather, soon becomes dissolved.
+</p>
+
+<p>
+Take one or two ounces of this chemical, heat it in the drying bath, or in
+a hot stove, to perfect dryness; place it in a small glass toy dish, or
+large watch crystal, and set it in the centre of your iodine box. Take
+this out and heat to dryness every morning. Adopt this process, and with
+your mercury at a high temperature, you will never be troubled with blue
+pictures.
+</p>
+
+<p>
+Young operators are apt to impute all want of success in operating to
+their chemicals, even though the cause is quite as likely to be elsewhere.
+Failure is quite likely to occur from dampness in the buffs, or in the
+polish; it is therefore necessary to be constantly on the guard in this
+quarter. With a view to this, always scrape your buffs with a dull knife,
+or with one blade of your shears, the first thing in the morning, and
+after brushing them thoroughly, dry them, either in the sun, by a stove,
+or in the buff-dryer. It is equally important that the polish and the
+brush should be kept dry.
+</p>
+
+<p>
+Want of success may arise from vapors of iodine or bromine in the camera
+box, mercury bath, or even in the buffs. It is incredible how small a
+quantity of these vapors will affect the effect of light when coming in
+contact with the plate, after or during the exposure in the camera. It is
+therefore necessary to be cautious not to mix chemicals, nor open your
+boxes or bottles in your room, but take them out to do it. Never hurry the
+operation through from lack of confidence in the result. The fact of
+anything being out of order, forms no excuse for slighting the process. If
+unsuccessful, do not pursue the same course every trial, but vary with a
+view to detect the cause of the difficulty.
+</p>
+
+<p>
+In case of a long series of failures, institute a regular course of
+investigation, after this manner, commencing where the trouble is most
+likely to occur:
+</p>
+
+<p>
+1. Are the plates well cleaned?
+</p>
+
+<p>
+2. Is the iodine dry? If the impressions come out blue, you may rest
+assured it is not. Take out the iodine, wipe and dry the box, and dry the
+calcium.
+</p>
+
+<p>
+3. Is the quick battery of the right strength? If dry, it must change the
+plate in from six to fifteen seconds. If any of the chloride of iodine
+class, it may vary from five seconds to a minute. Begin by coating light,
+and increase on each trial, observing the effect. If the light side of the
+picture seems loth to come out, and shows no contrast with the dark side,
+it is to be inferred that your battery is too strong, and must be reduced
+with water or set out in the open air for a few minutes, with the lid off.
+If working an old battery, never renew very strong, or it will work dark
+and heavy. A battery, to work well, should be gradually losing strength,
+but never gaining. An old battery, however, may be quickened up and made
+to work well for some time, by adding five of six drops of sulphuric acid,
+repeating the quantity as often as necessary, providing always that acid
+be not used in manufacturing the quick.
+</p>
+
+<p>
+4. Have the plates lost their sensitiveness by being many times exposed to
+mercury? Clean and burn them; but if French plates, burn light, or you
+spoil them.
+</p>
+
+<p>
+5. Are the buff s dry and clean? Examine the plate critically after
+buffing to detect any appearance of scum or film on the surface. If so,
+the longer you buff the more it shows. Scrape and dry the buffs
+thoroughly.
+</p>
+
+<p>
+6. Is the mercury free from scum and dirt? If not, filter. Is it also far
+enough from the coating boxes? Should be at least three feet, and kept
+covered.
+</p>
+
+<p>
+7. Is the mercury sufficiently heated? This is important. Long exposure,
+however, will answer the same purpose.
+</p>
+
+<p>
+8. Are your lenses clean, and in proper place?
+</p>
+
+<p>
+9. Are the tablets in focus with the ground-glass? If you can attribute
+the failure to none of these, mix a new box of some other kind of quick,
+say the dry, for instance. If you fail in the same manner here, take time,
+wash your buffs, overhaul all the chemicals, and start anew. Do not be
+discouraged.
+</p>
+
+<p>
+There is no day so dark but that the sun will shine again. We will close
+with this brief summary of advice:
+</p>
+
+<p>
+Clean your plates. Keep everything dry. Keep the mercury hot. Follow these
+instructions carefully, and you must succeed.
+</p>
+
+<h3>
+HINTS AND CAUTIONS.
+</h3>
+
+<p>
+First of all, cleanliness should be observed. When there is dust or dirt
+about your room, particularly about the work-bench, failures will be
+frequent; for the smallest particles of rotten-stone, when allowed to come
+in contact with the buffs, will produce scratches on the surface of the
+plate, which very much injures the operation, and often causes failures.
+</p>
+
+<p>
+Dust flying about the room is injurious, if allowed to fall on the plate,
+either before or after it has been coated, as it causes black spots which
+cannot be removed.
+</p>
+
+<p>
+The polished plate should not be allowed to come in contact with a strong
+current of air, for it tends to oxidize the surface. Breathing on the
+surface should also be avoided, for the same reason.
+</p>
+
+<p>
+The plate should, in all cases, be buffed immediately before using, and
+not allowed to stand any length of time. It should be held with the
+polished face downward.
+</p>
+
+<p>
+It is always best that the plate should be of the same temperature of the
+atmosphere in the room.
+</p>
+
+<p>
+Keep the camera and mercury-bath perfectly free from the vapors of iodine
+and bromine; for the presence of the slightest degree of either of the
+above will injure the impression in no small degree. As a preventive, let
+the camera be exposed to the sun or fire for a few minutes in the morning.
+</p>
+
+<p>
+Filter your mercury often, to keep the surface free from film and dust.
+</p>
+
+<p>
+The hyposulphite solution should be filtered through sponge every time it
+is used.
+</p>
+
+<p>
+The direct rays of light must not enter the camera in conjunction with
+those reflected from the object; or the picture will be veiled, and the
+color of the plate changed to a thick green.
+</p>
+
+<p>
+If the plate be iodized only to a light-yellow, the result might be of a
+bluish or grey tinge: and this is generally the case, when the quick is
+new and strong, and there is an excess of it on the plate, and yet not
+enough to form the bromide iodide of silver; in which case it would wholly
+spoil the impression.
+</p>
+
+<p>
+Your iodine will be found to operate more successfully, when the time
+required for coating the plate does not fall short of fifteen seconds, or
+exceed one minute.
+</p>
+
+<p>
+Too quick coating can be avoided by using less iodine in your box. In the
+summer months, when the weather is 80 deg. and over, one quarter of an
+ounce, or even less, will work to advantage.
+</p>
+
+<h3>
+ELECTROTYPING.
+</h3>
+
+<p>
+I am indebted to Mr. J. H. Fitzgibbons for the following process, which he
+employed in producing the excellent specimens he exhibited at the Crystal
+Palace:
+</p>
+
+<p>
+&ldquo;I shall endeavor to lay down in as comprehensive a manner as possible the
+method by which I have been enabled to produce the most satisfactory
+results. I use a Smee&rsquo;s battery (another kind will do). After filling the
+cell, of common size, nearly full with water; add about quarter of an
+ounce of sulphuric acid. Mix this well, and let it stand for about three
+hours, or until the action of the battery becomes weak, when it is in
+order to work with a very uniform action. Put one pound of sulphate of
+copper in one quart of water; stir it until the sulphate of copper is all
+dissolved, and then add one half ounce of sulphuric acid and a quarter of
+an ounce of nitric acid. This solution, well mixed, should be filtered,
+and it is ready for use. It is very important that the solution should be
+kept clean, clear, and free from all foreign substance. The above quantity
+of this solution will be found sufficient for electrotyping a dozen of the
+sixth-size plates. When it is required to be strengthened, it is only
+necessary to add a little of the sulphate of copper.
+</p>
+
+<p>
+&ldquo;With the battery prepared as above, and the solution of sulphate of
+copper in a vessel of proper dimensions to receive your plate, connect the
+galvanic current, and immerse the impressioned plate, letting it remain
+until a thin film of copper has been formed, then the battery can be
+strengthened, and the impression will be of sufficient thickness to be
+removed in from eight to twelve hours. An old Daguerreotype plate attached
+to the opposite pole of the battery (copper side towards the face of the
+plate to be electrotyped), will answer the same purpose as the
+silver-plate.
+</p>
+
+<p>
+&ldquo;The great difficulty in taking an electrotype impression, and preserving
+the original, has been attributed to the battery being too powerful. I am
+led to believe from practice that the principal difficulty has been in the
+Daguerreotype plate itself, for if we use an impression that has been
+taken but a few days, and taken in the usual way, we will find it
+difficult to succeed without spoiling both the copy and original, and so
+also with an old impression.
+</p>
+
+<p>
+&ldquo;I have found the most certain method to be as follows:&mdash;Coat the
+Daguerreotype plate as usual, except use less of the accelerators, the
+proportion of iodine coating being greater, of course the time of exposure
+in the camera will be lengthened. Mercurialize it at about a temperature
+requiring to develop the image, from six to eight minutes, at least.
+Gilding the Daguerreotype has much to do towards producing a good
+electrotype copy. This should be done by applying a little heat, and
+gilding very slowly, giving a coating of gold with the greatest possible
+uniformity. By this method, I have been enabled to produce any number of
+proofs. I have produced a dozen from one impression, and it remains as
+perfect as when first taken.
+</p>
+
+<p>
+&ldquo;By a little judgment and care the operator will be enabled to produce the
+electrotype copy of the Daguerreotype plate without any difficulty. The
+electrotype copy should be immediately put under a glass and sealed in the
+same manner as the ordinary Daguerreotype.&rdquo;
+</p>
+
+<h3>
+CRAYON DAGUERREOTYPES.
+</h3>
+
+<p>
+This process is patented in the United States, by J. A. Whipple, of
+Boston, and of course no honorable person will use it for his own benefit
+without purchasing a right.
+</p>
+
+<p>
+A white back-ground is generally employed, the object being to blur the
+lower portion of the plate, leaving the head of the subject in relief.
+Every Daguerreotypist is familiar with the fact that a motion of any body
+between the camera and the sitter will cause a &ldquo;blur.&rdquo; Cut a piece of thin
+paper and scallop it, making a semicircle. This is kept straight by means
+of a wire frame, and it is to be moved in front of the lower part of the
+body of the sitter during the time of exposure of the plate in the camera.
+Develop over mercury as usual, and the result will be a crayon
+Daguerreotype.
+</p>
+
+<p>
+Another method is to have a wheel with a hole cut through it of a diameter
+of about 12 inches. This hole is so cut as to leave teeth resembling those
+of a large saw. This wheel is so arranged that it can be turned around,
+which should be done during the time of exposure in the camera. It must be
+placed between the camera and the sitter, and at such a distance from the
+camera as to allow such proportion of the body of the sitter be seen upon
+the ground-glass as is desired. It will be readily seen that by turning
+this wheel during the operation will produce the same result as the paper
+being moved in the other method. The teeth make the &ldquo;blur.&rdquo; The side of
+the wheel towards the camera may be black, by which means the result will
+be a dark instead of a light border.
+</p>
+
+<h3>
+ILLUMINATED DAGUERREOTYPES.
+</h3>
+
+<p>
+This process is also patented, and the remarks on the preceding subject
+will apply in this case. The plate is prepared and exposed as in the usual
+method of the Daguerreotype. A white back-ground is employed. Let the head
+of the sitter come in the middle of the plate, and before exposing it to
+the vapors of mercury, put a small mat or diaphragm, having a small hole
+through it, over or directly on the surface of the plate. This diaphragm
+should be bevelled, and the bevel should be towards the surface of the
+plate; this, in order to prevent too sharp a line on the impression. It
+will be readily seen that if an impressioned plate so covered is placed
+over the mercury, it will be developed on such portions only as are
+exposed. The principle is so familiar that further explanations are
+unnecessary.
+</p>
+
+<h3>
+NATURAL COLORS IN HELIOGRAPHY.
+</h3>
+
+<p>
+This subject is worthy the attention of every operator. The following
+process is so plain and easy of trial that any Daguerreotypist can try it.
+This is as given by Mr. James Campbell, and was published in Humphrey&rsquo;s
+Journal of the Daguerreotype and Photographic Arts, vol. 5, page 11. Mr.
+Campbell has done much to further the process announced by M. Neipce, and
+his experiments have proved highly successful.
+</p>
+
+<p>
+The following is submitted as worthy of trial:
+</p>
+
+<p>
+&ldquo;The proper preparation of the chloridated plate, to enable it to receive
+colored impressions is an object of the first importance to those wishing
+to experiment on it, and consequently requires particular notice. The
+plate may be prepared by making it the positive pole of a battery, and
+letting it at the same time be immersed in chlorine water. The negative
+pole should be a slip of platinum. All the colors may be produced from a
+plate so prepared if the chlorine and water are in the right proportions;
+but generally one color or the other predominates, according to the amount
+of chlorine in the liquid. By adding the chlorides of strontian, uranium,
+potassium, sodium, iron, or copper to the liquid, various effects may be
+produced, and these bodies will be found to produce the same color on the
+plate that their flame gives to alcohol.
+</p>
+
+<p>
+&ldquo;The honor of this discovery is due to M. Neipce. Copper gives a
+variegated flame; hence many colors may be impressed on a plate prepared
+with a solution of its chloride.
+</p>
+
+<p>
+&ldquo;M. Neipce recommends a solution of the mixed chlorides of copper and
+iron, and it is with these, that I have been most successful. As the
+chlorides of copper and iron are not much used in the arts, they are not
+generally found for sale in the shops; and it may be well to furnish those
+not much versed in chemistry with an easy method of preparing them.
+</p>
+
+<p>
+&ldquo;They may be made directly from either metal by dissolving it in
+hydrochloric acid; but they may be formed by a cheaper method, and by
+which also the acid fumes are avoided.
+</p>
+
+<p>
+&ldquo;Sulphate of iron or copper, or both together, may be dissolved in water
+and then neutralized with common crude potash, or its carbonate or
+bicarbonate&mdash;known commonly as pearl ash and saleratus. If either of the
+latter be used, there will be formed sulphate of potash and a carbonate of
+the metal used, and there will also be a considerable effervescence of
+carbonic acid, which will, if care is not taken, cause the mixture to run
+over the vessel. After the copper or iron salt is neutralized, which is
+known by its ceasing to effervesce, the carbonate of the metal will settle
+slowly, and will at first nearly fill the vessel. The supernatant fluid,
+which is sulphate of potash in solution, may now be carefully poured off,
+and its place filled with water; this operation should be repeated several
+times until the water which passes off is tasteless. The carbonate of the
+metal rapidly changes to an oxide by contact with the air, and it will
+generally be found, when it is sufficiently washed, that it is at least
+half oxide. On adding hydrochloric acid cautiously to the mixture, a
+chloric of the metal will be formed, and carbonic acid will be evolved
+from the remaining carbonate. The chloride formed is soluble; but as there
+are two chlorides of these metals, and we wish to produce the one which
+contains the most chlorine, it is best to add the acid cautiously until
+the solution is decidedly acid. After filtering the solution, it is fit
+for use; and it should be preserved in well-stoppered bottles. The water
+used should be rain or distilled water.
+</p>
+
+<p>
+&ldquo;About one part of the mixed chlorides should be used to three or four of
+water.
+</p>
+
+<p>
+&ldquo;The battery may be either Smee&rsquo;s, Daniell&rsquo;s, or Grove&rsquo;s; if of either of
+the former, it should be of two series; if of the latter, one cup is
+sufficient.
+</p>
+
+<p>
+&ldquo;The plate on being immersed in the liquid, almost instantly takes a
+violet color. It should be allowed to remain from two to five minutes,
+according to the strength of the battery, and until it becomes nearly
+black. It should now be carefully washed, and afterwards heated over a
+spirit lamp until it takes a cherry-red color, and it is then ready for
+exposure in the camera. Before speaking of exposing the plate, it may be
+well to speak of some difficulties which the inexperienced operator may
+find in preparing it. If the battery is not in good order, and a
+sufficient current is not passed through the solution, the plate will
+become coated&mdash;and apparently almost as well as when the battery is
+working well&mdash;but on exposure it will give a negative picture, and but
+little colored; while if the battery is in good order, the impression is
+invariably positive.
+</p>
+
+<p>
+&ldquo;Sometimes on heating the plate after washing, the surface is covered with
+spots or assumes a variegated appearance. This indicates that the solution
+is impure, or that the plate have not been thoroughly washed and are still
+contaminated with the soluble chlorides which are contained in the
+solution.
+</p>
+
+<p>
+&ldquo;From the fact that the plate if prepared with positive electricity gives
+a positive picture, while it prepared otherwise it gives a negative, it is
+evident that electricity plays an important part in this process. The same
+is true to some extent with the compounds formed with iodine, bromine, and
+fluorine.
+</p>
+
+<p>
+&ldquo;On heating the plate, the brown coating of chloride melts into a
+translucent enamel, and the heat should be withdrawn when a cherry-red
+color is produced. It the heat is continued longer, the plate assumes a
+lighter color, and becomes less sensitive; and the enamel will finally
+scale off. To produce a picture by the ordinary process of M. Neipce,
+unaccelerated, it should be exposed for from three to five hours to
+sunlight in the camera, though pictures may be procured by contact, in
+from fifteen to thirty minutes.&rdquo;
+</p>
+
+<h3>
+MULTIPLYING DAGUERREOTYPES ON ONE PLATE.
+</h3>
+
+<p>
+I have produced some interesting specimens of the Daguerreotypic art, by
+exposing in the camera only a portion of the sensitive plate to the action
+of light. When on the exposed portion an image is formed, then taking the
+tablet into the dark room, change ends and expose the sensitive portion,
+and produce another image, developing as usual. This plan is adapted for
+taking likenesses for lockets. Two images can be presented as sitting side
+by side, by covering half the plate with black paper, and exposing as
+before. In this manner we have been enabled to surprise persons by
+exhibiting their portrait on the same plate with a stranger&rsquo;s.
+Daguerreotypists must be cautious in practicing this, as it might not be
+agreeable to the parties whose likenesses are together, by the above
+process. It is impossible to produce an impression without a line being
+seen where the edge of the paper prevented the operation of the light.
+</p>
+
+<p>
+I have recently seen a fine specimen produced by another plan, which far
+exceeds the above, there being no line, or any peculiarity denoting two
+exposures. The specimen referred to, was a gentleman represented on one
+plate by two full length portraits. This was produced by using a black
+velvet for the background. The plate was exposed sufficient time to
+produce one impression, and then the gentleman assumed another position,
+and is repeated as looking at himself. From the fact that the time
+required to develop black velvet being so much longer than that for
+producing a portrait, we are enabled to produce the above interesting
+results.
+</p>
+
+<h3>
+DEPOSIT IN GILDING.
+</h3>
+
+<p>
+Regarding specks from bad water, I would remark that gilding should be
+made only with distilled water. Thus made, it produces very little
+deposit, even by long keeping. It therefore preserves its original
+strength, and works with great uniformity.
+</p>
+
+<p>
+Every grain of deposit contains at least 7-10 its weight of gold, easily
+discoverable by the blowpipe. Such gilding is continually deteriorating,
+which with good chloride and distilled water may be prevented. Distilled
+water should also be used for the hyposulphite. and for cleaning plates.
+Any good, clear water may be afterwards used for washing off, with equally
+good results. I am very rarely troubled with specs, and deem this as the
+main reason.
+</p>
+
+<p>
+With a portable still attached to a cooking stove, I obtain half a gallon
+of water per hour, and with very little trouble. A small tin retort or
+still connected with a Leibig&rsquo;s condenser, would not add much to the
+&ldquo;traps&rdquo; of the travelling operator, and save him many a disreputable
+specimen.&mdash;T. J. BAILEY.&mdash;Humphrey&rsquo;s Journal.
+</p>
+
+<h3>
+PRACTICAL HINTS ON THE DAGUERREOTYPE.
+</h3>
+
+<p>
+The following is from Humphrey&rsquo;s Journal, vol. 5, and from the pen of Dr.
+WM. HARRINGTON, one of the most able writers upon the subject of the
+Daguerreotype in this country:
+</p>
+
+<h3>
+THE CAUSE OF THE DIFFICULTY THAT SOMETIMES OCCURS TO PREVENT THE
+PRODUCTION OF A CLEAR IMPRESSION UPON A DAGUERREOTYPE PLATE.
+</h3>
+
+<p>
+Beyond all doubt this is traceable to dampness. Truly this is not a new
+thought; but where does this dampness come from? How does it originate,
+and where is it located? Generally it has been referred to a point
+entirely remote from its real location.
+</p>
+
+<p>
+This dampness exists particularly upon the surface of the plate; is
+obviously derived immediately from the atmosphere; and is owing to a
+certain relative temperature of the plate with the hygrometric condition
+of the atmosphere.
+</p>
+
+<p>
+Whenever this relation exists between the plate and atmosphere, a
+precipitation of moisture takes place upon the surface of the plate, which
+render all efforts at polishing impracticable. This interference is not
+confined to the buffing operation alone, but sometimes is discoverable
+even in the ordinary process of scouring. Every one at all experienced in
+this art will remember that it is not always an easy matter for him, by
+scouring, to bring his plate to the desired lustre. All his efforts become
+unavailing; the more he rubs, the duller the surface of his plate appears;
+and although he renews his cotton repeatedly, still he is obliged to
+content himself with an unsatisfactory finish.
+</p>
+
+<p>
+This relative condition is not confined to any particular season of the
+year, nor to any certain thermometric temperature; but may occur in summer
+as well as in winter; the weather being warm or cold, wet or dry, clear or
+cloudy, raining or shining. Under any of these circumstances, if the
+relation of the plate and atmosphere be such as to invite upon the plate a
+precipitation of humidity from the atmosphere, the prospect of producing a
+clear impression is quite problematical.
+</p>
+
+<p>
+It is reasonable to expect this occurrence from the fact that metal is a
+good radiator, and radiation reduces the temperature of a metallic body
+below that of the atmosphere. Consequently, if this relative condition
+happens, the result will be as I have stated.
+</p>
+
+<p>
+Bodies may be colder than the atmosphere and yet derive no moisture from
+it; while at the same time the driest atmosphere is not devoid of
+moisture, but will part with it under certain conditions.
+</p>
+
+<p>
+Assuming for granted that this relative condition between the plate and
+atmosphere, disposing the former to receive the humidity of the latter,
+constitutes the great obstacle the operator has to contend with in
+producing, a clear proof upon the plate, the remedy naturally suggests
+itself, and is very simple. It consists in merely heating the plate above
+the temperature of the atmosphere, previous to polishing, and retaining
+that temperature during the operation. Various measures might be devised
+to effect the desired object; one of which consists of a sheet-iron box,
+heated from the inside by a spirit-lamp, upon the top of which are to be
+kept the plates ready to undergo the process of being polished; the blocks
+of the swing or any other vice; or the iron bed belonging to Lewis&rsquo;s vice.
+</p>
+
+<p>
+In cold weather, when it is necessary to keep a fire in the preparation
+room, all of the above may be so arranged in the vicinity of the fire as
+to receive the requisite degree of heat for the purpose specified.
+</p>
+
+<p>
+This part of the subject, however, is left entirely for the ingenuity of
+the operator. No matter by hat means he accomplishes the object; all that
+is required is to heat the plate above the temperature of the atmosphere
+and retain that heat during the process of polishing.
+</p>
+
+<p>
+Since the adoption of this method, in connection with my partner, T. J.
+Dobyns, even in this humid climate of ours, when everything in the room is
+dripping with moisture, it has been attended with invariable success.
+</p>
+
+<h3>
+CHOICE OF PLATES, ETC.
+</h3>
+
+<p>
+In the great catalogue of complaints made by operators, none is more
+common than that alleged against the quality of plates in general use.
+Although the greatest diversity of opinion exists upon this subject,
+nevertheless the plates of every manufactory share in this universal
+condemnation.
+</p>
+
+<p>
+To be sure it cannot be denied but that this necessary article of utility
+in the photographic art has undergone a sad deterioration in quality owing
+to the increasing demand and great reduction in price&mdash;the plates of the
+present day being by no means so heavily coated with silver as
+formerly&mdash;but the complaint alluded to is not predicated so much upon the
+thinness of silver as upon a mysterious something which has conferred upon
+the plates the epithet of not good.
+</p>
+
+<p>
+That this complaint is in a great measure groundless appears evident from
+the fact that while, with the same brand of plates one operator can work
+successfully, another encounters the greatest difficulty; while one is
+able to produce beautifully clear and altogether satisfactory results, the
+other labors under the troublesome annoyance of innumerable specks, large
+dark insensitive patches and brown map-like portions, together with divers
+other blemishes, sufficient to prevent him from obtaining anything like a
+tolerable impression.
+</p>
+
+<p>
+From this wide difference in the results of the two operators using
+identically the same article, it is but reasonable to conclude that the
+complaint is founded in error; while the inference is no more than just,
+that the fault may be traced to a want of practical skill on the part of
+the complaining operator himself; rather than to the inferior quality of
+the plates.
+</p>
+
+<p>
+The question, then, whether the plates are unfit for use, or whether those
+who pronounce them so understand how to use them, appears to be
+satisfactorily answered. It therefore becomes a matter worthy of
+investigation, to ascertain what superior judgment and skill one operator
+possesses over another which enable him to work successfully a quality of
+plate, pronounced by the other entirely useless.
+</p>
+
+<p>
+Suppose we make a critical examination of one of the repudiated plates.
+From its external appearance we have little hesitation in pronouncing it
+to be French; indeed, this presumption is strongly corroborated by the
+fact that it is ornamented upon one of its corners with a brand to
+designate the manufactory from which it emanated.
+</p>
+
+<p>
+Upon close inspection we cannot fail to notice a striking peculiarity upon
+the surface; the roughness is very remarkable; the planishing hammer has
+left amazingly visible indications of its busy work. One would suppose the
+manufacturer intended the surface of the plate to represent the
+undulations of the sea, instead of that smooth and level character so
+strongly recommended by M. Daguerre.
+</p>
+
+<p>
+Such a plate necessarily requires at the hand of the operator considerable
+labor before the surface is in a proper condition to receive a suitable
+polish from the buffer. The least reflection in the world should teach any
+one that so long as the undulatory character continues upon the surface of
+the plate, it is in a very imperfect condition for buffing, because the
+buffer cannot touch every point equally; the elevated portions alone
+receiving a high degree of polish while the depressed portion, from their
+roughness acting as nuclei, gather dust, rouge, and other foreign bodies,
+so detrimental to sensitiveness. The secret of the superior judgment and
+skill of one operator over another, is intimately connected with this
+point: his success depends very much upon the first process of cleaning
+the plate.
+</p>
+
+<p>
+Let us examine the manipulation of the complaining operator. He takes one
+of these plates and gives it a careful scouring with rotten-stone and
+alcohol or any other liquid preferred for this part of the operation&mdash;that
+is, he gives it what he terms a careful scouring&mdash;very gently indeed
+because, from the frequent trials he is in the habit of making in the
+camera, he fears he will rub the silver entirely away before he succeeds
+in obtaining a good impression. The dark patches, specks, and granular
+appearance resulting entirely from the unevenness of the surface of the
+plate, look like copper to him, and he is surprised that he should have
+rubbed away the silver so soon, particularly by such delicate handling.
+</p>
+
+<p>
+The judgment and experience of the successful operator, however, teach him
+that scouring injures a plate less than buffing. He knows that unless the
+hammer marks be obliterated, he cannot by the buffer produce a surface of
+uniform polish and sensitiveness, without which a fair proof is extremely
+doubtful; he knows that the time employed in the preliminary operation of
+cleaning the plate properly is economy.
+</p>
+
+<p>
+There is a style of French plates in the market, denominated heavy, which
+are truly excellent, if properly managed. Much patience, however, is
+required to remove the marks of the hammer; but with tripoli and alcohol
+the surface is readily cut down, and the plate is then susceptible of a
+beautiful black lustre by polishing with the buffer. The complaining
+operator could not succeed by his own method with one of the plates; he
+would encounter all manner of clouds and other unaccountable phenomena; he
+would imagine this plate entirely worn out before it was half cleaned, and
+soon fix in his own estimation the reputation of the heavy plate.
+</p>
+
+<p>
+In making a choice of plates, therefore, it would appear to be a matter of
+perfect indifference with an experienced operator what kind he would use,
+except so far only as the labor required in cleaning them was to be taken
+into consideration.
+</p>
+
+<p>
+The distinction between a scale plate, a Scovill No. 1, S. F., heavy A,
+star, crescent, eagle, or any other brand, consists in the superior finish
+of some, and the thinness of the silver in the cheaper qualities.
+</p>
+
+<p>
+Consequently, let the complaining operator but employ the diligence
+inculcated in this article, to clean his plate thoroughly, so as to bring
+it to a perfectly even and level surface, and he will seldom be troubled
+with specks, clouds, dark patches, and the host of other obstacles which
+heretofore have tormented him.
+</p>
+
+<h2><a name="chap06"></a>CHAPTER VI.</h2>
+
+<p class="letter">
+AN ACCOUNT OF WOLCOTT AND JOHNSON&rsquo;S EARLY EXPERIMENTS, IN THE
+DAGUERREOTYPE. BY JOHN JOHNSON.
+</p>
+
+<p class="noindent">
+[From Humphrey&rsquo;s Journal, vol. ii 1851]
+</p>
+
+<p>
+As a general thing, however perfect any invention may be deemed by the
+inventor or discoverer, it falls to the lot of most, to be the subject of
+improvement and advancement, and especially is this the case with those
+new projects in science which open an untrodden field to the view of the
+artisan. Such has been, in an eminent degree, the case with the discovery
+first announced to the world by Mons. Jean Jaques Claude Daguerre, of
+Paris, in the year 1839, and which excited unbounded astonishment,
+curiosity and surprise. It may be questioned had any other than Daguerre
+himself discovered a like beautiful combination, whether the world would
+have been favored with details exhibiting so much care, patience and
+perseverance as the Daguerreotype on its introduction. Shortly after,
+these details reached the United States, by Professor S. F. B. Morse, of
+New York, who was, at the time of the discovery, residing in Paris. By
+this announcement, the whole scientific corps was set in operation, many
+repeating the experiments, following carefully the directions pointed out
+by Daguerre, as being necessary to success. Among the number in the United
+States, was Alexander S. Wolcott (since deceased) and myself; both of this
+city. On the morning of the 6th day of October, 1839, I took to A.
+Wolcott&rsquo;s residence, a full description of Daguerre&rsquo;s discovery, he being
+at the time engaged in the department of Mechanical Dentistry, on some
+work requiring his immediate attention, the work being promised at 2 P.M.
+that day; having, therefore, no opportunity to read the description for
+himself (a thing he was accustomed to do at all times, when investigating
+any subject). I read to him the paper, and proposed to him that if he
+would plan a camera (a matter he was fully acquainted with, both
+theoretically and practically), I would obtain the materials as specified
+by Daguerre. This being agreed to, I departed for the purpose, and on my
+return to his shop, he handed me the sketch of a camera box, without at
+all explaining in what manner the lens was to be mounted. This I also
+undertook to procure. After 2, P.M., he had more leisure, when he
+proceeded to complete the camera, introducing for that purpose a reflector
+in the back of the box, and also to affix a plate holder on the inside,
+with a slide to obtain the focus on the plate, prepared after the manner
+of Daguerre. While Mr. Wolcott was engaged with the camera, I busied
+myself in polishing the silver plate, or rather silver plated copper; but
+ere reaching the end preparatory to iodizing, I found I had nearly or
+quite removed the silver surface from off the plate, and that being the
+best piece of sliver-plated copper to be found, the first remedy at hand
+that suggested itself, was a burnisher, and a few strips were quickly
+burnished and polished. Meantime, the camera being finished, Mr. Wolcott,
+after reading for himself Daguerre&rsquo;s method of iodizing, prepared two
+plates, and placing them in the camera, guessed at the required time they
+should remain exposed to the action of the light; after mercurializing
+each in turn, and removing the iodized surface with a solution of common
+salt two successful impressions were obtained, each unlike the other!
+Considerable surprise was excited by this result, for each plate was
+managed precisely like the other. On referring to Daguerre, no explanation
+was found for this strange result; time, however, revealed to us that one
+picture was positive, and the other negative. On this subject I shall have
+much to say during the progress of the work. Investigating, the cause of
+this difference occupied the remainder of that day. However, another
+attempt was agreed upon, and the instruments, plates, etc., prepared and
+taken up into an attic room, in a position most favorable for light.
+Having duly arranged the camera, I sat for five minutes, and the result
+was a profile miniature (a miniature in reality,) or a plate not quite
+three-eighths of an inch square. Thus, with much deliberation and study,
+passed the first day in Daguerreotype&mdash;little dreaming or knowing into
+what a labyrinth such a beginning was hastening us.
+</p>
+
+<p>
+[Description of apparatus represented on pages 192 and 199:] <br /><br />
+A.&mdash;The Box&mdash;about 4 inches long by about 2 outside diameter.<br /> B.&mdash;The
+Reflector soldered to a brass screw, and mounted in the rear of the box.<br />
+c.&mdash;The slide to regulate the focus to the plate holder.<br /> d.&mdash;The
+standard to the plate holder screwed to the slide.<br /> f.&mdash;The
+plate-holder frame having two small ledges, * *, for the plate to rest
+upon.
+</p>
+
+<p class="noindent">
+{192}
+</p>
+
+<p class="noindent">
+g.&mdash;The plate resting upon the ledge., * *, and kept against the frame by
+the spring <br /> h. The plates used were about 3/8 of an inch square.<br />
+A.&mdash;The window with the sashes removed.
+</p>
+
+<p>
+B and C (p. 199) are large looking-glasses mounted as plain reflectors,
+the lower one C having rotary motion upon the saddle, resting upon the
+sill of the window in order to direct the rays of the sun upon the
+reflector B, at any hour of the day&mdash;the vertical motion of the reflector
+C being necessary, the sun varying in altitude so much during the hours
+most favorable to the production of portraits. The reflector C was {193}
+kept up to the required position by the handle lever, upright post and
+bolts. Reflector B was hinged at its upper end at the top of the window
+frame, the only motion being necessary was that which would reflect upon
+the sitter the incident rays from reflector C&mdash;the reflector B being kept
+at the required angle by the connecting lever m, etc. Suitable
+back-grounds were placed behind the sitter.
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig12.gif" width="376" height="396" alt="[Illustration: Fig. 12]" />
+</div>
+
+<p>
+The reflector B and C, had frequently to be renewed, the heat of the sun
+soon destroying their brilliance or power of reflecting, light, before
+renewing them, however, we resorted to the springing of them, by which
+means their power was increased for a period.
+</p>
+
+<p>
+The camera or reflecting apparatus, invented by Mr. Wolcott, was, from the
+nature of the case, better adapted at that day to the taking of portraits
+from life, than any other instruments. After carefully examining the
+camera described by Daguerre, and the time stated as necessary to produce
+action for an image, it became evident to the mind of Mr. Wolcott at once,
+that more light could be obtained (as the field of view required was not
+large) by employing a reflector of short focus and wide aperture, than
+from a lens arrangement, owing to spherical aberration and other causes.
+Many experiments having been tried with the small instrument figured (p.
+199), a reflector for taking portraits from life was determined on, having
+eight inches diameter, with twelve inches focal distance for parallel
+rays; this was to admit plates of two inches wide by two and a half long
+Mr. Wolcott having on hand reflectors of the right diameter, for Newtonian
+telescopes, of eight feet focal distance, resolved (as it was a matter of
+experiment) to grind down or increase the curve for the focal distance
+before named&mdash;this required time. In the mean time, many plans were
+pursued for making good plates, and the means of finishing, them. As the
+completion of the large reflector drew to a close, our mutual friend,
+Henry Fitz, Jr., returned from England, whither he had been on a visit,
+and when he heard what we were about, kindly offered his assistance; he
+being well versed in optics, and having been before engaged with Mr.
+Wolcott, in that and other business is offer was gladly accepted&mdash;Mr.
+Wolcott himself having frequent engagement; to fill as operator in the
+details of mechanical dentistry. Thus, by the aid of Mr. Fitz, the
+reflector was polished, and experiments soon after tried on plates of two
+by tow and a half inches, with tolerable success. Illness on my part quite
+suspended further trial for nearly four weeks.
+</p>
+
+<p>
+On my recovery, early in January, 1840, our experiments were again resumed
+with improved results, so much so as to induce Mr. Wolcott and myself to
+entertain serious thoughts of making a business of the taking of
+likenesses from life, intending to use the reflecting apparatus invented
+by Mr. Wolcott, and for which he obtained Letters Patent, on the 8th day
+of May, 1840. Up to January 1st, 1840, all experiments had been tried on
+an economical scale, and the apparatus then made, was unfit for public
+exhibition; we resolved to make the instruments as perfect as possible
+while they were in progress of manufacture. Experiments were made upon
+mediums for protecting the eyes from the direct light of the sun, and also
+upon the best form and material for a back-ground to the likenesses. The
+length of time required for a &ldquo;sitting,&rdquo; even with the reflecting
+apparatus, was such as to render the operation anything but pleasant.
+Expedients were ever ready in the hands of Wolcott: blue glass was tried
+and abandoned in consequence of being, at that time, unable to procure a
+piece of uniform density and surface: afterwards a series of thin muslin
+screens secured to wire frames were prepared as a substitute for blue
+glass. The objections to these screens, however, were serious, inasmuch as
+a multiplication of them became necessary to lessen the intensity of the
+light sufficiently for due protection to the eyes, without which, the
+likenesses, other than profiles, were very unpleasant to look upon. Most
+of the portraits, then of necessity were profiles formed upon
+back-grounds, the lighter parts relieved upon black, and the darker parts
+upon light ground; the back-ground proper being of light colored material
+with black velvet so disposed upon the light ground, this being placed
+sufficiently far from the sitter, to produce harmony of effect when viewed
+in the field of the camera. Other difficulties presented themselves
+seriously to the working of the discovery of Daguerre, to portrait
+taking&mdash;one of which was the necessity for a constant and nearly
+horizontal light, that the shaded portions of the portrait should not be
+too hard, and yet, at the same time, be sufficiently well developed
+without the &ldquo;high light&rdquo; of the picture becoming overdone, solarized or
+destroyed. In almost all the early specimens of the Daguerreotype,
+extremes of light and shade presented themselves, much to the annoyance of
+the early operators, and seriously objectionable were such portraits. To
+overcome this difficulty, Mr. Wolcott mounted, with suitable joints, upon
+the top of his camera, a large looking-glass or plane reflector, in such a
+manner that the light of the sun (as a strong light was absolutely
+necessary), when falling upon the glass could be directed upon the person
+in an almost horizontal direction.
+</p>
+
+<p>
+Early in February, 1840, Mr. Johnson, Sen., (since deceased) sailed for
+Europe with a few specimen likenesses taken with the instruments completed
+as above, with the intention of patenting the invention. On his arrival a
+joint arrangement was effected with Mr. Richard Beard, of London, in
+patenting and working the invention in England. Up to February, 1840, but
+few friends had been made acquainted with the progress of the art in the
+hands of Mr. Wolcott and myself. From time to time reports reached us from
+various sources of the success of others, and specimens of landscapes,
+etc., were exhibited at Dr. James R. Chilton&rsquo;s laboratory, in Broadway,
+much to the gratification of the numerous visitors and anxious expectants
+for this most wonderful discovery. Dr. Chilton, Professor J. J. Mapes,
+Professor J. W. Draper. Professor S. F. B. Morse, all of this city; Mr.
+Cornelius, Dr. Goddard and others of Philadelphia; Mr. Southworth,
+Professor Plumbe, and numerous others were early in the field; all,
+however, using the same description of camera as that of Daguerre, with
+modification for light, either by enlargement by lens and aperture for
+light, or by shortening the focal distance.
+</p>
+
+<p>
+At a conversational meeting of the Mechanics&rsquo; Institute, Professor J. J.
+Mapes being present, a question was asked if any one present could give
+information relative to portraiture from life by the Daguerreotype. Mr.
+Kells, a friend of Mr. Wolcott and a scientific and practical man (since
+deceased), at once marked out upon the black-board, the whole as contrived
+by Mr. Wolcott. This gave publicity to the invention of Mr. Wolcott.
+Shortly after, Professor Mapes, Dr. Chilton, and many others, sat for
+their portraits, and were highly gratified. Professor Morse also came and
+proposed to Mr. Wolcott to join him in the working of the invention, etc.
+</p>
+
+<p>
+From this time much interest was manifested by our friends in our
+progress. Rooms were obtained in the Granite Buildings, corner of Broadway
+and Chambers street, and fitted for business. The rooms being small, it
+was soon found impracticable to use the arrangement of looking-glass, as
+previously spoken of; a new plan became necessary, to introduce which, the
+sashes were removed, {199} and two large looking-glasses were mounted in
+proper frames, thus:&mdash;
+</p>
+
+<div class="fig" style="width:100%;">
+<img src="images/fig13.gif" width="723" height="376" alt="[Illustration: Fig. 13]" />
+</div>
+
+<p>
+Just in front, and between the sitter and {200} the reflector, upon a
+proper stand, were used those paper muslin screen before described; also
+screens of tissue paper. These screens, however, when they were used,
+required so much time for a sitting, that some other medium, as a
+protection to the eyes, became absolutely necessary. The most plausible
+thing that suggested itself was blue glass; but, as this could not be
+found, numerous were the expedients proposed by the friends of the art,
+who from time to time visited our rooms. At the suggestion of Professor
+Mapes (who is ever ready to assist those in perplexity), a trough of plate
+glass s, about twenty-eight inches square in the clear, and from three to
+four inches thick, was filled with a solution of ammonia sulphate of
+copper, and mounted on the frame as in the sketch, which, for a time,
+answered extremely well; soon, however, decomposition of this solution
+became apparent from the increased length of time required for a sitting,
+although to the eye of an observer, no visible cause for such long
+sittings could be pointed out. Professor Mapes being appealed to,
+suggested that to the above solution a little acid be added which acted
+like a charm&mdash;shortening the time for a sitting from six, eight, or ten
+minutes to that of about one. Decomposition, however, would go on by the
+action of light and heat through the solution. New solutions were tried,
+when the whole were finally abandoned as being, too uncertain and
+troublesome. (The reflecting apparatus R, was placed upon the stand as in
+the sketch, with a wedge for elevating the camera, between it and the
+table, to obtain the image properly upon the plate.) A quantity of blue
+window glass was next obtained, and holes drilled through the corners of
+it, and several sheets were wired together to increase the size, and, when
+complete, was suspended from the ceiling in its proper place, and so
+arranged that when a person was sitting, this sheet of glass could be
+moved to and from, the object of which was to prevent shadows on the face
+of the sitter produced from the uneven surface of the glass. This latter
+contrivance was used until a perfect plate of glass was procured.
+</p>
+
+<p>
+The number of persons desirous of obtaining, their miniatures, induced
+many to entertain the idea of establishing themselves in the Art as a
+profession, and numerous were the applications for information; many
+persons paying for their portraits solely with the view of seeing the
+manner of our manipulations, in order that they might obtain information
+to carry on likeness-taking as a business.
+</p>
+
+<p>
+The reflecting camera being a very troublesome instrument to make, and
+difficulties besetting us from every source, but little attention could be
+given to teaching others; and, indeed, as the facts seemed to be at this
+time, we knew but little of the necessary manipulations ourselves. In
+course of time, several established themselves. The first one, after
+ourselves, who worked the discovery of Daguerre for portrait taking in
+this city, was a Mr. Prosch; followed soon after by many others, in almost
+all cases copying the reflecting arrangement for light, as figured above,
+many using it even after we had long abandoned that arrangement for a
+better one.
+</p>
+
+<p>
+Innumerable obstacles to the rapid advance of the daguerreotype, presented
+themselves almost hourly, much to the annoyance of ourselves, and those
+dependent upon our movements for their advancement. Among the most
+difficult problems of the day, was the procuring of good plates. Messrs.
+Corduran &amp; Co. were among the first to supply the trade; at that early
+day, however, it was a very rare thing, to be able to procure an even
+perfect surface, from the fact that a pure surface of silver could
+scarcely be obtained, the manufacturers deeming it too much trouble to
+prepare silver plated copper with pure silver&mdash;the result was, that in
+attempting to polish perfectly such plated metal as could be procured, the
+plates would become cloudy, or colored in spots, from the fact of having
+more or less alloy, according as more or less of the silver surface was
+removed in polishing the plate fit for an impression. To explain more
+clearly, it was the practice of most silver platers to use an alloy for
+silver-plating. In the reduction of the ingot to sheet metal, annealing
+has to be resorted to, and acid pickles to remove oxides, etc. The number
+of times the plated metal is exposed to heat and acid in its reduction to
+the required thickness, produces a surface of pure silver. The most of
+this surface is, however, so rough as to be with difficulty polished,
+without in places removing entirely this pellicle of pure metal, and
+exposing a polished surface of the alloy used in plating. Whenever such
+metal was used, very unsightly stains or spots frequently disfigured the
+portraits. The portrait, or portion of it, developed upon the pure silver,
+being much lighter or whiter than that developed upon the alloy; it
+therefore appeared that the purer the silver, the more sensitive the plate
+became. Accordingly, we directed Messrs. Scovills, of Connecticut, to
+prepare a roll of silver-plated metal, with pure silver; it fortunately
+proved to be a good article, but, unfortunately, a pound of this metal
+(early in 1840) cost the round sum of $9. Like descriptions of metal, the
+same gentlemen would be glad to furnish, at this time, for $4. Soon after
+this, some samples of English plated metal, of a very superior quality,
+came to our possession, and relieved us from the toil of making and
+plating one plate at a time, an expedient we were compelled to resort to,
+to command material to meet the pressing demands for portraits.
+</p>
+
+<p>
+Having it now in our power to obtain good plated metal, a more rapid mode
+of polishing than that recommended by Daguerre was attempted as follows:
+</p>
+
+<p>
+This metal was cut to the desired size, and having a pair of &ldquo;hand rolls&rdquo;
+at hand, each plate, with its silvered side placed next to the highly
+polished surface of a steel die, was passed and repassed through the rolls
+many times, by which process a very smooth, perfect surface was obtained.
+The plates were then annealed, and a number of plates thus prepared were
+fastened to the bottom of a box a few inches deep a foot wide, and
+eighteen inches long; this box was placed upon a table and attached to a
+rod connected to the face plate of a lathe, a few inches from its centre,
+so as to give the box a reciprocating motion. A quantity of emery was now
+strewn over the plates, and the lathe set in motion. The action produced
+wag a friction or rubbing of the emery over the surface of the plates.
+</p>
+
+<p>
+When continued for some time, a greyish polish was the result. Linseed,
+when used in the same manner, gave us better hope of success, and the next
+step resorted to was to build a wheel and suspend it after the manner of a
+grindstone. The plates being secured to the inner side of the wheel or
+case, and as this case revolved, the seeds would constantly keep to the
+lower level, and their sliding over the surface of the plates would polish
+or burnish their surfaces. This, with the former, was soon abandoned;
+rounded shots of silver placed in the same wheel were found not to perform
+the polishing so well as linseed. Buff-wheels of leather with rotten-stone
+and oil, proved to be far superior to all other contrivances; and,
+subsequently, at the suggestion of Professor Draper, velvet was used in
+lieu of buff leather, and soon superseded all other substances, both for
+lathe and hand-buffs, and I would add, for the benefit of new beginners
+that those who are familiar with its use, prefer cotton velvet. The only
+requisite necessary is, that the buffs made of cotton velvet should be
+kept dry and warm.
+</p>
+
+<p>
+The greater number of operators, with whose practice I am familiar, use,
+for polishing plates, prepared tripoli, imported from France, or Browne&rsquo;s
+rotten-stone. The former of these articles is very objectionable, inasmuch
+as there is no positive certainty of being enabled to procure or make the
+article of uniform grit&mdash;the nature of the substance rendering, it
+impossible to reduce it to varying degrees of evenness, by the well known
+process of washing, for that purpose, and the burning of rotten-stone
+changes its chemical nature somewhat, at the same time rendering, this
+invaluable article harsh and gritty. And especially, no reliance can be
+placed upon burned rotten stone if purchased from those who do not give
+very great attention and care to its preparation; and the same remarks
+apply to rouge.
+</p>
+
+<p>
+The best article for polishing Daguerreotype plates is rotten-stone, such
+as can be procured in any town, prepared after the following manner:
+Procure, say half a dozen wide-mouthed bottles, of suitable dimensions,
+numbering each from one to six. Put into No. 1 about half a pound of
+rotten-stone, and nearly fill the bottle with water. Then, with a proper
+stick or spatule, mix well the rotten-stone and water; after which, let
+No. 1 rest for, say one minute, then carefully pour off into bottle No. 2
+(or, what would be better, draw off by a syphon) as much of the floating
+particles of rotten-stone as is suspended in the water. Again fill bottle
+No. 1 with water, agitate it as before, and decant it to bottle No. 2,
+care being taken to draw off only the suspended particles of rotten-stone.
+</p>
+
+<p>
+When a sufficient quantity of washings from bottle No. 1 is collected into
+bottle No. 2, a similar process must be gone through, as above stated, for
+No. 1; the difference being in the care required, and in the time allowed
+between the stirring or mixing the rotten-stone and water. The floating
+particles of rotten-stone, after four minutes&rsquo; subsiding, will be found
+fine enough for the finest Daguerreotype polishing required.
+</p>
+
+<p>
+A quantity of such washings may be collected in a large bottle, and
+allowed to stand a few hours, when all the rotten-stone will have settled.
+The water may be poured off and the rotten-stone put into an evaporating
+dish, and while being dried, must be constantly stirred to obtain an
+impalpable powder.
+</p>
+
+<p>
+Further washings may in like manner be resorted to for finer qualities of
+rotten-stone. In my practice, I have used the articles at two and four
+minutes&rsquo; settling, and occasionally have prepared it after standing for
+eight minutes. So fine a quality as this, however, is seldom required. In
+using, rotten-stone, I mix with it, for polishing, fine olive oil, until I
+obtain a thin paste&mdash;and the best of all methods for polishing (well
+planished) Daguerreotype plates, is one like that used for glass by lens
+polishers; that is, by using a disc or buff-wheel, and having, a suitable
+holder by which to secure the plate, and then by pressing the plate
+against the revolving buff, well saturated with the mixed oil and
+rotten-stone, a very good surface is obtained. A quantity of plates may be
+prepared in this way, and all the adhering oil, etc., may be removed by a
+clean hand, or lathe buff, after which each plate must be heated to the
+point necessary to burn off the remaining oil great care being required
+not to overheat the plate. A very slight excess of temperature will at
+once destroy all the polish previously obtained. The test for ascertaining
+the right temperature is at hand; the adhering oil will be driven from the
+plate in the form of smoke when the right temperature is reached. The
+moment the smoke ceases to rise from the plate, the heat must be removed,
+and the plate quickly cooled upon a piece of iron.
+</p>
+
+<p>
+A quantity of plates thus prepared may be kept on hand for any required
+time, and the labor of one minute, with a lathe or hand-buff with dry
+charcoal, or rather, prepared lampblack, will perfectly polish the surface
+ready for indexing, etc. This lampblack also requires some care in
+preparing. Take a small-size crucible, properly temper it by a slow fire,
+that it may not be cracked after which, fill it with common lampblack,
+cover it over with a piece of soap-stone, and again replace it in the
+fire. Build a good hard coal fire around it continue the heat for two or
+three hours, being careful not to raise the cover till the crucible be
+quite cold. Pulverize when using it. It is very desirable to keep this
+lampblack dry and warm. Some operators use much rouge I would recommend
+the above in preference; but those who feel that they cannot dispense with
+the use of rouge, had better try a large addition of prepared lampblack to
+a small one of rouge, as this latter article, unless great pains be taken
+in its preparation, will adhere and work itself into the body of the
+surface, so that it cannot be removed therefrom; and I have seen many
+specimens of Daguerreotype very much injured in effect from this rouge
+tint disseminated throughout their shaded features, at the same time that
+the whole general effect of such pictures is that of a want of life. It is
+true that with the use of rouge a very high degree of polish may be
+obtained, but probably not higher than can be produced with many other
+substances of a less objectionable nature.
+</p>
+
+<p>
+From the announcement of the discovery by Daguerre to the beginning of the
+year 1840, I am not aware of any attempt to lessen the time for the action
+of an image, or an impression, other than that of the reflecting camera
+invented by Mr. Wolcott. Early, however, in 1840, Mr. Wolcott was desirous
+to be enabled to further shorten the time for a sitting, and having some
+knowledge of bromine and its action, by request, Dr. Chilton prepared a
+small quantity; but Mr. Wolcott did not succeed very well with it, he
+having invariably used too much in combination with iodine to produce that
+sensitive coating now well known to the profession. Professor Morse, of
+this city, Dr. Goddard, of Philadelphia, and others, in the years 1840 and
+1841, were acquainted with the use of bromine. N. Griffing, of this city,
+or myself, used with tolerable success, iodine in large excess to nitric
+acid and water; and, subsequently, to nitro muriatic acid (which reacted
+and formed a peculiar chloride of iodine); this latter combination proved
+to be preferable to simple iodine, at the same time somewhat more
+sensitive, and was used by me in this city up to the time of my leaving
+for London (October 1, 1840). On arriving in London, I instituted a series
+of experiments in the various chemical combinations, solely with the view
+to be enabled to obtain more speedily a portrait than it was practicable
+to do with any known chemicals at that date. The high latitude, and the
+winter season of the year rendering but a feeble light at best, the
+greater the necessity for a more sensitive chemical preparation to the
+shortening the time for a sitting. Near the beginning of the year 1841, I
+discovered and practically applied, chloride of iodine to great advantage,
+and, as far as memory serves me, I believe the first used in this country
+was some made and shipped, Messrs. Harnden &amp; Co., from London, to Mr.
+Wolcott, in New York.
+</p>
+
+<p>
+About the same time, Mr. John Goddard, of London (who was associated with
+myself), discovered a rather valuable combination of chemicals, consisting
+of a mixture of iodine, bromine, iodus, and iodic acid, and a proper
+combination of those bodies gave an action somewhat more sensitive than
+chloride of iodine&mdash;but the &ldquo;high lights&rdquo; of the portraits would become
+solarized or overdone, more frequently with this combination than with the
+chloride of iodine. Throughout the year 1841, I used, with great success,
+chloride of iodine, applied as one coating&mdash;occasionally in conjunction
+with Mr. Wolcott, attempting the use of iodine, bromine, and chlorine, and
+at times with more or less success. The difficulty of exactly combining,
+the three elements above mentioned, in order to produce a certainty of
+result with harmony of effect, was the work of many months, with great
+labor and study, the slightest modification requiring a long, series of
+practical experiments, a single change consuming, frequently, an entire
+day in instituting comparisons, etc., etc.
+</p>
+
+<p>
+Early in the year, 1842, I discovered a combination of chemicals (now
+known in London as &ldquo;Wolcott&rsquo;s Mixture,&rdquo; in hermetically sealed bulbs) of
+exceeding uniform character, very sensitive to the action of light, and
+specimens produced in 1842-3, with this combination, will bear comparison
+with the best specimens produced at this late date.
+</p>
+
+<p>
+About the same time, I discovered that however much overdone a
+Daguerreotype might be, the means were at hand to save or redeem it. It
+has long, since been known to operators, that if a plate be exposed to
+light after being coated, unless it be again coated, a clear and distinct
+picture could not be obtained upon the same plate without first
+repolishing and recoating the same, care being taken that no light fall
+upon the prepared surface. To prevent solarization, coat a plate as usual,
+expose to the action of light any required time (according to
+circumstances), say from quarter to one half more time than would be
+required in the ordinary method of procedure; observe, before putting the
+plate in the mercury box, place it over the vapor of iodine, bromine, or
+chlorine, etc. (carefully excluding the light), for a very brief period,
+great care being required to have the selected vapor very much diluted
+with air, in order to success. Many experiments will be required ere
+arriving at satisfactory results. Specimens now unknown to general
+operators, for harmony of effect, have been, and may again be produced by
+the method pointed out above. I have found the best general effect, and
+the most certain result to follow from the use of the vapor of
+chlorine&mdash;but this requires more than ordinary care. I would, therefore,
+recommend the use of iodine. Thus: to a few grains of iodine, add an ounce
+of warm water (which will become tinged with iodine); when cold, to half a
+pint of pure water in a new and clean coating box, put, of the above,
+fifty drops; stir and mix well this small quantity of iodine in with the
+water; in ten minutes this box will be ready for use. Great care and
+judgment will be required in the application of this vapor to the plate;
+if the plate remain over the vapor too long, the developed picture will
+have a faint and misty appearance; if not exposed long enough, the &ldquo;high
+light&rdquo; will be solarized. I have great hope of the ultimate use of this
+process, as it is the only means yet discovered to be enabled to secure
+specimens of extremes of light and shade, yet producing harmony of effect;
+and I would call the attention of the profession to the fact, that a plate
+may be exposed to the action of light for any length of time (a thousand
+times longer than required to act for the lesser quantity of mercury to
+deposit itself, or that amount necessary to form a perfect specimen), and
+be restored by the application of any of the vapors above mentioned,
+remarking that for extremes for solarization, denser vapors will be
+required. Much remains to be done with this discovery to the application
+of the Daguerreotype.
+</p>
+
+<p>
+<br /><br /><br />
+</p>
+
+<h3>
+HUMPHREY&rsquo;S JOURNAL OF THE DAGUERREOTYPE &amp; PHOTOGRAPHIC ARTS.
+</h3>
+
+<p>
+The above-named publication is well known as the best and most valuable
+one devoted to the Photographic Science in this country. Humphrey&rsquo;s
+Journal made its appearance November 1st, 1850, and consequently is the
+first and oldest serial offered to the Photographic world.
+</p>
+
+<p>
+The art of producing Portraits and Landscapes by means of Light, has
+recently taken a new and enlivening impulse, which will in all probability
+lead to important and interesting results. No practical Daguerreotypist,
+Photographer, or amateur, should be without the means at hand for securing
+all of the information upon this subject. Each should be ready to receive
+and apply the improvements as they may be developed. In order to
+accomplish this, it is a matter of great importance to the Practitioner or
+Experimenter that he should have a reliable medium through which he can
+obtain information. In what source can the inquirer better place his
+confidence than in a regular Journal, whose editor is literally a
+practical person, and familiar with the manipulations necessary for
+producing Portraits upon &ldquo;Daguerreotype Plates,&rdquo; and upon glass and paper?
+Such is the conductor of Humphrey&rsquo;s Journal.
+</p>
+
+<p>
+This Journal is published once every two weeks, and contains all the
+improvements relating to the Art, and is the only American Journal whose
+editor is practically acquainted with the process for producing
+Daguerreotypes, Ambrotypes, and Photographs. The first No. of Vol. X. is
+dated May 1st, 1858. The terms (Two Dollars per annum) are trifling
+compared with the vast amount of information furnished.
+</p>
+
+<p>
+AMBROTYPES.&mdash;Humphrey&rsquo;s Journal contains everything novel which appears
+upon this subject, and has already presented more new, important, and
+original matter than can be found in any other place.
+</p>
+
+<p>
+Many are the letters we have received during the term of the last volume,
+in which the writer has stated that a single number of Humphrey&rsquo;s Journal
+has contained information of more value to him than &ldquo;several times the
+amount paid for the entire volume.&rdquo;
+</p>
+
+<p>
+Our resources have grown up around us, and our facilities for procuring,
+as well as distributing, all such facts and improvements as will benefit
+as well as instruct all who have the progress of the Art at heart, are as
+ample as they can well be made.
+</p>
+
+<p>
+The future volumes will be abundantly furnished with original writings
+from persons of standing in the scientific world; and the practical
+Photographer will here find a full account of such improvements as may
+from time to time develop themselves.
+</p>
+
+<p>
+From the editor&rsquo;s long practical experience in the Heliographic Science,
+he will be enabled to present the subject in a plain, clear, and concise
+manner.
+</p>
+
+<p>
+Read what the Editors say of Humphrey&rsquo;s Journal:&mdash;
+</p>
+
+<p>
+&ldquo;We have received a copy of a valuable Journal (Humphrey&rsquo;s) published in
+New York, which has reached the 18th number of Vol. VI.... We now have the
+pleasure of quoting from our trans-atlantic coadjutor.&rdquo;&mdash;Liverpool
+Photographic Jour.
+</p>
+
+<p>
+&ldquo;Humphrey&rsquo;s Journal is practical as well as scientific in
+character.&rdquo;&mdash;American Journal of Science and Arts.
+</p>
+
+<p>
+&ldquo;It treats the subject knowingly and with force.&rdquo;&mdash;New York Tribune.
+</p>
+
+<p>
+&ldquo;It is both a popular and interesting publication.&rdquo;&mdash;Mechanics&rsquo; Magazine.
+</p>
+
+<p>
+&ldquo;It is highly useful to all who practice &lsquo;shadow catching.&rsquo;&rdquo;&mdash;Ohio State
+Journal.
+</p>
+
+<p>
+&ldquo;The work is neatly gotten up, and contains many interesting varieties in
+this new field of science.&rdquo;&mdash;Times.
+</p>
+
+<p>
+&ldquo;It should be hailed and encouraged, not only by Daguerreotypists
+themselves, but by every lover of Science and Art.&rdquo;&mdash;The Democrat.
+</p>
+
+<p>
+&ldquo;We cannot too strongly urge all artists, and those persons who feel an
+interest in the Heliographic Arts and Sciences, to take a copy of the
+work.&rdquo;&mdash;Sentinel.
+</p>
+
+<p>
+&ldquo;It is indicative of talent worthy of the important Art it is designed to
+elevate.&rdquo;&mdash;American.
+</p>
+
+<p>
+&ldquo;This Art is entitled to its own organ, which could not have fallen into
+better hands than those of the editor of &lsquo;Humphrey&rsquo;s
+Journal.&rsquo;&rdquo;&mdash;Transcript.
+</p>
+
+<p>
+&ldquo;It is a scientific work of interest and usefulness.&rdquo;&mdash;Star of the North.
+</p>
+
+<p>
+&ldquo;This Journal answers many points heretofore regarded as
+inexplicable.&rdquo;&mdash;Hudson River Chronicle.
+</p>
+
+<p>
+&ldquo;It is rich with interest.&rdquo;&mdash;North American.
+</p>
+
+<p>
+&ldquo;It contains all the &lsquo;Improvements.&rsquo;&rdquo;&mdash;Delta.
+</p>
+
+<p>
+&ldquo;It teaches us how to take our own portraits.&rdquo;&mdash;Bee.
+</p>
+
+<p>
+&ldquo;It will cultivate a taste for Daguerreotypes.&rdquo;&mdash;Commercial Advertiser.
+</p>
+
+<p>
+&ldquo;It should be in the hands of all.&rdquo;&mdash;Reveille.
+</p>
+
+<p>
+&ldquo;It is the Daguerreotypist&rsquo;s friend.&rdquo;&mdash;London News.
+</p>
+
+<p>
+&ldquo;It should be found in every library.&rdquo;&mdash;Evening Journal.
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<p>
+From some of our Subscribers
+</p>
+
+<p>
+&ldquo;Humphrey&rsquo;s Journal has been the means of saving much time and money, for
+by its instruction I have been enabled to produce some of the finest Paper
+Pictures I have ever seen.&rdquo; W. P.
+</p>
+
+<p>
+&ldquo;Don&rsquo;t fail to send me the Journal, for I would not be without it for five
+times the amount of subscription. It is the only publication I can depend
+upon.&rdquo; A. G. R.
+</p>
+
+<p>
+&ldquo;Your treatment of the humbugs and humbugging members of the profession,
+is of the most valuable importance to us practical Daguerreans. Go on. God
+speed! Here is the amount for the renewal of my subscription.&rdquo; E. F. S.
+</p>
+
+<p>
+&ldquo;How can any Operator afford to be without it?&rdquo; L. L. H.
+</p>
+
+<p>
+&ldquo;Here are five dollars: send me Humphrey&rsquo;s Journal to this amount. I will
+not be without it.&rdquo; M. S.
+</p>
+
+<p>
+&ldquo;It is my best friend.&rdquo; J. E. W.
+</p>
+
+<p>
+We might quote like commendatory extracts enough to more than ten times
+fill this page.
+</p>
+
+<p>
+Humphrey&rsquo;s Journal contains 16 octavo pages of reading matter.
+</p>
+
+<h3>
+TERMS.
+</h3>
+
+<pre xml:space="preserve">
+One copy per annum, in advance . . . . . . $2 00
+Three copies, do. do. . . . . . . $5 00
+Six copies, do. do. . . . . . . $9 00
+</pre>
+
+<p>
+The thousands who read it cannot be induced to remain without it. All who
+desire to keep up with the improvements should subscribe for a copy.
+</p>
+
+<p>
+Subscription price Two Dollars per year.
+</p>
+
+<p>
+Don&rsquo;t fail to become a subscriber. Address <br /><br /> S. D. HUMPHREY
+Office, 37 Lispenard Street, NEW YORK.
+</p>
+
+<h3>
+THE PRACTICAL MANUAL OF THE COLLODION PROCESS.<br /> BY S. D. HUMPHREY.<br />
+THIRD EDITION
+</h3>
+
+<p>
+This Edition contains all the Improvements in the Art made public up to
+the day of publication, and gives complete Practical Instructions for
+making Collodion Positives or Ambrotypes, Collodion Negatives, Printing,
+etc., etc. The quick, great and unprecedented sale of the first and second
+editions demonstrates, more than the strongest language could possibly do,
+the extraordinary and increasing popularity of this work. The Third
+Edition contains two hundred and sixteen 12mo. pages, of a larger size and
+in smaller type than either of the preceding editions, and is illustrated
+with numerous wood-cuts. It is intended to be the best practical work
+extant; substantially bound in cloth, price One Dollar; forwarded by mail
+(postage prepaid). Address
+</p>
+
+<p class="noindent">
+S. D. HUMPHREY, New York
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<h3>
+A GUIDE TO PHOTOGRAPHY,
+</h3>
+
+<p>
+Containing simple and concise directions for obtaining Views, Portraits,
+etc., by the chemical agency of Light, by W. H. Thornthwaite, author of
+&ldquo;Photogenic Manipulations,&rdquo; etc. Illustrated with numerous wood-cuts. The
+Book contains more than one hundred 12mo pages, bound in board, and is
+sold at twenty-five cents per copy, or five copies for one dollar. Address
+</p>
+
+<p class="noindent">
+S. D. HUMPHREY, New York
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<p class="noindent">
+HOLMES, BOOTH &amp; HAYDENS,<br /> MANUFACTURERS OF<br /> DAGUERREOTYPE
+CASES,<br /> PLATES, CAMERAS,<br /> MATTINGS, PRESERVERS, ETC., ETC.
+</p>
+
+<p class="noindent">
+MANUFACTURERS AND IMPORTERS OF EVERY VARIETY OF AMBROTYPE, <br /> AND
+PHOTOGRAPHIC GOODS,
+</p>
+
+<p>
+Of the Best and most approved Quality.
+</p>
+
+<p class="noindent">
+ESPECIAL ATTENTION GIVEN TO THE FURNISHING OF EVERY ARTICLE USED IN THE
+PRACTICE OF THE DAGUERREOTYPE
+</p>
+
+<p>
+Depot 81 Chambers and 63 Reade St., New York.
+</p>
+
+<p>
+Manufactory at Waterbury, Conn.
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<h3>
+HOLMES, BOOTH &amp; HAYDENS&rsquo; CAMERAS
+</h3>
+
+<p>
+From 1/4 to the Mammoth size. These CAMERAS are of the most superior make,
+and all subjected to the most thorough test before being offered for sale.
+</p>
+
+<p>
+VIEW CAMERAS, made expressly for taking views: an entirely new article.
+</p>
+
+<p>
+DAGUERREOTYPE PLATES, OF EVERY VARIETY, AND WE WOULD CALL PARTICULAR
+ATTENTION TO THE
+</p>
+
+<p>
+Wreath, and H. B. &amp; H. Eagle 40 Plates, AS HAVING NO EQUALS IN THE
+MARKET.
+</p>
+
+<p>
+SOLE AGENTS FOR THE CELEBRATED H. B. AND N. P. FRENCH PLATES.
+</p>
+
+<p>
+Always on hand a complete assortment of Ambrotype and Photographic goods.
+</p>
+
+<p>
+SOLE AGENTS FOR THE Patent solid glass corner Plate Holders.
+</p>
+
+<p>
+All orders will receive prompt attention, and be forwarded with dispatch.
+</p>
+
+<p class="noindent">
+HOLMES, BOOTH &amp; HAYDENS, 81 Chambers, and 63 Reade St. New York.
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<h3>
+SCOVILL MANUFACTURING CO.
+</h3>
+
+<p class="noindent">
+MANUFACTURER OF<br /> DAGUERREOTYPE PLATES,<br /> MATTINGS,<br /> PRESERVERS,
+CASES,<br /> APPARATUS, etc., etc.
+</p>
+
+<p>
+Importers and Dealers in every description of Daguerreotype, Photographic,
+AND AMBROTYPE GOODS,
+</p>
+
+<p>
+The SCOVILL MANUFACTURING COMPANY flatter themselves that an experience of
+nearly twenty years in the business and the most extensive variety of the
+above Goods in the United States, entitle them to the continuance of
+orders for the Domestic and Foreign trade, which will receive the most
+careful attention.
+</p>
+
+<p>
+Park Building, New York. Entrances&mdash;36 Park Row, 4 Beekman, and 141 Nassau
+Street.
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<h3>
+SCOVILL MANUFACTURING CO.
+</h3>
+
+<p>
+Would call especial attention to their large variety of
+</p>
+
+<p>
+CASES,
+</p>
+
+<p>
+Embracing many Fancy Styles made only by themselves, and to which they are
+constantly adding New Designs.
+</p>
+
+<p class="noindent">
+Union Cases,<br /> Of all sizes, with Riveted Hinges.<br /> AGENTS FOR THE
+SALE OF<br /> C. C. HARRISON&rsquo;S CAMERAS,
+</p>
+
+<p>
+with improvements, which we are now prepared to sell at reduced prices,
+and warranted to give better satisfaction than ever before DAGUERREOTYPE
+PLATES, H. B.&mdash;N. P.&mdash;Star and other brands PLATE GLASS, embracing
+three-quarters white: Crown and all other varieties. We would call
+particular attention to our Black Glass, made expressly for Ambrotypes.
+</p>
+
+<p class="noindent">
+CHEMICALS,<br /> for the Daguerreotype and Photographic Art.<br /> Iodized
+and Plain COLLODION. Gun Cotton, etc., etc.<br /> Tagliabue&rsquo;s
+Collodiometres and Actino-Hydrometres, for<br /> testing Chemicals.
+</p>
+
+<p>
+APPARATUS OF EVERY VARIETY.
+</p>
+
+<p>
+Gutta Percha, Porcelain, and Glassware of all kinds used in the Art.
+</p>
+
+<p>
+A large assortment of Gilt Frames always on hand and made to order.
+</p>
+
+<p>
+Ambrotype Shields, with solid corners of a new style.
+</p>
+
+<p>
+All orders will meet with prompt attention
+</p>
+
+<p class="noindent">
+SCOVILL MANUFACTURING CO.,<br /> PARK BUILDINGM<br /> New York<br /> 36 Park
+Row, 4 Beckman, and<br /> 141 Nassau Street.
+</p>
+
+<p>
+<br /><br />
+</p>
+
+<h3>
+HARDWICH&rsquo;S PHOTOGRAPHIC CHEMISTRY<br /> AMERICAN EDITION.
+</h3>
+
+<p class="noindent">
+A MANUAL of<br /> PHOTOGRAPHIC CHEMISTRY,<br /> <br /> INCLUDING THE PRACTICE
+OF THE COLLODION PROCESS.
+</p>
+
+<p class="noindent">
+BY
+</p>
+
+<p class="noindent">
+T. FREDERICK HARDWICH,
+</p>
+
+<p class="noindent">
+LECTURER ON PHOTOGRAPHY IN KINGS COLLEGE, LONDON;<br /> LATE DEMONSTRATOR
+OF CHEMISTRY IN KING&rsquo;S COLLEGE.
+</p>
+
+<p class="noindent">
+Last Edition,
+</p>
+
+<p>
+The above is the title of this new and valuable work. It is too well known
+to need any further comment in this place. This volume contains nearly 300
+large duodecimo pages, bound in red cloth, $1.00. Copies to be forwarded
+by mail, $1.18, postage pre-paid.
+</p>
+
+<p class="noindent">
+S. D. HUMPHREY,<br /> Photographic<br /> Book Publisher,<br /> 37 LISPENARD<br />
+STREET, NEW YORK,
+</p>
+
+<p>
+N.B. Postage stamps taken.
+</p>
+
+<pre>
+
+
+
+
+
+End of the Project Gutenberg EBook of American Handbook of the Daguerrotype, by Samuel D. Humphrey
+
+*** END OF THIS PROJECT GUTENBERG EBOOK AMERICAN HANDBOOK OF THE DAGUERROTYPE ***
+
+***** This file should be named 167-h.htm or 167-h.zip *****
+This and all associated files of various formats will be found in:
+ http://www.gutenberg.org/1/6/167/
+
+Produced by Gregory Walker, for the Digital Daguerreian Archive Project.
+
+Updated editions will replace the previous one--the old editions will
+be renamed.
+
+Creating the works from print editions not protected by U.S. copyright
+law means that no one owns a United States copyright in these works,
+so the Foundation (and you!) can copy and distribute it in the United
+States without permission and without paying copyright
+royalties. Special rules, set forth in the General Terms of Use part
+of this license, apply to copying and distributing Project
+Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm
+concept and trademark. Project Gutenberg is a registered trademark,
+and may not be used if you charge for the eBooks, unless you receive
+specific permission. If you do not charge anything for copies of this
+eBook, complying with the rules is very easy. You may use this eBook
+for nearly any purpose such as creation of derivative works, reports,
+performances and research. They may be modified and printed and given
+away--you may do practically ANYTHING in the United States with eBooks
+not protected by U.S. copyright law. Redistribution is subject to the
+trademark license, especially commercial redistribution.
+
+START: FULL LICENSE
+
+THE FULL PROJECT GUTENBERG LICENSE
+PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK
+
+To protect the Project Gutenberg-tm mission of promoting the free
+distribution of electronic works, by using or distributing this work
+(or any other work associated in any way with the phrase "Project
+Gutenberg"), you agree to comply with all the terms of the Full
+Project Gutenberg-tm License available with this file or online at
+www.gutenberg.org/license.
+
+Section 1. General Terms of Use and Redistributing Project
+Gutenberg-tm electronic works
+
+1.A. By reading or using any part of this Project Gutenberg-tm
+electronic work, you indicate that you have read, understand, agree to
+and accept all the terms of this license and intellectual property
+(trademark/copyright) agreement. If you do not agree to abide by all
+the terms of this agreement, you must cease using and return or
+destroy all copies of Project Gutenberg-tm electronic works in your
+possession. If you paid a fee for obtaining a copy of or access to a
+Project Gutenberg-tm electronic work and you do not agree to be bound
+by the terms of this agreement, you may obtain a refund from the
+person or entity to whom you paid the fee as set forth in paragraph
+1.E.8.
+
+1.B. "Project Gutenberg" is a registered trademark. It may only be
+used on or associated in any way with an electronic work by people who
+agree to be bound by the terms of this agreement. There are a few
+things that you can do with most Project Gutenberg-tm electronic works
+even without complying with the full terms of this agreement. See
+paragraph 1.C below. There are a lot of things you can do with Project
+Gutenberg-tm electronic works if you follow the terms of this
+agreement and help preserve free future access to Project Gutenberg-tm
+electronic works. See paragraph 1.E below.
+
+1.C. The Project Gutenberg Literary Archive Foundation ("the
+Foundation" or PGLAF), owns a compilation copyright in the collection
+of Project Gutenberg-tm electronic works. Nearly all the individual
+works in the collection are in the public domain in the United
+States. If an individual work is unprotected by copyright law in the
+United States and you are located in the United States, we do not
+claim a right to prevent you from copying, distributing, performing,
+displaying or creating derivative works based on the work as long as
+all references to Project Gutenberg are removed. Of course, we hope
+that you will support the Project Gutenberg-tm mission of promoting
+free access to electronic works by freely sharing Project Gutenberg-tm
+works in compliance with the terms of this agreement for keeping the
+Project Gutenberg-tm name associated with the work. You can easily
+comply with the terms of this agreement by keeping this work in the
+same format with its attached full Project Gutenberg-tm License when
+you share it without charge with others.
+
+1.D. The copyright laws of the place where you are located also govern
+what you can do with this work. Copyright laws in most countries are
+in a constant state of change. If you are outside the United States,
+check the laws of your country in addition to the terms of this
+agreement before downloading, copying, displaying, performing,
+distributing or creating derivative works based on this work or any
+other Project Gutenberg-tm work. The Foundation makes no
+representations concerning the copyright status of any work in any
+country outside the United States.
+
+1.E. Unless you have removed all references to Project Gutenberg:
+
+1.E.1. The following sentence, with active links to, or other
+immediate access to, the full Project Gutenberg-tm License must appear
+prominently whenever any copy of a Project Gutenberg-tm work (any work
+on which the phrase "Project Gutenberg" appears, or with which the
+phrase "Project Gutenberg" is associated) is accessed, displayed,
+performed, viewed, copied or distributed:
+
+ This eBook is for the use of anyone anywhere in the United States and
+ most other parts of the world at no cost and with almost no
+ restrictions whatsoever. You may copy it, give it away or re-use it
+ under the terms of the Project Gutenberg License included with this
+ eBook or online at www.gutenberg.org. If you are not located in the
+ United States, you'll have to check the laws of the country where you
+ are located before using this ebook.
+
+1.E.2. If an individual Project Gutenberg-tm electronic work is
+derived from texts not protected by U.S. copyright law (does not
+contain a notice indicating that it is posted with permission of the
+copyright holder), the work can be copied and distributed to anyone in
+the United States without paying any fees or charges. If you are
+redistributing or providing access to a work with the phrase "Project
+Gutenberg" associated with or appearing on the work, you must comply
+either with the requirements of paragraphs 1.E.1 through 1.E.7 or
+obtain permission for the use of the work and the Project Gutenberg-tm
+trademark as set forth in paragraphs 1.E.8 or 1.E.9.
+
+1.E.3. If an individual Project Gutenberg-tm electronic work is posted
+with the permission of the copyright holder, your use and distribution
+must comply with both paragraphs 1.E.1 through 1.E.7 and any
+additional terms imposed by the copyright holder. Additional terms
+will be linked to the Project Gutenberg-tm License for all works
+posted with the permission of the copyright holder found at the
+beginning of this work.
+
+1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm
+License terms from this work, or any files containing a part of this
+work or any other work associated with Project Gutenberg-tm.
+
+1.E.5. Do not copy, display, perform, distribute or redistribute this
+electronic work, or any part of this electronic work, without
+prominently displaying the sentence set forth in paragraph 1.E.1 with
+active links or immediate access to the full terms of the Project
+Gutenberg-tm License.
+
+1.E.6. You may convert to and distribute this work in any binary,
+compressed, marked up, nonproprietary or proprietary form, including
+any word processing or hypertext form. However, if you provide access
+to or distribute copies of a Project Gutenberg-tm work in a format
+other than "Plain Vanilla ASCII" or other format used in the official
+version posted on the official Project Gutenberg-tm web site
+(www.gutenberg.org), you must, at no additional cost, fee or expense
+to the user, provide a copy, a means of exporting a copy, or a means
+of obtaining a copy upon request, of the work in its original "Plain
+Vanilla ASCII" or other form. Any alternate format must include the
+full Project Gutenberg-tm License as specified in paragraph 1.E.1.
+
+1.E.7. Do not charge a fee for access to, viewing, displaying,
+performing, copying or distributing any Project Gutenberg-tm works
+unless you comply with paragraph 1.E.8 or 1.E.9.
+
+1.E.8. You may charge a reasonable fee for copies of or providing
+access to or distributing Project Gutenberg-tm electronic works
+provided that
+
+* You pay a royalty fee of 20% of the gross profits you derive from
+ the use of Project Gutenberg-tm works calculated using the method
+ you already use to calculate your applicable taxes. The fee is owed
+ to the owner of the Project Gutenberg-tm trademark, but he has
+ agreed to donate royalties under this paragraph to the Project
+ Gutenberg Literary Archive Foundation. Royalty payments must be paid
+ within 60 days following each date on which you prepare (or are
+ legally required to prepare) your periodic tax returns. Royalty
+ payments should be clearly marked as such and sent to the Project
+ Gutenberg Literary Archive Foundation at the address specified in
+ Section 4, "Information about donations to the Project Gutenberg
+ Literary Archive Foundation."
+
+* You provide a full refund of any money paid by a user who notifies
+ you in writing (or by e-mail) within 30 days of receipt that s/he
+ does not agree to the terms of the full Project Gutenberg-tm
+ License. You must require such a user to return or destroy all
+ copies of the works possessed in a physical medium and discontinue
+ all use of and all access to other copies of Project Gutenberg-tm
+ works.
+
+* You provide, in accordance with paragraph 1.F.3, a full refund of
+ any money paid for a work or a replacement copy, if a defect in the
+ electronic work is discovered and reported to you within 90 days of
+ receipt of the work.
+
+* You comply with all other terms of this agreement for free
+ distribution of Project Gutenberg-tm works.
+
+1.E.9. If you wish to charge a fee or distribute a Project
+Gutenberg-tm electronic work or group of works on different terms than
+are set forth in this agreement, you must obtain permission in writing
+from both the Project Gutenberg Literary Archive Foundation and The
+Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm
+trademark. Contact the Foundation as set forth in Section 3 below.
+
+1.F.
+
+1.F.1. Project Gutenberg volunteers and employees expend considerable
+effort to identify, do copyright research on, transcribe and proofread
+works not protected by U.S. copyright law in creating the Project
+Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm
+electronic works, and the medium on which they may be stored, may
+contain "Defects," such as, but not limited to, incomplete, inaccurate
+or corrupt data, transcription errors, a copyright or other
+intellectual property infringement, a defective or damaged disk or
+other medium, a computer virus, or computer codes that damage or
+cannot be read by your equipment.
+
+1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right
+of Replacement or Refund" described in paragraph 1.F.3, the Project
+Gutenberg Literary Archive Foundation, the owner of the Project
+Gutenberg-tm trademark, and any other party distributing a Project
+Gutenberg-tm electronic work under this agreement, disclaim all
+liability to you for damages, costs and expenses, including legal
+fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT
+LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE
+PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE
+TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE
+LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR
+INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH
+DAMAGE.
+
+1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a
+defect in this electronic work within 90 days of receiving it, you can
+receive a refund of the money (if any) you paid for it by sending a
+written explanation to the person you received the work from. If you
+received the work on a physical medium, you must return the medium
+with your written explanation. The person or entity that provided you
+with the defective work may elect to provide a replacement copy in
+lieu of a refund. If you received the work electronically, the person
+or entity providing it to you may choose to give you a second
+opportunity to receive the work electronically in lieu of a refund. If
+the second copy is also defective, you may demand a refund in writing
+without further opportunities to fix the problem.
+
+1.F.4. Except for the limited right of replacement or refund set forth
+in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO
+OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.
+
+1.F.5. Some states do not allow disclaimers of certain implied
+warranties or the exclusion or limitation of certain types of
+damages. If any disclaimer or limitation set forth in this agreement
+violates the law of the state applicable to this agreement, the
+agreement shall be interpreted to make the maximum disclaimer or
+limitation permitted by the applicable state law. The invalidity or
+unenforceability of any provision of this agreement shall not void the
+remaining provisions.
+
+1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the
+trademark owner, any agent or employee of the Foundation, anyone
+providing copies of Project Gutenberg-tm electronic works in
+accordance with this agreement, and any volunteers associated with the
+production, promotion and distribution of Project Gutenberg-tm
+electronic works, harmless from all liability, costs and expenses,
+including legal fees, that arise directly or indirectly from any of
+the following which you do or cause to occur: (a) distribution of this
+or any Project Gutenberg-tm work, (b) alteration, modification, or
+additions or deletions to any Project Gutenberg-tm work, and (c) any
+Defect you cause.
+
+Section 2. Information about the Mission of Project Gutenberg-tm
+
+Project Gutenberg-tm is synonymous with the free distribution of
+electronic works in formats readable by the widest variety of
+computers including obsolete, old, middle-aged and new computers. It
+exists because of the efforts of hundreds of volunteers and donations
+from people in all walks of life.
+
+Volunteers and financial support to provide volunteers with the
+assistance they need are critical to reaching Project Gutenberg-tm's
+goals and ensuring that the Project Gutenberg-tm collection will
+remain freely available for generations to come. In 2001, the Project
+Gutenberg Literary Archive Foundation was created to provide a secure
+and permanent future for Project Gutenberg-tm and future
+generations. To learn more about the Project Gutenberg Literary
+Archive Foundation and how your efforts and donations can help, see
+Sections 3 and 4 and the Foundation information page at
+www.gutenberg.org
+
+
+
+Section 3. Information about the Project Gutenberg Literary Archive Foundation
+
+The Project Gutenberg Literary Archive Foundation is a non profit
+501(c)(3) educational corporation organized under the laws of the
+state of Mississippi and granted tax exempt status by the Internal
+Revenue Service. The Foundation's EIN or federal tax identification
+number is 64-6221541. Contributions to the Project Gutenberg Literary
+Archive Foundation are tax deductible to the full extent permitted by
+U.S. federal laws and your state's laws.
+
+The Foundation's principal office is in Fairbanks, Alaska, with the
+mailing address: PO Box 750175, Fairbanks, AK 99775, but its
+volunteers and employees are scattered throughout numerous
+locations. Its business office is located at 809 North 1500 West, Salt
+Lake City, UT 84116, (801) 596-1887. Email contact links and up to
+date contact information can be found at the Foundation's web site and
+official page at www.gutenberg.org/contact
+
+For additional contact information:
+
+ Dr. Gregory B. Newby
+ Chief Executive and Director
+ gbnewby@pglaf.org
+
+Section 4. Information about Donations to the Project Gutenberg
+Literary Archive Foundation
+
+Project Gutenberg-tm depends upon and cannot survive without wide
+spread public support and donations to carry out its mission of
+increasing the number of public domain and licensed works that can be
+freely distributed in machine readable form accessible by the widest
+array of equipment including outdated equipment. Many small donations
+($1 to $5,000) are particularly important to maintaining tax exempt
+status with the IRS.
+
+The Foundation is committed to complying with the laws regulating
+charities and charitable donations in all 50 states of the United
+States. Compliance requirements are not uniform and it takes a
+considerable effort, much paperwork and many fees to meet and keep up
+with these requirements. We do not solicit donations in locations
+where we have not received written confirmation of compliance. To SEND
+DONATIONS or determine the status of compliance for any particular
+state visit www.gutenberg.org/donate
+
+While we cannot and do not solicit contributions from states where we
+have not met the solicitation requirements, we know of no prohibition
+against accepting unsolicited donations from donors in such states who
+approach us with offers to donate.
+
+International donations are gratefully accepted, but we cannot make
+any statements concerning tax treatment of donations received from
+outside the United States. U.S. laws alone swamp our small staff.
+
+Please check the Project Gutenberg Web pages for current donation
+methods and addresses. Donations are accepted in a number of other
+ways including checks, online payments and credit card donations. To
+donate, please visit: www.gutenberg.org/donate
+
+Section 5. General Information About Project Gutenberg-tm electronic works.
+
+Professor Michael S. Hart was the originator of the Project
+Gutenberg-tm concept of a library of electronic works that could be
+freely shared with anyone. For forty years, he produced and
+distributed Project Gutenberg-tm eBooks with only a loose network of
+volunteer support.
+
+Project Gutenberg-tm eBooks are often created from several printed
+editions, all of which are confirmed as not protected by copyright in
+the U.S. unless a copyright notice is included. Thus, we do not
+necessarily keep eBooks in compliance with any particular paper
+edition.
+
+Most people start at our Web site which has the main PG search
+facility: www.gutenberg.org
+
+This Web site includes information about Project Gutenberg-tm,
+including how to make donations to the Project Gutenberg Literary
+Archive Foundation, how to help produce our new eBooks, and how to
+subscribe to our email newsletter to hear about new eBooks.
+
+
+
+</pre>
+
+</body>
+</html>
diff --git a/167-h/images/fig1.gif b/167-h/images/fig1.gif
new file mode 100644
index 0000000..1e808dc
--- /dev/null
+++ b/167-h/images/fig1.gif
Binary files differ
diff --git a/167-h/images/fig10.gif b/167-h/images/fig10.gif
new file mode 100644
index 0000000..3b72658
--- /dev/null
+++ b/167-h/images/fig10.gif
Binary files differ
diff --git a/167-h/images/fig11.gif b/167-h/images/fig11.gif
new file mode 100644
index 0000000..814f2d1
--- /dev/null
+++ b/167-h/images/fig11.gif
Binary files differ
diff --git a/167-h/images/fig12.gif b/167-h/images/fig12.gif
new file mode 100644
index 0000000..c3b5177
--- /dev/null
+++ b/167-h/images/fig12.gif
Binary files differ
diff --git a/167-h/images/fig13.gif b/167-h/images/fig13.gif
new file mode 100644
index 0000000..a5a7f70
--- /dev/null
+++ b/167-h/images/fig13.gif
Binary files differ
diff --git a/167-h/images/fig2.gif b/167-h/images/fig2.gif
new file mode 100644
index 0000000..adb45e2
--- /dev/null
+++ b/167-h/images/fig2.gif
Binary files differ
diff --git a/167-h/images/fig3.gif b/167-h/images/fig3.gif
new file mode 100644
index 0000000..1518604
--- /dev/null
+++ b/167-h/images/fig3.gif
Binary files differ
diff --git a/167-h/images/fig4.gif b/167-h/images/fig4.gif
new file mode 100644
index 0000000..d655854
--- /dev/null
+++ b/167-h/images/fig4.gif
Binary files differ
diff --git a/167-h/images/fig5.gif b/167-h/images/fig5.gif
new file mode 100644
index 0000000..bef4047
--- /dev/null
+++ b/167-h/images/fig5.gif
Binary files differ
diff --git a/167-h/images/fig8a.gif b/167-h/images/fig8a.gif
new file mode 100644
index 0000000..b51ef25
--- /dev/null
+++ b/167-h/images/fig8a.gif
Binary files differ
diff --git a/167-h/images/fig8b.gif b/167-h/images/fig8b.gif
new file mode 100644
index 0000000..b743eae
--- /dev/null
+++ b/167-h/images/fig8b.gif
Binary files differ
diff --git a/167-h/images/fig9.gif b/167-h/images/fig9.gif
new file mode 100644
index 0000000..700661b
--- /dev/null
+++ b/167-h/images/fig9.gif
Binary files differ
diff --git a/167-h/images/titlepage.gif b/167-h/images/titlepage.gif
new file mode 100644
index 0000000..44f5867
--- /dev/null
+++ b/167-h/images/titlepage.gif
Binary files differ
diff --git a/LICENSE.txt b/LICENSE.txt
new file mode 100644
index 0000000..6312041
--- /dev/null
+++ b/LICENSE.txt
@@ -0,0 +1,11 @@
+This eBook, including all associated images, markup, improvements,
+metadata, and any other content or labor, has been confirmed to be
+in the PUBLIC DOMAIN IN THE UNITED STATES.
+
+Procedures for determining public domain status are described in
+the "Copyright How-To" at https://www.gutenberg.org.
+
+No investigation has been made concerning possible copyrights in
+jurisdictions other than the United States. Anyone seeking to utilize
+this eBook outside of the United States should confirm copyright
+status under the laws that apply to them.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..05575f1
--- /dev/null
+++ b/README.md
@@ -0,0 +1,2 @@
+Project Gutenberg (https://www.gutenberg.org) public repository for
+eBook #167 (https://www.gutenberg.org/ebooks/167)
diff --git a/old/167.txt b/old/167.txt
new file mode 100644
index 0000000..2ad99aa
--- /dev/null
+++ b/old/167.txt
@@ -0,0 +1,5132 @@
+The Project Gutenberg EBook of American Handbook of the Daguerrotype, by
+Samuel D. Humphrey
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever. You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.net
+
+
+Title: American Handbook of the Daguerrotype
+
+Author: Samuel D. Humphrey
+
+Release Date: July 7, 2008 [EBook #167]
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK AMERICAN HANDBOOK - DAGUERROTYPE ***
+
+
+
+
+Produced by Gregory Walker, for the Digital Daguerreian Archive Project.
+
+
+
+
+
+
+
+
+
+
+[Illustration: Title page]
+
+
+
+This etext was created by Gregory Walker, Austin, Texas, for the
+Digital Daguerreian Archive Project.
+
+Internet: gwalker@netcom.com CompuServe: 73577,677
+
+Page numbers explicitly referred to in the text are marked at their
+beginning by "[page ##]" on a separate line. The location of the
+illustrations in the text are marked by "[amdg_##.gif]" on a separate
+line. I hope this etext inspires a wider interest in the origins of
+photography and in the modern practice of the Daguerreian Art.
+
+
+[Updater's note: In this version, the above page numbering convention
+has been replaced by "{##}" sequences placed in line with the
+surrounding text.]
+
+
+
+
+
+AMERICAN HAND BOOK
+
+OF THE
+
+DAGUERREOTYPE
+
+
+GIVING
+
+THE MOST APPROVED AND CONVENIENT
+
+METHODS FOR PREPARING THE CHEMICALS, AND
+
+THE COMBINATIONS USED IN THE ART.
+
+
+CONTAINING THE
+
+DAGUERREOTYPE, ELECTROTYPE,
+
+AND VARIOUS OTHER PROCESSES EMPLOYED IN TAKING
+
+HELIOGRAPHIC IMPRESSIONS.
+
+
+
+BY
+
+S. D. HUMPHREY
+
+
+
+FIFTH EDITION
+
+
+
+NEW YORK:
+
+PUBLISHED BY S. D. HUMPHREY
+
+37 LISPENARD STREET
+
+1858
+
+
+
+
+Entered, according to Act of Congress, in the year 1858, by S. D.
+HUMPHREY, In the Clerk's Office of the District Court of the Southern
+District of New York.
+
+
+
+
+To J. GURNEY, WHOSE PROFESSIONAL SKILL, SCIENTIFIC ACCURACY, AND
+ENERGETIC PERSEVERANCE, HAVE WON FOR HIM UNIVERSAL ESTEEM, THIS WORK IS
+MOST RESPECTFULLY INSCRIBED.
+
+
+
+
+PREFACE.
+
+There is not an Amateur or practical Daguerreotypist, who has not felt
+the want of a manual--Hand Book, giving concise and reliable
+information for the processes, and preparations of the Agents employed
+in his practice.
+
+Since portraits by the Daguerreotype are at this time believed to be
+more durable than any other style of "Sun-drawing," the author has hit
+upon the present as being an appropriate time for the introduction of
+the Fifth Edition of this work. The earlier edition having a long
+since been wholly; exhausted, the one now before you is presented.
+
+The endeavor has been to point out the readiest and most approved
+Methods of Operation, and condense in its pages; as much practical
+information as its limits will admit. An extended Preface is
+unnecessary, since the aim and scope of this work are sufficiently
+indicated by the title.
+
+S. D. HUMPHREY NEW YORK, 1858.
+
+
+
+
+CONTENTS
+
+CHAPTER I.
+
+Polishing the Daguerreotype Plate--Buffing the Plate--Coating the
+Plate--Exposure of the Plate in the Camera--Position Developing the
+Daguerreotype--Exposure to Mercury--Removing the Coating--Gilding or
+fixing the Image--Coloring Daguerreotype, . . . . . 18
+
+
+CHAPTER II.
+
+Coloring Back Grounds--Transparent ditto--Gilding Dissolvent--Solution
+for removing Specks--Solarized Impression--To Purify Water--Cleaning
+Mercury--Adhesive Paper--Black Stain for Apparatus--Sealing Wax for
+Bottles--Rouge--Rotten Stone--Potassa Solution--Hyposulphite
+Solution--Substitute for do.--Gilding Solution--Solution for increasing
+the Brilliancy of the Daguerreotype--Bleaching Solution;--Cold
+Gilding--Neutralizing Agents--Buff Dryer--Keeping Buffs in
+order--Cleaning Buckskins--Reflector for taking Views, . . . . 52
+
+
+CHAPTER III.
+
+Bromine and its Compounds--Iodine and its Compounds--Chlorine and its
+Compounds--Cyanide of Potassium--Hyposulphite of Soda--Hyphosulphite of
+Gold--Nitric Acid--Nitro-Muriatic Acid--Hydrochloric Acid--Hydrofluoric
+Acid--Sulphuric Acid--Accelerating Substances--Liquid Sensitives--Dry
+Sensitives, etc., etc., . . . . . 72
+
+
+CHAPTER IV.
+
+Light--Optics--Solar Spectrum--Decomposition of Light--Light, Heat, and
+Actinism--Blue Paper and Color for the Walls of the Operating
+Room--Proportions of Light, Heat and Actinism composing a
+Sunbeam--Refraction--Reflection--Lenses--Copying Spherical
+Aberration--Chromatic Aberration, . . . 131
+
+
+CHAPTER V.
+
+To make Plates for the Daguerreotype--Determining the Time of Exposure
+in the Camera--Instantaneous Process for Producing
+Daguerreotype--Galvanizing the Daguerreotype Plate--Silvering
+Solution--Daguerreotype without Mercury--Management of Chemicals--Hints
+and Cautions--Electrotyping--Crayon Daguerreotypes--Illuminated
+Daguerreotypes--Natural Colors in Heliography--Multiplying
+Daguerreotypes on one Plate--Deposit in Gilding--Practical Hints on the
+Daguerreotype, . . . 149
+
+
+CHAPTER VI.
+
+An Account of Wolcott and Johnson's Early experiments in the
+Daguerreotype, . . . 188
+
+
+
+
+AMERICAN HAND-BOOK of THE DAGUERREOTYPE.
+
+
+CHAPTER I.
+
+Polishing the Daguerreotype Plate--Buffing the Plate--Coating the
+Plate--Exposure of the Plate in the Camera--Position--Developing the
+Daguerreotype--Exposure to Mercury--Removing the Coating--Gilding or
+fixing the Image--Coloring Daguerreotype.
+
+
+Polishing the Daguerreotype Plate.--I shall endeavor to present to the
+reader the process I have found productive of good and satisfactory
+results, presenting the same in a clear and concise manner, so that any
+one, by following the various manipulations given, will be enabled to
+succeed. If there is any one part of the process in Daguerreotype in
+which operators fail more than all others, it is in not properly
+preparing the plate. It has truly been said that it would take a
+volume to describe all the methods that have been suggested for
+polishing the plate.
+
+I shall confine myself to the following description, which has been
+successfully practised, also most generally adopted by our operators,
+and I believe equal, if not superior to any other method, yet at the
+same time it is not of so much importance what particular method is
+employed, so that it be thoroughly and skillfully carried out.
+
+There is a general tendency with beginners to slight this operation;
+hence the necessity of adopting a system which precludes the
+possibility of doing so. During many years' study and practice in the
+art, I have tried numerous methods and substances for the better
+accomplishment of the end in view, and have finally settled upon the
+following, as being (so far as experience allows me to Judge) the modus
+operandi, best suited to all circumstances; under no condition would I
+approve of a method less rigorous or precise.
+
+The operator being provided with a bottle of finely prepared rotten
+stone, cover the mouth of the bottle with a piece of thick paper, this
+perforated with a pin so that the rotten stone can be dusted on the
+plate. Fasten the plate on the holder, take the rotten stone (Becker's
+can always be depended upon), and dust on lightly until the surface is
+freely covered; now drop on the plate's surface a few drops of an
+alcoholic solution.*
+
+* This solution is composed of equal parts of alcohol and water, for
+the summer, and in winter three parts alcohol to one of water; a few
+drops of potassa solution may be added, and is known to have a decided
+effect upon the plate.
+
+Take a patch of Canton flannel; in order to prevent the moisture from
+the hand it should have a thick, firm texture: with this rub the plate
+in circles across, then back covering one-half of the former row of
+circles in each crossing until you have gone over the plate and back to
+the point of beginning, occupying at least half a minute in the
+operation, for a small plate, and so in proportion for the other sizes.
+
+Care should be observed to keep the patch wet with the alcoholic
+solution forming a paste on the surface of the plate; the motion of the
+hand should be brisk and free, not hurried, and the pressure about
+equal to that of a pound weight. When the cotton is disposed to adhere
+to the plate, and slip from under the finger, spread the fore and
+middle fingers a little apart, then pressing down, bring them together
+in such a manner as to form a fold in the cloth between them, by which
+means you will hold it perfectly secure.
+
+Avoid wetting the fingers, and should they perspire, wipe them often,
+as the moisture penetrating the cotton and coming in contact with the
+plate, would cause streaks it would be difficult to remove. I will
+here remark that many operators use much more cotton flannel than there
+is need of. I have found in my experience that a single patch, about
+one and half inch square, will be better for cleaning a number of
+plates than a new piece for every plate. This is the case for the wet,
+and for the dryrubbing two or three pieces will be found to answer.
+Thus with four or five cloths a dozen plates may be prepared.
+
+Some operators use prepared cotton, and think it more convenient than
+the flannel. This may be had prepared free from seeds and in a very
+perfect state, if wished.
+
+In going over the plate, great care should be observed, in touching its
+surface as equally as possible. The greatest care should be taken
+neither to touch the plate with the fingers, nor that part of the
+cotton flannel which is to come in contact with its surface; take a
+clean piece of flannel by one corner, snap it smartly to free it from
+dust and loose fibres, lay it face-side upward, dust on a little fine
+rotten stone; with this, polish around, or across, or in circles,
+lightly and briskly, passing gradually over the whole surface of the
+plate, as was done before with the wet. The plate should now exhibit a
+bright, clear, uniform surface, with a strong metallic lustre,
+perfectly free from any appearance of film; if not, the last polished
+should be continued until the effect is obtained, and when once
+obtained, the plate is ready for buffing.
+
+Buffing the Plate.--There are a variety of ways and means employed in
+this part of the operation. Some choose wheels, and others prefer the
+ordinary hand-buff. I have been unable to detect any peculiar advantage
+in the use of the wheel except in the facility of the operation; no
+doubt, however, but there is a saving of time, particularly in the
+preparation of the larger plates. For general use, we have not seen a
+wheel better adapted for this purpose than the one patented by Messrs.
+Lewis.
+
+It is generally well to use a hand-buff before placing the plate on the
+wheel; this is in order to prevent, as far as possible, the dust or
+other substance that may be on the surface of the plate from coming in
+contact with the cover of the wheel. I will here follow out the use of
+the hand-buffs (two are necessary) as they are mostly used.
+
+In the morning, before using the buffs, brush both as clean as
+possible, in order to free them from dust; then with the blade of a
+pair of shears, held perpendicular, rub the buffs from end to end; then
+knock them both together in order to free them from all dust or other
+substances, occasionally exposing them to the sun or to the fire.
+
+With one of the buffs (reserving the finest and softest for the last
+operation), powder its face with fine rouge and brush off slightly,
+leaving only the finest particles in it. Every operator should have
+two plate-holders; one for cleaning and one for buffing the plate; for
+when using only one, the rotten stone is liable to get on the buff and
+scratch the plate.
+
+Rest the fingers of the left hand on the back of the buff, near the
+farther end, with about the same pressure as in cleaning, while with
+the right you bear on the handle to correspond, and give the buff a
+free, easy, horizontal motion, passing it very nearly the whole length
+over the plate each time. Continue this operation in such a manner
+that the plate will on all parts of its surface have received an equal
+amount of polish. This buff once well filled with polish, add but
+little after, say a small quantity once in two or three plates. The
+polish as well as the buffs must be kept perfectly dry.
+
+The second buff should always be in the best order, and if this is the
+case, but little polish after the first need be used. Much depends
+upon the last finish of the surface of the plate, and as a fine
+impression is desired in the same ratio, the operator must exercise
+care and skill in this operation. Some buff the smaller plates on the
+hands, by resting them on the fingers in such a manner that the buff
+cannot touch them; some by holding the edges with thumb and little
+finger, with the remaining fingers under, or on the back; and others
+buff on the holder. When this last method is adopted, it requires the
+greatest caution to prevent the dust from getting on the buff. The
+holder should be wiped clean.
+
+The plate frequently slips off or around, and the buff comes in contact
+with the bed of the holder. When, however, the operator is so
+unfortunate as to meet with this mishap, the utmost care must be
+observed in thoroughly cleaning the buff cover before further buffing.
+In this last buffing it may be continued as before, except without the
+application of polish powder to the last buff. Examine the surface
+occasionally, and buff more lightly towards the close of the operation,
+using at last the mere weight of the buff. This last buffing should
+occupy as long a time as the first.
+
+The point to be aimed at is, the production of a surface of such
+exquisite polish as to be itself invisible, like the surface of a
+mirror. The secret of producing pictures discernible in any light,
+lies in this: the more dark, deep and mirror-like the surface of the
+plate, the more nearly do we approach to perfection.
+
+In all cases, very light and long continued buffing is productive of
+the greater success, since by that means a more perfect polish can be
+obtained.
+
+The question is often asked, why is it that the plates receive the
+coating so unevenly? I will answer by saying that it may arise from
+two causes: the first and most general cause is that those parts of the
+plate's surface which will receive the heaviest coating have been more
+thoroughly polished, and the consequence is that it is more sensitive
+to the chemical operation; second, and might perhaps be considered a
+part of the first, the heat of the plate may not be equal in all its
+parts; this may arise from the heat caused by the friction in buffing.
+It is a well known fact, with which every observing practitioner is
+familiar, that a silver plate at a temperature of 45 deg. or less,
+exposed to the vapors of iodine, is less sensitive and takes a longer
+time to coat, than when it is at a temperature of 60 deg. or more.
+
+Whenever a view is to be taken, or any impression which requires the
+plate to be turned on the side, it should be buffed in the other
+direction, so that the marks will always be horizontal, when the
+picture is in position. With the finest possible polish, the plate is
+ready for the coating box.
+
+The question is often asked by operators, what is the state of the
+plate when polished and allowed to stand for a time before using? To
+meet this point we hare only to consider the silver and the power
+acting upon it. Pure atmosphere does not act upon silver; but we do
+not have this about in our operating rooms, as it is more or less
+charged with sulphurated hydrogen, which soon tarnishes the surface of
+the plate with a film of brown sulphurate. It is this that sometimes
+causes the specks which appear on finishing the impression, and are a
+great annoyance. Hence we see that the plate should be buffed just
+before receiving the vapor of iodine. Mr Hunt gives his opinion of the
+use of diluted nitric acid as the best solution for freeing, the
+surface of the plate; he says:
+
+"Numerous experiments on plated copper, pure silver plates, and on
+silvered glass and paper, have convinced me that the first operation of
+polishing with nitric acid, etc., is essential to the production of the
+most sensitive surface. All who will take the trouble to examine the
+subject, will soon be convinced that the acid softens the silver,
+bringing it to a state in which it is extremely susceptible of being
+either oxydized or iodized, according as the circumstances may occur of
+its exposure to the atmosphere or the iodine."
+
+I cannot see the objection to this solution; not, however, in general
+use. Our operators do not find it of sufficient importance to the
+success of their pictures to accept it, the alcoholic solution being in
+its nature less objectionable.
+
+I will say here, that a plate submitted to only an ordinary polish is
+found to contain numberless minute particles of the powder made use of.
+Should the same plate be buffed for a long time, the polish will nearly
+all disappear, leaving the cavities in the surface free for the action
+of agents employed in subsequent operation. For this reason, I find
+that great amount of polishing powder should not be applied to the last
+buff, and it is obvious that three buffs can be employed to adventure;
+the two last should not receive any polishing materials. I have
+examined a plate that was considered to possess a fine finish, and
+similar had produced good impressions; these same plates, when
+subjected to a long and light buffing, would present a surface no finer
+in appearance to the naked eye; but upon exposure to the solar
+radiation, would produce a well-defined image in one fourth less time
+than the plate without the extra buffing.
+
+Coating the Plate.--For this purpose our mechanics and artists have
+provided a simple apparatus called a coating-box, which is so arranged
+as to be perfectly tight, retaining the vapor of the iodine or
+accelerators, and at the same time allowing, by means of a slide, the
+exposure of the plate to these vapors. They can readily be obtained by
+application to any dealer, all of whom can furnish them.
+
+The principal difficulty in coating the plate, is that of preserving
+the exact proportion between the quantity of iodine and bromine, or
+quick. It is here necessary to say, that hardly any two persons see
+alike the same degree of color, so as to be enabled to judge correctly
+the exact tint, i. e. what one might describe as light rose red, might
+appear to another as bright or cherry red; consequently, the only rule
+for the student in Daguerreotype, is to study what appears to him to be
+the particular tint or shade required to aid him to produce the desired
+result. Practise has proved that but a slight variation in the
+chemical coating, of the Daguerreotype plate will very materially
+affect the final result.
+
+The operator will proportion the coating of iodine and bromine or
+accelerators according to the strength and composition of the latter.
+
+Experience proves that the common impressions, iodized to a rather
+light yellow gold tint, and brought by the bromine to a very light,
+rose color, have their whites very intense, and their deep shades very
+black. It is also known that if you employ a thicker coating of iodine
+and apply upon it a proportionate tint of bromine, so as to obtain a
+deep rose tint, delineations will be less marked, and the image have a
+softer tone. This effect has been obvious to everyone who has
+practised the art. Thus I may observe that the light coatings produce
+strong contrast of light and shade, and that this contrast grows
+gradually less, until in the very heavy coating it almost wholly
+disappears. From this it will readily be perceived that the middle
+shades are the ones to be desired for representing the harmonious
+blending of the lights and shades.
+
+Then, if we examine, with respect to strength, or depth of tone, and
+sharpness of impression, we see that the light coating, produces a very
+sharp but shallow impression; while the other extreme gives a deep but
+very dull one. Here, then, are still better reasons for avoiding
+either extreme. The changes through which the plate passes in coating
+may be considered a yellow straw color or dark orange yellow, a rose
+color more or less dark in tint, or red violet, steel blue or indigo,
+and lastly green. After attaining this latter color, the plate resumes
+a light yellow tint, and continues to pass successively a second time,
+with very few exceptions, through all the shades above mentioned.
+
+I will here present some excellent remarks upon this subject by Mr.
+Finley. This gentleman says:
+
+"It is well known to all who have given much attention to the subject,
+that an excess of iodine gives the light portions of objects with
+peculiar strength and clearness, while the darker parts are retarded,
+as it were, and not brought out by that length of exposure which
+suffices for the former. Hence, statuary, monuments, and all objects
+of like character, were remarkably well delineated by the original
+process of Daguerre; the plate being coated with iodine alone. An
+excess of bromine, to a certain degree, has the opposite effect; the
+white portions of the impression appearing of a dull, leaden hue, while
+those which should be black, or dark, appear quite light. This being
+the case, I conclude there must be a point between the two extremes
+where light and dark objects will be in photogenic equilibrium. The
+great object, therefore, is to maintain, as nearly as possible, a
+perfect balance between the two elements entering into union to form
+the sensitive coating of the plate, in order that the lights and shades
+be truly and faithfully represented, and that all objects, whether
+light or dark, be made to appear so far conformable to nature, as is
+consistent with the difference in the photogenic energy of the
+different colored rays of light. It is this nicely-balanced
+combination which ensures, in the highest degree, a union of the
+essential qualities of a fine Daguerreotype, viz., clearness and
+strength, with softness and purity of tone.
+
+"So far as I know, it is the universal practice of operators to judge
+of the proportion of iodine and bromine in coating the plate, by two
+standards of color the one fixed upon for the iodine, the other for the
+additional coating of bromine. Now I maintain that these alone form a
+very fallacious standard; first, because the color appears to the eye
+either lighter or darker, according as there is more or less light by
+which we inspect the coating; and secondly, because if it occur that we
+are deceived in obtaining the exact tint for the first coating, we are
+worse misled in obtaining the second, for if the iodine coating be too
+light, then an undue proportion of bromine is used in order to bring it
+to the second standard, and vice versa."
+
+The iodine box should be kept clean and dry. The plate immediately
+after the last buffing, should be placed over the iodine, and the
+coating will depend upon the character of the tone of the impression
+desired. Coating over dry iodine to an orange color, then over the
+accelerator, to a light rose, and back over iodine one sixth as long as
+first coating, will produce a fine, soft tone, and is the coating
+generally used for most accelerators. The plate iodized to a dark
+orange yellow, or tinged slightly with incipient rose color, coated
+over the accelerator to a deep rose red, then back over iodine
+one-tenth as long as at first coating, gives a clear, strong, bold,
+deep impression.
+
+I will here state a singular fact, which is not generally known to the
+operator. If a plate, coated over the iodine to a rose red, and then
+exposed to strong dry quick or weak bromine water, so that a change of
+color can be seen, then recoated over the iodine twice as long as at
+first coating, it will be found far more sensitive when exposed to the
+light than when it has been recoated over the iodine one-fourth of the
+time of the first coating.
+
+Probably the best accelerating combination is the American compound
+formerly known as "Gurney's American compound," or some of the
+combinations of bromide of lime. The first is thought to possess
+perhaps more uniformity in its action than any other combination I have
+ever used.
+
+The plate once coated should be kept excluded from the light by means
+of the plate holder for the camera box.
+
+I will notice one of the principal causes having a tendency to prevent
+the perfect uniformity of chemical action, between the iodine and
+silver; hydrogen, or the moisture in the atmosphere, makes a very
+perceptible barrier. This moisture may arise as the result of the
+cold, from a want of friction in the buffing of the plate, which,
+coming in contact with the warmer air, as a writer on this subject says:
+
+"It is well known that as often as bodies, when cold, are exposed to a
+warmer air, the humidity contained in them is condensed. It is to this
+effect that we must attribute the difficulty experienced in operating
+in most cases." This is corroborated by the results experienced by our
+operators. So it is seen that the plate should be of a temperature
+above that of the atmosphere. Mr. Gurney submits his plates to a
+gentle heat from a spirit lamp just before exposing them to the vapor
+of iodine. Experience has convinced me that a plate heated to about 80
+deg. before being exposed to iodine will present a far better defined
+image than a plate at a temperature of 50 deg. I account for this by
+noticing that, at a higher temperature, the plate throws off any larger
+crystals that might otherwise be deposited, receiving only the finer,
+thus producing a more perfect chemical combination of iodide of silver.
+I would call the attention of the operator to this point, as presenting
+something of interest, and which may direct in a way of accelerating
+the future operations.
+
+That the presence of a film of moisture over the plate is a preventive
+of uniform chemical action, may be readily understood from the fact
+that iodine is almost insoluble in water, requiring seven thousand
+parts of water to dissolve one of iodine, or one grain to a gallon of
+water. Yet its affinities for silver and other substances are so
+powerful as to prevent its existing in an insulated state, hence we can
+account for the frequent occurrence of a plate presenting parts of an
+image over its surface. It is quite evident that those parts of
+plate's surface covered with moisture are nothing like as sensitive to
+the iodine as those parts perfectly free.
+
+Exposure of the plate in the Camera, and Position.--The time of
+exposure necessary to produce an image upon the Daguerreotype plate,
+can only be determined by experiment, and requires a liberality of
+judgment to be exercised on the part of the operator. The constant
+variation of the light renders it impossible to lay down any exact rule
+upon this point. Light is not alone to be considered; the amount of
+coating exercises a deviating influence, also the subjects to be
+represented are not equally photogenic, some requiring much longer time
+of exposure than others. This may be easily observed by exposing the
+plate at the same time to a plaster bust and a piece of black velvet,
+the first being a much stronger reflector of light than the latter: the
+time necessary to produce a well developed image of the velvet being
+about six times longer than that required to produce an equally defined
+image of plaster. The manner of judging correctly of the time is by
+the appearance of impression after it has been developed by the
+mercurial vapors. Should it present a deep blue or black appearance it
+is solarized or over-timed. This sometimes is to an extent, that a
+perfect negative is formed, the white being represented black, and the
+dark light.
+
+An object requiring the particular care and attention of the operator
+is the proper focus. It is not unfrequently the complaint of sitters
+that their hands are represented as being magnified and greatly out of
+proportion with the general figure. This is the case also with the
+nose and eyes, but in a less degree. As this cannot be wholly
+remedied, it is desirous to come as near as possible, and in order to
+do this, it is necessary to present the figure in such a position as to
+bring it as nearly as possible upon the same plane by making all parts
+nearly at equal distance from the lenses. This must be done by the
+sitter inclining the head and bust formed to a natural, easy position,
+and placing the hands closely to the body, thus preserving a propel
+proportion, and giving a lively familiarity to the general impression.
+It is not an uncommon fault among our less experienced operators to
+give a front view of the face of nearly every individual, regardless of
+any particular form, and this is often insisted upon by the sitter,*
+who seems to think the truth of the picture exists principally in the
+eyes staring the beholder full in the face.
+
+* I might here picture some curious scenes experienced by our operators
+Every one is familiar with a certain class of our community whose ideas
+of the importance of a free and easy position of the body are too
+closely confined with stays, attention to toilet, tightly fitting dress
+coats and the like, to admit of being represented as if nature had
+endowed them with least possible power of flexibility. To such we
+would suggest the following, to be well learned and retained in the
+mind while presenting themselves before the Daguerreotype camera:
+
+"The experience of one who has often been Daguerreotyped, is, to let
+the operator have his own way."
+
+Nothing, in many instances, can be more out of place in a Daguerreotype
+portrait than this, for let a man with a thin, long,
+defeated-politician-face, be represented by a directly front view, we
+have, to all appearances, increased the width of the face to such an
+extent as to reveal it flat and broad, losing the characteristic point
+by which it would be the most readily recognized. The method we should
+adopt in taking the likeness of such an individual as above, would be
+to turn the face from the camera, so as to present the end of the nose
+and the prominence of the cheek bone equally distant from the lenses,
+and then focusing on the corner of the eye towards the nose, we cannot
+in many cases, fail to produce an image with the lips, chin, hair, eyes
+and forehead in the minutest possible definition.
+
+It should be the study of every operator to notice the effect of the
+lights and shades while arranging the sitter, and at the same time be
+very particular to give ease in the position.
+
+No matter how successful the chemical effect may have been, should the
+image appear stiff and monument-like, all is lost. "In the
+masterpiece, grace and elegance must be combined."
+
+I will here use the words of another, which are very true:
+
+"So great is the difference in many faces, when inspected in opposite
+directions, that one of the two views, however accurately taken, would
+not communicate the likeness--it not being, the usually observed
+characteristic form. When the right view of the head is obtained, it
+is first necessary to consider the size of the plate it is to be taken
+on, so as to form an idea of the proportion the head should bear to it.
+The mind must arrange these points before we commence, or we shall find
+everything, too large or too small for the happy proportion of the
+picture, and the conveying of a just notion of the stature. The work
+will have to be done over, and time sacrificed, if this is not attended
+to. The adjustment of the head to the size of the plate (as seen from
+the margin of the mat), is not to be taught: everyone must bring
+himself, by scrutinizing practice, to mathematical accuracy; for
+something will be discovered in every face which can be surmounted only
+by experience.
+
+"The eye nearest the camera, in a three-quarter-face, is placed in the
+middle of the breadth of the plate; the chin, in a person of middle
+stature, in the middle of the length, and higher according to the
+proportional height of the person."
+
+In regard to the proper elevation of the camera, it may be here stated
+that I have found it best in taking portraits where the hands are
+introduced, to place the camera at about equal height with the eyes of
+the sitter, in order to bring the face and hands equi-distant from the
+tube. It will be found, if the above be followed, that by attaching a
+string to the camera tube, and making a semi-circle, that the face and
+hands of the sitter will occupy a corresponding distance, and the
+consequence is that the impression will appear without the hands being
+magnified. It has been found that a person with a freckly face can
+have as fine, fair, and clear an impression as the most perfect
+complexion; this may be done by the subject rubbing the face until it
+is very red. The effect is to lessen the contrast, by giving the
+freckles and skin the same color and the photogenic intensity of the
+red and yellow being nearly the same, an impression can be produced
+perfectly clear.
+
+When a child is to be taken, and there are doubts of its keeping still,
+the operation may be accelerated by placing it nearer the window
+bringing the screen nearer, and placing a white muslin cloth over the
+head; this will enable you to work in one third of the usual time.
+Should the person move, or the plate become exposed to the light, it
+may be restored to its original sensitiveness by placing it over the
+quick, one or two seconds.
+
+Developing the Daguerreotype.--After the plate has been submitted to
+the operation of the light, the image is still invisible. It requires
+to be exposed to the vapors of heated mercury. It is not absolutely
+necessary to apply artificial heat to the mercury to develop the image,
+for fair proofs have been produced by placing a plate over the bath at
+the ordinary temperature of the atmosphere. This plan, however,
+requires a long time and cannot be adopted in practice, even if it were
+advisable. The time more usually required in developing the image over
+the mercurial vapors, is about two minutes, and the temperature is
+raised to a point necessary to produce the desired effect in that time.
+This point varies as indicated by different scales, but for the
+ordinary scales it is not far from 90 deg. cen.
+
+The mercury bath is accompanied with a centigrade thermometer, by which
+the heat is regulated. Those furnished by the manufacturers are not
+always correct, and it requires some experience to find the proper
+degree on the scale.
+
+I would here remark that it is advisable, when placing the spirit lamp
+under the bath, to so arrange it that the position of applied heat
+should always be on the same point, viz., should the heat be directly
+under the bulb containing the thermometer it would raise the mercury in
+the tube to the point marked, and the temperature of that in the bath
+would be far below what it should be; hence it is (where time is
+followed for developing) that many failures occur. This is observed
+more readily in the large baths made of thick iron, particularly upon
+first heating. In practice I apply the heat as nearly as possible
+between the centre of the bottom of the bath and the bulb containing
+the mercury tube. It is advisable to keep the lamp lighted under the
+bath from the time of commencing in the morning to the close of
+business at night. By this means you have a uniformity of action, that
+cannot be otherwise obtained.
+
+It is well known to the experienced Daguerreotypist, that different
+atmospheres have a decided effect upon the mercury in developing the
+Daguerreotype. It will require a greater degree of heat for one
+atmosphere than for another. Experience alone determines this little
+difference.
+
+In summer, on cloudy and stormy days, mercurial vapors rise more
+readily and quickly than in the temperature of autumn or winter. From
+60 degrees upwards towards the boiling point (660 deg.), the vapors of
+mercury rise in greater abundance and collect in larger globules on
+cold surfaces.
+
+For various reasons I prefer a high temperature and short exposure. It
+accelerates the process. It renders the lights of the picture more
+strong and clear, while the deep shades are more intense. It gives a
+finer lustre to the drapery. The solarized portions also are very
+seldom blue, especially after gilding. If heated too high, however,
+the light parts become of a dead, chalky white, and the shadows are
+injured by numerous little globules of mercury deposited over them.
+Just the right quantity of mercury leaves the impression of a
+transparent, pearly white tone, which improves in the highest degree in
+gilding. To mercurialize with exactness is a nice point. If there is
+reason to suspect having timed rather short in the camera, reduce the
+time over mercury in a corresponding proportion. A dark impression
+will be ruined by the quantity of mercury which would only improve a
+light one.
+
+If practicable, it is most expedient that the plate be submitted to the
+action of mercury immediately on coming from the camera. I have
+frequently, however, carried plates for miles in the plate-holders and
+after exposing in the camera, brought them back to expose to mercury,
+and obtained fair proofs; but for the reason before given, it is
+advisable to carry along the bath, and bring out the impression on the
+spot.
+
+It is sometimes the practice of inexperienced operators to take the
+plate off the bath and examine the impression by solar light. This
+plan should be abandoned, as it is almost sure to produce a dense blue
+film over the shadows.
+
+This I am led to believe is occasioned by the action of light on the
+yet sensitive portions of the plate, and made to appear only by
+subsequent exposure to mercury, being equivalent to solarization.
+
+There has been little said by our professors upon the subject of the
+position of the plates while exposed to the mercurial vapour. Mr.
+Hunt, in referring to this subject, says: "Daguerre himself laid much
+stress upon the necessity of exposing the plate to the mercury at an
+angle of about 45 deg.. This, perhaps, is the most convenient position
+as it enables the operator to view the plate distinctly, and watch the
+development of the design; but beyond this, I am satisfied there exists
+no real necessity for angular position. Both horizontally and
+vertically, I have often produced equally effective Daguerreotypes." I
+presume from the last sentence of Mr. Hunt, that he has confined his
+experiments to the smaller sized plates. Hence he may not have thought
+of the effect of the vertical exposure of a large plate.
+
+In America this is a subject of no little importance. When an
+impression is to be developed upon a plate fifteen by seventeen inches,
+were we to use an angle of about 45 deg., it would be found to make a
+perceptible difference in the appearance of the image. By examining
+the wood tops of our baths as formerly made, it will be found that
+there is a great variation in the distance from the mercury to the
+different portions of the plate. By measuring one of these tops for
+the size plate above mentioned, I find the distance to the nearest
+point between the mercury and the plate, to be thirteen, and the middle
+point sixteen, and the furthest point twenty-one and a half inches: by
+this we see that one point of the plate is eight and a half inches
+further from the mercury than the nearest point; even this is not the
+variation there would necessarily be, were we to adopt the angle of 45
+deg. as urged by Daguerre.
+
+Among our principal professors, the bevel top will not be found in use
+where the large plates are used. Should any one feel desirous to test
+more minutely the effect produced by a bevel top bath, I would suggest
+to them to place a frame, so constructed as to hold three sixth size
+plates, and fit it to the top of the bath, and so arrange it with
+openings that the plates may be placed, one at the nearest point of the
+mercury, the second midway, and the third to the greatest distance, and
+by placing the plates over at one and the same time, the experimenter
+will be enabled to judge if there exists a difference in the
+developing. In speaking of the above, reference is had to baths to the
+ordinary heights used by operators.
+
+We will now proceed to examine the effect produced by mercurial vapor
+upon the plate at different lengths of exposure. In some
+investigations which I have made upon the appearance of the
+Daguerreotype impressions when developed over mercury at 90 deg. C.
+(194 deg. F.), the following was the result. Plates, coated and
+exposed to light in our usual manner of operating, produced on exposure
+of
+
+1/2 minute, whole impression, deep blue.
+
+1 minute, ashy and flat; no shadows; linen, deep blue.
+
+1 1/2 minute, coarse and spongy; shadows, muddy; drapery, dirty reddish
+brown.
+
+2 minutes, shallow or watery; shadows, yellowish; drapery, brown.
+
+2 1/4 minutes, soft; face, scarcely white; shadows, neutral; drapery,
+fine dark brown linen somewhat blue.
+
+2 1/2 minutes, clear and pearly; shadows, clear and positive, of a
+purple tint; drapery, jet black, with the dark shades slightly frosted
+with mercury.
+
+2 3/4 to 3 minutes, hard and chalky; shadows, harsh; drapery,
+roughened, and misty with excess of mercury.
+
+The foregoing results will be found general.
+
+There are numerous opinions among our operators in regard to the
+quantity of mercury necessary for a bath. As regards this, I need only
+say, similar results occur when two pounds or two ounces are used, but
+the quantity generally employed is about a quarter of a pound. I am of
+the opinion that one ounce will answer as well as a larger quantity. I
+know of no better proof in favor of a small quantity than that
+presented in the following incident. Several years since, an operator
+(Mr. Senter, of Auburn, N.Y.) of my acquaintance, was requested to go
+several miles to take a Daguerreotype portrait of a deceased person.
+He packed up his apparatus and proceeded over a rough road for some
+distance to the house where he was to take the portrait, and arranging
+his apparatus, with all the expedition which the occasion required,
+after having everything in usual order (as was supposed), he proceeded
+and took some ten or twelve very superior impressions. They were fine,
+clear, and well developed. After taking the number ordered, he
+proceeded to repack his apparatus, and to his surprise, when he took up
+the bottle he carried the mercury in, he found it still filled, and
+none in the bath, except only such particles as had adhered to the
+sides, after dusting and being jolted for several miles over the rough
+road. From this it will be seen that a very little mercury will
+suffice to develop fine proofs. I saw some of the impressions referred
+to above, and they were certainly well developed, and very superior
+specimens of our art.
+
+Removing the Coating.--After the impression has been developed over the
+mercurial vapor, the next step is to remove the sensitive coating. For
+this purpose the following solution is used:
+
+Put about two ounces of hyposulphite of soda in a pint of water, which
+should always be filtered before using. A convenient way of doing this
+is to have two bottles, and a large funnel with a sponge pressed into
+the neck of it; or, what is better, some filtering paper folded in it.
+The solution in one bottle, the funnel is placed in the other, and the
+picture held over it; when the solution is poured on the plate, it runs
+from it into the filter, and is always ready for use.
+
+It is best that the washing be done immediately on the plate coming
+from the mercury bath. If allowed to stand long with the coating on,
+it assumes a very dark tint--as the operation of the light continues,
+though less active than while exposed in the camera, and destroys that
+brightness which would otherwise have been obtained. It is preferable
+to wash and gild a picture without it first being dried; yet when there
+are doubts of its giving satisfaction, there would sometimes be a
+saving by drying and getting the decision of the subject before
+gilding, as this last injures the plate for another impression. First,
+light your spirit-lamp, then with your plyers take the plate by the
+lower right-hand corner, holding it in such a manner that the plyers
+will form in a line with the upper left-hand corner; pour on, slowly,
+the hyposulphite solution, slightly agitating the plate, until all the
+coating is dissolved off; then rinse off with clean water, and if it is
+not to be gilded, dry by holding the plate perpendicular with the
+bottom left-hand corner lowest, and applying the blaze of the
+spirit-lamp to the back, at the same time blowing gently downward on
+the face of the plate.
+
+The hyposulphite solution should be often filtered through a sponge,
+and it will answer for a great number of washings. Yet it is observed
+that the mercury collects in this solution in small globules; these
+often come in contact with the plate, causing white spots, which spoil
+the impression. They should be guarded against, and the solution
+renewed. Again, in order to prevent streaks or scum on the surface of
+the plate, it is necessary that the coating should be removed with a
+good degree of uniformity. I find in practice that the hyposulphite of
+soda in our market varies much as regards strength, and consequently
+the rule to be adopted is to make a solution of sufficient strength to
+remove the coating in about ten seconds. I am aware that it may be
+said that this strong solution would have a tendency to injure the
+impression by destroying in a measure the sharpness of outline. To
+meet this, it need only to be said that the preventive is, to not let
+the solution rest on the surface of the plate for a longer time than is
+absolutely necessary, and then it should be drenched copiously with
+water; hence a chemical action upon the image is prevented and the
+general operation facilitated. This plan is adopted by our first
+operators with the greatest success.
+
+If the operator should allow the hyposulphite solution to run over the
+plate unevenly, it is quite likely that white or blue streaks would
+result. These it is impossible to remove without injury to the
+impression. Some, in order to prevent this, breathe over the surface,
+thus moistening it and putting it in a condition to receive the
+solution with greater uniformity. The plate should be well washed with
+water before gilding.
+
+Gilding, or Fixing the Image.--The next process to be given is that for
+fixing the image on the plate. This is done by precipitating a thin
+film of gold over the surface and is productive of the most brilliant
+effect when prepared immediately after the plate has been washed with
+water after the application of the hyposulphite solution, and before
+the plate has been allowed to dry. When, however, the plate has been
+dried and allowed to stand for any time, before gilding, the
+hyposulphite wash should be applied as at first, in order to destroy
+any chemical coating that may have been formed on exposure of the plate
+to the air. For gilding the larger plates, we have a gilding stand so
+constructed that the plate can be put on a perfect level. In practice,
+I prefer holding the plate with nippers, fastened at one corner. Hold
+the plate in the same manner as in removing the coating; pour on the
+gilding, newly filtered, until the surface is wholly covered, and with
+the blaze of the spirit lamp, at least three inches high, apply it to
+the back of the plate, moving it about, that the surface may be heated
+with as much uniformity as possible. Continuing this operation, the
+surface will generally become covered with small yellow bubbles which
+soon disappear, leaving the image clear and distinct.
+
+It is advisable to make use of a lamp having a sufficiently strong
+flame to produce the effect in a few minutes. If after a first
+heating, it is found that the impression can admit of a greater degree
+of intensity, it might be heated anew; but that is seldom necessary,
+and often by trying to do too, well, the operator, if he persists in
+heating certain parts of the plate, may find the liquid dry up just
+above the flame, and inevitably cause a stain*; or else the blacks are
+covered with a film, or even the coating of gold may suddenly
+exfoliate, when small particles are detached from the plate. The
+impression is then entirely spoiled, but the plate may be re-polished.
+
+* This can be remedied, however, if it is immediately washed over with
+the same solution that is on the plate, so that the surface shall not
+become cool; continue for a short time to apply the lamp under, and
+agitate the plate slightly, and it will soon be free from all
+imperfections and give a fine clear tone.
+
+It is not unfrequent that the surface assumes a dark, cloudy
+appearance. This is generally the best sign that the gilding will
+bring out the impression with the greatest degree of distinctness.
+Soon, the clouds gradually begin to disappear, and, "like a thing of
+life" stands forth the image, clothed with all the brilliancy and
+clearness that the combined efforts of nature and art can produce.
+When in the operator's judgment the operation has arrived at the
+highest state of perfection, rinse suddenly, with an abundance of clean
+water, and dry as before described.
+
+When an impression is dark, the gilding process may be longer
+continued; but when light, it should be gilded quickly, as lengthening
+the time tends to bleach the impression and make it too white. The
+cause of this appears to be, that with a moderate heat the chlorine is
+merely set free from the gold, and remaining in the solution, instead
+of being driven off, with its powerful bleaching, properties, it
+immediately acts upon the shades of the picture. A dark impression can
+thus, by a low heat, long-continued, be made quite light. To procure
+the best effect, then, heat suddenly with a large blaze, and judging it
+to be at the maximum, cool as suddenly as possible.
+
+When the hyposulphite of gold is used instead of the chloride, a less
+heat should be employed.
+
+Coloring Daguerreotypes.--Of all the so-called improvements in the
+Daguerreotype, the coloring is the least worthy of notice. Yet the
+operator is often, in fact most generally, called upon to hide an
+excellent specimen under paint. I can conceive of nothing more perfect
+in a Daguerreotype than a finely-developed image, with clearness of
+lights and shadows, possessing the lively tone resulting from good
+gilding. Such pictures, however, are not always had, and then color
+may perform the part of hiding the imperfections. We present the
+following method as given in Willat's Manual:
+
+"Daguerreotype portraits are now commonly met with beautifully colored;
+but the coloring is a process requiring great care and judgment, and
+many good pictures are spoiled in fruitless experiments. Several
+different methods of coloring have been proposed. The simplest mode
+appears to be that of using dry colors prepared in the following
+manner: A little of the color required, very finely ground, is thrown
+into a glass containing water, in which a few grains of gum arabic have
+been dissolved. After standing a few moments, the mixture may be
+passed through bibulous paper, and the residue perfectly dried for use.
+The principal colors used are Carmine, Chrome Yellow, Burnt Sienna,
+Ultramarine and White; boxes fitted with sets of colors properly
+prepared, may be obtained of the dealers, and include Carmine, White,
+Lilac, Sky Blue, Pink, Yellow, Flesh color, Orange, Brown, Purple,
+Light Green, Dark Green and Blue. With a few colors, however, all the
+rest may be made thus: Orange, by Yellow and Red; Purple, with Blue
+and Red; Green, Blue and Yellow; Brown, with Umber, Carmine and Lamp
+Black; Scarlet, Carmine and Light Red. While it is true that a little
+color may relieve the dark metallic look of some Daguerreotypes, it
+must not be concealed that the covering of the fine delicate outline
+and exquisite gradations of tone of a good picture with such a coating,
+is barbarous and unartistic.
+
+"The prevaling taste is, however, decidedly for colored proofs, and the
+following directions will assist the amateur in ministering to this
+perverted taste, should he be so inclined. The coloring should
+commence with the face, and the flesh tint must be stippled on (not
+rubbed) with a small camel's-hair brush, beginning from the centre of
+the cheek, taking great care not to go over the outline of the face,
+and also not to have too much color in the brush; the eyes and eyebrows
+must not be touched with color. After the flesh color is applied, take
+a piece of very soft cotton and pass it very gently backwards and
+forwards over the face, so as to soften down the color, and then apply
+the carmine to give the required tint. For men, the darker tints
+should predominate, and for women the warmer. Very light hair may be
+improved by a slight tint of brown, or yellow and brown, according to
+the color. In coloring the drapery, the same care must be used. No
+rules can be laid down for all the different colors required, and the
+amateur had better obtain the assistance or advice of some one
+accustomed to the use of colors. A little white with a dash of blue or
+a little silver, will improve white linen, lace, etc. The jewelry may
+be touched with gold or silver from the shells, moistened with
+distilled water, and laid on with a fine-pointed sable-hair brush.
+
+"Brilliants may be represented by picking the plate with the point of a
+pin or knife."
+
+
+
+
+MISCELLANEOUS.
+
+
+CHAPTER II.
+
+Coloring Back Grounds--Transparent ditto--Gilding Dissolvent Solution
+for removing Specks--Solarized Impression--To Purify Water--Cleaning
+Mercury--Adhesive Paper--Black Stain for Apparatus--Sealing Wax for
+Bottles--Rouge--Rotten Stone--Potassa Solution--Hyposulphite
+Solution--Substitute for do.--Gilding Solution--Solution for increasing
+the Brilliancy of the Daguerreotype--Bleaching Solution;--Cold
+Gilding--Neutralizing Agents--Buff Dryer--Keeping Buffs in
+order--Cleaning Buckskins--Reflector for taking Views.
+
+
+To Color Back-grounds--To obtain a properly colored back ground is a
+matter of no little importance to the Daguerreotype operator. I had
+nearly exhausted all patience, and tried the skill of painters to
+obtain a back-ground that would be suitable to my purpose; but all to
+no avail. At last I adopted the following method, and at a cost of
+coloring of twenty-five cents, can now produce a back-ground far more
+valuable than those which had cost five dollars before.
+
+Take common earth paint, such as is used in painting roofs; mix this
+with water to about the consistency of cream; then to four quarts of
+this mixture add about one pint of glue water (common glue dissolved in
+water, also about as thick as cream). This last will cause the paint
+to adhere to the cloth, to which it is applied with a common white-wash
+brush. By applying the brush on the coating while it is wet, it may be
+so blended that not a line can be seen, and a perfectly smooth color of
+any shade can be obtained. The shade of color I use is a light
+reddish-brown. Tripoli, rotten-stone, or any earthy matter, may be
+applied in the same manner.
+
+Transparent or Invisible Back-ground.--I give this as originally
+published in my System of Photography, 1849:
+
+"Take a large woollen blanket with long nap, the longer and rougher it
+is the finer will be the effect produced; stretch it on a frame of
+sufficient size, and suspend the frame at the centre of the upper end
+by a string fastened to a nail in the ceiling, from three to five feet
+back of the sitter. Having arranged this, fasten another string to the
+side of the frame, and while the operation is going on in the camera,
+swing the back-ground from right to left, continuing this during the
+whole time of sitting, and you have a clear "transparent" back-ground,
+which throws the image out in bold relief, and renders the surface of
+the plate invisible. If equalled at all it is only by atmospheric
+back-ground. I consider it to be the best ever known, and think it
+needs but to be tried to afford satisfactory proof that it is so.
+Although used by few before, since the first edition of this work at
+least two thirds of the operators have adopted its use; for any one can
+at once understand the principle and the effect which it produces."
+
+It may be added that a motion imparted to to any back-ground where
+softness is desired, produces an excellent effect.
+
+Gilding Dissolvent.--To one quart of muriatic acid add as much oxide of
+iron (common iron rust) as it will dissolve in two days. This may be
+done by putting in the oxide in excess. It should be frequently shook,
+and when wanted for bottling it should be allowed to stand in order to
+settle. When this is done the solution may be poured off, and reduced
+by adding to it an equal quantity of water; then it is ready for use.
+This constitutes a gilding dissolvent now in our market.
+
+Solution for Removing Specks.--There is probably no one cause of
+complaint so general as "what makes those black specks?" There are
+several causes which produce them, and probably the most general are
+dust, rouge, or a spray of moisture on the plate. It this be the case,
+there is no solution which can remove them, as they have prevented a
+chemical action with the silver, and their removal would only expose
+the surface of the plate which in itself would afford a contrast with
+the impression. Another and less dangerous source of these specks is
+organic matter contained in the solution employed in dissolving the
+chemicals, or the water in washing. Much of the hyposulphite of soda
+in market contains a sulphuret, which, coming in contact with the
+silver surface, immediately causes oxidation. Such spots, as well also
+as most all others found on the plate after it has been exposed in the
+camera, can be removed by the following, solution: To one ounce of
+water add a piece of cyanide of potassium the size of a pea; filter the
+solution and apply by pouring it on the surface of the plate. In all
+cases the plate should first be wet with water. Apply a gentle heat,
+and soon the spots disappear, leaving the impression clear and free
+from all organic matter.
+
+In the absence of cyanide of potassium, a solution of pure hyposulphite
+of soda will answer as a fair substitute.
+
+To Redeem, a Solarized Impression.--The Daguerreotype plate, prepared
+in the ordinary manner, should be exposed in the camera a sufficient
+time to solarize the impression. Then, before it be exposed to the
+vapor of mercury, expose it for a very brief period to the vapor of
+either chlorine, bromine or iodine. Then expose over mercury, as
+usual. I have produced singularly interesting results by this process.
+
+To Purify Water.--Filter the water well, and then add about three drops
+of nitric acid to the pint. This can be used as absolutely pure water,
+but I would recommend the use of distilled water as preferable.
+
+Cleaning Mercury.--Make a small bag of chamois skin, pour in the
+mercury, and squeeze it through the leather. Repeat this several
+times, and filter by means of a funnel made of paper, with a very small
+aperture, through which it will escape and leave the particles of dust,
+or other substances, in the paper. A paper with a pinhole through it
+will answer as well, and it is less difficult to make.
+
+Adhesive Paper.--Take gum arabic, four ounces, put it in a wide-mouthed
+bottle and pour on water about one-third above the gum. Add half ounce
+of isinglass, or fish glue, and a small piece of loaf sugar. Let all
+dissolve, and spread over French letter paper, with a brush or piece of
+sponge. If once spreading is not enough, perform the same operation a
+second time.
+
+Black Stain for Apparatus.--Dissolve gum shellac in alcohol, or procure
+shellac varnish at the druggists', stir in lampblack, and apply with a
+sponge or bit of rag. This will adhere to metal, as well as wood, and
+is used for the inside of camera, tubes, etc.
+
+Sealing Wax for Bottles.--Melt together six parts rosin and one
+beeswax, and add a small quantity of lampblack; or, if red is
+preferable, add red lead. Common white wax is best, as most chemicals
+act less upon it.
+
+When bottles containing bromine are to be sealed, it is well to grease
+the stopper. This, however, only when the bottle is in frequent use,
+for if it were to be sent by any conveyance it would be likely to fly
+out.
+
+Rouge.--The method employed by Lord Ross is probably unsurpassed in the
+production of rouge. He has given his process as follows:
+
+"I prepare the peroxide of iron by precipitation with water of ammonia,
+from a pure dilute solution of sulphate of iron; the precipitate is
+washed, pressed in a screw press till nearly dry, and exposed to a heat
+which in the dark appears a dull, low red. The only points of
+importance are, that the sulphate of iron should be pure, that the
+water of ammonia should be decidedly in excess, and that the heat
+should not exceed that I have described. The color will be a bright
+crimson inclining to yellow. I have tried both potash and soda, pure,
+instead of water of ammonia, but after washing with some degree of
+care, a trace of the alkali still remained, and the peroxide was of an
+ochrey color, till overheated, and did not polish properly."
+
+Care should be observed to apply rouge in a dry state to the surface of
+the plate.
+
+I would remark, that so far as my experience has gone, I consider good
+rouge fully equal to any other polishing, material for the last or
+finishing polishing; consequently I shall not take up my space in
+enumerating any of the great variety that find few advocates.
+
+Why Rouge is to be preferred.--"Because it burnishes better, and
+because it assists in fixing the layer of gold, rendering it less
+susceptible of being removed in scales when heated too much."
+
+Rotten Stone.--"Purchase the best ground rotten stone of the druggist,
+put a few ounces at a time in a wedgewood or porcelain mortar, with
+plenty of clean rain water. This should have about forty drops of
+nitric acid to the quart. Grind well, and after letting the mortar
+stand two minutes, pour into a third. After remaining undisturbed
+eight minutes, finally pour off into a fourth to settle. Rinse back
+the sediment in the second and third, and grind over with a new batch.
+Repeat the operation till you have all in the fourth vessel. Let this
+stand several hours, and pour off the water very carefully. Set the
+deposit in the sun, or by a stove to dry. When perfectly dry,
+pulverize, and it is ready for use. With a little trouble you will
+obtain in this way a much better article than can generally be bought
+of dealers. For the last washing, alcohol, or a mixture of alcohol and
+water, is preferable."
+
+Potassa Solution.--The use of a solution of potassa in the preparation
+of the plate was suggested in the early history of the Daguerreotype.
+It was thought to possess some peculiar property for improving the tone
+of the impression. It is used for moistening the rotten stone in
+polishing the plate, and may be prepared by putting about an ounce and
+a half of alcohol in a close bottle, and add half a stick of caustic
+potash. This will soon become of a deep red color. For use, fill your
+small bottle, having a quill in the cork, with alcohol, and add a few
+drops of the above, or enough to change it to a bright orange or
+saffron color.
+
+A Substitute for the Hyposulphite Solution.--M. DAGUERRE recommends the
+use of a solution of salt water for removing the coating off the plate.
+I found this of some service at one time during my travels. My
+hyposulphite bottle got broke and its contents lost, so as only to
+leave enough for preparing gilding. I resorted to the use of salt
+solution, and found it to answer well. Make a saturated solution of
+salt in water. First wash the plate with clear water; then immerse it
+in the saline solution, when it should be agitated, and the coating
+will soon disappear. Another process with a salt solution of half the
+strength of the above is very interesting and effectual. The plate
+having been dipped into cold water, is placed in a solution of common
+salt, of moderate strength; it lies without being acted upon at all;
+but if it be now touched on one corner with a piece of zinc, which has
+been scraped bright, the yellow coat of iodine moves off like a wave
+and disappears. It is a very pretty process. The zinc and silver
+forming together a voltaic pair, with the salt water intervening,
+oxidation of the zinc takes place, and the silver surface commences to
+evolve hydrogen gas; while this is in a nascent condition it decomposes
+the film of iodide of silver, giving rise to the production of
+hydriodic acid, which is very soluble in water, and hence instantly
+removed.
+
+This process, therefore, differs from that with hyposulphite. The
+latter acts by dissolving the iodide of silver, the former by
+decomposing it. It is necessary not to leave the zinc in contact too
+long, or it deposits stains, and in large plates the contact should be
+made at the four corners successively, to avoid this accident.
+
+Gilding Solution.--To one pint of pure rain or distilled water add
+fifteen grains of pure chloride of gold, and to another pint add sixty
+grains of hyposulphite of soda. When dissolved, pour the gold solution
+into the hyposulphite by small quantities, shaking well after each
+addition. The soda solution must not be poured into the gold, as the
+gold would be immediately decomposed, and the solution turn black, and
+be unfit for use.
+
+Some operators add muriate of potash and other substances, but these do
+not possess any advantage except in cases where it is necessary to
+bleach the solarized portions of the impression, and when such is the
+case, chloride of sodium (common salt) is probably as effective and is
+the most convenient. Add about a teaspoonful to two ounces of the
+gilding.
+
+Solution, for Increasing the Brilliancy of the Daguerreotype.--This
+solution will have the effect to thoroughly cleanse the surface of the
+gilded plate and excite a powerful influence on the general character
+of the impression. To a solution of three ounces of water, in which is
+dissolved a quarter of an ounce of cyanide of potassium, add one
+teaspoonful of a solution containing six ounces of water and half an
+ounce of each pure carbonate of potash, alum, common salt, gallic acid,
+sulphate of copper, and purified borax. While the plate is wet, pour
+on a little, and heat it with a powerful blaze. The effect will be
+quickly produced, in from three to fifteen seconds. Rinse and dry, as
+in the gilding.
+
+Bleaching Solution.--Make a saturated solution of muriate of ammonia
+(sal ammoniac) in pure water, and filter through paper. Reduce with an
+equal quantity of water when used. When the linen or any other portion
+of the impression is badly solarized, after removing the coating, rinse
+with water; then pour this upon the surface in the same manner as the
+gilding solution. If the solarization be very deep, apply the lamp
+beneath, and warm the plate a trifle. Now pour off, and, without
+rinsing, apply the gilding. The whole operation must be quickly
+performed, or the chlorine soon attacks the shades of the picture.
+When properly done, however, the solarized parts are restored to a
+clear, transparent white.
+
+Electro, or Cold Gilding.--This process I have adopted, and it produces
+exceedingly beautiful impressions for the stereoscope, adding a great
+charm to the pleasing effect of that instrument. It also possesses a
+pretty and curious effect on views. It is easy of trial, and may be
+used by dissolving one gramme of chloride of gold in half a litre of
+ordinary water, and thirty grammes of hyposulphite of soda in another
+half litre of similar water; then pour the solution of chloride of gold
+into that of soda, by little and little, agitating it exactly as in M.
+Fizeau's preparation, of which there is but a variation.
+
+When you wish to use it, pour some into a plate, or any other vessel of
+the same kind, sufficient to cover the proof; then, after having added
+to it a drop of ammonia, immerse the plate in it as soon as you take it
+out of the mercury-box, after having wiped its back and edges, and
+agitate the mixture quickly from right to left, so as to dissolve
+rapidly the coating of iodide of silver as usual. As soon as the plate
+appears white, cease all rapid motion, but continue to give it a slight
+undulating one; for if it were allowed to remain still for only a few
+minutes, the proof would be clouded. By little and little, the surface
+of the plate takes a yellow tint, which darkens more and more,
+approaching to bistre. You stop therefore, at the color you wish; and
+when the proof has been washed and dried, in the manner previously
+explained, it will be found to be fixed, without any stain, with a
+limpid surface, and an extraordinary warm tone. If you were to augment
+the proportions of the ammonia or chloride of gold, the operation would
+progress much quicker, but then the middle of the proof would be always
+much clearer than towards the border. The mixture may be used several
+times without being renewed. It does not, however, give such a
+beautiful color to the impression as when it is newly prepared. By
+communicating to the vessel containing the solution a continual motion,
+the impression, when once immersed, will be fixed. During that time,
+and while attending to anything else, watch its color; and at the end
+of ten minutes or a quarter of an hour, take it out of the bath and dry
+it.
+
+Agent for Neutralizing Bromine, Chlorine, and Iodine Vapors.--Aqua
+ammonia, sprinkled about the chemical or coating room, will soon
+neutralize all the vapor in the atmosphere of either chlorine, bromine,
+or iodine. No operator should be without, at least, a six-ounce bottle
+filled with ammonia. A little of its vapor about the camera-box has a
+decided and happy effect. Burnt coffee, pulverized, has also the
+property of destroying the vapors of the above chemicals, as also
+almost any other agent employed about the Daguerreotype room. Its
+deodorizing properties are such that if brought in contact with air
+filled with the odor of decomposing meat, it will instantly destroy all
+disagreeable smell. It can easily be used in the Daguerreotype room by
+placing a little of the raw bean, finely pulverized, on an old plate,
+and roasting it over the spirit-lamp.
+
+Buff Dryer.--There are various methods for keeping buffs dry and free
+from dust. Some place a sheet of iron against the wall at an angle
+sufficient to put a lamp between it and the wall, and then let the buff
+rest against the top of the sheet. By this method the buff is for its
+full length close to the heated iron, and at the same time exposed to
+the heated atmosphere and any dust that may be free. I would recommend
+some arrangement by which the buff would be inclosed. I have found the
+following to answer the purpose well, which is a box of sheet iron
+twenty inches long, eight wide and five high, with one end left open
+and the other closed; the cover is made of the same material, with the
+edges bent over to go on and off. There are several wires running
+through the centre of the sides, which it is necessary to cover with
+cloth or paper to absorb all the moisture that may be made by applying
+the heat, and the buffs are put in and taken out at the open end. In
+order that the heat may be as nearly uniform as possible, an iron bar
+one inch wide, eighteen inches long and one half inch thick, is so bent
+that the centre is one quarter inch from the bottom of the box, and
+that at least two inches of each end come in contact with the bottom;
+this being riveted on the bottom, and a lamp with a small blaze applied
+to the centre of the bar of iron. This will constitute one of the best
+and cheapest buff dryers in use. It may be suspended from the wall by
+placing wires around it, or it may stand upon legs. Perhaps a more
+convenient plan is to place it under the workbench in a similar
+position to a drawer. One precaution is necessary: when first heating
+the dryer, apply but a very gentle heat. This will prevent an
+accumulation of moisture, which would otherwise pass off in steam,
+coming in contact with the buff, thus causing a dampness. Another
+caution: never have the temperature of the air in the heater more than
+ten degrees above that which surrounds it.
+
+When wheels are used, they should be encased in a sheet iron or wood
+case. All those made for our market are provided in this respect.
+
+Keeping Buffs in Order.--This is one of the most important objects to
+arrest the attention of the operator. Every buff is more or less
+liable to get out of order by dust falling upon or coming in contact
+with the polishing powder employed in cleaning the plate. The edge of
+every plate should be thoroughly wiped and freed from any material that
+may adhere while cleaning. I have adopted the following method, which
+proves highly successful:
+
+Rub the buff leather, holding the face down, with the sharp edge of a
+pair of shears or a piece of glass. This brings out any portion of the
+skin which may have become matted from any moisture, and also takes out
+any substance imbedded in it, and prevents it from scratching. Then,
+with a stiff brush, rub the buff well, and it will be found to work
+well. This same process employ on wheels and hand buffs every morning,
+or oftener, as occasion requires.
+
+Preparing Buffs.--Two of these are necessary. That part of the stick
+to be covered should be about eighteen or twenty inches long, and three
+wide, and made crowning on the face from one end to the other, about
+one half inch. Before covering, these are to be padded with two or
+three thicknesses of Canton flannel. The buff should not be too hard,
+but padded with flannel, so that by drawing it over the plate, it may
+touch across the surface. The only proper material for buffs is
+prepared buckskin; and if prepared in a proper manner, this needs
+nothing but to be tacked upon the stick. There are several varieties
+of wheels employed; the one most generally adopted is Lewis' patent,
+which consists of several varieties of wheels. Any operator can make a
+suitable wheel on the same plan of a turning lathe.
+
+To Clean Buckskins.--When the operator is compelled to purchase an
+unprepared buckskin, the following is a good process for cleaning it:
+There is always in the buckskin leather that is purchased, more or less
+of an oily matter, which is acquired in its preparation, sometimes even
+amounting, to a third of its weight. The following is the mode of
+ridding it of this noxious ingredient: Dissolve, in about six or seven
+quarts of filtered water, about five ounces of potash; when dissolved,
+wash with the solution an ordinary buckskin; when it has been well
+stirred in the liquid, the water becomes very soapy, owing to the
+combination of the potash with the oily matters contained in the skin.
+Throw away this solution and use some fresh water without potash and
+rather tepid; change it several times until it remains quite limpid.
+Then gently stretch the skin to dry in an airy shaded place. When
+thoroughly dried, rub it well between the hands. It thus becomes very
+pliant and velvet-like.
+
+Reflectors for Taking Views.--There have been excellent cameras
+introduced for taking views, but the time of exposure, which is
+increased in proportion to the focal length, is considered an
+objection; consequently many adhere to the old plan of using the
+speculum, or rather, substitute a mirror. I now have one which I have
+used for several years and find it equal to any article of the kind
+have ever tried. One is easily made by a tin man, at a trifling
+expense. Procure a piece of best plate looking-glass, two and a half
+by five inches for a quarter, or four by eight for a half-sized camera;
+put a piece of pasteboard of the same size on the back, to protect the
+silvering, and stick around the edge in the same manner as in putting
+up a picture. Take a sheet of tin for the large size, or a half sheet
+for the other; place the glass crosswise in the centre; bend the ends
+of the tin over the edge of the glass and turn them back so as to form
+a groove to hold the glass, and still allow it to slide out and in.
+These ends of the tin must be turned out flaring, that they may not
+reflect in the glass.
+
+Have a tin band about an inch wide made to fit close on the end of the
+camera tube; place it on, and taking the tin containing the glass,
+bring it to an angle of forty-five degrees with the tube, extending
+nearly the whole length of the glass in front of the lenses; lap the
+loose ends of the tin on each side of the tin rim, and having your
+camera turned on the side to throw the view lengthwise, arrange the
+exact angle by examining the image on the ground-glass. When you have
+it exactly right, hold it while it is soldered fast to the band. Take
+out your glass and stain the tin black, to prevent reflection.
+
+
+
+
+CHEMICALS.
+
+CHAPTER III.
+
+Bromine and its Compounds--Iodine and its Compounds--Chlorine and its
+compounds--Cyanide of Potassium--Hyposulphite of Soda--Hyposulphite of
+Gold--Nitric Acid--Nitro-Muriatic Acid--Hydrochloric Acid--Hydrofluoric
+Acid--Sulphuric Acid--Accelerating Substances--Liquid Sensitives--Dry
+Sensitives, etc., etc.
+
+
+BROMINE.
+
+An article so extensively used in the practice of the Daguerreotypic
+art as Bromine, is deserving of especial attention, and accordingly
+every person should endeavor to make himself familiar with its
+properties and applications.
+
+History.--This element was discovered in 1826 by M. Balard, in the
+mother-liquor, or residue of the evaporation of sea-water. It is named
+from its offensive odor (bromos, bad odor). In nature it is found in
+sea-water combined with alkaline bases, and in the waters of many
+saline springs and inland seas. The salt springs of Ohio abound in the
+compounds of bromine, and it is found in the waters of the Dead Sea.
+The only use which has been made of bromine in the arts is in the
+practice of photography. It is also used in medicine In a chemical
+point of view it is very interesting, from its similarity in
+properties, and the parallelism of its compounds to chlorine and iodine.
+
+Dr. D. Alter, of Freeport, Pa., is the only American manufacturer, and
+furnishes all of the "American Bromine." Yet we understand much
+purporting to be of German manufacture is prepared from that made in
+Freeport. This is done by individuals in this city, who get well paid
+for the deception.
+
+For the successful application of bromine as an accelerating agent, we
+are indebted to Mr. John Goddard of London, who at the time was
+associated with Mr. John Johnson, now a resident of this city.
+
+Preparation.--The mother-liquor containing bromides is treated with a
+current of chlorine gas, which decomposes these salts, setting the
+bromine free, which at once colors the liquid to a reddish brown color.
+Ether is added and shaken with the liquid, until all the bromine is
+taken up by the ether, which acquires a fine red color and separates
+from the saline liquid.
+
+{74}
+
+Solution of caustic potash is then added to the ethereal solution,
+forming bromide of potassium and bromate of potash. This solution is
+evaporated to dryness, and the salts being collected are heated in a
+glass retort with sulphuric acid and a little oxide of manganese. The
+bromine is distilled, and is condensed in a cooled receiver, into a red
+liquid.
+
+Properties.--Bromine somewhat resembles chlorine in its odor, but is
+more offensive. At common temperatures it is a very volatile liquid,
+of a deep red color, and with a specific gravity of 3, being one of the
+heaviest fluids known. Sulphuric acid floats on its surface, and is
+used to prevent its escape. At zero it freezes into a brittle solid.
+A few drops in a large flask will fill the whole vessel when slightly
+warmed, with blood red vapors, which have a density of nearly 6.00, air
+being one. It is a non-conductor of electricity, and suffers no change
+of properties from heat, or any other of the imponderable agents. It
+dissolves slightly in water, forming a bleaching solution.
+
+Chloride of Bromine.--This as an accelerating agent is by many
+considered superior {75} to the other Bromide combinations. It can be
+readily prepared by passing a current of chlorine through a vessel
+containing bromine. A mixture of two parts muriatic acid and one of
+black oxide of manganese, should be put into a flask having a bent tube
+to conduct the chlorine vapor into the bromine in another vessel. This
+last vessel should also be supplied with a bent tube for conducting the
+combined vapors with a third vessel or receiver. On the application of
+the heat from a spirit lamp to the bottom of the flask, a current of
+chlorine gas will be disengaged, and pass into the bromine, when it
+readily combines, and gives off a vapor, which, when condensed in the
+third vessel, forms a volatile yellowish-red liquid. It is best, even
+at ordinary temperature, to place the receiver in an ice bath. For
+manner of using, see farther on, under head of Accelerators.
+
+Bromides.--A bromide treated with oil of vitriol, disengages
+chlorohyadic acid; but vapors of bromine are constantly disengaged, at
+the same time imparting a brown color to the gas. If the bromide be
+treated with a mixture of sulphuric acid, and peroxide of manganese,
+bromide is only disengaged. A solution of a bromide gives, with of
+nitrate {76} silver, a light yellowish white precipitate of bromide of
+silver, which is insoluble in an excess of acid, and readily dissolves
+in ammonia. The precipitated bromide is colored by light like the
+chloride, but is immediately tinged brown, while the chloride assumes
+at first a violet hue. The bromides, in solution, are readily
+decomposed and chloride being set free, colors the liquid brown.
+
+In the whole range of heliographic chemicals there is probably not
+another collection less understood and being so productive of
+interesting investigation as the bromides.
+
+Bromide of Iodine.--M. de Valicours furnishes us with the best method
+for preparing this mixture:
+
+"Into a bottle of the capacity of about two ounces, pour thirty or
+forty drops of bromine, the precise quantity not being of importance.
+Then add, grain by grain, as much iodine as the bromine will dissolve
+till quite saturated. This point is ascertained when some grains of
+the iodine remain undissolved. They may remain in the bottle, as they
+will not interfere with the success of the preparation.
+
+"The bromide of iodine thus prepared, from its occupying so small a
+space, can very easily be carried, but in this state it is much too
+concentrated to be used. When it is to be employed, pour a small
+quantity, say fifteen drops, by means of a dropping-tube, into a bottle
+containing about half an ounce of filtered river water. It will easily
+be understood that the bromide of iodine can be used with a greater or
+less quantity of water without altering the proportion which exists
+between the bromine and iodine."
+
+This article forms a very good dry accelerator, and is by some persons
+thought superior to all others, as it works with great uniformity, and
+is less liable to scum the plate in coating at high temperatures, or
+when the thermometer indicates a heat above 60 deg.
+
+Bromide of Potassium--Is prepared by mixing bromine and a solution of
+pure potass together, and evaporating to dryness; it crystallizes in
+small cubes, and dissolves readily in water. This agent is extensively
+employed in the paper and glass processes.
+
+Bromide of Lime. This the principal accelerator used in the American
+practice, and is the best of all dry combinations at present employed.
+There are many reasons why the dry is advantageous; these are too
+familiar to repeat.
+
+"The bromide of lime may be produced by allowing bromine vapor to act
+upon hydrate of lime for some hours. The most convenient method of
+doing this is to place some of the hydrate at the bottom of the flask,
+and then put some bromine into a glass capsule supported a little above
+the lime. As heat is developed during the combination, it is better to
+place the lower part of the flask in water at the temperature of about
+50 deg. Fah.; the lime gradually assumes a beautiful scarlet color,
+and acquires an appearance very similar to that of the red iodide of
+mercury. The chloro-iodide of lime may be formed in the same manner;
+it has a deep brown color. Both these compounds, when the vapor
+arising from them is not too intense, have an odor analogous to that of
+bleaching powder, and quite distinguishable from chlorine, bromine, or
+iodine alone."
+
+Farther on, I have given, in connection with accelerators, a process I
+adopt, which is far less tedious and equally reliable.
+
+Bromide of Silver--May be formed by pouring an alkaline bromide into a
+solution of nitrate of silver, in the shape of a white, slightly
+yellowish precipitate, which is insoluble in water and nitric acid, but
+readily dissolves in ammonia and the alkaline hyposulphites. Chlorine
+easily decomposes bromide of silver, and transforms it into chloride.
+
+M. Biot has expressed his opinion, that it is not possible to find any
+substance more sensitive to light than the bromide of silver. This is
+true to a certain extent, but in combination with deoxidizing agents,
+other preparations have a decided superiority over the pure bromide of
+silver.
+
+Bromide of Gold--Is readily prepared by adding a little bromide to the
+brown gold of the assayers, and allowing it to remain some time under
+water, or assisting its action by a gentle heat. It forms a salt of a
+bright crimson color, but in its general properties is precisely
+similar to the chloride used in gilding.
+
+Bromide of Magnesia--Is prepared in the same manner as bromide of lime.
+
+This mixture is particularly adapted for hot climates, and is used in
+this country by some few who regard its use as a valuable secret.
+
+Bromide of Starch.--This preparation is much used, but not alone. It
+is combined with lime by putting about one part in measure of starch to
+four of lime. It is prepared by adding bromine to finely pulverized
+starch, in the same manner as bromide of lime. (See Accelerators.)
+
+Experiments with Bromine.--Place in a very flaring wine glass a few
+drops (say ten) of bromine, then place a small piece of phosphorus
+about one-twentieth of an inch in diameter. Place the latter on the
+end of a stick from five to ten feet in length. So place it that the
+phosphorus can be dropped into the glass, and in an instant combustion
+giving a loud report will be the result.
+
+b. Expose a daguerreotype plate to the vapor of bromine, it assumes a
+leaden-grey color, which, blackens by light very readily. Exposing
+this to mercury will not produce any decided action upon the lights.
+Immerse it in the solution of the muriate of soda, and the parts
+unacted upon by light becomes a jet black, while the parts on which the
+light has acted will be dissolved off, leaving a clean coating of
+silver. This will be a most decided black picture on a white ground.
+
+c. Expose an impressioned plate, that has been sufficient time in the
+camera to become solarized, to the vapors of bromine, and the
+impression will be fully developed and exhibit no signs of
+solarization. The exposure over the bromine most be very brief.
+Chlorine or iodine will produce the same result. The latter is
+preferable.
+
+Again, should the impressioned plate be exposed too long over the vapor
+of bromine, the impression would be rendered wholly insensitive to the
+mercurial vapor. Hence this method is resorted to for restoring the
+sensibility of the plate when there is reason to believe that the
+impression would not be a desirable one; as, for example, if a likeness
+of a child be wanted, and it had moved before the plate had been
+sufficiently long exposed in the camera, the plate may be restored to
+its original sensitiveness by re-coating over bromine, as above, thus
+saving the time and labor of re-preparing the plate for the chemicals.
+
+d. If by accident (we would not advise a trial to any extent of this),
+you should inhale a quantity of the vapor of bromine, immediately
+inhale the vapor of aqua ammonia, as this neutralizes the dangerous
+effect of the bromine vapor. Every operator should be provided with a
+bottle of ammonia, as a little sprinkled about the chemical room soon
+disinfects it of all iodine or bromine vapor, and also tends to
+facilitate the operation in the camera.
+
+
+IODINE.
+
+History of Iodine.--This is one of the simple chemical bodies which was
+discovered in 1812 by M. Courtois, of Paris, a manufacturer of
+saltpetre, who found it in the mother-water of that salt. Its
+properties were first studied into by M. Gay Lussac. It partakes much
+of the nature of chlorine and bromine. Its affinity for other
+substances is so powerful as to prevent it from existing in an isolated
+state. It occurs combined with potassium and sodium in many mineral
+waters, such as the brine spring of Ashby-de-la-Zouche, and other
+strongly saline springs. This combination exists sparingly in
+sea-water, abundantly in many species of fucus or sea-weed, and in the
+kelp made from them. It is an ingredient in the Salt Licks, saline,
+and brine springs of this country, especially of those in the valley of
+the Mississippi. It is sparingly found in fresh-water plants, as well
+also in coal, and in combination with numerous other bodies.
+
+Fermented liquors contain iodine; wine, cider, and perry are more
+iodureted than the average of fresh waters. Milk is richer in iodine
+than wine; independently of the soil, with which it varies, the
+proportion of iodine in milk is in the inverse ratio of the abundance
+of that secretion. Eggs (not the shell) contain much iodine. A fowl's
+egg weighing 50 gr. contains more iodine than a quart of cow's milk.
+Iodine exists in arable land. It is abundant in sulphur, iron, and
+manganese ores, and sulphuret of mercury: but rare in gypsum, chalk,
+calcareous and silicious earths. Any attempt to extract iodine
+economically should be made with the plants of the ferro-iodureted
+fresh waters. Most of the bodies regarded by the therapeutists as
+pectoral and anti-scrofulous are rich in iodine.
+
+It is probably to the application of this body that we owe the
+discovery of the daguerreotype. There is no record of the precise date
+when Daguerre commenced experimenting with iodine, but by the published
+correspondence between him and M. Neipce, his partner, it was previous
+to 1833. There is no doubt, however, that the first successful
+application was made in 1838, as the discovery was reported to the
+world early in January, 1839.
+
+Preparation.--Iodine is mostly prepared from kelp, or the half
+vitrified ashes of seaweed, prepared by the inhabitants of the western
+islands, and the northern shores of Scotland and Ireland. It is
+treated with water, which washes out all the soluble salts, and the
+filtered solution is evaporated until nearly all the carbonate of soda
+and other saline matters have crystallized out. The remaining liquor,
+which contains the iodine, is mixed with successive portions of
+sulphuric acid in a leaden retort, and after standing some days to
+allow the sulphureted hydrogen, etc., to escape, peroxide of manganese
+is added, and the whole gently heated. Iodine distills over in a
+purple vapor, and is condensed in a receiver, or in a series of
+two-necked globes.
+
+Properties.--Iodine is solid at the ordinary temperature, presenting
+the appearance of dark-grey or purple spangles, possessing a high
+degree of metallic lustre. It somewhat resembles plumbago, with which
+it is sometimes diluted, particularly when it is fine. Operators
+should endeavor to secure the larger crystals. It melts at 224.6 deg.,
+forming a brown or nearly black liquid. It boils at about 356 deg.,
+and emits a very deep violet colored vapor. It gives off a very
+appreciable vapor, sufficient for all purposes of forming the iodide of
+silver on the daguerreotype plate, at a temperature of 45 deg. or even
+lower. Iodine crystallizes readily. Every operator has found upon the
+side of the jar in his coating-box, perfectly regular crystals,
+deposited there by sublimation.
+
+Water dissolves but a small proportion of iodine, requiring 7000 parts
+of water to dissolve one of iodine, {85} or one grain to the gallon of
+water. Alcohol and ether dissolve it freely, as does a solution of
+nitrate or hydrochlorate of ammonia and of iodides.
+
+The density of solid iodine is 4.95; that of its vapor 8.716. It
+greatly resembles chlorine and bromine in its combinations, but its
+affinities are weaker. It does not destroy the majority of organic
+substances, and vegetable colors generally resist its action. It
+combines with several organic substances, imparting to them peculiar
+colors. It colors the skin brown, but the stain soon disappears.
+
+Chloride of Iodine--Is formed by passing chlorine into a bottle
+containing some iodine. This can be readily done by pouring one ounce
+and a half of muriatic acid upon a quarter of an ounce of powdered
+black oxide of manganese, and heat it gradually in a flask, to which is
+adapted a bent glass tube. This tube must connect with the bottle
+containing the iodine, and the yellowish-green gas disengaged will
+readily combine with the iodine, forming a deep red liquid, and the
+operation is complete. The use of chloride of iodine will be referred
+to in connection with the Accelerators.
+
+{86}
+
+Iodides.--The iodide treated with the oil of vitriol, instantly
+produces a considerable deposit of iodine; and if the mixture be
+heated, intense violent vapors are disengaged. The reaction is due to
+the decomposition of oil of vitriol by iodohydric acid, water and
+sulphurous acid being formed, and iodine set free. The iodides in
+solution are decomposed by chlorine, iodine being precipitated, the
+smallest quantity of which in solution is instantly detected by its
+imparting to starch an intensely blue color.
+
+Iodide of Potassium.*--This compound is easily made in the following
+manner: Subject to a moderate heat a mixture of 100 parts of iodine, 75
+of carbonate of potash, 30 of iron filings, and 120 parts of water.
+This mass must be thoroughly dried and then heated to redness; the
+resulting reddish powder is to be washed with water, and the solution
+obtained filtered, and evaporated to dryness. It is found that 100
+parts of iodine yield 135 parts of very white, but slightly alkaline,
+iodide of potassium.
+
+* I shall present the preparation of only a few iodides, and such as
+are more intimately connected with the Daguerreotype.
+
+Experiment.--On projecting dry pulverized iodide of potassium into
+fused anhydrous phosphoric acid, a violent disengagement of iodine
+takes place, attended by a transient ignition; fused hydrate of
+phosphoric acid liberates iodine abundantly from iodide of potassium;
+this reaction is accompanied by the phenomenon of flame and formation
+of a considerable quantity of hydriodic acid.
+
+Iodide of Mercury.--For the preparation of iodide of mercury, Dublanc
+recommends to cover 100 grms. of mercury with 1 kilogrm. of alcohol,
+to add 124 grms. of iodine gradually in portions of ten grms., and
+agitating between each fresh addition, until the alcohol becomes
+colorless again. After the addition of the last 4 grms. the alcohol
+remains colored, the whole of the mercury having become converted into
+iodide. The resulting preparation is washed with alcohol; it is
+crystalline and of a hyacinth color.
+
+Iodide of Silver.--This compound is formed upon every plate upon which
+a Daguerreotype is produced. The vapor of iodine coming in contact
+with the silver surface, forms an iodide which is peculiarly sensitive
+to light.
+
+The various colors produced are owing to the thickness of the coating,
+and the maximum sensibility of the coating, as generally adopted, is
+when it assumes a deep yellow, or slightly tinged with rose color.
+
+This compound is largely employed in most photographic processes on
+paper, and may be easily prepared by the following formula: By adding
+iodide of potassium to a solution of nitrate of silver, a
+yellowish-white precipitate of iodide of silver is obtained, which is
+insoluble in water, slightly soluble in nitric acid, and soluble in a
+small degree in ammonia, which properties seem easily to distinguish it
+from the chloride and bromide of silver. Chlorine decomposes it and
+sets the iodine free, and chlorohydric acid converts it into a
+chloride. It fuses below a red heat. Although the effect of light on
+the iodide is less rapid than on the chloride, the former sooner
+turning black, assuming a brown tinge; but when in connection with
+gallic acid and the ferrocyanate of potash, it forms two of the most
+sensitive processes on paper.
+
+Iodide of silver dissolves easily in a solution of iodide of potassium,
+and the liquid deposits in evaporation crystals of a double iodide.
+
+Iodide of Gold.--If a solution of potassium be added to a solution of
+chloride of gold, a precipitate of iodide of gold takes place, soluble
+in an excess of the precipitate. A little free potash should be added
+to combine with any iodide that may chance to be set free by the
+chloride of gold.
+
+Iodide of Lime is prepared by adding iodine to hydrate of lime (which
+will be referred to farther on) until the mixture assumes a light
+yellow shade, when wanted for combinations with accelerators, or to a
+dark brown when employed for the first coating. This latter mixture
+has been sold in our market under the name of "Iodide of Brome."
+
+Iodide of Bromine.--(See page 76.)
+
+Experiments with Iodine.--Place a plate which has been exposed in the
+camera over the vapor of iodine for a very brief period, and it will
+present the appearance of the impression having been solarized.
+
+b. Upon a Daguerreotype plate, from which an impression has been
+effaced by rubbing or otherwise, the picture may be made to reappear by
+merely coating it over with iodine.
+
+c. Place in a vessel a little water, into which put the smallest
+possible quantity of free iodine and add a little starch, and the
+liquid will instantly assume a blue color. Advantage is taken of this
+fact in the laboratory to detect the presence of iodine in liquids.
+The starch should be dissolved in boiling water and allowed to cool.
+There are numerous other interesting experiments that can be performed
+by the aid of iodine, but it is unnecessary here to consume more space.
+
+
+CHLORINE.
+
+History.--The Swedish chemist, Scheele, in 1774, while examining the
+action of hydrochloric acid on peroxide of manganese, first noticed
+this element. He called it dephlogisticated muriatic acid. It was
+afterwards, by the French nomenclaturists, termed oxygenated muriatic
+acid, conceiving it to be a compound of oxygen and muriatic acid. This
+view of its notice was corrected by Sir H. Davy (in 1809), who gave it
+the present name. In 1840-41, this gas vas employed for accelerating
+the operation of light upon the iodized Daguerreotype plate. John
+Goddard, Wolcott & Johnson, Claudet, Draper, Morse and others, were
+among the first made acquainted with its use. Count Rumford, Ritter,
+Scheele, Seebert and others, experimented with chlorine in regard to
+its effect when exposed to the action of light in combination with
+silver. In 1845, M. Edward Becquerel announced that he had "been
+successful in obtaining, by the agency of solar radiations, distinct
+impressions, of the colors of nature."
+
+On the 4th of March, 1851, Neipce, St. Victor, a former partner of
+DAGUERRE, announced that he had produced "all the colors by using a
+bath of bichloride of copper, and that a similar phenomenon occurs with
+all salts of copper, mixed with chlorine."
+
+Preparation.--This is easily accomplished by putting about two parts of
+hydrochloric (muriatic) acid on one of powdered black oxide of
+manganese, and heating it gradually in a flask or retort, to which may
+be adapted a bent glass tube. A yellowish-green gas is disengaged,
+which being conducted through the glass tube to the bottom of a bottle,
+can readily be collected, being much heavier than the air, displaces it
+completely and the bottle is filled (which can be seen by the green
+color); a greased stopper is tightly fitted to it, and another bottle
+may be substituted.
+
+In all experiments with chlorine, care should be taken not to inhale
+the gas!
+
+Properties.--Chlorine is a greenish-yellow gas (whence its name, from
+chloros, green), with a powerful and suffocating odor, and is wholly
+irrespirable. Even when much diluted with air, it produces the most
+annoying irritation of the throat, with stricture of the chest and a
+severe cough, which continues for hours, with the discharge of much
+thick mucus. The attempt to breathe the undiluted gas would be fatal;
+yet, in a very small quantity, and dissolved in water, it is used with
+benefit by patients suffering under pulmonary consumption.
+
+Under a pressure of about four atmospheres, it becomes a limpid fluid
+of a fine yellow color, which does not freeze at zero, and is not a
+conductor of electricity. It immediately returns to the gaseous state
+with effervescence on removing the pressure.
+
+Water recently boiled will absorb, if cold, about twice its bulk of
+chlorine gas, acquiring its color and characteristic properties. The
+moist gas, exposed to a cold of 32 deg., yields beautiful yellow
+crystals, which are a definite compound of one equivalent of chlorine
+and ten of water. If these crystals are hermetically sealed up in a
+glass tube, they will, on melting, exert such a pressure as to liquefy
+a portion of the gas, which is distinctly seen as a yellow fluid, not
+miscible with the water which is present. Chlorine is one of the
+heaviest of the gases, its density being 2.47, and 100 cubic inches
+weighing 76.5 grains.
+
+Chlorine Water.--This combination, which is used in conducting M.
+Neipce's process, can be readily prepared by conducting the gas into a
+bottle containing distilled water. One part water dissolves two parts
+of chlorine.
+
+Chlorides.--The metallic chlorides are nearly all soluble in water;
+that of silver and protochloride of mercury being the only exceptions.
+A metallic chloride, treated with oil of vitriol, disengages
+chlorohydric acid. Heated with a mixture of peroxide of manganese and
+sulphuric acid, chlorine is given off, which is easily recognized by
+its odor and other physical properties.
+
+The chlorides dissolve in water; give with nitrate of silver, a white
+precipitate, even in highly diluted solutions, becoming violet colored
+and finally black when exposed to the light. The rapidity of the
+change of color is proportioned to the intensity of the light. It is
+insoluble in nitric acid, but readily soluble in ammonia; it fuses
+without decomposition, forming, when cold, a tough, horny mass, and is
+reduced by hydrogen and by fusion with carbonate of soda, or with resin.
+
+Chloride of Bromine. (See page 74.)
+
+Chloride of Iodine. (See page 85.)
+
+Chloride of potassium.--or (Muriate of Potassa).--Dissolve half an
+ounce of carbonate of potassa in water, and neutralize with muriatic
+acid. Upon concentrating the solutions, cubic crystals will be
+obtained, having a taste similar to common salt. They consist of
+potassium and chloride, and when dissolved in water they may be
+regarded as muriate of potassa.
+
+Chloride of Lime.--Mix half an ounce of slacked lime (hydrate of lime)
+with six ounces of water, and conduct into this milk of lime, with
+frequent agitation, as much chlorine gas as will evolve from two ounces
+of muriatic acid and half an ounce of black oxide of manganese. The
+liquid clarifies by standing; may be regarded as a solution of chloride
+of lime, and must be protected from the air and light. It may also be
+made without putting in the water with the hydrate of lime, by merely
+passing the chlorine into the hydrate of lime. This last is by some
+used in preparations for accelerating the operation of taking
+Daguerreotypes, but when used for this purpose it is in small
+quantities.
+
+Chloride of Calcium.--To one part of water add two parts of muriatic
+acid, and add pieces of common chalk until effervescence ceases; then
+filter through cotton cloth and evaporate it by placing it in all
+earthen or porcelain dish, over a slow fire, to the consistency of a
+syrup. When cooling, large prismatic crystals of chloride of calcium
+are formed. These must be quickly dried by pressing between folds of
+blotting paper and kept carefully excluded from the air, as it readily
+attracts hydrogen. For most daguerreotype purposes, the syrup may be
+at once evaporated to dryness. This is frequently placed in the iodine
+coating box for the purpose of keeping the atmosphere dry. It is so
+easily made that every operator can provide himself with it in a short
+time, and at little expense.
+
+Chloride of Gold.--Is prepared by dissolving gold in aqua regia, a
+composition of one part of nitric to two parts of muriatic acid. Gold
+foil is the best for our purposes; coin, however, answers, in most
+cases, for the daguerreotype operator, as the alloy, being so slight is
+not noticed in the gilding process. When the latter is used, it will
+facilitate the operation to beat it out, forming a thin sheet, and then
+cutting in small strips. Where purity is required, foil is better.
+The gold is placed in three or four times its own weight of the above
+acids. For this purpose, an evaporating dish is best (a common saucer
+will do); a moderate heat may be applied to favor the action. The
+mixture should be stirred often with a glass rod; care should be
+observed not to apply too much heat, for at a temperature of about 300
+deg. the chlorine would be expelled and leave a metallic precipitate,
+which would require re-dissolving. Acid may at any time be added if
+necessary to dissolve the gold, but it is advisable to add as little
+excess as possible, as it would require more time to evaporate. After
+all the gold has dissolved, and the liquid assumes a deep red color,
+the solution should be allowed to cool, being stirred nearly all the
+time. This salt is of a reddish-brown color. It is rarely we find in
+our market good chloride of gold, as common, salt is used for the bulk;
+and when the bottles are labelled "15 grains," "20 grains," nine-tenths
+do not in reality contain exceeding five grains of chloride of gold.
+The salt is mixed with the above solution when it is cooling, and gives
+bright yellow crystals, which some of our uninformed operators conceive
+to be the best quality.
+
+Chloride of Silver.--(Oxide of Silver.)--Take any quantity of silver
+coin or other silver, roll or hammer it thin; cut in small pieces.
+This in order to save time. Put the silver in a glass or earthen
+vessel (Florence flask is best); pour in nitric acid and water, about
+three parts of the former to one of the latter. The operation of
+cutting up the silver may be facilitated by applying a gentle heat.
+This blue solution consists of oxide of silver and oxide of copper,
+both combined with nitric acid. Should the operator wish a pure
+solution of silver, which, however, is not always used, he may obtain
+it in the following manner:
+
+To separate the two metals contained in the above solution from each
+other, put some bright copper coins into the solution and set it aside
+in a warm place for three or four days, occasionally giving it a
+circular motion. The separated laminae are pure silver, which is to be
+digested with ammonia until it ceases to be colored blue. The silver,
+after being washed and dried, is again dissolved in nitric acid, and
+the liquid, diluted with water, is kept as solution, of silver.
+
+Either of the above solutions (the one of oxide of silver and copper,
+and the pure silver solution) may be prepared for use by putting them
+in a bottle, with a quantity of water, and adding common fine salt, you
+obtain a white curdy precipitate of chloride of silver. No matter how
+much salt is used, provided enough be added to throw down all the
+chloride of silver. This solution should be well agitated and then
+allowed to stand for a few minutes; thus the white precipitate is in
+the bottom of the bottle. When the water has become clear, pour it off
+with care, leaving the sediment behind, then add a fresh quantity of
+clean water, shake, let settle, and pour off as before. Repeat the
+same for several times, and the excess of salt will disappear, leaving
+the white precipitate, which may be drained of the water and dried in
+the dark, and kept free from light and air.
+
+
+CYANIDE OF POTASSIUM.
+
+Cyanide of Potassium.--This important article is worthy the undivided
+attention of every Daguerreotypist. I here give Mr. Smee's process for
+its preparation. This is from that author's work entitled, "Electro
+Metallurgy," American edition:
+
+"The cyanide of potassium, so often alluded to while treating of the
+metallo-cyanides, may be formed in several ways. It may be obtained by
+heating to a dull redness the yellow ferrocyanate of potash, in a
+covered vessel, filtering and rapidly evaporating it. The objection to
+this method, however, is that without great care the whole of the
+ferrocyanate is not decomposed, a circumstance which much reduces its
+value for electro-metallurgy. By boiling, however, the ignited residue
+with spirits of wine this difficulty is said to be overcome, as the
+ferrocyanate is absolutely insoluble in that menstruum, while the
+cyanuret, at that heat, freely dissolves, and is as easily re-deposited
+on cooling.
+
+"There is, however, a much better process by which this salt may be
+formed, viz. by simply transmitting hydrocyanic acid through
+potassium. Although the modes of making this acid are very numerous,
+there is but one which is likely to be employed on a very large scale,
+and that is its formation from the yellow ferrocyanate by means of
+sulphuric acid. This process is performed as follows: any given
+weight of the yellow salt is taken and dissolved in about five times
+its weight of water; this is placed in a retort, or some such analogous
+vessel, to which is then added a quantity of strong sulphuric acid,
+twice the weight of the salt, and diluted with three or four times its
+quantity of water. A pipe is carried from the neck of the retort to
+the receiving bottle, which should be kept as cool as possible.
+
+"For small operations, those invaluable vessels, Florence flasks,
+answer well: a bent tube being connected at one end to its month, the
+other passing into the second vessel; heat should be cautiously applied
+by means of an Argand lamp, a little vessel of sand being placed under
+the flask, which helps the acid to decompose the salt. Prussic acid is
+then generated and passes through the tube to the recipient vessel,
+which is to be charged with liquor potassae.
+
+"When the potash is saturated, the operation is completed. The Germans
+recommend a strong, alcoholic solution of potassa to be used in the
+second vessel, for in this case, the hydrocyanic or prussic acid
+combines with the potassa, forming a hydrocyanate of potassa, or, the
+water being abstracted, the cyanuret of potassium, which spontaneously
+precipitates, on the saturation of the fluid, the cyanuret, being
+insoluble in strong alcohol. The ferrocyanate of potash may be
+considered as containing three equivalents of hydrocyanic acid, two of
+potash and one of iron; but, unfortunately, we can only obtain half the
+acid from the salt, owing to the formation of a compound during its
+decomposition which resists the action of the acid. The decomposition
+of this salt taking 2 equivalents or 426 grains (to avoid fractions)
+would afford 3 equivalents or 81 grains of hydrocyanic, or prussic
+acid, capable of forming 198 grains of cyanuret of potassium, while in
+the retort there would remain 384 grains or 3 equivalents of bisulphate
+of potash, and 1 equivalent or 174 grains of a peculiar compound, said
+to contain 3 equivalents of cyanogen, 1 of potassium, and one of iron
+(Pereira). It is manifest that, but for this later compound, we might
+double the quantity of hydrocyanic acid from the yellow salt."
+
+The decomposition just described is the one usually received; but too
+much reliance must not be placed on its accuracy, for the analysis of
+the several compounds is too difficult for the results to be fully
+admitted. The residue left in the retort speedily turns to one of the
+blues, identical with, or allied to, Prussian blue. This is at best a
+disagreeable process to conduct, for the hydrocyanic acid formed
+adheres so strongly to the glass, that, instead of being freely given
+off, bubbles are evolved suddenly with such explosive violence as
+occasionally to crack the vessel. This may be remedied as far as
+possible by the insertion of plenty of waste pieces of platinum--if
+platinized, so much the better, as that facilitates the escape of the
+gas. The heat should be applied to every part of the vessel, and the
+flame should not be allowed to play upon one single part alone. Large
+commercial operations are performed in green glass or stone-ware
+retorts.
+
+"Now for one word of advice to the tyro: Remember that you are working
+with prussic acid; therefore, never conduct the process in a room, the
+fumes being quite as poisonous as the solution of the acid itself;
+moreover, have always a bottle of ammonia or chlorine by your side,
+that should you have chanced to inhale more than is pleasant, it will
+be instantly at hand to counteract any bad effects. It is stated by
+Pereira, that a little sulphuric acid or hydroferrocyanic acid passes
+to the outer vessel, but probably the amount would be of no consequence
+for electro-metallurgy, otherwise, it might be as well to use a
+Woulfe's apparatus, and discard the salt formed in the first vessel.
+To the large manufacturer it may be worth considering whether some
+other metallo-cyanuret, formed in a similar manner to the
+ferrocyanuret, might not be more advantageously employed, because the
+residue of the process last described contains a large quantity of
+cyanogen which the acid is unable to set free.
+
+"There are other modes of procuring prussic acid, besides the one which
+has been so tediously described; but these are found to be more
+expensive. The only one which I shall now notice is the process by
+which it is obtained from bicyanide of mercury. The bicyanide of
+mercury itself is formed when peroxide of mercury is digested with
+Prussian blue, the peroxide of mercury abstracting the whole of the
+cyanogen from the blue, and leaving the oxides of iron at the bottom of
+the vessel. The solution may be evaporated to dryness, and one part of
+the salt dissolved in six of water; one part of muriatic acid, sp. gr.
+1.15, is then added, and the solution distilled, when the whole of the
+hydrocyanic acid passes over, and by being conducted into a solution of
+potassa, as in the former process, forms cyanuret of potassium. This
+process, though easier than the first described, is rather given as a
+resource under peculiar circumstances than as one to be adopted by the
+large manufacturer. The expense is the only objection, but in a small
+quantity this cannot be a consideration.
+
+"In giving this very rough outline of the general mode of forming
+salts, the minutiae necessary for chemical work have altogether been
+avoided, and those parts alone are entered upon which are more
+immediately necessary for the electro metallurgist to know and practice
+for himself. This will account for the long description of the
+cyanuret of potassium, while the preparation of the equally important
+and even more used acids, the sulphuric, muriatic, etc., commonly found
+in commerce, are altogether neglected.
+
+"In using solutions of cyanide of potassium, the workman should not
+immerse his arms into them, otherwise it occasionally happens that the
+solution produces very troublesome eruptions over the skin."
+
+
+HYPOSULPHITE OF SODA.
+
+Hyposulphite of Soda.--This salt forms one of the important chemicals
+for the Daguerreotype operator. Its application to this art is of an
+interesting nature. It is used to dissolve the sensitive salt of
+silver which remains unchanged during the exposure in the camera. It
+has the property of readily dissolving the chloride, bromide and iodide
+of silver. It should be pure and free from sulphuret of sodium; should
+this last be present, it will cause brown spots of sulphurated silver
+upon the Daguerreotype impression. This annoyance is a great source of
+complaint from many operators, and ever will be, so long as it is
+prepared by men who have no reputation to lose, and whose eyes are
+blinded by the "Almighty Dollar."
+
+A good article may be prepared as follows:
+
+"Mix one pound of finely pulverized carbonate of soda with ten ounces
+of flowers of sulphur, and heat the mixture slowly in a porcelain dish
+till the sulphur melts. Stir the fused mass, so as to expose all its
+parts freely to the atmosphere, whereby it passes from the state of a
+sulphuret, by the absorption of atmospheric oxygen, into that of a
+sulphite, with the phenomenon of very slight incandescence. Dissolve
+in water, filter the solution, and boil it immediately along with
+flowers of sulphur. The filtered concentrated saline liquid will
+afford, on cooling, a large quantity of pure and beautiful crystals of
+hyposulphite of soda."
+
+Hyposulphite of Gold.--This compound salt is by a few considered
+preferable to the chloride of gold, but our experience has induced us
+to use the latter, believing we are enabled to produce a more brilliant
+and warm-toned impression with it. When the hyposulphite of gold is
+used in gilding, it requires less heat and a longer application, as
+there is some danger of producing a glossy scum over some parts of the
+surface of the plate. I prepare this salt as follows:
+
+Dissolve one part chloride of gold and four parts hyposulphite of soda
+in equal quantities of distilled water: pour the gold into the
+hyposulphite solution, in the same manner as in mixing the gilding
+solution; let it stand until it becomes limpid; filter and evaporate to
+dryness. Re-dissolve and add a few grains of burnt alum.
+
+After standing a few hours, filter and evaporate again. If not
+sufficiently pure, repeat the crystallization until it is so. For
+gilding, dissolve in water and use in the same manner as the common
+gilding solution.
+
+N.B.--The four following mixtures were employed in Neipce's process in
+his earliest experiments:
+
+Aqueous Solution of Bichloride of Mercury.--Eight grains of bichloride
+of mercury in 10,000 grains of distilled water.
+
+Solution of Cyanide of Mercury.--A flask of distilled water is
+saturated with cyanide of mercury, and a certain quantity is decanted,
+which is diluted with an equal quantity of distilled water.
+
+Acidulated White Oil of Petroleum.--This oil is acidulated by mixing
+with it one tenth of pure nitric acid, leaving it for at least 48
+hours, occasionally agitating the flask. The oil, which is acidulated,
+and which then powerfully reddens litmus paper, is decanted. It is
+also a little colored, but remains very limpid.
+
+Solution of Chloride of Gold and Platinum.--In order not to multiply
+the solutions, take the ordinary chloride of gold, used for fixing the
+impressions, and which is composed of 1 gramme of chloride of gold and
+50 grains of hyposulphate of soda, to a quart of distilled water.
+
+With respect to chloride of platinum, 4 grains must be dissolved in 3
+quarts of distilled water; these two solutions are mixed in equal
+quantities.
+
+Acids.--I shall not go into the preparations of the various acids
+employed in the Daguerreotype. This would be useless to the operator,
+as there are few, if any, that it would be advisable to prepare. It is
+only necessary for the experimenter to be made acquainted with their
+properties, and this in order to prevent any haphazard experiments,
+which are too common among operators. Any person who may be desirous
+to try an experiment, should first study the agents he wishes to
+employ. By so doing much time and money will be saved; while the
+searcher after new discoveries would rarely become vexed on account of
+his own ignorance, or be obliged to avail himself of the experience of
+others in any department of science.
+
+Nitric Acid--Exists in combination with the bases, potash, soda, lime,
+magnesia, in both the mineral and vegetable kingdoms, and is never
+found insoluble. It has the same constituents as common air, but in
+different proportions. The strongest nitric acid contains in every
+pound, two and a quarter ounces of water. Pure nitric acid is
+colorless, with a specific gravity of 1.5, and boiling at 248 deg.. It
+is a most powerful oxidizing agent, and is decomposed with more or less
+rapidity, by almost all the metals, to which it yields a portion of its
+oxygen.
+
+The nitric acid of commerce, is generally the article used by the
+Daguerreotypist. This usually contains some chlorine and sulphuric
+acid. It is obtained by the distillation of saltpetre with sulphuric
+acid. It is employed in the Daguerreotype process for dissolving
+silver, preparing chloride or oxide, nitrate of silver, [the former
+used in galvanizing,] and in combination with muriatic acid for
+preparing chloride of gold, used in gilding. It is also used by some
+for preparing the plate.
+
+Acidulated Solution.--This solution is used for cleaning the surface of
+the Daguerreotype plate. It has the property of softening the silver,
+and bringing it to a state in which it is very susceptible of being
+either oxidized or iodized, hence it contributes to increase the
+sensibility of the plate. The proportions are to one drop of acid add
+from 15 to 20 drops of water, or make the solution about like sharp
+vinegar to the taste.
+
+Nitro-Muriatic Acid.--Aqua Regia is a compound menstruum invented by
+the alchemists for dissolving gold. It is composed of colorless nitric
+acid (aqua-fortis) and ordinary muriatic acid; the mixture is yellow,
+and acquires the power of dissolving gold and platinum. These
+materials are not properly oxidized; it nearly causes their combination
+with chlorine, which is in the Muriatic acid.
+
+Hydrochloric Acid (Muriatic Acid).--This acid forms a valuable addition
+to the chemicals employed by the practical Daguerreotypist. This acid
+is formed by acting upon common salt (which is chloride of sodium) by
+concentrated sulphuric acid. The water of the acid is decomposed, and
+its hydrogen combines with the chloride of the salt to form muriatic
+acid, and this unites with the sulphuric acid to form sulphate of soda;
+60 parts of common salt and 49 parts of concentrated sulphuric acid,
+afford, by this mutual action, 37 parts of muriatic acid and 72 parts
+of sulphate of soda. The muriatic acid of commerce has usually a
+yellowish tinge, but when chemically pure it is colorless. The former
+is commonly contaminated with sulphurous acid, sulphuric acid,
+chlorine, iron, and sometimes with arsenic.
+
+Muriatic acid, from the fact of the presence of the chlorine, is used
+in the Daguerreotype process for dissolving gold, and in combination
+with various accelerators. Its presence can be detected by ammonia. A
+strip of paper dipped in this and waved to and fro will emit a thick
+white smoke if the acid vapor be in the atmosphere. The ammonia
+neutralizes the acid fumes. By reversing the experiment we can
+determine whether vapor of ammonia be in the air, and also deprive
+these suffocating and dangerous gases of their injurious properties,
+and remove them from the air. Every Daguerreotype operator should be
+furnished with, at least, a six ounce bottle of aqua ammonia. Its
+operation is very nearly the same on bromine and iodine vapor.
+
+Hydrofluoric Acid (Fluorohydric Acid).--This acid is used to form some
+of the most volatile and sensitive compounds employed in the
+Daguerreotype. It is one of the most dangerous bodies to experiment
+with: it is volatile and corrosive, giving off dense white fumes in the
+air. It combines with water with great heat. At 32 deg. it condenses
+into a colorless fluid, with a density 1.069. It is obtained from
+decomposition of fluorspar by strong sulphuric acid. It readily
+dissolves the silica in glass, and consequently cannot be kept in a
+vessel of that material. It is prepared and kept in lead. It is
+employed in accelerators on account of its fluorine.
+
+One small drop on the tongue of a dog causes death. The operator who
+wishes to use it should pour some of the liquid for which he intends it
+into a graduate, or other vessel, and then add the desired quantity of
+acid. If by accident any of the spray should fall upon the skin, it
+should at once be copiously drenched with water.
+
+Sulphuric Acid.--There are two sorts of this acid: one is an oily,
+fuming liquid; this is made in Nordhausen, in Saxony, and is commonly
+called "Nordhausen sulphuric acid," or oil of vitriol. The other which
+is the kind used in connection with the Daguerreotype, is common
+sulphuric acid. It is somewhat thinner, and when undiluted is not
+fuming. This acid may be obtained in a solid and dry state, called
+anhydrous sulphuric acid.
+
+The common sulphuric acid is made by burning sulphur, which forms
+sulphurous acid. To convert this into sulphuric acid and gain more
+oxygen, nitric acid, which is rich in that body, is added. It forms a
+limpid, colorless fluid, of a specific gravity of 1.8. It boils at 620
+deg.; it freezes at 15 deg. It is acrid and caustic, and intensely
+acid in all its characters, even when largely diluted.
+
+Its attraction for basis is such that it separates or expels all other
+acids, more or less perfectly, from their combinations. Its affinity
+for water is such that it rapidly absorbs it from the atmosphere, and
+when mixed with water much heat is evolved. It acts energetically upon
+animal and vegetable substances, and is a poisonous, dangerous
+substance to get on the skin. It is a powerful oxidizing agent; hence
+its use in the galvanic battery, for which purpose it is mostly used by
+the Daguerreotypist. The fumes of this being so much more offensive
+than nitric acid, the latter is sometimes used. It is also employed in
+some of the more sensitive accelerators.
+
+
+ACCELERATING SUBSTANCES.
+
+Remarks on the Accelerating substances Used in the Daguerreotype.--I
+have now arrived at a point in this work, where the eye of the
+Daguerreotype public will intently search for something new. This
+search will prove in vain, at least so far as regards those who have
+enjoyed and embraced the opportunities for studying the principles of
+our art. Every experienced operator has in a degree become familiar
+with the mechanical uses of all the agents employed, while I fear but
+few understand the properties, and laws governing those properties,
+which are so indispensable to produce an image impressed upon the
+silver surface.
+
+There are three substances which form the bases for producing a
+Daguerreotype; silver, iodine and bromine. Each forms a separate body
+which is indispensable to the operators success as the art is now
+practiced in America. With these three, compounds of great variety are
+formed.
+
+The silver surface is first thoroughly cleaned and freed from all
+organic matter, then exposed to vapor of iodine, producing an iodide of
+silver. The plate upon which is this salt, is again exposed to the
+vapor of bromine, forming a bromo-iodide of silver, a salt also.
+
+As most of the various accelerators are compounds of bromine, with
+either chlorine or fluorine combination, they partake somewhat of the
+nature of these latter, giving results which can be detected by the
+experienced operator. Thus muriatic acid is added for its chlorine,
+which can generally be detected by the impression produced, being of a
+light, soft, mellow tone, and in most cases presenting a brilliant
+black to that colored drapery. Those who wish to experiment with
+agents for accelerating substances, should first study to well
+understand their peculiar nature and properties; as well, also, to
+endeavor to find out what will be the probable changes they undergo in
+combination as an accelerator. This should be done before making the
+experiments. From the foregoing it will be seen that numerous
+compounds are formed from the same basis, and, consequently, it would
+be a waste of time and a useless appropriation to devote more of our
+space than is necessary to give the principal and most reliable
+combination.
+
+In America, the words "Quick" and "Quick Stuff," are more generally
+used for and instead of the more proper names, "Sensitives," or
+"Accelerators," etc. As it has by use become common, I frequently use
+it in this work.
+
+Liquid Accelerator, No. 1.--This mixture was used by me in 1849, and is
+given as it appeared in my "System of Photography," published at the
+above date:
+
+Take pure rain or distilled water, one quart, filter through paper into
+a ground stopper bottle, and add, for warm weather, one and a half
+ounce chloride of iodine; or for cold, one ounce; then add one ounce
+bromine, and shake well. Now with care not to allow the vapor to
+escape, add drop by drop, thirty drops of aqua ammonia, shaking well at
+each drop. Care must be taken not to add more at a time, as it evokes
+too much heat. This mixed, in equal proportions with John Roach's
+quick, forms an excellent chemical combination. For this purpose, take
+one and a half ounce of each, to which add ten ounces water, for warm
+weather, or from six to seven for cold. Pour the whole into a large
+box, and it will work from two to four months. I am now using (1849)
+one charged as above which has been in constant use for three months,
+and works uniformly well. The above is right for half or full size
+boxes, but half of it would be sufficient for a quarter size box.
+
+Coat to the first shade of rose over iodine, change to a deep rosy red
+over quick, and black about one tenth the first.
+
+I would not now recommend the addition of "John Roach's quick," as I
+believe equally good results can be produced without it. This liquid
+is now used by many, and is very good for taking views.
+
+Lime Water Quick.--This mixture is more used at present than all the
+other liquids ever introduced. It produced the most uniform results,
+giving the fine soft tone so characteristic in pictures produces from
+accelerators containing chlorine. To one quart of lime water (this can
+be had of any druggist) add one and a half ounce of pulverized alum.
+This should be shook at intervals for twenty--four hours; then add one
+ounce of chloride of iodine and three fourths ounce of bromine.
+
+Lime Water.--This is easily prepared by putting lime into water, say a
+piece of quick-lime about the size of an egg into one quart of water.
+This should be shook occasionally for two or three days and allowed to
+settle, when the water can be poured off and used.
+
+Use.--To one part of quick add six parts of water; coat to a light
+yellow over the iodine, to a rose color over the quick, and recoat
+about one tenth. The above coating may be increased or diminished, it
+matters not, so that there is not too much, and the proper proportions
+are preserved. Some add to the above a small quantity of magnesia, say
+about a teaspoonful to the quart of liquid.
+
+Liquid Accelerator, No. 2.--The following was for a long time used by
+one of the first houses in the United States, and probably was one of
+the first liquids ever used. It produces a fine-toned picture, but is
+not considered as sure as the lime water quick:
+
+Take rain water one quart, add pulverized alum until it is a little
+sour to the taste, and a small piece, say one half inch square, of
+magnesia. Filter through paper, and add chloride of iodine one half
+ounce, bromine sufficient to take it up, which is a little less than
+half an ounce.
+
+Charge with one of quick to six of water; coat over iodine to a soft
+yellow, nearly, but not quite, bordering on a rose; over quick to a
+dark purple, or steel, and back one sixth to one tenth.
+
+Wolcott's American Mixture.--Van Loan Quick.--This mixture was first
+formed and used by T. Wolcott & Johnson and gained great celebrity for
+its productions. I have now a bottle hermetically sealed that contains
+about a half ounce of this mixture prepared in 1841 by John Johnson,
+now a resident of this city, and the former partner of Mr. Wolcott.
+The preparation of this mixture, as furnished by Mr. Johnson himself,
+is given as follows:
+
+"One part of bromine, eight parts of nitric acid, sixteen parts of
+muriatic acid, water one hundred parts. This mixture should be allowed
+to stand for several days; it improves by age.
+
+"Use.--A few drops say, 6 to 12, of this mixture, should be put into
+about 6 or 8 ounces of water; it will require frequent replenishing by
+the addition of a few more drops. The plate should be coated over the
+dry iodine to a red just bordering on a slate, and then exposed to the
+mixture only sufficiently long to change the color. If this is not
+done in less than six seconds it is not strong enough. Re-coat over
+the iodine full one fourth as long as first coating."
+
+This exceedingly volatile compound is difficult to control from its
+instability; it is but little used. The impressions successfully
+produced by this mixture are very brilliant, and possess a pleasing
+peculiarity.
+
+
+DRY SENSITIVES.
+
+Hydrate of Lime.--The operation by which water is combined with lime is
+called slaking. Take a piece of quick lime, common lime used in
+mortar, and immerse it in warm water for about fifteen seconds; then
+place it in an iron or tin vessel. It will soon begin to swell,
+evolving a great deal of heat and emitting steam, and soon falls into a
+fine powder, hydrate of lime. This should be well stirred and allowed
+to cool, and then bottled in order to prevent it from giving off the
+hydrate and recovering the carbonic acid from the atmosphere. The last
+is detrimental to its use with bromine, and is one cause of the
+complaint that "it will not take bromine." The hydrate of lime should,
+not be dried over a heat, as has been supposed by many, for in that
+case the hydrogen is expelled and it returns to a carbonate. It is
+advisable to cool it in a damp place like a ground cellar. Much of the
+lime in our market will not, except it be quite damp, combine with the
+bromine. This is owing to impurities. Nothing is equal to
+oyster-shell lime, which I use altogether.
+
+Bromide of Lime.--In preparing large quantities of this, we adopt the
+following method: Fill a four-quart bottle about two-thirds full of
+hydrate of lime; pour into this about one or two ounces of bromine;
+then shake well, add more of the bromine, shake well and let it stand
+for a few hours, adding sufficient bromine to give it a fine red color.
+It is better when kept in the large bottles, as it forms a more perfect
+combination: in other words it improves by age.
+
+Use.--Coat over the iodine to a rose red and then over this mixture to
+a purple or slate; recoat over the first about one fourth as long as
+first coating.
+
+Gurneys American Compound.--Of this compound there are two
+combinations, one for use, when the temperature of the atmosphere is
+above 65 or 70 deg., and the other at a lower temperature. The first
+is called No. 1, the second No. 2.
+
+No. 1 is prepared by placing hydrate of lime in a bottle, say to three
+quarts of the hydrate of lime, add one ounce of pulverized burnt alum,
+and as much chloride of lime as can be put on a quarter of a dollar,
+and from 15 to 30 grains of dry pulverized iodine, or enough to change
+the color of the hydrate of lime, to the slightest possible tinge of
+yellow. There had better be less than carry the color to a deeper
+shade. The object of using the iodine is to form a compound with
+bromine that is not so volatile as the bromine itself. No matter how
+little iodine is combined with the bromine, the vapors possess their
+relative proportion; hence, only enough iodine to prevent "flaring," or
+as it is often termed a "scum-coating," is used. The iodine should be
+thoroughly combined with the lime, which will take about one or two
+days. Should add bromine the same as in bromide of lime, until the
+compound assumes a light red color.
+
+No. 2 is prepared in the same manner as No. 1, except the addition of
+the iodine, which is omitted.
+
+Use.--No. 1. Coat over the iodine to a bright yellow color, then over
+the compound, No. 1, to red color, recoat over iodine, about one sixth
+as long, as the time occupied in first coating.
+
+No. 2. Coat over iodine same as above, except recoat over the iodine
+about one fourth to one half as long as first coating.
+
+Dry Quick, No. 1.--Bromide of Lime and Starch.--The following compound
+forms an excellent accelerator, and is used by many. It is claimed for
+this preparation, that it will hold the bromine longer than others
+where starch is not employed. As regards this claim we do not think it
+can be substantiated. Our experience in practice has led us to the
+conclusion that there is no great difference as respects durability,
+but there is some little difference as regards the tone of the
+impressions produced by its use.
+
+To one quart of hydrate of lime add one quart of finely pulverized
+starch. To this mixture add bromine, until it assumes a deep yellow or
+pink color.
+
+Starch may be added to any of the dry mixtures.
+
+Use.--Coat over the iodine to a deep yellow, then over this quick to a
+red color, recoat about one sixth of the time of first coating.
+
+I will here again remark, that the exact color of the coating is not
+essentially provided a proper proportion is preserved.
+
+I have never seen it stated, though it be a fact worthy of note, that a
+proportionate time for coating over the iodine and accelerator, will
+not answer. For example: if a plate exposed to the vapor of iodine be
+perfectly coated in sixteen seconds, and then exposed to an
+accelerator, (not having iodine in its combination) receives its
+coating in four seconds, it will be found that a proper proportionate
+coating cannot be preserved by adopting, a proportion of time, but on
+the contrary, the time will diminish; for exposure over the
+accelerator, as in the above example, if it be desired to coat the
+plate with twice as much iodine as in the above example, the time would
+be, over iodine thirty-two seconds, and over the accelerator (to
+possess a proper proportion) from six to seven seconds. Hence it is
+that many inexperienced operators, when wishing to vary their usual
+manner of coating, fail in producing a favorable result. They coat
+calculating a proportion of time when they should not.
+
+Dry Quick, No. 2.--Bromide of Lime and Magnesia.--To one quart of
+hydrate of lime add one quart of magnesia, and mix them well together;
+add bromine same as in preparing bromide of lime; coat the same as over
+dry quick No. 1. This combination produces very uniform results, and
+is worked with much success by beginners.
+
+Chloro-Bromide of Lime.--To the bromide of lime add chloride of bromine
+until the mixture becomes a pale yellow color, resembling sulphur. It
+should be shook well, and enough of the chloride of bromine added to
+bring the compound to a deep blood red color.
+
+Use.--Coat over the iodine to a pink color, and then over the above to
+a red, or just changing the color. It should be remembered that
+accelerators containing chlorine do not admit of a great change of
+color of coating on the plate.
+
+Iodide of Starch.--This mixture can be employed for coating over in
+warm weather, and prevent the flashing resulting at high temperatures.
+It may be used the same as the iodide alone.
+
+To six ounces of finely pulverized starch, add one fourth ounce of dry
+iodine.
+
+Use.--Same as the dry iodine alone.
+
+The same combination may be made with lime, magnesia and other
+substances.
+
+Concentrated Solution of Iodine for First Coating.--It may appear
+strange to some of our old operators that an aqueous solution of iodine
+can be used for coating the plate and forming the iodide of silver. It
+has long been a cry among most operators that it is impossible to
+succeed when the iodine box contains dampness. Now this is a great
+mistake, and we will here state that in all cases where dampness
+appears upon a properly prepared Daguerreotype plate, it is the result
+of a different temperature of the metal from the air which surrounds
+it. Mr. Senter, of Auburn, was the first of our operators who used a
+solution of iodine for coating the plate, and we several years since
+saw his results, which would rival the production of any other
+operator. A concentrated solution of iodine is prepared by putting
+into a common bottle two thimblesful of hyposulphite of soda and a
+rather larger quantity of iodine, so that there may be more than
+sufficient. Add to it about 40 ounces of common water (heated to 60 or
+70 degrees), by little and little, moving, the bottle to warm it, for
+fear of breaking. After shaking it a short time, the water is rapidly
+and strongly colored. The solution should be poured into a bottle with
+a ground stopper, and when cool used for iodizing.
+
+A solution of sufficient strength can be made by moistening or just
+covering the iodine with water.
+
+Chloride of Iodine as an Accelerator.--This is probably one of the best
+accelerators that can be used for coating the plate for taking views;
+it works too slow, however, to meet the wants of the operating room,
+yet its use was formerly, for a long time, adhered to by some of our
+best professors. In producing views with this, we are successful in
+obtaining well-developed impressions, with a depth of tone and richness
+of appearance not to be met with in the productions of any other
+substances. I give its use as furnished me by an old and experienced
+operator, and published in Humphrey's Journal, vol. i. p. 180:
+
+"As the process of using chloride of iodine may be of interest to some
+of our subscribers, I take pleasure in giving the following
+manipulation. To one ounce of chloride of iodine add two ounces of
+water; place this mixture in a coating-box, the same as quick stuff;
+coat the plate with dry iodine to a light yellow, or lemon color; then
+bring the coating to a deep pink over the chloride. The plate must be
+recoated over the dry iodine."
+
+This combination has been very successfully used in one of our most
+extensive establishments in this city, and the superiority of the
+pictures produced by it was considered as an equivalent for the
+additional time required to bring out the impressions.
+
+Chlorine as an Accelerator.--I shall here refer to but a single
+experiment in which I employed chlorine gas for coating the plate. I
+was provided with a retort, the neck of which was fitted to the jar of
+my coating-box, through a hole drilled for its reception. This was
+fitted perfectly tight in my coating-box. I placed some pure undiluted
+bromine water and the agents necessary for producing chlorine gas (in
+small quantity) in the retort. The result was that my first experiment
+produced an impression completely solarized in all its parts by an
+exposure of four seconds of time, which would have required an exposure
+of twenty seconds to produce a perfectly developed impression by the
+usual process.
+
+Another trial immediately produced one of the finest toned impressions
+I ever saw, perfectly developed in one second of time.
+
+My next two or three experiments proved total failures. I was unable
+to produce even a sign of an impression. By accident my retort was
+broken, and not being in a locality convenient to obtain another, my
+experiments were necessarily suspended.
+
+My attention was not called to this subject again for several years,
+when I noticed an account of some similar experiments by F. A. P.
+Barnard and Dr. W. H. Harrington, the latter of whom is now of the firm
+of Dobyns & Harrington, of New Orleans.
+
+From reading this article, I found my own difficulties explained. Too
+much of the chlorine gas was present in my coating jar. I would like
+to see some of our enterprising operators investigate this combination.
+
+It is a singular fact, that the vapors of bromine and chlorine
+combining upon the iodide of silver, produce a more sensitive coating
+than when the two are combined in solution, as in chloride of bromine
+solution. Those having Humphrey's Journal at hand, can refer to vol.
+i. p. 142.
+
+To use Bromine Water or other Accelerators in Hot Weather.--An
+excellent plan for using bromine water is as follows:
+
+Fill a two-ounce bottle quarter full of it, and then fill the bottle
+with fine sand, which serves to preserve a low temperature; then place
+the bottle in a porous cup, same as used in the battery; fill this also
+with sand, and close the end with plaster of Paris. Place this in a
+coating-box, and it will be found to act with great uniformity and be
+quite permanent.
+
+Bromide of Lime, another accelerator, can be used in the same manner,
+except it is, only necessary, when a solid sensitive is used, to mix it
+with the sand without placing it in a bottle. This method is employed
+with great success by a few, who have regarded it as a secret worth
+keeping.
+
+A Combination, requiring the Use of only One Coating-box.--It is often
+wondered by beginners, why some solution requiring only one coating
+cannot be employed. This can be done, but the results are not so
+satisfactory as when two or more are employed. Such an accelerator may
+be produced by adding alcoholic solution of iodine to a solution of
+chlorate of potash, until the latter will take up no more of the
+former, and to each ounce, by measure of this solution, ten drops of a
+saturated solution of bromide in water are added. The solution of
+chlorate of potash is made by diluting, one part of a saturated
+solution of the salt with ten parts of water. The use of the chlorate
+is simply as a solvent of iodine.
+
+Fats as Accelerators.--The use of fats, oils, or greasy substances, has
+been one of the most emphatic prohibitions about the Daguerreotype
+plate. Yet it has been proved that its presence in a small quantity
+upon the silver surface has the effect of reducing the time of exposure
+in the camera from two-thirds to three-fourths. An application may be
+made as follows: Pour sweet oil, or rub beef or mutton fat, on a common
+buff, which is free from all polishing powders. With this, buff a
+well-cleaned plate, and it will leave a scum, which should be mostly
+removed by using another buff, which should be clean. Coat the plate
+in the usual manner, and the result will be a great reduction in the
+time of exposure in the camera. The impression produced upon a plate
+so prepared presents, when coming from the vapor of mercury, a grey,
+scummy appearance, which, on the application of heat in gilding, does
+not improve; hence its use is not generally adopted.
+
+We have instituted some investigations upon this subject, and in the
+present volume, we shall not refer to it further. Those wishing to
+learn more fully the effect of light upon organic substances will find
+Robert Hunt's "Researches on Light" an invaluable work.
+
+
+
+
+LIGHT AND OPTICS.
+
+
+CHAPTER IV.
+
+Light--Optics--Solar Spectrum--Decomposition of Light--Light, Heat, and
+Actinism--Blue Paper and Color for the Walls of the Operating
+Room--Proportions of Light, Heat, and Actinism composing a
+Sunbeam--Refraction--Reflection--Lenses--Copying Spherical
+Aberration--Chromatic Aberration.
+
+
+It is advisable that persons engaging in the Daguerreotype art should
+have at least a little knowledge of the general principles of light and
+optics. It is not the author's design here to give a full treatise on
+these subjects, but he only briefly refers to the matter, giving a few
+facts.
+
+It has been well observed by an able writer, that it is impossible to
+trace the path of a sunbeam through our atmosphere without feeling a
+desire to know its nature, by what power it traverses the immensity of
+space, and the various modifications it undergoes at the surfaces and
+interior of terrestrial substances.
+
+Light is white and colorless, as long as it does not come in contact
+with matter. When in apposition with any body, it suffers variable
+degrees of decomposition, resulting in color, as by reflection,
+dispersion, refraction, and unequal absorption.
+
+To Sir I. Newton the world is indebted for proving the compound nature
+of a ray of white light emitted from the sun. The object of this work
+is not to engage in an extended theory upon the subject of light, but
+to recur only to some points of more particular interest to the
+photographic operator.
+
+The decomposition of a beam of light can be noticed by exposing it to a
+prism. If, in a dark room, a beam of light be admitted through a small
+hole in a shutter, it will form a white round spot upon the place where
+it falls. If a triangular prism of glass be placed on the inside of
+the dark room, so that the beam of light falls upon it, it no longer
+has the same direction, nor does it form a round spot, but an oblong
+painted image of seven colors--red, orange, yellow, green, blue,
+indigo, and violet. This is called the solar spectrum, and will be
+readily understood by reference to the accompanying diagram, Fig. 1.
+
+{133}
+
+To those who are unacquainted with the theory of light (and for their
+benefit this chapter is given), it may be a matter of wonder how a beam
+of light can be divided.
+
+[Illustration: Fig. 1 (amdg_1.gif)]
+
+This can be understood when I say, that white light is a bundle of
+colored rays united together, and when so incorporated, they are
+colorless; but in passing through the prism the bond of union is
+severed, and the colored rays come out singly and separately, because
+each ray has a certain amount of refracting (bending) power, peculiar
+to itself. These rays always hold the same relation to each other, as
+may be seen by comparing every spectrum or rainbow; there is never any
+confusion or misplacement.
+
+There are various other means of decomposing {134} white light besides
+the prism, of which one of the principal and most interesting to the
+Daguerreotypist is by reflection from colored bodies. If a beam of
+white light falls upon a white surface, it is reflected without change;
+but if it falls upon a red surface, only the red ray is reflected: so
+also with yellow and other colors. The ray which is reflected
+corresponds with the color of the object. It is this reflected
+decomposed light which prevents the beautifully-colored image we see
+upon the ground glass in our cameras.
+
+[Illustration: Fig. 2 (amdg_2.gif)]
+
+A sunbeam may be capable of three divisions--LIGHT, HEAT, and ACTINISM;
+the last causes all the chemical changes, and is the acting power upon
+surfaces prepared to receive the photographic image. The accompanying
+illustration, Fig. 2, will readily bring to the mind of the reader the
+relation of these one to another, and their intensities in the
+different parts of a decomposed sunbeam.
+
+The various points of the solar spectrum are represented in the order
+in which they occur between A, and B, this exhibits the limits of the
+Newtonian spectrum, corresponding with Fig. 1. Sir John Herschel and
+Seebeck have shown that there exists, beyond the violet, a faint violet
+light, or rather a lavender to b, to which gradually becomes colorless;
+similarly, red light exists beyond the assigned limits of the red ray
+to a. The greatest amount of actinic power is shown at E opposite the
+violet; hence this color "exerts" the greatest amount of influence in
+the formation of the photographic image.
+
+(Blue paper and blue color have been somewhat extensively used by our
+Daguerreotype operators in their operating rooms and skylights, in
+order to facilitate the operation in the camera. I fancy, however,
+that this plan cannot be productive of as much good as thought by some,
+from the fact, that the light falling upon the subject, and then
+reflected into the camera, is, coming through colorless glass, not
+affected by such rays as may be reflected from the walls of the
+operating room; and even if it were so, I conceive that it would be
+injurious, by destroying the harmony of shadows which might otherwise
+occur.) The greatest amount of white light is at C; the yellow contains
+less of the chemical power than any other portion of the solar
+spectrum. It has been found that the most intense heat is at the
+extreme red, b.
+
+Artificial lights differ in their color; the white light of burning
+charcoal, which is the principal light from candles, oil and gas,
+contains three rays--red, yellow, and blue. The dazzling light emitted
+from lime intensely heated, known as the Drummond light, gives the
+colors of the prism almost as bright as the solar spectrum.
+
+If we expose a prepared Daguerreotype plate or sensitive paper to the
+solar spectrum, it will be observed that the luminous power (the
+yellow) occupies but a small space compared with the influence of heat
+and chemical power. R. Hunt, in his Researches on Light, has presented
+the following remarks upon the accompanying illustration:
+
+[Illustration: Fig. 3 (amdg_3.gif)]
+
+"If the linear measure, or the diameter of a circle which shall include
+the luminous rays, is 25, that of the calorific spectrum will be 42.10,
+and of the chemical spectrum 55.10. Such a series of circles may well
+be used to represent a beam from the sun, which may be regarded as an
+atom of Light, surrounded with an invisible atmosphere of Heat, and
+another still more extended, which possesses the remarkable property of
+producing chemical and molecular change.
+
+A ray of light, in passing obliquely through any medium of uniform
+density, does not change its course; but if it should pass into a
+denser body, it would turn from a straight line, pursue a less oblique
+direction, and in a line nearer to a perpendicular to the surface of
+that body. Water exerts a stronger refracting power than air; and if a
+ray of light fall upon a body of this fluid its course is changed, as
+may be seen by reference to Fig. 4.
+
+[Illustration: Fig. 4 (amdg_4.gif)]
+
+It is observed that it proceeds in a less oblique direction (towards
+the dotted line), and, on passing on through, leaves the liquid,
+proceeding in a line parallel to that at which it entered. It should
+be observed that at the surface of bodies the refractive power is
+exerted, and that the light proceeds in a straight line until leaving
+the body. The refraction is more or less, and in all cases in
+proportion as the rays fall more or less obliquely on the refracting
+surface. It is this law of optics which has given rise to the lenses
+in our camera tubes, by which means we are enabled to secure a
+well-delineated representation of any object we choose to picture.
+
+When a ray of light passes from one medium to another, and through that
+into the first again, if the two refractions be equal, and in opposite
+directions, no sensible effect will be produced.
+
+The reader may readily comprehend the phenomena of refraction, by means
+of light passing through lenses of different curves, by reference to
+the following diagrams:--
+
+[Illustration: Fig. 5, 6, 7 (amdg_5.gif)]
+
+Fig 5 represents a double-convex lens, Fig. 6 a double-concave, and
+Fig. 7 a concavo-convex or meniscus. By these it is seen that a
+double-convex lens tends to condense the rays of light to a focus, a
+double-concave to scatter them, and a concavo-convex combines both
+powers.
+
+If parallel rays of light fall upon a double-convex lens, D D, Fig. 8,
+they will be refracted (excepting such as pass directly through the
+centre) to a point termed the principal focus.
+
+[Illustration: Fig. 8a (amdg_8a.gif)]
+
+The lines A B C represent parallel rays which pass through the lens, D
+D, and meet at F; this point being the principal focus, its distance
+from the lens is called the focal length. Those rays of light which
+are traversing a parallel course, when they enter the lens are brought
+to a focus nearer the lens than others. Hence the difficulty the
+operator sometimes experiences by not being able to "obtain a focus,"
+when he wishes to secure a picture of some very distant objects; he
+does not get his ground glass near enough to the lenses. Again, the
+rays from an object near by may be termed diverging rays. This will be
+better comprehended by reference to Fig. 9, where it will be seen that
+the dotted lines, representing parallel rays, meet nearer the lenses
+than those from the point A. The closer the object is to the lenses,
+the greater will be the divergence. This rule is applicable to
+copying. Did we wish to copy a 1/6 size Daguerreotype on a 1/16 size
+plate, we should place it in such a position to the lenses at A that
+the focus would be at F, where the image would be represented at about
+the proper size. Now, if we should wish to copy the 1/6 size picture,
+and produce another of exactly the same dimensions, we have only to
+bring it nearer to the lenses, so that the lens D E shall be
+equi-distant from the picture and the focus, i. e. from A to B. The
+reason of this is, that the distance of the picture from the lens, in
+the last copy, is less than the other, and the divergence has
+increased, throwing, the focus further from the lens."
+
+[Illustration: Fig. 9 (amdg_9.gif)]
+
+These remarks have been introduced here as being important for those
+who may not understand the principles of enlarging or reducing pictures
+in copying.
+
+I would remark that the points F and A, in Fig. 9, are termed
+"conjugate foci."
+
+If we hold a double-convex lens opposite any object, we find that an
+inverted image of that object will be formed on a paper held behind it.
+To illustrate this more clearly, I will refer to the following woodcut:
+
+[Illustration: Fig. 10 (amdg_10.gif)]
+
+"If A B C is an object placed before a convex lens, L L, every point of
+it will send forth rays in all directions; but, for the sake of
+simplicity, suppose only three points to give out rays, one at the top,
+one at the middle, and one at the bottom; the whole of the rays then
+that proceed from the point A, and fall on the lens L L, will be
+refracted and form an image somewhere on the line A G E, which is drawn
+direct through the centre of the lens; consequently the focus E,
+produced by the convergence of the rays proceding from A, must form an
+image of A, only in a different relative position; the middle point of
+C being in a direct line with the axis of the lens, will have its image
+formed on the axis F, and the rays proceeding from the point B will
+form an image at D; so that by imagining luminous objects to be made up
+of all infinite number of radiating points and the rays from each
+individual point, although falling on the whole surface of the lens, to
+converge again and form a focus or representation of that point from
+which the rays first emerged, it will be very easy to comprehend how
+images are formed, and the cause of those images being reversed.
+
+"It must also be evident, that in the two triangles A G B and D G E,
+that E D, the length of the image, must be to A B, the length of the
+object, as G D, the distance of the image, is to G B, the distance of
+the object from the lens.
+
+It will be observed that in the last cut the image produced by the lens
+is curved. Now, it would be impossible to produce a well-defined image
+from the centre to the edge upon a plain surface; the outer edges would
+be misty, indistinct, or crayon-like. The centre of the image might be
+represented clear and sharp on the ground glass, yet this would be far
+from the case in regard to the outer portions. This is called
+spherical aberration, and to it is due the want of distinctness which
+is frequently noticed around the edges of pictures taken in the camera.
+To secure a camera with a flat, sharp, field, should be the object of
+every operator; and, in a measure, this constitutes the great
+difference in cameras manufactured in this country.
+
+Spherical aberration is overcome by proper care in the formation of the
+lens: "It can be shown upon mathematical data that a lens similar to
+that given in the following diagram--one surface of which is a section
+of an ellipse, and the other of a circle struck from the furthest of
+the two foci of that ellipse--produces no aberration.
+
+"At the earliest period of the employment of the camera obscura, a
+double-convex lens was used to produce the image; but this form was
+soon abandoned, on account of the spherical aberration so caused.
+Lenses for the photographic camera are now always ground of a
+concavo-convex form, or meniscus, which corresponds more nearly to the
+accompanying diagram."
+
+[Illustration: Fig. 11 (amdg_11.gif)]
+
+Chromatic Aberration is another difficulty that opticians have to
+contend with in the manufacturing of lenses. It will be remembered,
+that in a former page (133) a beam of light is decomposed by passing
+through a glass prism giving seven distinct colors--red, orange,
+yellow, green, blue, indigo and violet.
+
+Now, as has been said before, the dissimilar rays having an unequal
+degree of refrangibility, it will be impossible to obtain a focus by
+the light passing through a double-convex lens without its being
+fringed with color. Its effect will be readily understood by reference
+to the accompanying cut.
+
+[Illustration: Fig. 8b (amdg_8b.gif)]
+
+If L L be a double convex-lens, and R R R parallel rays of white light,
+composed of the seven colored rays, each having a different index of
+refraction, they cannot be refracted to one and the same point; the red
+rays, being the least refrangible, will be bent to r, and the violet
+rays, being the most refrangible, to v: the distance v r constitutes
+the chromatic aberration, and the circle, of which the diameter is a l,
+the place or point of mean refraction, and is called the circle of
+least aberration. If the rays of the sun are refracted by means of a
+lens, and the image received on a screen placed between C and o, so as
+to cut the cone L a l L, a luminous circle will be formed on the paper,
+only surrounded by a red border, because it is produced by a section of
+the cone L a l L, of which the external rays L a L l, are red; if the
+screen be moved to the other side of o, the luminous circle will be
+bordered with violet, because it will be a section of the cone M a M l,
+of which the exterior rays are violet. To avoid the influence of
+spherical aberration, and to render the phenomena of coloration more
+evident, let an opaque disc be placed over the central portion of the
+lens, so as to allow the rays only to pass which are at the edge of the
+glass; a violet image of the sun will then be seen at v, red at r, and,
+finally, images of all the colors of the spectrum in the intermediate
+space; consequently, the general image will not only be confused, but
+clothed with prismatic colors."
+
+To overcome the difficulty arising from the chromatic aberration, the
+optician has only to employ a combination of lenses of opposite focal
+length, and cut from glass possessing different refrangible powers, so
+that the rays of light passing through the one are strongly refracted,
+and in the other are bent asunder again, reproducing white light.
+
+To the photographer one of the most important features, requiring his
+particular attention, is, that he be provided with a good lens. By the
+remarks given in the preceding pages, he will be enabled, in a measure,
+to judge of some of the difficulties to which he is occasionally
+subjected. We have in this country but two or three individuals who
+are giving their attention to the manufacture of lenses, and their
+construction is such, that they are quite free from the spherical or
+chromatic aberration.
+
+
+
+CHAPTER V.
+
+To make Plates for the Daguerreotype--Determining the Time of Exposure
+in the Camera--Instantaneous Process for Producing
+Daguerreotype--Galvanizing the Daguerreotype Plate--Silvering
+Solution--Daguerreotype without Mercury--Management of Chemicals--Hints
+and Cautions--Electrotyping--Crayon Daguerreotypes--Illuminated
+Daguerreotypes--Natural Colors in Heliography--Multiplying
+Daguerreotypes on one Plate--Deposit in Gilding--Practical Hints on the
+Daguerreotype.
+
+
+TO MAKE PLATES FOR THE DAGUERREOTYPE.
+
+I do not give the method employed by our regular plate manufacturers;
+this is not important, as the operator could not possibly profit by it
+from the fact of the great expense of manufacturing. The following
+will be found practical:
+
+Procure a well planished copper plate of the required size, and well
+polish it, first with pumice stone and water, then with snake stone,
+jewelers' rouge. Plates can be purchased in a high state of
+preparation from the engravers. Having prepared the copper-plate, well
+rub it with salt and water, and then with the silvering powder. No
+kind answers better than that used by clock-makers to silver their
+dial-plates. It is composed of one part of well washed chloride of
+silver, five parts of cream of tartar, and four parts of table salt.
+This powder must be kept in a dark vessel, and in a dry place. For a
+plate six inches by five, as much of this composition as can be taken
+up on a shilling is sufficient. It is to be laid in the centre of the
+copper, and the figures being wetted, to be quickly rubbed over every
+part of the plate, adding occasionally a little damp salt. The copper
+being covered with the silvering is to be speedily well washed in
+water, in which a little soda is dissolved, and as soon as the surface
+is of a fine silvery whiteness, it is to be dried with a very clean
+warm cloth. In this state the plates may be kept for use. The first
+process is to expose the plate to the heat of a spirit flame, until the
+silvered surface becomes of a well-defined golden-yellow color; then,
+when the plate is cold, take a piece of cotton, dipped in very dilute
+nitric acid, and rub lightly over it until the white hue is restored,
+and dry it with very soft clean cloths. A weak solution of the
+hydriodate of potash, in which a small portion of iodine is dissolved,
+is now passed over the plate with a wide camel's hair brush. The
+silver is thus converted, over its surface, into an ioduret of silver;
+and in this state it is exposed to light, which blackens it. When dry,
+it is to be again polished, either with dilute acid or a solution of
+carbonate of soda, and afterwards with dry cotton, and the smallest
+possible portion of prepared chalk: by this means a surface of the
+highest polish is produced. The rationale of this process is, in the
+first place, the heat applied dries off any adhering acid, and effects
+more perfect union between the copper and silver, so as to enable it to
+bear the subsequent processes. The first yellow surface appears to be
+an oxide of silver with, possibly, a minute quantity of copper in
+combination, which being removed leaves a surface chemically pure.
+
+Another Method.--The best and simplest mode with which we are
+acquainted is to divide an earthenware vessel with a diaphragm: one
+side should be filled with a very dilute solution of sulphuric acid,
+and the other with either a solution of ferroprussiate of potash, or
+muriate of soda, saturated with chloride of silver. The copper plate,
+varnished on one side, is united, by means of a copper wire, with a
+plate of zinc. The zinc plate being immersed in the acid, and the
+copper in the salt, a weak electric current is generated, which
+precipitates the silver in a very uniform manner over the entire
+surface.
+
+Another Method.--A piece of brass or of polished copper, brass is
+preferred, is perfectly planished and its surface made perfectly clean.
+A solution of nitrate of silver, so weak that the silver is
+precipitated slowly, and a brownish color, on the brass, is laid
+uniformly over it, "at least three times," with a camel's hair pencil.
+After each application of the nitrate, the plate should be rubbed
+gently in one direction, with moistened bitartrate of potassa, applied
+with buff. This coat of silver receives a fine polish from peroxide of
+iron and buff. Proofs are said to have been taken on it, comparable
+with those obtained on French plates.
+
+
+M. SOLIEL'S PROCESS FOR DETERMINING THE TIME OF EXPOSURE IN THE CAMERA.
+
+M. Soliel has proposed the use of the chloride of silver to determine
+the time required to produce a good impression on the iodated plate in
+the camera. His method is to fix at the bottom of a tube, blackened
+within, a piece of card, on which chloride of silver, mixed with gum or
+dextrine, is spread. The tube thus disposed is turned from the side of
+the object of which we wish to take the image, and the time that the
+chloride of silver takes to become of a greyish slate color will be the
+time required for the light of the camera to produce a good effect on
+the iodated silver.
+
+
+INSTANTANEOUS PROCESS FOR PROCURING DAGUERREOTYPES.
+
+The following method of producing Daguerreotypes has by some been named
+as above. Most experienced operators have been long acquainted with
+the effect of the vapor of ammonia upon the chemically coated plate. I
+will here insert Mr. W. H. Hewett's plan of proceeding. This
+gentleman, in referring to it (published in 1845), says:
+
+"This improvement consists in using the vapor of ammonia, as an object
+to accelerate the action of light upon the plate. The effect is
+produced upon a simple iodized plate, but still more upon a plate
+prepared in the ordinary way, with both iodine and bromine. By this
+means, the author obtained impressions instantaneously in the sunshine,
+and in five to ten seconds in a moderate light; and he hopes to be able
+to take moving objects. It can be applied by exposing the prepared
+plate over a surface of water, to which a few drops of ammonia have
+been added (sufficient to make it smell of ammonia); or the vapor can
+be introduced into the camera during the action. In fact, the presence
+of ammonia, in the operating-room, appears to have a good effect, as it
+also neutralizes the vapors of iodine and bromine that may be floating
+about, and which are so detrimental to the influences of light upon the
+plate."
+
+
+GALVANIZING THE DAGUERREOTYPE PLATE.
+
+In consideration of the importance of galvanized plates, I shall
+endeavor to give as plain and concise a manner of manipulation as
+possible. For some time it was a question among the operators
+generally, as to the beneficial result of electrotyping, the
+Daguerreotype plate, but for a few years past our first operators have
+found it a fact, that a well electro-silvered surface is the best for
+producing a portrait by the Daguerreotype.
+
+From my own experiments, I have found that a plate, by being
+galvanized, can be rendered more sensitive to the operation of the
+light in proportion of one to five, viz.: if a plate as furnished by
+the market, be cleaned, polished, coated and exposed in the camera, if
+the required time to freely develop an impression be ten seconds, a
+similar plate prepared in like manner and galvanized, will produce an
+equally well-defined image in eight seconds. In connection with this
+subject, there is one fact worthy of notice; a plate with a very heavy
+coating of pure silver, will not produce an equally developed image, as
+a plate with a thinner coating, hence the thin coating, providing it
+entirely covers the surface, is the best, and is the one most to be
+desired. The experiment is plain and simple. Let the slate receive a
+heavy or thick coating by the electrotype, then polish, coat, expose in
+the usual manner, and the result will be a flat, ashy, indistinct
+impression; when, on the other hand, the thin coating will produce a
+bright, clear and distinct image, with all the details delineated.
+
+The style of battery best for the purpose has been, and now is, a
+question of dispute among operators; some preferring the Daniell
+battery to Smee's. Some claim the superiority of the first from its
+uniformity of action; others, of the latter, for its strength. I
+consider either good, and for the inexperienced would prefer the
+Daniell. This is more simple in its construction, while it has
+certainty in action. The more skillful electrotyper would prefer
+Smee's, and this is the one most generally in use. I would remark that
+the plan of galvanizing plates should be followed by every operator,
+and when once thoroughly tested, no one will abandon it.
+
+
+SILVERING SOLUTION.
+
+To any desired quantity of chloride of silver in water add, little by
+little, cyanide of potassium, shaking well at each addition, until all
+the cyanide is dissolved. Continue this operation, and add the
+cyanide, until all the precipitate is taken up and held in solution.
+
+This solution is now ready for the plate-cup. Enough water may be added
+to cover any sized plate when held perpendicular in the cup. The
+strength of the solution may be kept up by occasionally adding the
+chloride of silver and cyanide of potassium. There should alway be a
+very little excess of the cyanide.
+
+The plate should be well cleaned and buffed, and the solution well
+stirred before it is immersed. Care should be observed to keep the
+solution clean, and allow no particle of dust to come in contact with
+the surface of the plate. The plate is now to be attached to the pole
+of the battery.
+
+After remaining a short time, it assumes a blue color; take it out,
+rinse freely with pure water, then dry with a spirit lamp, and it is
+ready for buffing. Buff and coat in the usual manner. Some operators
+are in the practice of immersing the plate in the solution and buffing
+twice. This additional silvering is no improvement wherever there has
+been a proper first coating.
+
+Sometimes the operator is troubled with streaks or scum on the plate.
+This may arise from three causes, all of which experience must teach
+the experimenter to avoid; first, too great an excess of cyanide in the
+solution; second, a lack of silver; third, the current too strong.
+Another annoyance arises from the solution being dirty and the dirt
+collecting on the surface. When this is the case, the dirt is sure to
+come in contact with the surface of the plate as it is plunged into the
+solution, and the result is a scum that it is difficult to dispose of.
+This can be prevented only by frequent filtering. One thing should
+always be borne in mind in electrotyping Daguerreotype plates--that in
+order to secure a perfectly coated surface, the plate should be
+perfectly cleaned. In this point, many who have tried the electrotype
+process have failed, attributing their ill success to other than the
+proper cause.
+
+
+
+DAGUERREOTYPES WITHOUT MERCURY.
+
+The following process possesses some interest, and is worthy a trial
+from operators. M. Natterer, of Vienna, discovered a process for
+obtaining proofs on iodized plates with the chloride of sulphur,
+without the use of mercury. A plate of silver is iodized in the usual
+manner, and then placed on the top of a vessel six or eight inches
+high, having at the bottom, in a small cup, a few drops of chloride of
+sulphur; it should remain exposed to the action of the vapor until the
+sombre yellow color is changed to a red, after which it is brought to a
+focus in the camera, where it is exposed to the light in the camera,
+for about the time necessary to produce an ordinary daguerreotype. The
+plate is then taken out and examined in the camera by the light of a
+candle. It often occurs that no trace of the image is as yet
+perceptible, but if the plate is heated by placing over a spirit lamp
+the unprepared side, or if left for some time in the dark, or, lastly,
+if exposed only a few seconds to a weak, dimmed light, the positive
+picture then appears with all its shades. Of these three modes of
+bringing out the image, the second is superior to the others.
+
+
+MANAGEMENT OF CHEMICALS.
+
+It is necessary, first of all, to know that you have a chemical which
+is capable of producing good results when in skillful hands. For this
+reason it is best to prepare your own quick, after some formula which
+is known to be good. Those quick-stuffs which contain chloride of
+iodine are noted for their depth of tone while they probably operate
+with less uniformity than those which are destitute of it. For
+operating under ordinary circumstances, especially with an inferior
+light, probably no accelerator is more quick and sure than Wolcott's.
+It also produces a very fine, white pleasing picture, though lacking
+that depth of impression so much to be desired. The dry quick operates
+with surety, and its use is simple and easy, producing an impression
+much like Wolcott's. For those having a good and permanent light,
+however, we would recommend a chemical giving more body to the
+impression.
+
+There is a class of accelerators called sensitives, claiming to work in
+from three to ten seconds, which, however, will be found very little,
+if any, more sensitive than this. We frequently work it with the
+ordinary coating in twelve and fifteen seconds. The manner in which
+the sensitives are worked is by coating very light. In this way, a
+flat, shallow picture is obtained in a few seconds; and the same can be
+done with any of the more volatile quicks.
+
+It is a fact not generally known, that a plate coated in a light
+chemical room is more sensitive than when coated in darkness. By
+admitting a free, uniform light, and exposing the plate to it a few
+seconds after coating, then timing short in the camera, a very light,
+clear impression is obtained. The time in the camera is reduced in
+proportion to the previous action of light. The shades, of course, are
+destroyed, and the tone injured; still, for taking children, we have
+succeeded better by this method than by the use of "sensitives." The
+discovery of this principle was accidental, while operating where the
+direct ray s of the sun, entering the window just before sunset, fell
+on the curtain of our dark room, rendering it very light within.
+
+The selection of iodine is not unimportant. Reject, at once, that
+which has anything like a dull, black, greasy appearance; and select
+that which is in beautiful large crystalline scales, of a purple color,
+and brilliant steel lustre.
+
+Solarization, and general blueness of all the light parts of the
+picture, were formerly great obstacles to success, though now scarcely
+thought of by first-class artists. Beginners in the art, however, are
+still apt to meet with this difficulty. It is occasioned by dampness
+in the iodine box, which causes the plate to become coated with a
+hydro-iodide of silver, instead of the iodide. The remedy is in drying
+your iodine. If in summer, you can open your box and set it in
+sunshine a few minutes; or if in winter, set it under a stove a short
+time. The true method, however, is to dry it by means of the chloride
+of calcium. It has such a remarkable affinity for water, that a small
+fragment placed in the open air, even in the dryest weather, soon
+becomes dissolved.
+
+Take one or two ounces of this chemical, heat it in the drying bath, or
+in a hot stove, to perfect dryness; place it in a small glass toy dish,
+or large watch crystal, and set it in the centre of your iodine box.
+Take this out and heat to dryness every morning. Adopt this process,
+and with your mercury at a high temperature, you will never be troubled
+with blue pictures.
+
+Young operators are apt to impute all want of success in operating to
+their chemicals, even though the cause is quite as likely to be
+elsewhere. Failure is quite likely to occur from dampness in the
+buffs, or in the polish; it is therefore necessary to be constantly on
+the guard in this quarter. With a view to this, always scrape your
+buffs with a dull knife, or with one blade of your shears, the first
+thing in the morning, and after brushing them thoroughly, dry them,
+either in the sun, by a stove, or in the buff-dryer. It is equally
+important that the polish and the brush should be kept dry.
+
+Want of success may arise from vapors of iodine or bromine in the
+camera box, mercury bath, or even in the buffs. It is incredible how
+small a quantity of these vapors will affect the effect of light when
+coming in contact with the plate, after or during the exposure in the
+camera. It is therefore necessary to be cautious not to mix chemicals,
+nor open your boxes or bottles in your room, but take them out to do
+it. Never hurry the operation through from lack of confidence in the
+result. The fact of anything being out of order, forms no excuse for
+slighting the process. If unsuccessful, do not pursue the same course
+every trial, but vary with a view to detect the cause of the difficulty.
+
+In case of a long series of failures, institute a regular course of
+investigation, after this manner, commencing where the trouble is most
+likely to occur:
+
+1. Are the plates well cleaned?
+
+2. Is the iodine dry? If the impressions come out blue, you may rest
+assured it is not. Take out the iodine, wipe and dry the box, and dry
+the calcium.
+
+3. Is the quick battery of the right strength? If dry, it must change
+the plate in from six to fifteen seconds. If any of the chloride of
+iodine class, it may vary from five seconds to a minute. Begin by
+coating light, and increase on each trial, observing the effect. If
+the light side of the picture seems loth to come out, and shows no
+contrast with the dark side, it is to be inferred that your battery is
+too strong, and must be reduced with water or set out in the open air
+for a few minutes, with the lid off. If working an old battery, never
+renew very strong, or it will work dark and heavy. A battery, to work
+well, should be gradually losing strength, but never gaining. An old
+battery, however, may be quickened up and made to work well for some
+time, by adding five of six drops of sulphuric acid, repeating the
+quantity as often as necessary, providing always that acid be not used
+in manufacturing the quick.
+
+4. Have the plates lost their sensitiveness by being many times
+exposed to mercury? Clean and burn them; but if French plates, burn
+light, or you spoil them.
+
+5. Are the buff s dry and clean? Examine the plate critically after
+buffing to detect any appearance of scum or film on the surface. If
+so, the longer you buff the more it shows. Scrape and dry the buffs
+thoroughly.
+
+6. Is the mercury free from scum and dirt? If not, filter. Is it
+also far enough from the coating boxes? Should be at least three feet,
+and kept covered.
+
+7. Is the mercury sufficiently heated? This is important. Long
+exposure, however, will answer the same purpose.
+
+8. Are your lenses clean, and in proper place?
+
+9. Are the tablets in focus with the ground-glass? If you can
+attribute the failure to none of these, mix a new box of some other
+kind of quick, say the dry, for instance. If you fail in the same
+manner here, take time, wash your buffs, overhaul all the chemicals,
+and start anew. Do not be discouraged.
+
+There is no day so dark but that the sun will shine again. We will
+close with this brief summary of advice:
+
+Clean your plates. Keep everything dry. Keep the mercury hot. Follow
+these instructions carefully, and you must succeed.
+
+
+HINTS AND CAUTIONS.
+
+First of all, cleanliness should be observed. When there is dust or
+dirt about your room, particularly about the work-bench, failures will
+be frequent; for the smallest particles of rotten-stone, when allowed
+to come in contact with the buffs, will produce scratches on the
+surface of the plate, which very much injures the operation, and often
+causes failures.
+
+Dust flying about the room is injurious, if allowed to fall on the
+plate, either before or after it has been coated, as it causes black
+spots which cannot be removed.
+
+The polished plate should not be allowed to come in contact with a
+strong current of air, for it tends to oxidize the surface. Breathing
+on the surface should also be avoided, for the same reason.
+
+The plate should, in all cases, be buffed immediately before using, and
+not allowed to stand any length of time. It should be held with the
+polished face downward.
+
+It is always best that the plate should be of the same temperature of
+the atmosphere in the room.
+
+Keep the camera and mercury-bath perfectly free from the vapors of
+iodine and bromine; for the presence of the slightest degree of either
+of the above will injure the impression in no small degree. As a
+preventive, let the camera be exposed to the sun or fire for a few
+minutes in the morning.
+
+Filter your mercury often, to keep the surface free from film and dust.
+
+The hyposulphite solution should be filtered through sponge every time
+it is used.
+
+The direct rays of light must not enter the camera in conjunction with
+those reflected from the object; or the picture will be veiled, and the
+color of the plate changed to a thick green.
+
+If the plate be iodized only to a light-yellow, the result might be of
+a bluish or grey tinge: and this is generally the case, when the quick
+is new and strong, and there is an excess of it on the plate, and yet
+not enough to form the bromide iodide of silver; in which case it would
+wholly spoil the impression.
+
+Your iodine will be found to operate more successfully, when the time
+required for coating the plate does not fall short of fifteen seconds,
+or exceed one minute.
+
+Too quick coating can be avoided by using less iodine in your box. In
+the summer months, when the weather is 80 deg. and over, one quarter of
+an ounce, or even less, will work to advantage.
+
+
+ELECTROTYPING.
+
+I am indebted to Mr. J. H. Fitzgibbons for the following process, which
+he employed in producing the excellent specimens he exhibited at the
+Crystal Palace:
+
+"I shall endeavor to lay down in as comprehensive a manner as possible
+the method by which I have been enabled to produce the most
+satisfactory results. I use a Smee's battery (another kind will do).
+After filling the cell, of common size, nearly full with water; add
+about quarter of an ounce of sulphuric acid. Mix this well, and let it
+stand for about three hours, or until the action of the battery becomes
+weak, when it is in order to work with a very uniform action. Put one
+pound of sulphate of copper in one quart of water; stir it until the
+sulphate of copper is all dissolved, and then add one half ounce of
+sulphuric acid and a quarter of an ounce of nitric acid. This
+solution, well mixed, should be filtered, and it is ready for use. It
+is very important that the solution should be kept clean, clear, and
+free from all foreign substance. The above quantity of this solution
+will be found sufficient for electrotyping a dozen of the sixth-size
+plates. When it is required to be strengthened, it is only necessary
+to add a little of the sulphate of copper.
+
+"With the battery prepared as above, and the solution of sulphate of
+copper in a vessel of proper dimensions to receive your plate, connect
+the galvanic current, and immerse the impressioned plate, letting it
+remain until a thin film of copper has been formed, then the battery
+can be strengthened, and the impression will be of sufficient thickness
+to be removed in from eight to twelve hours. An old Daguerreotype
+plate attached to the opposite pole of the battery (copper side towards
+the face of the plate to be electrotyped), will answer the same purpose
+as the silver-plate.
+
+"The great difficulty in taking an electrotype impression, and
+preserving the original, has been attributed to the battery being too
+powerful. I am led to believe from practice that the principal
+difficulty has been in the Daguerreotype plate itself, for if we use an
+impression that has been taken but a few days, and taken in the usual
+way, we will find it difficult to succeed without spoiling both the
+copy and original, and so also with an old impression.
+
+"I have found the most certain method to be as follows:--Coat the
+Daguerreotype plate as usual, except use less of the accelerators, the
+proportion of iodine coating being greater, of course the time of
+exposure in the camera will be lengthened. Mercurialize it at about a
+temperature requiring to develop the image, from six to eight minutes,
+at least. Gilding the Daguerreotype has much to do towards producing a
+good electrotype copy. This should be done by applying a little heat,
+and gilding very slowly, giving a coating of gold with the greatest
+possible uniformity. By this method, I have been enabled to produce
+any number of proofs. I have produced a dozen from one impression, and
+it remains as perfect as when first taken.
+
+"By a little judgment and care the operator will be enabled to produce
+the electrotype copy of the Daguerreotype plate without any difficulty.
+The electrotype copy should be immediately put under a glass and sealed
+in the same manner as the ordinary Daguerreotype."
+
+
+CRAYON DAGUERREOTYPES.
+
+This process is patented in the United States, by J. A. Whipple, of
+Boston, and of course no honorable person will use it for his own
+benefit without purchasing a right.
+
+A white back-ground is generally employed, the object being to blur the
+lower portion of the plate, leaving the head of the subject in relief.
+Every Daguerreotypist is familiar with the fact that a motion of any
+body between the camera and the sitter will cause a "blur." Cut a piece
+of thin paper and scallop it, making a semicircle. This is kept
+straight by means of a wire frame, and it is to be moved in front of
+the lower part of the body of the sitter during the time of exposure of
+the plate in the camera. Develop over mercury as usual, and the result
+will be a crayon Daguerreotype.
+
+Another method is to have a wheel with a hole cut through it of a
+diameter of about 12 inches. This hole is so cut as to leave teeth
+resembling those of a large saw. This wheel is so arranged that it can
+be turned around, which should be done during the time of exposure in
+the camera. It must be placed between the camera and the sitter, and
+at such a distance from the camera as to allow such proportion of the
+body of the sitter be seen upon the ground-glass as is desired. It
+will be readily seen that by turning this wheel during the operation
+will produce the same result as the paper being moved in the other
+method. The teeth make the "blur." The side of the wheel towards the
+camera may be black, by which means the result will be a dark instead
+of a light border.
+
+
+ILLUMINATED DAGUERREOTYPES.
+
+This process is also patented, and the remarks on the preceding subject
+will apply in this case. The plate is prepared and exposed as in the
+usual method of the Daguerreotype. A white back-ground is employed.
+Let the head of the sitter come in the middle of the plate, and before
+exposing it to the vapors of mercury, put a small mat or diaphragm,
+having a small hole through it, over or directly on the surface of the
+plate. This diaphragm should be bevelled, and the bevel should be
+towards the surface of the plate; this, in order to prevent too sharp a
+line on the impression. It will be readily seen that if an
+impressioned plate so covered is placed over the mercury, it will be
+developed on such portions only as are exposed. The principle is so
+familiar that further explanations are unnecessary.
+
+
+NATURAL COLORS IN HELIOGRAPHY.
+
+This subject is worthy the attention of every operator. The following
+process is so plain and easy of trial that any Daguerreotypist can try
+it. This is as given by Mr. James Campbell, and was published in
+Humphrey's Journal of the Daguerreotype and Photographic Arts, vol. 5,
+page 11. Mr. Campbell has done much to further the process announced
+by M. Neipce, and his experiments have proved highly successful.
+
+The following is submitted as worthy of trial:
+
+"The proper preparation of the chloridated plate, to enable it to
+receive colored impressions is an object of the first importance to
+those wishing to experiment on it, and consequently requires particular
+notice. The plate may be prepared by making it the positive pole of a
+battery, and letting it at the same time be immersed in chlorine water.
+The negative pole should be a slip of platinum. All the colors may be
+produced from a plate so prepared if the chlorine and water are in the
+right proportions; but generally one color or the other predominates,
+according to the amount of chlorine in the liquid. By adding the
+chlorides of strontian, uranium, potassium, sodium, iron, or copper to
+the liquid, various effects may be produced, and these bodies will be
+found to produce the same color on the plate that their flame gives to
+alcohol.
+
+"The honor of this discovery is due to M. Neipce. Copper gives a
+variegated flame; hence many colors may be impressed on a plate
+prepared with a solution of its chloride.
+
+"M. Neipce recommends a solution of the mixed chlorides of copper and
+iron, and it is with these, that I have been most successful. As the
+chlorides of copper and iron are not much used in the arts, they are
+not generally found for sale in the shops; and it may be well to
+furnish those not much versed in chemistry with an easy method of
+preparing them.
+
+"They may be made directly from either metal by dissolving it in
+hydrochloric acid; but they may be formed by a cheaper method, and by
+which also the acid fumes are avoided.
+
+"Sulphate of iron or copper, or both together, may be dissolved in
+water and then neutralized with common crude potash, or its carbonate
+or bicarbonate--known commonly as pearl ash and saleratus. If either
+of the latter be used, there will be formed sulphate of potash and a
+carbonate of the metal used, and there will also be a considerable
+effervescence of carbonic acid, which will, if care is not taken, cause
+the mixture to run over the vessel. After the copper or iron salt is
+neutralized, which is known by its ceasing to effervesce, the carbonate
+of the metal will settle slowly, and will at first nearly fill the
+vessel. The supernatant fluid, which is sulphate of potash in
+solution, may now be carefully poured off, and its place filled with
+water; this operation should be repeated several times until the water
+which passes off is tasteless. The carbonate of the metal rapidly
+changes to an oxide by contact with the air, and it will generally be
+found, when it is sufficiently washed, that it is at least half oxide.
+On adding hydrochloric acid cautiously to the mixture, a chloric of the
+metal will be formed, and carbonic acid will be evolved from the
+remaining carbonate. The chloride formed is soluble; but as there are
+two chlorides of these metals, and we wish to produce the one which
+contains the most chlorine, it is best to add the acid cautiously until
+the solution is decidedly acid. After filtering the solution, it is
+fit for use; and it should be preserved in well-stoppered bottles. The
+water used should be rain or distilled water.
+
+"About one part of the mixed chlorides should be used to three or four
+of water.
+
+"The battery may be either Smee's, Daniell's, or Grove's; if of either
+of the former, it should be of two series; if of the latter, one cup is
+sufficient.
+
+"The plate on being immersed in the liquid, almost instantly takes a
+violet color. It should be allowed to remain from two to five minutes,
+according to the strength of the battery, and until it becomes nearly
+black. It should now be carefully washed, and afterwards heated over a
+spirit lamp until it takes a cherry-red color, and it is then ready for
+exposure in the camera. Before speaking of exposing the plate, it may
+be well to speak of some difficulties which the inexperienced operator
+may find in preparing it. If the battery is not in good order, and a
+sufficient current is not passed through the solution, the plate will
+become coated--and apparently almost as well as when the battery is
+working well--but on exposure it will give a negative picture, and but
+little colored; while if the battery is in good order, the impression
+is invariably positive.
+
+"Sometimes on heating the plate after washing, the surface is covered
+with spots or assumes a variegated appearance. This indicates that the
+solution is impure, or that the plate have not been thoroughly washed
+and are still contaminated with the soluble chlorides which are
+contained in the solution.
+
+"From the fact that the plate if prepared with positive electricity
+gives a positive picture, while it prepared otherwise it gives a
+negative, it is evident that electricity plays an important part in
+this process. The same is true to some extent with the compounds
+formed with iodine, bromine, and fluorine.
+
+"On heating the plate, the brown coating of chloride melts into a
+translucent enamel, and the heat should be withdrawn when a cherry-red
+color is produced. It the heat is continued longer, the plate assumes
+a lighter color, and becomes less sensitive; and the enamel will
+finally scale off. To produce a picture by the ordinary process of M.
+Neipce, unaccelerated, it should be exposed for from three to five
+hours to sunlight in the camera, though pictures may be procured by
+contact, in from fifteen to thirty minutes."
+
+
+MULTIPLYING DAGUERREOTYPES ON ONE PLATE.
+
+I have produced some interesting specimens of the Daguerreotypic art,
+by exposing in the camera only a portion of the sensitive plate to the
+action of light. When on the exposed portion an image is formed, then
+taking the tablet into the dark room, change ends and expose the
+sensitive portion, and produce another image, developing as usual.
+This plan is adapted for taking likenesses for lockets. Two images can
+be presented as sitting side by side, by covering half the plate with
+black paper, and exposing as before. In this manner we have been
+enabled to surprise persons by exhibiting their portrait on the same
+plate with a stranger's. Daguerreotypists must be cautious in
+practicing this, as it might not be agreeable to the parties whose
+likenesses are together, by the above process. It is impossible to
+produce an impression without a line being seen where the edge of the
+paper prevented the operation of the light.
+
+I have recently seen a fine specimen produced by another plan, which
+far exceeds the above, there being no line, or any peculiarity denoting
+two exposures. The specimen referred to, was a gentleman represented
+on one plate by two full length portraits. This was produced by using
+a black velvet for the background. The plate was exposed sufficient
+time to produce one impression, and then the gentleman assumed another
+position, and is repeated as looking at himself. From the fact that
+the time required to develop black velvet being so much longer than
+that for producing a portrait, we are enabled to produce the above
+interesting results.
+
+
+DEPOSIT IN GILDING.
+
+Regarding specks from bad water, I would remark that gilding should be
+made only with distilled water. Thus made, it produces very little
+deposit, even by long keeping. It therefore preserves its original
+strength, and works with great uniformity.
+
+Every grain of deposit contains at least 7-10 its weight of gold,
+easily discoverable by the blowpipe. Such gilding is continually
+deteriorating, which with good chloride and distilled water may be
+prevented. Distilled water should also be used for the hyposulphite.
+and for cleaning plates. Any good, clear water may be afterwards used
+for washing off, with equally good results. I am very rarely troubled
+with specs, and deem this as the main reason.
+
+With a portable still attached to a cooking stove, I obtain half a
+gallon of water per hour, and with very little trouble. A small tin
+retort or still connected with a Leibig's condenser, would not add much
+to the "traps" of the travelling operator, and save him many a
+disreputable specimen.--T. J. BAILEY.--Humphrey's Journal.
+
+
+PRACTICAL HINTS ON THE DAGUERREOTYPE.
+
+The following is from Humphrey's Journal, vol. 5, and from the pen of
+Dr. WM. HARRINGTON, one of the most able writers upon the subject of
+the Daguerreotype in this country:
+
+
+THE CAUSE OF THE DIFFICULTY THAT SOMETIMES OCCURS TO PREVENT THE
+PRODUCTION OF A CLEAR IMPRESSION UPON A DAGUERREOTYPE PLATE.
+
+Beyond all doubt this is traceable to dampness. Truly this is not a
+new thought; but where does this dampness come from? How does it
+originate, and where is it located? Generally it has been referred to
+a point entirely remote from its real location.
+
+This dampness exists particularly upon the surface of the plate; is
+obviously derived immediately from the atmosphere; and is owing to a
+certain relative temperature of the plate with the hygrometric
+condition of the atmosphere.
+
+Whenever this relation exists between the plate and atmosphere, a
+precipitation of moisture takes place upon the surface of the plate,
+which render all efforts at polishing impracticable. This interference
+is not confined to the buffing operation alone, but sometimes is
+discoverable even in the ordinary process of scouring. Every one at
+all experienced in this art will remember that it is not always an easy
+matter for him, by scouring, to bring his plate to the desired lustre.
+All his efforts become unavailing; the more he rubs, the duller the
+surface of his plate appears; and although he renews his cotton
+repeatedly, still he is obliged to content himself with an
+unsatisfactory finish.
+
+This relative condition is not confined to any particular season of the
+year, nor to any certain thermometric temperature; but may occur in
+summer as well as in winter; the weather being warm or cold, wet or
+dry, clear or cloudy, raining or shining. Under any of these
+circumstances, if the relation of the plate and atmosphere be such as
+to invite upon the plate a precipitation of humidity from the
+atmosphere, the prospect of producing a clear impression is quite
+problematical.
+
+It is reasonable to expect this occurrence from the fact that metal is
+a good radiator, and radiation reduces the temperature of a metallic
+body below that of the atmosphere. Consequently, if this relative
+condition happens, the result will be as I have stated.
+
+Bodies may be colder than the atmosphere and yet derive no moisture
+from it; while at the same time the driest atmosphere is not devoid of
+moisture, but will part with it under certain conditions.
+
+Assuming for granted that this relative condition between the plate and
+atmosphere, disposing the former to receive the humidity of the latter,
+constitutes the great obstacle the operator has to contend with in
+producing, a clear proof upon the plate, the remedy naturally suggests
+itself, and is very simple. It consists in merely heating the plate
+above the temperature of the atmosphere, previous to polishing, and
+retaining that temperature during the operation. Various measures
+might be devised to effect the desired object; one of which consists of
+a sheet-iron box, heated from the inside by a spirit-lamp, upon the top
+of which are to be kept the plates ready to undergo the process of
+being polished; the blocks of the swing or any other vice; or the iron
+bed belonging to Lewis's vice.
+
+In cold weather, when it is necessary to keep a fire in the preparation
+room, all of the above may be so arranged in the vicinity of the fire
+as to receive the requisite degree of heat for the purpose specified.
+
+This part of the subject, however, is left entirely for the ingenuity
+of the operator. No matter by hat means he accomplishes the object;
+all that is required is to heat the plate above the temperature of the
+atmosphere and retain that heat during the process of polishing.
+
+Since the adoption of this method, in connection with my partner, T. J.
+Dobyns, even in this humid climate of ours, when everything in the room
+is dripping with moisture, it has been attended with invariable success.
+
+
+CHOICE OF PLATES, ETC.
+
+In the great catalogue of complaints made by operators, none is more
+common than that alleged against the quality of plates in general use.
+Although the greatest diversity of opinion exists upon this subject,
+nevertheless the plates of every manufactory share in this universal
+condemnation.
+
+To be sure it cannot be denied but that this necessary article of
+utility in the photographic art has undergone a sad deterioration in
+quality owing to the increasing demand and great reduction in
+price--the plates of the present day being by no means so heavily
+coated with silver as formerly--but the complaint alluded to is not
+predicated so much upon the thinness of silver as upon a mysterious
+something which has conferred upon the plates the epithet of not good.
+
+That this complaint is in a great measure groundless appears evident
+from the fact that while, with the same brand of plates one operator
+can work successfully, another encounters the greatest difficulty;
+while one is able to produce beautifully clear and altogether
+satisfactory results, the other labors under the troublesome annoyance
+of innumerable specks, large dark insensitive patches and brown
+map-like portions, together with divers other blemishes, sufficient to
+prevent him from obtaining anything like a tolerable impression.
+
+From this wide difference in the results of the two operators using
+identically the same article, it is but reasonable to conclude that the
+complaint is founded in error; while the inference is no more than
+just, that the fault may be traced to a want of practical skill on the
+part of the complaining operator himself; rather than to the inferior
+quality of the plates.
+
+The question, then, whether the plates are unfit for use, or whether
+those who pronounce them so understand how to use them, appears to be
+satisfactorily answered. It therefore becomes a matter worthy of
+investigation, to ascertain what superior judgment and skill one
+operator possesses over another which enable him to work successfully a
+quality of plate, pronounced by the other entirely useless.
+
+Suppose we make a critical examination of one of the repudiated plates.
+From its external appearance we have little hesitation in pronouncing
+it to be French; indeed, this presumption is strongly corroborated by
+the fact that it is ornamented upon one of its corners with a brand to
+designate the manufactory from which it emanated.
+
+Upon close inspection we cannot fail to notice a striking peculiarity
+upon the surface; the roughness is very remarkable; the planishing
+hammer has left amazingly visible indications of its busy work. One
+would suppose the manufacturer intended the surface of the plate to
+represent the undulations of the sea, instead of that smooth and level
+character so strongly recommended by M. Daguerre.
+
+Such a plate necessarily requires at the hand of the operator
+considerable labor before the surface is in a proper condition to
+receive a suitable polish from the buffer. The least reflection in the
+world should teach any one that so long as the undulatory character
+continues upon the surface of the plate, it is in a very imperfect
+condition for buffing, because the buffer cannot touch every point
+equally; the elevated portions alone receiving a high degree of polish
+while the depressed portion, from their roughness acting as nuclei,
+gather dust, rouge, and other foreign bodies, so detrimental to
+sensitiveness. The secret of the superior judgment and skill of one
+operator over another, is intimately connected with this point: his
+success depends very much upon the first process of cleaning the plate.
+
+Let us examine the manipulation of the complaining operator. He takes
+one of these plates and gives it a careful scouring with rotten-stone
+and alcohol or any other liquid preferred for this part of the
+operation--that is, he gives it what he terms a careful scouring--very
+gently indeed because, from the frequent trials he is in the habit of
+making in the camera, he fears he will rub the silver entirely away
+before he succeeds in obtaining a good impression. The dark patches,
+specks, and granular appearance resulting entirely from the unevenness
+of the surface of the plate, look like copper to him, and he is
+surprised that he should have rubbed away the silver so soon,
+particularly by such delicate handling.
+
+The judgment and experience of the successful operator, however, teach
+him that scouring injures a plate less than buffing. He knows that
+unless the hammer marks be obliterated, he cannot by the buffer produce
+a surface of uniform polish and sensitiveness, without which a fair
+proof is extremely doubtful; he knows that the time employed in the
+preliminary operation of cleaning the plate properly is economy.
+
+There is a style of French plates in the market, denominated heavy,
+which are truly excellent, if properly managed. Much patience,
+however, is required to remove the marks of the hammer; but with
+tripoli and alcohol the surface is readily cut down, and the plate is
+then susceptible of a beautiful black lustre by polishing with the
+buffer. The complaining operator could not succeed by his own method
+with one of the plates; he would encounter all manner of clouds and
+other unaccountable phenomena; he would imagine this plate entirely
+worn out before it was half cleaned, and soon fix in his own estimation
+the reputation of the heavy plate.
+
+In making a choice of plates, therefore, it would appear to be a matter
+of perfect indifference with an experienced operator what kind he would
+use, except so far only as the labor required in cleaning them was to
+be taken into consideration.
+
+The distinction between a scale plate, a Scovill No. 1, S. F., heavy A,
+star, crescent, eagle, or any other brand, consists in the superior
+finish of some, and the thinness of the silver in the cheaper qualities.
+
+Consequently, let the complaining operator but employ the diligence
+inculcated in this article, to clean his plate thoroughly, so as to
+bring it to a perfectly even and level surface, and he will seldom be
+troubled with specks, clouds, dark patches, and the host of other
+obstacles which heretofore have tormented him.
+
+
+
+CHAPTER VI.
+
+AN ACCOUNT OF WOLCOTT AND JOHNSON'S EARLY EXPERIMENTS, IN THE
+DAGUERREOTYPE. BY JOHN JOHNSON.
+
+
+[From Humphrey's Journal, vol. ii 1851]
+
+As a general thing, however perfect any invention may be deemed by the
+inventor or discoverer, it falls to the lot of most, to be the subject
+of improvement and advancement, and especially is this the case with
+those new projects in science which open an untrodden field to the view
+of the artisan. Such has been, in an eminent degree, the case with the
+discovery first announced to the world by Mons. Jean Jaques Claude
+Daguerre, of Paris, in the year 1839, and which excited unbounded
+astonishment, curiosity and surprise. It may be questioned had any
+other than Daguerre himself discovered a like beautiful combination,
+whether the world would have been favored with details exhibiting so
+much care, patience and perseverance as the Daguerreotype on its
+introduction. Shortly after, these details reached the United States,
+by Professor S. F. B. Morse, of New York, who was, at the time of the
+discovery, residing in Paris. By this announcement, the whole
+scientific corps was set in operation, many repeating the experiments,
+following carefully the directions pointed out by Daguerre, as being
+necessary to success. Among the number in the United States, was
+Alexander S. Wolcott (since deceased) and myself; both of this city.
+On the morning of the 6th day of October, 1839, I took to A. Wolcott's
+residence, a full description of Daguerre's discovery, he being at the
+time engaged in the department of Mechanical Dentistry, on some work
+requiring his immediate attention, the work being promised at 2 P.M.
+that day; having, therefore, no opportunity to read the description for
+himself (a thing he was accustomed to do at all times, when
+investigating any subject). I read to him the paper, and proposed to
+him that if he would plan a camera (a matter he was fully acquainted
+with, both theoretically and practically), I would obtain the materials
+as specified by Daguerre. This being agreed to, I departed for the
+purpose, and on my return to his shop, he handed me the sketch of a
+camera box, without at all explaining in what manner the lens was to be
+mounted. This I also undertook to procure. After 2, P.M., he had more
+leisure, when he proceeded to complete the camera, introducing for that
+purpose a reflector in the back of the box, and also to affix a plate
+holder on the inside, with a slide to obtain the focus on the plate,
+prepared after the manner of Daguerre. While Mr. Wolcott was engaged
+with the camera, I busied myself in polishing the silver plate, or
+rather silver plated copper; but ere reaching the end preparatory to
+iodizing, I found I had nearly or quite removed the silver surface from
+off the plate, and that being the best piece of sliver-plated copper to
+be found, the first remedy at hand that suggested itself, was a
+burnisher, and a few strips were quickly burnished and polished.
+Meantime, the camera being finished, Mr. Wolcott, after reading for
+himself Daguerre's method of iodizing, prepared two plates, and placing
+them in the camera, guessed at the required time they should remain
+exposed to the action of the light; after mercurializing each in turn,
+and removing the iodized surface with a solution of common salt two
+successful impressions were obtained, each unlike the other!
+Considerable surprise was excited by this result, for each plate was
+managed precisely like the other. On referring to Daguerre, no
+explanation was found for this strange result; time, however, revealed
+to us that one picture was positive, and the other negative. On this
+subject I shall have much to say during the progress of the work.
+Investigating, the cause of this difference occupied the remainder of
+that day. However, another attempt was agreed upon, and the
+instruments, plates, etc., prepared and taken up into an attic room, in
+a position most favorable for light. Having duly arranged the camera,
+I sat for five minutes, and the result was a profile miniature (a
+miniature in reality,) or a plate not quite three-eighths of an inch
+square. Thus, with much deliberation and study, passed the first day
+in Daguerreotype--little dreaming or knowing into what a labyrinth such
+a beginning was hastening us.
+
+[Description of apparatus represented on pages 192 and 199:]
+
+ A.--The Box--about 4 inches long by about 2 outside diameter.
+ B.--The Reflector soldered to a brass screw, and mounted in the
+ rear of the box.
+ c.--The slide to regulate the focus to the plate holder.
+ d.--The standard to the plate holder screwed to the slide.
+ f.--The plate-holder frame having two small ledges, * *, for the
+ plate to rest upon.
+
+{192}
+
+ g.--The plate resting upon the ledge., * *, and kept against the
+ frame by the spring h. The plates used were about 3/8 of an inch
+ square.
+ A.--The window with the sashes removed.
+
+B and C (p. 199) are large looking-glasses mounted as plain reflectors,
+the lower one C having rotary motion upon the saddle, resting upon the
+sill of the window in order to direct the rays of the sun upon the
+reflector B, at any hour of the day--the vertical motion of the
+reflector C being necessary, the sun varying in altitude so much during
+the hours most favorable to the production of portraits. The reflector
+C was {193} kept up to the required position by the handle lever,
+upright post and bolts. Reflector B was hinged at its upper end at the
+top of the window frame, the only motion being necessary was that which
+would reflect upon the sitter the incident rays from reflector C--the
+reflector B being kept at the required angle by the connecting lever m,
+etc. Suitable back-grounds were placed behind the sitter.
+
+[Illustration: Fig. 12 (amdg_12.gif)]
+
+The reflector B and C, had frequently to be renewed, the heat of the
+sun soon destroying their brilliance or power of reflecting, light,
+before renewing them, however, we resorted to the springing of them, by
+which means their power was increased for a period.
+
+The camera or reflecting apparatus, invented by Mr. Wolcott, was, from
+the nature of the case, better adapted at that day to the taking of
+portraits from life, than any other instruments. After carefully
+examining the camera described by Daguerre, and the time stated as
+necessary to produce action for an image, it became evident to the mind
+of Mr. Wolcott at once, that more light could be obtained (as the field
+of view required was not large) by employing a reflector of short focus
+and wide aperture, than from a lens arrangement, owing to spherical
+aberration and other causes. Many experiments having been tried with
+the small instrument figured (p. 199), a reflector for taking portraits
+from life was determined on, having eight inches diameter, with twelve
+inches focal distance for parallel rays; this was to admit plates of
+two inches wide by two and a half long Mr. Wolcott having on hand
+reflectors of the right diameter, for Newtonian telescopes, of eight
+feet focal distance, resolved (as it was a matter of experiment) to
+grind down or increase the curve for the focal distance before
+named--this required time. In the mean time, many plans were pursued
+for making good plates, and the means of finishing, them. As the
+completion of the large reflector drew to a close, our mutual friend,
+Henry Fitz, Jr., returned from England, whither he had been on a visit,
+and when he heard what we were about, kindly offered his assistance; he
+being well versed in optics, and having been before engaged with Mr.
+Wolcott, in that and other business is offer was gladly accepted--Mr.
+Wolcott himself having frequent engagement; to fill as operator in the
+details of mechanical dentistry. Thus, by the aid of Mr. Fitz, the
+reflector was polished, and experiments soon after tried on plates of
+two by tow and a half inches, with tolerable success. Illness on my
+part quite suspended further trial for nearly four weeks.
+
+On my recovery, early in January, 1840, our experiments were again
+resumed with improved results, so much so as to induce Mr. Wolcott and
+myself to entertain serious thoughts of making a business of the taking
+of likenesses from life, intending to use the reflecting apparatus
+invented by Mr. Wolcott, and for which he obtained Letters Patent, on
+the 8th day of May, 1840. Up to January 1st, 1840, all experiments had
+been tried on an economical scale, and the apparatus then made, was
+unfit for public exhibition; we resolved to make the instruments as
+perfect as possible while they were in progress of manufacture.
+Experiments were made upon mediums for protecting the eyes from the
+direct light of the sun, and also upon the best form and material for a
+back-ground to the likenesses. The length of time required for a
+"sitting," even with the reflecting apparatus, was such as to render
+the operation anything but pleasant. Expedients were ever ready in the
+hands of Wolcott: blue glass was tried and abandoned in consequence of
+being, at that time, unable to procure a piece of uniform density and
+surface: afterwards a series of thin muslin screens secured to wire
+frames were prepared as a substitute for blue glass. The objections to
+these screens, however, were serious, inasmuch as a multiplication of
+them became necessary to lessen the intensity of the light sufficiently
+for due protection to the eyes, without which, the likenesses, other
+than profiles, were very unpleasant to look upon. Most of the
+portraits, then of necessity were profiles formed upon back-grounds,
+the lighter parts relieved upon black, and the darker parts upon light
+ground; the back-ground proper being of light colored material with
+black velvet so disposed upon the light ground, this being placed
+sufficiently far from the sitter, to produce harmony of effect when
+viewed in the field of the camera. Other difficulties presented
+themselves seriously to the working of the discovery of Daguerre, to
+portrait taking--one of which was the necessity for a constant and
+nearly horizontal light, that the shaded portions of the portrait
+should not be too hard, and yet, at the same time, be sufficiently well
+developed without the "high light" of the picture becoming overdone,
+solarized or destroyed. In almost all the early specimens of the
+Daguerreotype, extremes of light and shade presented themselves, much
+to the annoyance of the early operators, and seriously objectionable
+were such portraits. To overcome this difficulty, Mr. Wolcott mounted,
+with suitable joints, upon the top of his camera, a large looking-glass
+or plane reflector, in such a manner that the light of the sun (as a
+strong light was absolutely necessary), when falling upon the glass
+could be directed upon the person in an almost horizontal direction.
+
+Early in February, 1840, Mr. Johnson, Sen., (since deceased) sailed for
+Europe with a few specimen likenesses taken with the instruments
+completed as above, with the intention of patenting the invention. On
+his arrival a joint arrangement was effected with Mr. Richard Beard, of
+London, in patenting and working the invention in England. Up to
+February, 1840, but few friends had been made acquainted with the
+progress of the art in the hands of Mr. Wolcott and myself. From time
+to time reports reached us from various sources of the success of
+others, and specimens of landscapes, etc., were exhibited at Dr. James
+R. Chilton's laboratory, in Broadway, much to the gratification of the
+numerous visitors and anxious expectants for this most wonderful
+discovery. Dr. Chilton, Professor J. J. Mapes, Professor J. W. Draper.
+Professor S. F. B. Morse, all of this city; Mr. Cornelius, Dr. Goddard
+and others of Philadelphia; Mr. Southworth, Professor Plumbe, and
+numerous others were early in the field; all, however, using the same
+description of camera as that of Daguerre, with modification for light,
+either by enlargement by lens and aperture for light, or by shortening
+the focal distance.
+
+At a conversational meeting of the Mechanics' Institute, Professor J.
+J. Mapes being present, a question was asked if any one present could
+give information relative to portraiture from life by the
+Daguerreotype. Mr. Kells, a friend of Mr. Wolcott and a scientific and
+practical man (since deceased), at once marked out upon the
+black-board, the whole as contrived by Mr. Wolcott. This gave
+publicity to the invention of Mr. Wolcott. Shortly after, Professor
+Mapes, Dr. Chilton, and many others, sat for their portraits, and were
+highly gratified. Professor Morse also came and proposed to Mr.
+Wolcott to join him in the working of the invention, etc.
+
+From this time much interest was manifested by our friends in our
+progress. Rooms were obtained in the Granite Buildings, corner of
+Broadway and Chambers street, and fitted for business. The rooms being
+small, it was soon found impracticable to use the arrangement of
+looking-glass, as previously spoken of; a new plan became necessary, to
+introduce which, the sashes were removed, {199} and two large
+looking-glasses were mounted in proper frames, thus:--
+
+[Illustration: Fig. 13 (amdg_13.gif)]
+
+Just in front, and between the sitter and {200} the reflector, upon a
+proper stand, were used those paper muslin screen before described;
+also screens of tissue paper. These screens, however, when they were
+used, required so much time for a sitting, that some other medium, as a
+protection to the eyes, became absolutely necessary. The most
+plausible thing that suggested itself was blue glass; but, as this
+could not be found, numerous were the expedients proposed by the
+friends of the art, who from time to time visited our rooms. At the
+suggestion of Professor Mapes (who is ever ready to assist those in
+perplexity), a trough of plate glass s, about twenty-eight inches
+square in the clear, and from three to four inches thick, was filled
+with a solution of ammonia sulphate of copper, and mounted on the frame
+as in the sketch, which, for a time, answered extremely well; soon,
+however, decomposition of this solution became apparent from the
+increased length of time required for a sitting, although to the eye of
+an observer, no visible cause for such long sittings could be pointed
+out. Professor Mapes being appealed to, suggested that to the above
+solution a little acid be added which acted like a charm--shortening
+the time for a sitting from six, eight, or ten minutes to that of about
+one. Decomposition, however, would go on by the action of light and
+heat through the solution. New solutions were tried, when the whole
+were finally abandoned as being, too uncertain and troublesome. (The
+reflecting apparatus R, was placed upon the stand as in the sketch,
+with a wedge for elevating the camera, between it and the table, to
+obtain the image properly upon the plate.) A quantity of blue window
+glass was next obtained, and holes drilled through the corners of it,
+and several sheets were wired together to increase the size, and, when
+complete, was suspended from the ceiling in its proper place, and so
+arranged that when a person was sitting, this sheet of glass could be
+moved to and from, the object of which was to prevent shadows on the
+face of the sitter produced from the uneven surface of the glass. This
+latter contrivance was used until a perfect plate of glass was procured.
+
+The number of persons desirous of obtaining, their miniatures, induced
+many to entertain the idea of establishing themselves in the Art as a
+profession, and numerous were the applications for information; many
+persons paying for their portraits solely with the view of seeing the
+manner of our manipulations, in order that they might obtain
+information to carry on likeness-taking as a business.
+
+The reflecting camera being a very troublesome instrument to make, and
+difficulties besetting us from every source, but little attention could
+be given to teaching others; and, indeed, as the facts seemed to be at
+this time, we knew but little of the necessary manipulations ourselves.
+In course of time, several established themselves. The first one,
+after ourselves, who worked the discovery of Daguerre for portrait
+taking in this city, was a Mr. Prosch; followed soon after by many
+others, in almost all cases copying the reflecting arrangement for
+light, as figured above, many using it even after we had long abandoned
+that arrangement for a better one.
+
+Innumerable obstacles to the rapid advance of the daguerreotype,
+presented themselves almost hourly, much to the annoyance of ourselves,
+and those dependent upon our movements for their advancement. Among
+the most difficult problems of the day, was the procuring of good
+plates. Messrs. Corduran & Co. were among the first to supply the
+trade; at that early day, however, it was a very rare thing, to be able
+to procure an even perfect surface, from the fact that a pure surface
+of silver could scarcely be obtained, the manufacturers deeming it too
+much trouble to prepare silver plated copper with pure silver--the
+result was, that in attempting to polish perfectly such plated metal as
+could be procured, the plates would become cloudy, or colored in spots,
+from the fact of having more or less alloy, according as more or less
+of the silver surface was removed in polishing the plate fit for an
+impression. To explain more clearly, it was the practice of most
+silver platers to use an alloy for silver-plating. In the reduction of
+the ingot to sheet metal, annealing has to be resorted to, and acid
+pickles to remove oxides, etc. The number of times the plated metal is
+exposed to heat and acid in its reduction to the required thickness,
+produces a surface of pure silver. The most of this surface is,
+however, so rough as to be with difficulty polished, without in places
+removing entirely this pellicle of pure metal, and exposing a polished
+surface of the alloy used in plating. Whenever such metal was used,
+very unsightly stains or spots frequently disfigured the portraits.
+The portrait, or portion of it, developed upon the pure silver, being
+much lighter or whiter than that developed upon the alloy; it therefore
+appeared that the purer the silver, the more sensitive the plate
+became. Accordingly, we directed Messrs. Scovills, of Connecticut, to
+prepare a roll of silver-plated metal, with pure silver; it fortunately
+proved to be a good article, but, unfortunately, a pound of this metal
+(early in 1840) cost the round sum of $9. Like descriptions of metal,
+the same gentlemen would be glad to furnish, at this time, for $4. Soon
+after this, some samples of English plated metal, of a very superior
+quality, came to our possession, and relieved us from the toil of
+making and plating one plate at a time, an expedient we were compelled
+to resort to, to command material to meet the pressing demands for
+portraits.
+
+Having it now in our power to obtain good plated metal, a more rapid
+mode of polishing than that recommended by Daguerre was attempted as
+follows:
+
+This metal was cut to the desired size, and having a pair of "hand
+rolls" at hand, each plate, with its silvered side placed next to the
+highly polished surface of a steel die, was passed and repassed through
+the rolls many times, by which process a very smooth, perfect surface
+was obtained. The plates were then annealed, and a number of plates
+thus prepared were fastened to the bottom of a box a few inches deep a
+foot wide, and eighteen inches long; this box was placed upon a table
+and attached to a rod connected to the face plate of a lathe, a few
+inches from its centre, so as to give the box a reciprocating motion.
+A quantity of emery was now strewn over the plates, and the lathe set
+in motion. The action produced wag a friction or rubbing of the emery
+over the surface of the plates.
+
+When continued for some time, a greyish polish was the result.
+Linseed, when used in the same manner, gave us better hope of success,
+and the next step resorted to was to build a wheel and suspend it after
+the manner of a grindstone. The plates being secured to the inner side
+of the wheel or case, and as this case revolved, the seeds would
+constantly keep to the lower level, and their sliding over the surface
+of the plates would polish or burnish their surfaces. This, with the
+former, was soon abandoned; rounded shots of silver placed in the same
+wheel were found not to perform the polishing so well as linseed.
+Buff-wheels of leather with rotten-stone and oil, proved to be far
+superior to all other contrivances; and, subsequently, at the
+suggestion of Professor Draper, velvet was used in lieu of buff
+leather, and soon superseded all other substances, both for lathe and
+hand-buffs, and I would add, for the benefit of new beginners that
+those who are familiar with its use, prefer cotton velvet. The only
+requisite necessary is, that the buffs made of cotton velvet should be
+kept dry and warm.
+
+The greater number of operators, with whose practice I am familiar,
+use, for polishing plates, prepared tripoli, imported from France, or
+Browne's rotten-stone. The former of these articles is very
+objectionable, inasmuch as there is no positive certainty of being
+enabled to procure or make the article of uniform grit--the nature of
+the substance rendering, it impossible to reduce it to varying degrees
+of evenness, by the well known process of washing, for that purpose,
+and the burning of rotten-stone changes its chemical nature somewhat,
+at the same time rendering, this invaluable article harsh and gritty.
+And especially, no reliance can be placed upon burned rotten stone if
+purchased from those who do not give very great attention and care to
+its preparation; and the same remarks apply to rouge.
+
+The best article for polishing Daguerreotype plates is rotten-stone,
+such as can be procured in any town, prepared after the following
+manner: Procure, say half a dozen wide-mouthed bottles, of suitable
+dimensions, numbering each from one to six. Put into No. 1 about half
+a pound of rotten-stone, and nearly fill the bottle with water. Then,
+with a proper stick or spatule, mix well the rotten-stone and water;
+after which, let No. 1 rest for, say one minute, then carefully pour
+off into bottle No. 2 (or, what would be better, draw off by a syphon)
+as much of the floating particles of rotten-stone as is suspended in
+the water. Again fill bottle No. 1 with water, agitate it as before,
+and decant it to bottle No. 2, care being taken to draw off only the
+suspended particles of rotten-stone.
+
+When a sufficient quantity of washings from bottle No. 1 is collected
+into bottle No. 2, a similar process must be gone through, as above
+stated, for No. 1; the difference being in the care required, and in
+the time allowed between the stirring or mixing the rotten-stone and
+water. The floating particles of rotten-stone, after four minutes'
+subsiding, will be found fine enough for the finest Daguerreotype
+polishing required.
+
+A quantity of such washings may be collected in a large bottle, and
+allowed to stand a few hours, when all the rotten-stone will have
+settled. The water may be poured off and the rotten-stone put into an
+evaporating dish, and while being dried, must be constantly stirred to
+obtain an impalpable powder.
+
+Further washings may in like manner be resorted to for finer qualities
+of rotten-stone. In my practice, I have used the articles at two and
+four minutes' settling, and occasionally have prepared it after
+standing for eight minutes. So fine a quality as this, however, is
+seldom required. In using, rotten-stone, I mix with it, for polishing,
+fine olive oil, until I obtain a thin paste--and the best of all
+methods for polishing (well planished) Daguerreotype plates, is one
+like that used for glass by lens polishers; that is, by using a disc or
+buff-wheel, and having, a suitable holder by which to secure the plate,
+and then by pressing the plate against the revolving buff, well
+saturated with the mixed oil and rotten-stone, a very good surface is
+obtained. A quantity of plates may be prepared in this way, and all
+the adhering oil, etc., may be removed by a clean hand, or lathe buff,
+after which each plate must be heated to the point necessary to burn
+off the remaining oil great care being required not to overheat the
+plate. A very slight excess of temperature will at once destroy all
+the polish previously obtained. The test for ascertaining the right
+temperature is at hand; the adhering oil will be driven from the plate
+in the form of smoke when the right temperature is reached. The moment
+the smoke ceases to rise from the plate, the heat must be removed, and
+the plate quickly cooled upon a piece of iron.
+
+A quantity of plates thus prepared may be kept on hand for any required
+time, and the labor of one minute, with a lathe or hand-buff with dry
+charcoal, or rather, prepared lampblack, will perfectly polish the
+surface ready for indexing, etc. This lampblack also requires some
+care in preparing. Take a small-size crucible, properly temper it by a
+slow fire, that it may not be cracked after which, fill it with common
+lampblack, cover it over with a piece of soap-stone, and again replace
+it in the fire. Build a good hard coal fire around it continue the
+heat for two or three hours, being careful not to raise the cover till
+the crucible be quite cold. Pulverize when using it. It is very
+desirable to keep this lampblack dry and warm. Some operators use much
+rouge I would recommend the above in preference; but those who feel
+that they cannot dispense with the use of rouge, had better try a large
+addition of prepared lampblack to a small one of rouge, as this latter
+article, unless great pains be taken in its preparation, will adhere
+and work itself into the body of the surface, so that it cannot be
+removed therefrom; and I have seen many specimens of Daguerreotype very
+much injured in effect from this rouge tint disseminated throughout
+their shaded features, at the same time that the whole general effect
+of such pictures is that of a want of life. It is true that with the
+use of rouge a very high degree of polish may be obtained, but probably
+not higher than can be produced with many other substances of a less
+objectionable nature.
+
+From the announcement of the discovery by Daguerre to the beginning of
+the year 1840, I am not aware of any attempt to lessen the time for the
+action of an image, or an impression, other than that of the reflecting
+camera invented by Mr. Wolcott. Early, however, in 1840, Mr. Wolcott
+was desirous to be enabled to further shorten the time for a sitting,
+and having some knowledge of bromine and its action, by request, Dr.
+Chilton prepared a small quantity; but Mr. Wolcott did not succeed very
+well with it, he having invariably used too much in combination with
+iodine to produce that sensitive coating now well known to the
+profession. Professor Morse, of this city, Dr. Goddard, of
+Philadelphia, and others, in the years 1840 and 1841, were acquainted
+with the use of bromine. N. Griffing, of this city, or myself, used
+with tolerable success, iodine in large excess to nitric acid and
+water; and, subsequently, to nitro muriatic acid (which reacted and
+formed a peculiar chloride of iodine); this latter combination proved
+to be preferable to simple iodine, at the same time somewhat more
+sensitive, and was used by me in this city up to the time of my leaving
+for London (October 1, 1840). On arriving in London, I instituted a
+series of experiments in the various chemical combinations, solely with
+the view to be enabled to obtain more speedily a portrait than it was
+practicable to do with any known chemicals at that date. The high
+latitude, and the winter season of the year rendering but a feeble
+light at best, the greater the necessity for a more sensitive chemical
+preparation to the shortening the time for a sitting. Near the
+beginning of the year 1841, I discovered and practically applied,
+chloride of iodine to great advantage, and, as far as memory serves me,
+I believe the first used in this country was some made and shipped,
+Messrs. Harnden & Co., from London, to Mr. Wolcott, in New York.
+
+About the same time, Mr. John Goddard, of London (who was associated
+with myself), discovered a rather valuable combination of chemicals,
+consisting of a mixture of iodine, bromine, iodus, and iodic acid, and
+a proper combination of those bodies gave an action somewhat more
+sensitive than chloride of iodine--but the "high lights" of the
+portraits would become solarized or overdone, more frequently with this
+combination than with the chloride of iodine. Throughout the year
+1841, I used, with great success, chloride of iodine, applied as one
+coating--occasionally in conjunction with Mr. Wolcott, attempting the
+use of iodine, bromine, and chlorine, and at times with more or less
+success. The difficulty of exactly combining, the three elements above
+mentioned, in order to produce a certainty of result with harmony of
+effect, was the work of many months, with great labor and study, the
+slightest modification requiring a long, series of practical
+experiments, a single change consuming, frequently, an entire day in
+instituting comparisons, etc., etc.
+
+Early in the year, 1842, I discovered a combination of chemicals (now
+known in London as "Wolcott's Mixture," in hermetically sealed bulbs)
+of exceeding uniform character, very sensitive to the action of light,
+and specimens produced in 1842-3, with this combination, will bear
+comparison with the best specimens produced at this late date.
+
+About the same time, I discovered that however much overdone a
+Daguerreotype might be, the means were at hand to save or redeem it.
+It has long, since been known to operators, that if a plate be exposed
+to light after being coated, unless it be again coated, a clear and
+distinct picture could not be obtained upon the same plate without
+first repolishing and recoating the same, care being taken that no
+light fall upon the prepared surface. To prevent solarization, coat a
+plate as usual, expose to the action of light any required time
+(according to circumstances), say from quarter to one half more time
+than would be required in the ordinary method of procedure; observe,
+before putting the plate in the mercury box, place it over the vapor of
+iodine, bromine, or chlorine, etc. (carefully excluding the light),
+for a very brief period, great care being required to have the selected
+vapor very much diluted with air, in order to success. Many
+experiments will be required ere arriving at satisfactory results.
+Specimens now unknown to general operators, for harmony of effect, have
+been, and may again be produced by the method pointed out above. I
+have found the best general effect, and the most certain result to
+follow from the use of the vapor of chlorine--but this requires more
+than ordinary care. I would, therefore, recommend the use of iodine.
+Thus: to a few grains of iodine, add an ounce of warm water (which
+will become tinged with iodine); when cold, to half a pint of pure
+water in a new and clean coating box, put, of the above, fifty drops;
+stir and mix well this small quantity of iodine in with the water; in
+ten minutes this box will be ready for use. Great care and judgment
+will be required in the application of this vapor to the plate; if the
+plate remain over the vapor too long, the developed picture will have
+a faint and misty appearance; if not exposed long enough, the "high
+light" will be solarized. I have great hope of the ultimate use of
+this process, as it is the only means yet discovered to be enabled to
+secure specimens of extremes of light and shade, yet producing harmony
+of effect; and I would call the attention of the profession to the
+fact, that a plate may be exposed to the action of light for any length
+of time (a thousand times longer than required to act for the lesser
+quantity of mercury to deposit itself, or that amount necessary to form
+a perfect specimen), and be restored by the application of any of the
+vapors above mentioned, remarking that for extremes for solarization,
+denser vapors will be required. Much remains to be done with this
+discovery to the application of the Daguerreotype.
+
+
+
+
+HUMPHREY'S JOURNAL OF THE DAGUERREOTYPE & PHOTOGRAPHIC ARTS.
+
+The above-named publication is well known as the best and most valuable
+one devoted to the Photographic Science in this country. Humphrey's
+Journal made its appearance November 1st, 1850, and consequently is the
+first and oldest serial offered to the Photographic world.
+
+The art of producing Portraits and Landscapes by means of Light, has
+recently taken a new and enlivening impulse, which will in all
+probability lead to important and interesting results. No practical
+Daguerreotypist, Photographer, or amateur, should be without the means
+at hand for securing all of the information upon this subject. Each
+should be ready to receive and apply the improvements as they may be
+developed. In order to accomplish this, it is a matter of great
+importance to the Practitioner or Experimenter that he should have a
+reliable medium through which he can obtain information. In what
+source can the inquirer better place his confidence than in a regular
+Journal, whose editor is literally a practical person, and familiar
+with the manipulations necessary for producing Portraits upon
+"Daguerreotype Plates," and upon glass and paper? Such is the
+conductor of Humphrey's Journal.
+
+This Journal is published once every two weeks, and contains all the
+improvements relating to the Art, and is the only American Journal
+whose editor is practically acquainted with the process for producing
+Daguerreotypes, Ambrotypes, and Photographs. The first No. of Vol. X.
+is dated May 1st, 1858. The terms (Two Dollars per annum) are trifling
+compared with the vast amount of information furnished.
+
+AMBROTYPES.--Humphrey's Journal contains everything novel which appears
+upon this subject, and has already presented more new, important, and
+original matter than can be found in any other place.
+
+Many are the letters we have received during the term of the last
+volume, in which the writer has stated that a single number of
+Humphrey's Journal has contained information of more value to him than
+"several times the amount paid for the entire volume."
+
+Our resources have grown up around us, and our facilities for
+procuring, as well as distributing, all such facts and improvements as
+will benefit as well as instruct all who have the progress of the Art
+at heart, are as ample as they can well be made.
+
+The future volumes will be abundantly furnished with original writings
+from persons of standing in the scientific world; and the practical
+Photographer will here find a full account of such improvements as may
+from time to time develop themselves.
+
+From the editor's long practical experience in the Heliographic
+Science, he will be enabled to present the subject in a plain, clear,
+and concise manner.
+
+Read what the Editors say of Humphrey's Journal:--
+
+"We have received a copy of a valuable Journal (Humphrey's) published
+in New York, which has reached the 18th number of Vol. VI.... We now
+have the pleasure of quoting from our trans-atlantic
+coadjutor."--Liverpool Photographic Jour.
+
+"Humphrey's Journal is practical as well as scientific in
+character."--American Journal of Science and Arts.
+
+"It treats the subject knowingly and with force."--New York Tribune.
+
+"It is both a popular and interesting publication."--Mechanics'
+Magazine.
+
+"It is highly useful to all who practice 'shadow catching.'"--Ohio
+State Journal.
+
+"The work is neatly gotten up, and contains many interesting varieties
+in this new field of science."--Times.
+
+"It should be hailed and encouraged, not only by Daguerreotypists
+themselves, but by every lover of Science and Art."--The Democrat.
+
+"We cannot too strongly urge all artists, and those persons who feel an
+interest in the Heliographic Arts and Sciences, to take a copy of the
+work."--Sentinel.
+
+"It is indicative of talent worthy of the important Art it is designed
+to elevate."--American.
+
+"This Art is entitled to its own organ, which could not have fallen
+into better hands than those of the editor of 'Humphrey's
+Journal.'"--Transcript.
+
+"It is a scientific work of interest and usefulness."--Star of the
+North.
+
+"This Journal answers many points heretofore regarded as
+inexplicable."--Hudson River Chronicle.
+
+"It is rich with interest."--North American.
+
+"It contains all the 'Improvements.'"--Delta.
+
+"It teaches us how to take our own portraits."--Bee.
+
+"It will cultivate a taste for Daguerreotypes."--Commercial Advertiser.
+
+"It should be in the hands of all."--Reveille.
+
+"It is the Daguerreotypist's friend."--London News.
+
+"It should be found in every library."--Evening Journal.
+
+
+
+From some of our Subscribers
+
+"Humphrey's Journal has been the means of saving much time and money,
+for by its instruction I have been enabled to produce some of the
+finest Paper Pictures I have ever seen." W. P.
+
+"Don't fail to send me the Journal, for I would not be without it for
+five times the amount of subscription. It is the only publication I
+can depend upon." A. G. R.
+
+"Your treatment of the humbugs and humbugging members of the
+profession, is of the most valuable importance to us practical
+Daguerreans. Go on. God speed! Here is the amount for the renewal of
+my subscription." E. F. S.
+
+"How can any Operator afford to be without it?" L. L. H.
+
+"Here are five dollars: send me Humphrey's Journal to this amount. I
+will not be without it." M. S.
+
+"It is my best friend." J. E. W.
+
+We might quote like commendatory extracts enough to more than ten times
+fill this page.
+
+Humphrey's Journal contains 16 octavo pages of reading matter.
+
+
+TERMS.
+
+ One copy per annum, in advance . . . . . . $2 00
+ Three copies, do. do. . . . . . . $5 00
+ Six copies, do. do. . . . . . . $9 00
+
+The thousands who read it cannot be induced to remain without it. All
+who desire to keep up with the improvements should subscribe for a copy.
+
+Subscription price Two Dollars per year.
+
+Don't fail to become a subscriber. Address
+
+ S. D. HUMPHREY
+ Office, 37 Lispenard Street,
+ NEW YORK.
+
+
+
+ THE PRACTICAL MANUAL OF THE COLLODION PROCESS.
+ BY S. D. HUMPHREY.
+ THIRD EDITION
+
+This Edition contains all the Improvements in the Art made public up to
+the day of publication, and gives complete Practical Instructions for
+making Collodion Positives or Ambrotypes, Collodion Negatives,
+Printing, etc., etc. The quick, great and unprecedented sale of the
+first and second editions demonstrates, more than the strongest
+language could possibly do, the extraordinary and increasing popularity
+of this work. The Third Edition contains two hundred and sixteen 12mo.
+pages, of a larger size and in smaller type than either of the
+preceding editions, and is illustrated with numerous wood-cuts. It is
+intended to be the best practical work extant; substantially bound in
+cloth, price One Dollar; forwarded by mail (postage prepaid). Address
+
+S. D. HUMPHREY, New York
+
+
+
+A GUIDE TO PHOTOGRAPHY,
+
+Containing simple and concise directions for obtaining Views,
+Portraits, etc., by the chemical agency of Light, by W. H.
+Thornthwaite, author of "Photogenic Manipulations," etc. Illustrated
+with numerous wood-cuts. The Book contains more than one hundred 12mo
+pages, bound in board, and is sold at twenty-five cents per copy, or
+five copies for one dollar. Address
+
+S. D. HUMPHREY, New York
+
+
+
+ HOLMES, BOOTH & HAYDENS,
+ MANUFACTURERS OF
+ DAGUERREOTYPE CASES,
+ PLATES, CAMERAS,
+
+MATTINGS, PRESERVERS, ETC., ETC.
+
+MANUFACTURERS AND IMPORTERS OF EVERY VARIETY OF AMBROTYPE, AND
+PHOTOGRAPHIC GOODS,
+
+Of the Best and most approved Quality.
+
+ESPECIAL ATTENTION GIVEN TO THE FURNISHING OF EVERY ARTICLE USED IN THE
+PRACTICE OF THE DAGUERREOTYPE
+
+Depot 81 Chambers and 63 Reade St., New York.
+
+Manufactory at Waterbury, Conn.
+
+
+
+HOLMES, BOOTH & HAYDENS' CAMERAS
+
+From 1/4 to the Mammoth size. These CAMERAS are of the most superior
+make, and all subjected to the most thorough test before being offered
+for sale.
+
+VIEW CAMERAS, made expressly for taking views: an entirely new article.
+
+DAGUERREOTYPE PLATES, OF EVERY VARIETY, AND WE WOULD CALL PARTICULAR
+ATTENTION TO THE
+
+Wreath, and H. B. & H. Eagle 40 Plates, AS HAVING NO EQUALS IN THE
+MARKET.
+
+SOLE AGENTS FOR THE CELEBRATED H. B. AND N. P. FRENCH PLATES.
+
+Always on hand a complete assortment of Ambrotype and Photographic
+goods.
+
+SOLE AGENTS FOR THE Patent solid glass corner Plate Holders.
+
+All orders will receive prompt attention, and be forwarded with
+dispatch.
+
+ HOLMES, BOOTH & HAYDENS,
+ 81 Chambers, and 63 Reade St.
+ New York.
+
+
+
+SCOVILL MANUFACTURING CO.
+
+ MANUFACTURER OF
+ DAGUERREOTYPE PLATES,
+ MATTINGS,
+ PRESERVERS, CASES,
+ APPARATUS, etc., etc.
+
+Importers and Dealers in every description of Daguerreotype,
+Photographic, AND AMBROTYPE GOODS,
+
+The SCOVILL MANUFACTURING COMPANY flatter themselves that an experience
+of nearly twenty years in the business and the most extensive variety
+of the above Goods in the United States, entitle them to the
+continuance of orders for the Domestic and Foreign trade, which will
+receive the most careful attention.
+
+Park Building, New York. Entrances--36 Park Row, 4 Beekman, and 141
+Nassau Street.
+
+
+
+
+SCOVILL MANUFACTURING CO.
+
+Would call especial attention to their large variety of
+
+CASES,
+
+Embracing many Fancy Styles made only by themselves, and to which they
+are constantly adding New Designs.
+
+ Union Cases,
+ Of all sizes, with Riveted Hinges.
+ AGENTS FOR THE SALE OF
+ C. C. HARRISON'S CAMERAS,
+
+with improvements, which we are now prepared to sell at reduced prices,
+and warranted to give better satisfaction than ever before
+DAGUERREOTYPE PLATES, H. B.--N. P.--Star and other brands PLATE GLASS,
+embracing three-quarters white: Crown and all other varieties. We
+would call particular attention to our Black Glass, made expressly for
+Ambrotypes.
+
+ CHEMICALS,
+ for the Daguerreotype and Photographic Art.
+ Iodized and Plain COLLODION. Gun Cotton, etc., etc.
+ Tagliabue's Collodiometres and Actino-Hydrometres, for
+ testing Chemicals.
+
+APPARATUS OF EVERY VARIETY.
+
+Gutta Percha, Porcelain, and Glassware of all kinds used in the Art.
+
+A large assortment of Gilt Frames always on hand and made to order.
+
+Ambrotype Shields, with solid corners of a new style.
+
+All orders will meet with prompt attention
+
+ SCOVILL MANUFACTURING CO.,
+ PARK BUILDING
+ New York
+ 36 Park Row, 4 Beckman, and
+ 141 Nassau Street.
+
+
+
+
+ HARDWICH'S PHOTOGRAPHIC CHEMISTRY
+ AMERICAN EDITION.
+
+ A MANUAL of
+ PHOTOGRAPHIC CHEMISTRY,
+
+INCLUDING THE PRACTICE OF THE COLLODION PROCESS.
+
+BY
+
+T. FREDERICK HARDWICH,
+
+ LECTURER ON PHOTOGRAPHY IN KINGS COLLEGE, LONDON;
+ LATE DEMONSTRATOR OF CHEMISTRY IN KING'S COLLEGE.
+
+Last Edition,
+
+The above is the title of this new and valuable work. It is too well
+known to need any further comment in this place. This volume contains
+nearly 300 large duodecimo pages, bound in red cloth, $1.00. Copies
+to be forwarded by mail, $1.18, postage pre-paid.
+
+ S. D. HUMPHREY,
+ Photographic
+ Book Publisher,
+ 37 LISPENARD
+ STREET, NEW YORK,
+
+N.B. Postage stamps taken.
+
+
+
+
+
+
+
+
+
+End of the Project Gutenberg EBook of American Handbook of the Daguerrotype, by
+Samuel D. Humphrey
+
+*** END OF THIS PROJECT GUTENBERG EBOOK AMERICAN HANDBOOK - DAGUERROTYPE ***
+
+***** This file should be named 167.txt or 167.zip *****
+This and all associated files of various formats will be found in:
+ http://www.gutenberg.org/1/6/167/
+
+Produced by Gregory Walker, for the Digital Daguerreian Archive Project.
+
+Updated editions will replace the previous one--the old editions
+will be renamed.
+
+Creating the works from public domain print editions means that no
+one owns a United States copyright in these works, so the Foundation
+(and you!) can copy and distribute it in the United States without
+permission and without paying copyright royalties. Special rules,
+set forth in the General Terms of Use part of this license, apply to
+copying and distributing Project Gutenberg-tm electronic works to
+protect the PROJECT GUTENBERG-tm concept and trademark. Project
+Gutenberg is a registered trademark, and may not be used if you
+charge for the eBooks, unless you receive specific permission. If you
+do not charge anything for copies of this eBook, complying with the
+rules is very easy. You may use this eBook for nearly any purpose
+such as creation of derivative works, reports, performances and
+research. They may be modified and printed and given away--you may do
+practically ANYTHING with public domain eBooks. Redistribution is
+subject to the trademark license, especially commercial
+redistribution.
+
+
+
+*** START: FULL LICENSE ***
+
+THE FULL PROJECT GUTENBERG LICENSE
+PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK
+
+To protect the Project Gutenberg-tm mission of promoting the free
+distribution of electronic works, by using or distributing this work
+(or any other work associated in any way with the phrase "Project
+Gutenberg"), you agree to comply with all the terms of the Full Project
+Gutenberg-tm License (available with this file or online at
+http://gutenberg.net/license).
+
+
+Section 1. General Terms of Use and Redistributing Project Gutenberg-tm
+electronic works
+
+1.A. By reading or using any part of this Project Gutenberg-tm
+electronic work, you indicate that you have read, understand, agree to
+and accept all the terms of this license and intellectual property
+(trademark/copyright) agreement. If you do not agree to abide by all
+the terms of this agreement, you must cease using and return or destroy
+all copies of Project Gutenberg-tm electronic works in your possession.
+If you paid a fee for obtaining a copy of or access to a Project
+Gutenberg-tm electronic work and you do not agree to be bound by the
+terms of this agreement, you may obtain a refund from the person or
+entity to whom you paid the fee as set forth in paragraph 1.E.8.
+
+1.B. "Project Gutenberg" is a registered trademark. It may only be
+used on or associated in any way with an electronic work by people who
+agree to be bound by the terms of this agreement. There are a few
+things that you can do with most Project Gutenberg-tm electronic works
+even without complying with the full terms of this agreement. See
+paragraph 1.C below. There are a lot of things you can do with Project
+Gutenberg-tm electronic works if you follow the terms of this agreement
+and help preserve free future access to Project Gutenberg-tm electronic
+works. See paragraph 1.E below.
+
+1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation"
+or PGLAF), owns a compilation copyright in the collection of Project
+Gutenberg-tm electronic works. Nearly all the individual works in the
+collection are in the public domain in the United States. If an
+individual work is in the public domain in the United States and you are
+located in the United States, we do not claim a right to prevent you from
+copying, distributing, performing, displaying or creating derivative
+works based on the work as long as all references to Project Gutenberg
+are removed. Of course, we hope that you will support the Project
+Gutenberg-tm mission of promoting free access to electronic works by
+freely sharing Project Gutenberg-tm works in compliance with the terms of
+this agreement for keeping the Project Gutenberg-tm name associated with
+the work. You can easily comply with the terms of this agreement by
+keeping this work in the same format with its attached full Project
+Gutenberg-tm License when you share it without charge with others.
+
+1.D. The copyright laws of the place where you are located also govern
+what you can do with this work. Copyright laws in most countries are in
+a constant state of change. If you are outside the United States, check
+the laws of your country in addition to the terms of this agreement
+before downloading, copying, displaying, performing, distributing or
+creating derivative works based on this work or any other Project
+Gutenberg-tm work. The Foundation makes no representations concerning
+the copyright status of any work in any country outside the United
+States.
+
+1.E. Unless you have removed all references to Project Gutenberg:
+
+1.E.1. The following sentence, with active links to, or other immediate
+access to, the full Project Gutenberg-tm License must appear prominently
+whenever any copy of a Project Gutenberg-tm work (any work on which the
+phrase "Project Gutenberg" appears, or with which the phrase "Project
+Gutenberg" is associated) is accessed, displayed, performed, viewed,
+copied or distributed:
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever. You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.net
+
+1.E.2. If an individual Project Gutenberg-tm electronic work is derived
+from the public domain (does not contain a notice indicating that it is
+posted with permission of the copyright holder), the work can be copied
+and distributed to anyone in the United States without paying any fees
+or charges. If you are redistributing or providing access to a work
+with the phrase "Project Gutenberg" associated with or appearing on the
+work, you must comply either with the requirements of paragraphs 1.E.1
+through 1.E.7 or obtain permission for the use of the work and the
+Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or
+1.E.9.
+
+1.E.3. If an individual Project Gutenberg-tm electronic work is posted
+with the permission of the copyright holder, your use and distribution
+must comply with both paragraphs 1.E.1 through 1.E.7 and any additional
+terms imposed by the copyright holder. Additional terms will be linked
+to the Project Gutenberg-tm License for all works posted with the
+permission of the copyright holder found at the beginning of this work.
+
+1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm
+License terms from this work, or any files containing a part of this
+work or any other work associated with Project Gutenberg-tm.
+
+1.E.5. Do not copy, display, perform, distribute or redistribute this
+electronic work, or any part of this electronic work, without
+prominently displaying the sentence set forth in paragraph 1.E.1 with
+active links or immediate access to the full terms of the Project
+Gutenberg-tm License.
+
+1.E.6. You may convert to and distribute this work in any binary,
+compressed, marked up, nonproprietary or proprietary form, including any
+word processing or hypertext form. However, if you provide access to or
+distribute copies of a Project Gutenberg-tm work in a format other than
+"Plain Vanilla ASCII" or other format used in the official version
+posted on the official Project Gutenberg-tm web site (www.gutenberg.net),
+you must, at no additional cost, fee or expense to the user, provide a
+copy, a means of exporting a copy, or a means of obtaining a copy upon
+request, of the work in its original "Plain Vanilla ASCII" or other
+form. Any alternate format must include the full Project Gutenberg-tm
+License as specified in paragraph 1.E.1.
+
+1.E.7. Do not charge a fee for access to, viewing, displaying,
+performing, copying or distributing any Project Gutenberg-tm works
+unless you comply with paragraph 1.E.8 or 1.E.9.
+
+1.E.8. You may charge a reasonable fee for copies of or providing
+access to or distributing Project Gutenberg-tm electronic works provided
+that
+
+- You pay a royalty fee of 20% of the gross profits you derive from
+ the use of Project Gutenberg-tm works calculated using the method
+ you already use to calculate your applicable taxes. The fee is
+ owed to the owner of the Project Gutenberg-tm trademark, but he
+ has agreed to donate royalties under this paragraph to the
+ Project Gutenberg Literary Archive Foundation. Royalty payments
+ must be paid within 60 days following each date on which you
+ prepare (or are legally required to prepare) your periodic tax
+ returns. Royalty payments should be clearly marked as such and
+ sent to the Project Gutenberg Literary Archive Foundation at the
+ address specified in Section 4, "Information about donations to
+ the Project Gutenberg Literary Archive Foundation."
+
+- You provide a full refund of any money paid by a user who notifies
+ you in writing (or by e-mail) within 30 days of receipt that s/he
+ does not agree to the terms of the full Project Gutenberg-tm
+ License. You must require such a user to return or
+ destroy all copies of the works possessed in a physical medium
+ and discontinue all use of and all access to other copies of
+ Project Gutenberg-tm works.
+
+- You provide, in accordance with paragraph 1.F.3, a full refund of any
+ money paid for a work or a replacement copy, if a defect in the
+ electronic work is discovered and reported to you within 90 days
+ of receipt of the work.
+
+- You comply with all other terms of this agreement for free
+ distribution of Project Gutenberg-tm works.
+
+1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm
+electronic work or group of works on different terms than are set
+forth in this agreement, you must obtain permission in writing from
+both the Project Gutenberg Literary Archive Foundation and Michael
+Hart, the owner of the Project Gutenberg-tm trademark. Contact the
+Foundation as set forth in Section 3 below.
+
+1.F.
+
+1.F.1. Project Gutenberg volunteers and employees expend considerable
+effort to identify, do copyright research on, transcribe and proofread
+public domain works in creating the Project Gutenberg-tm
+collection. Despite these efforts, Project Gutenberg-tm electronic
+works, and the medium on which they may be stored, may contain
+"Defects," such as, but not limited to, incomplete, inaccurate or
+corrupt data, transcription errors, a copyright or other intellectual
+property infringement, a defective or damaged disk or other medium, a
+computer virus, or computer codes that damage or cannot be read by
+your equipment.
+
+1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right
+of Replacement or Refund" described in paragraph 1.F.3, the Project
+Gutenberg Literary Archive Foundation, the owner of the Project
+Gutenberg-tm trademark, and any other party distributing a Project
+Gutenberg-tm electronic work under this agreement, disclaim all
+liability to you for damages, costs and expenses, including legal
+fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT
+LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE
+PROVIDED IN PARAGRAPH F3. YOU AGREE THAT THE FOUNDATION, THE
+TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE
+LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR
+INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH
+DAMAGE.
+
+1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a
+defect in this electronic work within 90 days of receiving it, you can
+receive a refund of the money (if any) you paid for it by sending a
+written explanation to the person you received the work from. If you
+received the work on a physical medium, you must return the medium with
+your written explanation. The person or entity that provided you with
+the defective work may elect to provide a replacement copy in lieu of a
+refund. If you received the work electronically, the person or entity
+providing it to you may choose to give you a second opportunity to
+receive the work electronically in lieu of a refund. If the second copy
+is also defective, you may demand a refund in writing without further
+opportunities to fix the problem.
+
+1.F.4. Except for the limited right of replacement or refund set forth
+in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER
+WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
+WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE.
+
+1.F.5. Some states do not allow disclaimers of certain implied
+warranties or the exclusion or limitation of certain types of damages.
+If any disclaimer or limitation set forth in this agreement violates the
+law of the state applicable to this agreement, the agreement shall be
+interpreted to make the maximum disclaimer or limitation permitted by
+the applicable state law. The invalidity or unenforceability of any
+provision of this agreement shall not void the remaining provisions.
+
+1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the
+trademark owner, any agent or employee of the Foundation, anyone
+providing copies of Project Gutenberg-tm electronic works in accordance
+with this agreement, and any volunteers associated with the production,
+promotion and distribution of Project Gutenberg-tm electronic works,
+harmless from all liability, costs and expenses, including legal fees,
+that arise directly or indirectly from any of the following which you do
+or cause to occur: (a) distribution of this or any Project Gutenberg-tm
+work, (b) alteration, modification, or additions or deletions to any
+Project Gutenberg-tm work, and (c) any Defect you cause.
+
+
+Section 2. Information about the Mission of Project Gutenberg-tm
+
+Project Gutenberg-tm is synonymous with the free distribution of
+electronic works in formats readable by the widest variety of computers
+including obsolete, old, middle-aged and new computers. It exists
+because of the efforts of hundreds of volunteers and donations from
+people in all walks of life.
+
+Volunteers and financial support to provide volunteers with the
+assistance they need, is critical to reaching Project Gutenberg-tm's
+goals and ensuring that the Project Gutenberg-tm collection will
+remain freely available for generations to come. In 2001, the Project
+Gutenberg Literary Archive Foundation was created to provide a secure
+and permanent future for Project Gutenberg-tm and future generations.
+To learn more about the Project Gutenberg Literary Archive Foundation
+and how your efforts and donations can help, see Sections 3 and 4
+and the Foundation web page at http://www.pglaf.org.
+
+
+Section 3. Information about the Project Gutenberg Literary Archive
+Foundation
+
+The Project Gutenberg Literary Archive Foundation is a non profit
+501(c)(3) educational corporation organized under the laws of the
+state of Mississippi and granted tax exempt status by the Internal
+Revenue Service. The Foundation's EIN or federal tax identification
+number is 64-6221541. Its 501(c)(3) letter is posted at
+http://pglaf.org/fundraising. Contributions to the Project Gutenberg
+Literary Archive Foundation are tax deductible to the full extent
+permitted by U.S. federal laws and your state's laws.
+
+The Foundation's principal office is located at 4557 Melan Dr. S.
+Fairbanks, AK, 99712., but its volunteers and employees are scattered
+throughout numerous locations. Its business office is located at
+809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email
+business@pglaf.org. Email contact links and up to date contact
+information can be found at the Foundation's web site and official
+page at http://pglaf.org
+
+For additional contact information:
+ Dr. Gregory B. Newby
+ Chief Executive and Director
+ gbnewby@pglaf.org
+
+
+Section 4. Information about Donations to the Project Gutenberg
+Literary Archive Foundation
+
+Project Gutenberg-tm depends upon and cannot survive without wide
+spread public support and donations to carry out its mission of
+increasing the number of public domain and licensed works that can be
+freely distributed in machine readable form accessible by the widest
+array of equipment including outdated equipment. Many small donations
+($1 to $5,000) are particularly important to maintaining tax exempt
+status with the IRS.
+
+The Foundation is committed to complying with the laws regulating
+charities and charitable donations in all 50 states of the United
+States. Compliance requirements are not uniform and it takes a
+considerable effort, much paperwork and many fees to meet and keep up
+with these requirements. We do not solicit donations in locations
+where we have not received written confirmation of compliance. To
+SEND DONATIONS or determine the status of compliance for any
+particular state visit http://pglaf.org
+
+While we cannot and do not solicit contributions from states where we
+have not met the solicitation requirements, we know of no prohibition
+against accepting unsolicited donations from donors in such states who
+approach us with offers to donate.
+
+International donations are gratefully accepted, but we cannot make
+any statements concerning tax treatment of donations received from
+outside the United States. U.S. laws alone swamp our small staff.
+
+Please check the Project Gutenberg Web pages for current donation
+methods and addresses. Donations are accepted in a number of other
+ways including including checks, online payments and credit card
+donations. To donate, please visit: http://pglaf.org/donate
+
+
+Section 5. General Information About Project Gutenberg-tm electronic
+works.
+
+Professor Michael S. Hart is the originator of the Project Gutenberg-tm
+concept of a library of electronic works that could be freely shared
+with anyone. For thirty years, he produced and distributed Project
+Gutenberg-tm eBooks with only a loose network of volunteer support.
+
+
+Project Gutenberg-tm eBooks are often created from several printed
+editions, all of which are confirmed as Public Domain in the U.S.
+unless a copyright notice is included. Thus, we do not necessarily
+keep eBooks in compliance with any particular paper edition.
+
+
+Most people start at our Web site which has the main PG search facility:
+
+ http://www.gutenberg.net
+
+This Web site includes information about Project Gutenberg-tm,
+including how to make donations to the Project Gutenberg Literary
+Archive Foundation, how to help produce our new eBooks, and how to
+subscribe to our email newsletter to hear about new eBooks.
diff --git a/old/167.zip b/old/167.zip
new file mode 100644
index 0000000..a989f47
--- /dev/null
+++ b/old/167.zip
Binary files differ
diff --git a/old/2008-07_167-h.zip b/old/2008-07_167-h.zip
new file mode 100644
index 0000000..8de2653
--- /dev/null
+++ b/old/2008-07_167-h.zip
Binary files differ
diff --git a/old/amdag10.txt b/old/amdag10.txt
new file mode 100644
index 0000000..11c5d9e
--- /dev/null
+++ b/old/amdag10.txt
@@ -0,0 +1,5099 @@
+
+Project Gutenberg Etext of American Handbook of the Daguerreotype
+
+Please take a look at the important information in this header.
+We encourage you to keep this file on your own disk, keeping an
+electronic path open for the next readers. Do not remove this.
+
+
+**Welcome To The World of Free Plain Vanilla Electronic Texts**
+
+**Etexts Readable By Both Humans and By Computers, Since 1971**
+
+*These Etexts Prepared By Hundreds of Volunteers and Donations*
+
+Information on contacting Project Gutenberg to get Etexts, and
+further information is included below. We need your donations.
+
+
+American Hand Book of the Daguerreotype by Samuel D. Humphrey
+
+September, 1994 [Etext #167]
+
+Project Gutenberg Etext of American Handbook of the Daguerreotype
+*****This file should be named amdag10.txt or amdag10.zip******
+
+Corrected EDITIONS of our etexts get a new NUMBER, amdag11.txt.
+VERSIONS based on separate sources get new LETTER, amdag10a.txt.
+The illustrations in GIF format are in amdgf10.zip.
+
+This etext was created by Gregory Walker, Austin, Texas,
+for the Digital Daguerreian Archive Project.
+Internet: gwalker@netcom.com CompuServe: 73577,677
+Page numbers explicitly referred to in the text are marked
+at their beginning by "[page ##]" on a separate line. The
+location of the illustrations in the text are marked by
+"[amdg_##.gif]" on a separate line. I hope this etext inspires
+a wider interest in the origins of photography and in the modern
+practice of the Daguerreian Art.
+
+We are now trying to release all our books one month in advance
+of the official release dates, for time for better editing. We
+have this as a goal to accomplish by the end of the year but we
+cannot guarantee to stay that far ahead every month after that.
+
+Please note: neither this list nor its contents are final till
+midnight of the last day of the month of any such announcement.
+The official release date of all Project Gutenberg Etexts is at
+Midnight, Central Time, of the last day of the stated month. A
+preliminary version may often be posted for suggestion, comment
+and editing by those who wish to do so. To be sure you have an
+up to date first edition [xxxxx10x.xxx] please check file sizes
+in the first week of the next month. Since our ftp program has
+a bug in it that scrambles the date [tried to fix and failed] a
+look at the file size will have to do, but we will try to see a
+new copy has at least one byte more or less.
+
+
+Information about Project Gutenberg (one page)
+
+We produce about two million dollars for each hour we work. The
+fifty hours is one conservative estimate for how long it we take
+to get any etext selected, entered, proofread, edited, copyright
+searched and analyzed, the copyright letters written, etc. This
+projected audience is one hundred million readers. If our value
+per text is nominally estimated at one dollar then we produce $4
+million dollars per hour this year as we release some eight text
+files per month: thus upping our productivity from $2 million.
+
+The Goal of Project Gutenberg is to Give Away One Trillion Etext
+Files by the December 31, 2001. [10,000 x 100,000,000=Trillion]
+This is ten thousand titles each to one hundred million readers,
+which is 10% of the expected number of computer users by the end
+of the year 2001.
+
+We need your donations more than ever!
+
+All donations should be made to "Project Gutenberg/IBC", and are
+tax deductible to the extent allowable by law ("IBC" is Illinois
+Benedictine College). (Subscriptions to our paper newsletter go
+to IBC, too)
+
+For these and other matters, please mail to:
+
+Project Gutenberg
+P. O. Box 2782
+Champaign, IL 61825
+
+When all other email fails try our Michael S. Hart, Executive
+Director:
+hart@vmd.cso.uiuc.edu (internet) hart@uiucvmd (bitnet)
+
+We would prefer to send you this information by email
+(Internet, Bitnet, Compuserve, ATTMAIL or MCImail).
+
+******
+If you have an FTP program (or emulator), please
+FTP directly to the Project Gutenberg archives:
+[Mac users, do NOT point and click. . .type]
+
+ftp mrcnext.cso.uiuc.edu
+login: anonymous
+password: your@login
+cd etext/etext91
+or cd etext92
+or cd etext93 [for new books] [now also in cd etext/etext93]
+or cd etext/articles [get suggest gut for more information]
+dir [to see files]
+get or mget [to get files. . .set bin for zip files]
+GET 0INDEX.GUT
+for a list of books
+and
+GET NEW GUT for general information
+and
+MGET GUT* for newsletters.
+
+**Information prepared by the Project Gutenberg legal advisor**
+(Three Pages)
+
+
+***START**THE SMALL PRINT!**FOR PUBLIC DOMAIN ETEXTS**START***
+Why is this "Small Print!" statement here? You know: lawyers.
+They tell us you might sue us if there is something wrong with
+your copy of this etext, even if you got it for free from
+someone other than us, and even if what's wrong is not our
+fault. So, among other things, this "Small Print!" statement
+disclaims most of our liability to you. It also tells you how
+you can distribute copies of this etext if you want to.
+
+*BEFORE!* YOU USE OR READ THIS ETEXT
+By using or reading any part of this PROJECT GUTENBERG-tm
+etext, you indicate that you understand, agree to and accept
+this "Small Print!" statement. If you do not, you can receive
+a refund of the money (if any) you paid for this etext by
+sending a request within 30 days of receiving it to the person
+you got it from. If you received this etext on a physical
+medium (such as a disk), you must return it with your request.
+
+ABOUT PROJECT GUTENBERG-TM ETEXTS
+This PROJECT GUTENBERG-tm etext, like most PROJECT GUTENBERG-
+tm etexts, is a "public domain" work distributed by Professor
+Michael S. Hart through the Project Gutenberg Association at
+Illinois Benedictine College (the "Project"). Among other
+things, this means that no one owns a United States copyright
+on or for this work, so the Project (and you!) can copy and
+distribute it in the United States without permission and
+without paying copyright royalties. Special rules, set forth
+below, apply if you wish to copy and distribute this etext
+under the Project's "PROJECT GUTENBERG" trademark.
+
+To create these etexts, the Project expends considerable
+efforts to identify, transcribe and proofread public domain
+works. Despite these efforts, the Project's etexts and any
+medium they may be on may contain "Defects". Among other
+things, Defects may take the form of incomplete, inaccurate or
+corrupt data, transcription errors, a copyright or other
+intellectual property infringement, a defective or damaged
+disk or other etext medium, a computer virus, or computer
+codes that damage or cannot be read by your equipment.
+
+LIMITED WARRANTY; DISCLAIMER OF DAMAGES
+But for the "Right of Replacement or Refund" described below,
+[1] the Project (and any other party you may receive this
+etext from as a PROJECT GUTENBERG-tm etext) disclaims all
+liability to you for damages, costs and expenses, including
+legal fees, and [2] YOU HAVE NO REMEDIES FOR NEGLIGENCE OR
+UNDER STRICT LIABILITY, OR FOR BREACH OF WARRANTY OR CONTRACT,
+INCLUDING BUT NOT LIMITED TO INDIRECT, CONSEQUENTIAL, PUNITIVE
+OR INCIDENTAL DAMAGES, EVEN IF YOU GIVE NOTICE OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+If you discover a Defect in this etext within 90 days of
+receiving it, you can receive a refund of the money (if any)
+you paid for it by sending an explanatory note within that
+time to the person you received it from. If you received it
+on a physical medium, you must return it with your note, and
+such person may choose to alternatively give you a replacement
+copy. If you received it electronically, such person may
+choose to alternatively give you a second opportunity to
+receive it electronically.
+
+THIS ETEXT IS OTHERWISE PROVIDED TO YOU "AS-IS". NO OTHER
+WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, ARE MADE TO YOU AS
+TO THE ETEXT OR ANY MEDIUM IT MAY BE ON, INCLUDING BUT NOT
+LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
+PARTICULAR PURPOSE.
+
+Some states do not allow disclaimers of implied warranties or
+the exclusion or limitation of consequential damages, so the
+above disclaimers and exclusions may not apply to you, and you
+may have other legal rights.
+
+INDEMNITY
+You will indemnify and hold the Project, its directors, officers,
+members and agents harmless from all liability, cost
+and expense, including legal fees, that arise directly or
+indirectly from any of the following that you do or cause:
+[1] distribution of this etext, [2] alteration, modification,
+or addition to the etext, or [3] any Defect.
+
+DISTRIBUTION UNDER "PROJECT GUTENBERG-tm"
+You may distribute copies of this etext electronically, or by
+disk, book or any other medium if you either delete this
+"Small Print!" and all other references to Project Gutenberg,
+or:
+
+[1] Only give exact copies of it. Among other things, this
+ requires that you do not remove, alter or modify the
+ etext or this "small print!" statement. You may however,
+ if you wish, distribute this etext in machine readable
+ binary, compressed, mark-up, or proprietary form,
+ including any form resulting from conversion by word pro-
+ cessing or hypertext software, but only so long as
+ *EITHER*:
+
+ [*] The etext, when displayed, is clearly readable, and
+ does *not* contain characters other than those
+ intended by the author of the work, although tilde
+ (~), asterisk (*) and underline (_) characters may
+ be used to convey punctuation intended by the
+ author, and additional characters may be used to
+ indicate hypertext links; OR
+
+ [*] The etext may be readily converted by the reader at
+ no expense into plain ASCII, EBCDIC or equivalent
+ form by the program that displays the etext (as is
+ the case, for instance, with most word processors);
+ OR
+
+ [*] You provide, or agree to also provide on request at
+ no additional cost, fee or expense, a copy of the
+ etext in its original plain ASCII form (or in EBCDIC
+ or other equivalent proprietary form).
+
+[2] Honor the etext refund and replacement provisions of this
+ "Small Print!" statement.
+
+[3] Pay a trademark license fee to the Project of 20% of the
+ net profits you derive calculated using the method you
+ already use to calculate your applicable taxes. If you
+ don't derive profits, no royalty is due. Royalties are
+ payable to "Project Gutenberg Association / Illinois
+ Benedictine College" within the 60 days following each
+ date you prepare (or were legally required to prepare)
+ your annual (or equivalent periodic) tax return.
+
+WHAT IF YOU *WANT* TO SEND MONEY EVEN IF YOU DON'T HAVE TO?
+The Project gratefully accepts contributions in money, time,
+scanning machines, OCR software, public domain etexts, royalty
+free copyright licenses, and every other sort of contribution
+you can think of. Money should be paid to "Project Gutenberg
+Association / Illinois Benedictine College".
+
+This "Small Print!" by Charles B. Kramer, Attorney
+Internet (72600.2026@compuserve.com); TEL: (212-254-5093)
+*END*THE SMALL PRINT! FOR PUBLIC DOMAIN ETEXTS*Ver.04.29.93*END*
+
+
+
+
+The Project Gutenberg Etext of American Hand Book of the Daguerreotype
+
+AMERICAN HAND BOOK OF THE DAGUERREOTYPE
+
+GIVING THE MOST APPROVED AND CONVENIENT METHODS FOR PREPARING
+THE CHEMICALS, AND THE COMBINATIONS USED IN THE ART.
+
+CONTAINING THE DAGUERREOTYPE, ELECTROTYPE, AND VARIOUS OTHER PROCESSES
+EMPLOYED IN TAKINGHELIOGRAPHIC IMPRESSIONS.
+
+BY S. D. HUMPHREY
+
+FIFTH EDITION
+
+NEW YORK: PUBLISHED BY S. D. HUMPHREY
+37 LISPENARD STREET
+1858
+
+
+
+Entered, according to Act of Congress, in the year 1858, by
+S. D. HUMPHREY, In the Clerk's Office of the District Court
+of the Southern District of New York.
+
+
+To J. GURNEY, WHOSE PROFESSIONAL SKILL, SCIENTIFIC ACCURACY,
+AND ENERGETIC PERSEVERANCE, HAVE WON FOR HIM UNIVERSAL ESTEEM,
+THIS WORK IS MOST RESPECTFULLY INSCRIBED.
+
+
+
+PREFACE.
+
+There is not an Amateur or practical Daguerreotypist, who has
+not felt the want of a manual--Hand Book, giving concise
+and reliable information for the processes, and preparations
+of the Agents employed in his practice.
+
+Since portraits by the Daguerreotype are at this time believed
+to be more durable than any other style of "Sun-drawing,"
+the author has hit upon the present as being an appropriate
+time for the introduction of the Fifth Edition of this work.
+The earlier edition having a long since been wholly;
+exhausted, the one now before you is presented.
+
+The endeavor has been to point out the readiest and most
+approved Methods of Operation, and condense in its pages;
+as much practical information as its limits will admit.
+An extended Preface is unnecessary, since the aim and scope
+of this work are sufficiently indicated by the title.
+
+S. D. HUMPHREY NEW YORK, 1858.
+
+
+
+CONTENTS
+
+CHAPTER I.
+
+Polishing the Daguerreotype Plate--Buffing the Plate--Coating the Plate--
+Exposure of the Plate in the Camera--Position Developing the Daguerreotype--
+Exposure to Mercury--Removing the Coating--Gilding or fixing the Image--
+Coloring Daguerreotype, . . . . . 18
+
+CHAPTER II.
+
+Coloring Back Grounds--Transparent ditto--Gilding Dissolvent--
+Solution for removing Specks--Solarized Impression--To Purify Water--
+Cleaning Mercury--Adhesive Paper--Black Stain for Apparatus--
+Sealing Wax for Bottles--Rouge--Rotten Stone--Potassa Solution--
+Hyposulphite Solution--Substitute for do.--Gilding Solution--
+Solution for increasing the Brilliancy of the Daguerreotype--
+Bleaching Solution;--Cold Gilding--Neutralizing Agents--
+Buff Dryer--Keeping Buffs in order--Cleaning Buckskins--
+Reflector for taking Views, . . . .52
+
+CHAPTER III.
+
+Bromine and its Compounds--Iodine and its Compounds--
+Chlorine and its Compounds--Cyanide of Potassium--
+Hyposulphite of Soda--Hyphosulphite of Gold--Nitric Acid--
+Nitro-Muriatic Acid--Hydrochloric Acid--Hydrofluoric Acid--
+Sulphuric Acid--Accelerating Substances--Liquid Sensitives--
+Dry Sensitives, etc., etc., . . . . .72
+
+CHAPTER IV.
+
+Light--Optics--Solar Spectrum--Decomposition of Light--Light, Heat,
+and Actinism--Blue Paper and Color for the Walls of the Operating Room--
+Proportions of Light, Heat and Actinism composing a Sunbeam--
+Refraction--Reflection--Lenses--Copying Spherical Aberration--
+Chromatic Aberration, . . . 131
+
+CHAPTER V.
+
+To make Plates for the Daguerreotype--Determining the Time of Exposure
+in the Camera--Instantaneous Process for Producing Daguerreotype--
+Galvanizing the Daguerreotype Plate--Silvering Solution--
+Daguerreotype without Mercury--Management of Chemicals--
+Hints and Cautions--Electrotyping--Crayon Daguerreotypes--
+Illuminated Daguerreotypes--Natural Colors in Heliography--
+Multiplying Daguerreotypes on one Plate--Deposit in Gilding--
+Practical Hints on the Daguerreotype, . . . 149
+
+CHAPTER VI.
+
+An Account of Wolcott and Johnson's Early experiments in the Daguerreotype,
+. . . 188
+
+
+
+AMERICAN HAND-BOOK of THE DAGUERREOTYPE.
+
+CHAPTER I.
+
+Polishing the Daguerreotype Plate--Buffing the Plate--Coating the Plate--
+Exposure of the Plate in the Camera--Position--Developing the Daguerreotype--
+Exposure to Mercury--Removing the Coating--Gilding or fixing the Image--
+Coloring Daguerreotype.
+
+Polishing the Daguerreotype Plate.--I shall endeavor to present to the reader
+the process I have found productive of good and satisfactory results,
+presenting the same in a clear and concise manner, so that any one,
+by following the various manipulations given, will be enabled to succeed.
+If there is any one part of the process in Daguerreotype in which operators
+fail more than all others, it is in not properly preparing the plate.
+It has truly been said that it would take a volume to describe all the methods
+that have been suggested for polishing the plate.
+
+I shall confine myself to the following description, which has been
+successfully practised, also most generally adopted by our operators,
+and I believe equal, if not superior to any other method, yet at the same
+time it is not of so much importance what particular method is employed,
+so that it be thoroughly and skillfully carried out.
+
+There is a general tendency with beginners to slight this operation; hence the
+necessity of adopting a system which precludes the possibility of doing so.
+During many years' study and practice in the art, I have tried numerous
+methods and substances for the better accomplishment of the end in view,
+and have finally settled upon the following, as being (so far as experience
+allows me to Judge) the modus operandi, best suited to all circumstances;
+under no condition would I approve of a method less rigorous or precise.
+
+The operator being provided with a bottle of finely prepared rotten stone,
+cover the mouth of the bottle with a piece of thick paper, this perforated
+with a pin so that the rotten stone can be dusted on the plate.
+Fasten the plate on the holder, take the rotten stone (Becker's can always
+be depended upon), and dust on lightly until the surface is freely covered;
+now drop on the plate's surface a few drops of an alcoholic solution.*
+
+*This solution is composed of equal parts of alcohol and water,
+for the summer, and in winter three parts alcohol to one of water;
+a few drops of potassa solution may be added, and is known to have
+a decided effect upon the plate.
+
+Take a patch of Canton flannel; in order to prevent the moisture
+from the hand it should have a thick, firm texture:
+with this rub the plate in circles across, then back covering
+onehalf of the former row of circles in each crossing until you
+have gone over the plate and back to the point of beginning,
+occupying at least half a minute in the operation, for a small plate,
+and so in proportion for the other sizes.
+
+Care should be observed to keep the patch wet with the alcoholic
+solution forming a paste on the surface of the plate;
+the motion of the hand should be brisk and free, not hurried,
+and the pressure about equal to that of a pound weight.
+When the cotton is disposed to adhere to the plate, and slip
+from under the finger, spread the fore and middle fingers
+a little apart, then pressing down, bring them together
+in such a manner as to form a fold in the cloth between them,
+by which means you will hold it perfectly secure.
+
+Avoid wetting the fingers, and should they perspire, wipe them often,
+as the moisture penetrating the cotton and coming in contact with
+the plate, would cause streaks it would be difficult to remove.
+I will here remark that many operators use much more cotton flannel than
+there is need of. I have found in my experience that a single patch,
+about one and half inch square, will be better for cleaning a number
+of plates than a new piece for every plate. This is the case for the wet,
+and for the dryrubbing two or three pieces will be found to answer.
+Thus with four or five cloths a dozen plates may be prepared.
+
+Some operators use prepared cotton, and think it more convenient
+than the flannel. This may be had prepared free from seeds
+and in a very perfect state, if wished.
+
+In going over the plate, great care should be observed, in touching
+its surface as equally as possible. The greatest care should be
+taken neither to touch the plate with the fingers, nor that part
+of the cotton flannel which is to come in contact with its surface;
+take a clean piece of flannel by one corner, snap it smartly
+to free it from dust and loose fibres, lay it face-side upward,
+dust on a little fine rotten stone; with this, polish around,
+or across, or in circles, lightly and briskly, passing gradually
+over the whole surface of the plate, as was done before with the wet.
+The plate should now exhibit a bright, clear, uniform surface,
+with a strong metallic lustre, perfectly free from any appearance of film;
+if not, the last polished should be continued until the effect
+is obtained, and when once obtained, the plate is ready for buffing.
+
+Buffing the Plate.--There are a variety of ways and means employed
+in this part of the operation. Some choose wheels, and others
+prefer the ordinary hand-buff. I have been unable to detect any
+peculiar advantage in the use of the wheel except in the facility
+of the operation; no doubt, however, but there is a saving
+of time, particularly in the preparation of the larger plates.
+For general use, we have not seen a wheel better adapted for this
+purpose than the one patented by Messrs. Lewis.
+
+It is generally well to use a hand-buff before placing the plate
+on the wheel; this is in order to prevent, as far as possible,
+the dust or other substance that may be on the surface of
+the plate from coming in contact with the cover of the wheel.
+I will here follow out the use of the hand-buffs (two are necessary)
+as they are mostly used.
+
+In the morning, before using the buffs, brush both as clean as possible,
+in order to free them from dust; then with the blade of a pair of shears,
+held perpendicular, rub the buffs from end to end; then knock them
+both together in order to free them from all dust or other substances,
+occasionally exposing them to the sun or to the fire.
+
+With one of the buffs (reserving the finest and softest for the last
+operation), powder its face with fine rouge and brush off slightly,
+leaving only the finest particles in it. Every operator should have
+two plate-holders; one for cleaning and one for buffing the plate;
+for when using only one, the rotten stone is liable to get on the buff
+and scratch the plate.
+
+Rest the fingers of the left hand on the back of the buff,
+near the farther end, with about the same pressure as in cleaning,
+while with the right you bear on the handle to correspond,
+and give the buff a free, easy, horizontal motion, passing it
+very nearly the whole length over the plate each time.
+Continue this operation in such a manner that the plate will on
+all parts of its surface have received an equal amount of polish.
+This buff once well filled with polish, add but little after,
+say a small quantity once in two or three plates.
+The polish as well as the buffs must be kept perfectly dry.
+
+The second buff should always be in the best order, and if this
+is the case, but little polish after the first need be used.
+Much depends upon the last finish of the surface of the plate,
+and as a fine impression is desired in the same ratio,
+the operator must exercise care and skill in this operation.
+Some buff the smaller plates on the hands, by resting them on
+the fingers in such a manner that the buff cannot touch them;
+some by holding the edges with thumb and little finger,
+with the remaining fingers under, or on the back; and others buff
+on the holder. When this last method is adopted, it requires
+the greatest caution to prevent the dust from getting on the buff.
+The holder should be wiped clean.
+
+The plate frequently slips off or around, and the buff comes
+in contact with the bed of the holder. When, however, the operator
+is so unfortunate as to meet with this mishap, the utmost care
+must be observed in thoroughly cleaning the buff cover before
+further buffing. In this last buffing it may be continued as before,
+except without the application of polish powder to the last buff.
+Examine the surface occasionally, and buff more lightly towards
+the close of the operation, using at last the mere weight of the buff.
+This last buffing should occupy as long a time as the first.
+
+The point to be aimed at is, the production of a surface of such exquisite
+polish as to be itself invisible, like the surface of a mirror.
+The secret of producing pictures discernible in any light, lies in this:
+the more dark, deep and mirror-like the surface of the plate, the more
+nearly do we approach to perfection.
+
+In all cases, very light and long continued buffing is productive
+of the greater success, since by that means a more perfect polish
+can be obtained.
+
+The question is often asked, why is it that the plates receive the coating
+so unevenly? I will answer by saying that it may arise from two causes:
+the first and most general cause is that those parts of the plate's
+surface which will receive the heaviest coating have been more
+thoroughly polished, and the consequence is that it is more sensitive
+to the chemical operation. second. and might perhaps be considered a part
+of the first, the heat of the plate may not be equal in all its parts;
+this may arise from the heat caused by the friction in buffing.
+It is a well known fact, with which every observing practitioner
+is familiar, that a silver plate at a temperature of 45 deg.
+or less, exposed to the vapors of iodine, is less sensitive and takes
+a longer time to coat, than when it is at a temperature of 60 deg.
+or more.
+
+Whenever a view is to be taken, or any impression which requires the plate
+to be turned on the side, it should be buffed in the other direction,
+so that the marks will always be horizontal, when the picture is in position.
+With the finest possible polish, the plate is ready for the coating box.
+
+The question is often asked by operators, what is the state of the
+plate when polished and allowed to stand for a time before using?
+To meet this point we hare only to consider the silver and the power
+acting upon it. Pure atmosphere does not act upon silver;
+but we do not have this about in our operating rooms, as it
+is more or less charged with sulphurated hydrogen, which soon
+tarnishes the surface of the plate with a film of brown sulphurate.
+It is this that sometimes causes the specks which appear
+on finishing the impression, and are a great annoyance.
+Hence we see that the plate should be buffed just before receiving
+the vapor of iodine. Mr Hunt gives his opinion of the use
+of diluted nitric acid as the best solution for freeing,
+the surface of the plate; he says:
+
+"Numerous experiments on plated copper, pure silver plates,
+and on silvered glass and paper, have convinced me that
+the first operation of polishing with nitric acid, etc., is
+essential to the production of the most sensitive surface.
+All who will take the trouble to examine the subject, will soon
+be convinced that the acid softens the silver, bringing it
+to a state in which it is extremely susceptible of being either
+oxydized or iodized, according as the circumstances may occur
+of its exposure to the atmosphere or the iodine."
+
+I cannot see the objection to this solution; not, however, in general use.
+Our operators do not find it of sufficient importance to the success
+of their pictures to accept it, the alcoholic solution being in its
+nature less objectionable.
+
+I will say here, that a plate submitted to only an ordinary polish
+is found to contain numberless minute particles of the powder
+made use of. Should the same plate be buffed for a long time,
+the polish will nearly all disappear, leaving the cavities
+in the surface free for the action of agents employed in
+subsequent operation. For this reason, I find that great amount
+of polishing powder should not be applied to the last buff,
+and it is obvious that three buffs can be employed to adventure;
+the two last should not receive any polishing materials.
+I have examined a plate that was considered to possess
+a fine finish, and similar had produced good impressions;
+these same plates, when subjected to a long and light buffing,
+would present a surface no finer in appearance to the naked eye;
+but upon exposure to the solar radiation, would produce
+a well-defined image in one fourth less time than the plate
+without the extra buffing.
+
+Coating the Plate.--For this purpose our mechanics and artists
+have provided a simple apparatus called a coating-box, which
+is so arranged as to be perfectly tight, retaining the vapor
+of the iodine or accelerators, and at the same time allowing,
+by means of a slide, the exposure of the plate to these vapors.
+They can readily be obtained by application to any dealer,
+all of whom can furnish them.
+
+The principal difficulty in coating the plate, is that of preserving
+the exact proportion between the quantity of iodine and bromine, or quick.
+It is here necessary to say, that hardly any two persons see alike
+the same degree of color, so as to be enabled to judge correctly
+the exact tint, i. e. what one might describe as light rose red,
+might appear to another as bright or cherry red; consequently, the only rule
+for the student in Daguerreotype, is to study what appears to him to be the
+particular tint or shade required to aid him to produce the desired result.
+Practise has proved that but a slight variation in the chemical coating,
+of the Daguerreotype plate will very materially affect the final result.
+
+The operator will proportion the coating of iodine and bromine or accelerators
+according to the strength and composition of the latter.
+
+Experience proves that the common impressions, iodized to a rather light
+yellow gold tint, and brought by the bromine to a very light, rose color,
+have their whites very intense, and their deep shades very black.
+It is also known that if you employ a thicker coating of iodine and apply
+upon it a proportionate tint of bromine, so as to obtain a deep rose tint,
+delineations will be less marked, and the image have a softer tone.
+This effect has been obvious to everyone who has practised the art.
+Thus I may observe that the light coatings produce strong contrast
+of light and shade, and that this contrast grows gradually less,
+until in the very heavy coating it almost wholly disappears.
+From this it will readily be perceived that the middle shades are
+the ones to be desired for representing the harmonious blending
+of the lights and shades.
+
+Then, if we examine, with respect to strength, or depth of tone, and sharpness
+of impression, we see that the light coating, produces a very sharp but
+shallow impression; while the other extreme gives a deep but very dull one.
+Here, then, are still better reasons for avoiding either extreme.
+The changes through which the plate passes in coating may be considered
+a yellow straw color or dark orange yellow, a rose color more or less
+dark in tint, or red violet, steel blue or indigo, and lastly green.
+After attaining this latter color, the plate resumes a light yellow tint,
+and continues to pass successively a second time, with very few exceptions,
+through all the shades above mentioned.
+
+I will here present some excellent remarks upon this subject by Mr. Finley.
+This gentleman says:
+
+"It is well known to all who have given much attention to the subject,
+that an excess of iodine gives the light portions of objects with
+peculiar strength and clearness, while the darker parts are retarded,
+as it were, and not brought out by that length of exposure which
+suffices for the former. Hence, statuary, monuments, and all objects
+of like character, were remarkably well delineated by the original
+process of Daguerre; the plate being coated with iodine alone.
+An excess of bromine, to a certain degree, has the opposite effect;
+the white portions of the impression appearing of a dull, leaden hue,
+while those which should be black, or dark, appear quite light.
+This being the case, I conclude there must be a point between the two
+extremes where light and dark objects will be in photogenic equilibrium.
+The great object, therefore, is to maintain, as nearly as possible,
+a perfect balance between the two elements entering into union
+to form the sensitive coating of the plate, in order that the lights
+and shades be truly and faithfully represented, and that all objects,
+whether light or dark, be made to appear so far conformable to nature,
+as is consistent with the difference in the photogenic energy
+of the different colored rays of light. It is this nicely-balanced
+combination which ensures, in the highest degree, a union of the essential
+qualities of a fine Daguerreotype, viz., clearness and strength,
+with softness and purity of tone.
+
+"So far as I know, it is the universal practice of operators
+to judge of the proportion of iodine and bromine in coating
+the plate, by two standards of color the one fixed upon for
+the iodine, the other for the additional coating of bromine.
+Now I maintain that these alone form a very fallacious standard.
+first, because the color appears to the eye either lighter
+or darker, according as there is more or less light by which we
+inspect the coating; and secondly, because if it occur that we
+are deceived in obtaining the exact tint for the first coating,
+we are worse misled in obtaining the second, for if the iodine
+coating be too light, then an undue proportion of bromine is used
+in order to bring it to the second standard, and vice versa."
+
+The iodine box should be kept clean and dry. The plate immediately
+after the last buffing, should be placed over the iodine, and the coating
+will depend upon the character of the tone of the impression desired.
+Coating over dry iodine to an orange color, then over the accelerator,
+to a light rose, and back over iodine one sixth as long as first coating,
+will produce a fine, soft tone, and is the coating generally used for
+most accelerators. The plate iodized to a dark orange yellow, or tinged
+slightly with incipient rose color, coated over the accelerator to a deep
+rose red, then back over iodine one-tenth as long as at first coating,
+gives a clear, strong, bold, deep impression.
+
+I will here state a singular fact, which is not generally known
+to the operator. If a plate, coated over the iodine to a rose red,
+and then exposed to strong dry quick or weak bromine water,
+so that a change of color can be seen, then recoated over the iodine
+twice as long as at first coating, it will be found far more
+sensitive when exposed to the light than when it has been recoated
+over the iodine one-fourth of the time of the first coating.
+
+Probably the best accelerating combination is the American
+compound formerly known as "Gurney's American compound,"
+or some of the combinations of bromide of lime.
+The first is thought to possess perhaps more uniformity in its
+action than any other combination I have ever used.
+
+The plate once coated should be kept excluded from the light
+by means of the plate holder for the camera box.
+
+I will notice one of the principal causes having a tendency
+to prevent the perfect uniformity of chemical action,
+between the iodine and silver; hydrogen, or the moisture
+in the atmosphere, makes a very perceptible barrier.
+This moisture may arise as the result of the cold, from a want
+of friction in the buffing of the plate, which, coming in contact
+with the warmer air, as a writer on this subject says:
+
+"It is well known that as often as bodies, when cold, are exposed
+to a warmer air, the humidity contained in them is condensed.
+It is to this effect that we must attribute the difficulty
+experienced in operating in most cases." This is corroborated
+by the results experienced by our operators. So it is seen that
+the plate should be of a temperature above that of the atmosphere.
+Mr. Gurney submits his plates to a gentle heat from a spirit
+lamp just before exposing them to the vapor of iodine.
+Experience has convinced me that a plate heated to about 80 deg.
+before being exposed to iodine will present a far better
+defined image than aplate at a temperature of 50 deg.
+I account for this by noticing that, at a higher temperature,
+the plate throws off any larger crystals that might otherwise
+be deposited, receiving only the finer, thus producing
+a more perfect chemical combination of iodide of silver.
+I would call the attention of the operator to this point,
+as presenting something of interest, and which may direct
+in a way of accelerating the future operations.
+
+That the presence of a film of moisture over the plate is a preventive
+of uniform chemical action, may be readily understood from the fact
+that iodine is almost insoluble in water, requiring seven thousand parts
+of water to dissolve one of iodine, or one grain to a gallon of water.
+Yet its affinities for silver and other substances are so powerful as to
+prevent its existing in an insulated state, hence we can account for the
+frequent occurrence of a plate presenting parts of an image over its surface.
+It is quite evident that those parts of plate's surface covered with moisture
+are nothing like as sensitive to the iodine as those parts perfectly free.
+
+Exposure of the plate in the Camera, and Position.--The time of
+exposure necessary to produce an image upon the Daguerreotype plate,
+can only be determined by experiment, and requires a liberality
+of judgment to be exercised on the part of the operator.
+The constant variation of the light renders it impossible to lay
+down any exact rule upon this point. Light is not alone to
+be considered; the amount of coating exercises a deviating influence,
+also the subjects to be represented are not equally photogenic,
+some requiring much longer time of exposure than others.
+This may be easily observed by exposing the plate at the same
+time to a plaster bust and a piece of black velvet, the first
+being a much stronger reflector of light than the latter:
+the time necessary to produce a well developed image
+of the velvet being about six times longer than that
+required to produce an equally defined image of plaster.
+The manner of judging correctly of the time is by the appearance
+of impression after it has been developed by the mercurial vapors.
+Should it present a deep blue or black appearance it is solarized
+or over-timed. This sometimes is to an extent, that a perfect
+negative is formed, the white being represented black,
+and the dark light.
+
+An object requiring the particular care and attention
+of the operator is the proper focus. It is not unfrequently
+the complaint of sitters that their hands are represented as being
+magnified and greatly out of proportion with the general figure.
+This is the case also with the nose and eyes, but in a less degree.
+As this cannot be wholly remedied, it is desirous to come as near
+as possible, and in order to do this, it is necessary to present
+the figure in such a position as to bring it as nearly as possible
+upon the same plane by making all parts nearly at equal distance
+from the lenses. This must be done by the sitter inclining
+the head and bust formed to a natural, easy position, and placing
+the hands closely to the body, thus preserving a propel proportion,
+and giving a lively familiarity to the general impression.
+It is not an uncommon fault among our less experienced operators
+to give a front view of the face of nearly every individual,
+regardless of any particular form, and this is often insisted upon
+by the sitter,* who seems to think the truth of the picture exists
+principally in the eyes staring the beholder full in the face.
+
+* I might here picture some curious scenes experienced
+by our operators Every one is familiar with a certain class
+of our community whose ideas of the importance of a free
+and easy position of the body are too closely confined
+with stays, attention to toilet, tightly fitting dress coats
+and the like, to admit of being represented as if nature
+had endowed them with least possible power of flexibility.
+To such we would suggest the following, to be well learned
+and retained in the mind while presenting themselves before
+the Daguerreotype camera:
+
+"The experience of one who has often been Daguerreotyped, is, to let
+the operator have his own way."
+
+Nothing, in many instances, can be more out of place in a
+Daguerreotype portrait than this, for let a man with a thin, long,
+defeated-politician-face, be represented by a directly front view,
+we have, to all appearances, increased the width of the face to such
+an extent as to reveal it flat and broad, losing the characteristic
+point by which it would be the most readily recognized.
+The method we should adopt in taking the likeness of such an
+individual as above, would be to turn the face from the camera,
+so as to present the end of the nose and the prominence of the cheek
+bone equally distant from the lenses, and then focusing on
+the corner of the eye towards the nose, we cannot in many cases,
+fail to produce an image with the lips, chin, hair, eyes and forehead
+in the minutest possible definition.
+
+It should be the study of every operator to notice the effect of the lights
+and shades while arranging the sitter, and at the same time be very particular
+to give ease in the position.
+
+No matter how successful the chemical effect may have been,
+should the image appear stiff and monument-like, all is lost.
+"In the masterpiece, grace and elegance must be combined."
+
+I will here use the words of another, which are very true:
+
+"So great is the difference in many faces, when inspected
+in opposite directions, that one of the two views,
+however accurately taken, would not communicate the likeness--
+it not being, the usually observed characteristic form.
+When the right view of the head is obtained, it is first necessary
+to consider the size of the plate it is to be taken on, so as
+to form an idea of the proportion the head should bear to it.
+The mind must arrange these points before we commence,
+or we shall find everything, too large or too small
+for the happy proportion of the picture, and the conveying
+of a just notion of the stature. The work will have to be
+done over, and time sacrificed, if this is not attended to.
+The adjustment of the head to the size of the plate
+(as seen from the margin of the mat), is not to be taught:
+everyone must bring himself, by scrutinizing practice,
+to mathematical accuracy; for something will be discovered
+in every face which can be surmounted only by experience.
+
+"The eye nearest the camera, in a three-quarter-face, is
+placed in the middle of the breadth of the plate; the chin,
+in a person of middle stature, in the middle of the length,
+and higher according to the proportional height of the person."
+
+In regard to the proper elevation of the camera, it may be here stated that I
+have found it best in taking portraits where the hands are introduced,
+to place the camera at about equal height with the eyes of the sitter,
+in order to bring the face and hands equi-distant from the tube.
+It will be found, if the above be followed, that by attaching a string
+to the camera tube, and making a semi-circle, that the face and hands
+of the sitter will occupy a corresponding distance, and the consequence
+is that the impression will appear without the hands being magnified.
+It has been found that a person with a freckly face can have
+as fine, fair, and clear an impression as the most perfect complexion;
+this may be done by the subject rubbing the face until it is very red.
+The effect is to lessen the contrast, by giving the freckles and skin
+the same color and the photogenic intensity of the red and yellow being
+nearly the same, an impression can be produced perfectly clear.
+
+When a child is to be taken, and there are doubts of its keeping still,
+the operation may be accelerated by placing it nearer the window bringing
+the screen nearer, and placing a white muslin cloth over the head;
+this will enable you to work in one third of the usual time.
+Should the person move, or the plate become exposed to the light,
+it may be restored to its original sensitiveness by placing it over
+the quick, one or two seconds.
+
+Developing the Daguerreotype.--After the plate has been submittedto
+the o peration of the light, the image is still invisible.
+It requires to be exposed to the vapors of heated mercury.
+It is not absolutely necessary to apply artificial heat to the mercury
+to develop the image, for fair proofs have been produced by placing
+a plate over the bath at the ordinary temperature of the atmosphere.
+This plan, however, requires a long time and cannot be adopted
+in practice, even if it were advisable. The time more usually
+required in developing the image over the mercurial vapors,
+is about two minutes, and the temperature is raised to a point
+necessary to produce the desired effect in that time.
+This point varies as indicated by different scales, but for
+the ordinary scales it is not far from 90 deg. cen.
+
+The mercury bath is accompanied with a centigrade thermometer,
+by which the heat is regulated. Those furnished by the manufacturers
+are not always correct, and it requires some experience to find
+the proper degree on the scale.
+
+I would here remark that it is advisable, when placing the spirit
+lamp under the bath, to so arrange it that the position of
+applied heat should always be on the same point, viz., should
+the heat be directly under the bulb containing the thermometer
+it would raise the mercury in the tube to the point marked,
+and the temperature of that in the bath would be far below what it
+should be; hence it is (where time is followed for developing)
+that many failures occur. This is observed more readily in the large
+baths made of thick iron, particularly upon first heating.
+In practice I apply the heat as nearly as possible between the centre
+of the bottom of the bath and the bulb containing the mercury tube.
+It is advisable to keep the lamp lighted under the bath from the time
+of commencing in the morning to the close of business at night.
+By this means you have a uniformity of action, that cannot
+be otherwise obtained.
+
+It is well known to the experienced Daguerreotypist,
+that different atmospheres have a decided effect upon
+the mercury in developing the Daguerreotype. It will require
+a greater degree of heat for one atmosphere than for another.
+Experience alone determines this little difference.
+
+In summer, on cloudy and stormy days, mercurial vapors rise more
+readily and quickly than in the temperature of autumn or winter.
+From 60 degrees upwards towards the boiling point (660 deg.),
+the vapors of mercury rise in greater abundance and collect
+in larger globules on cold surfaces.
+
+For various reasons I prefer a high temperature and short exposure.
+It accelerates the process. It renders the lights of the picture
+more strong and clear, while the deep shades are more intense.
+It gives a finer lustre to the drapery. The solarized
+portions also are very seldom blue, especially after gilding.
+If heated too high, however, the light parts become of a dead,
+chalky white, and the shadows are injured by numerous little
+globules of mercury deposited over them. Just the right
+quantity of mercury leaves the impression of a transparent,
+pearly white tone, which improves in the highest degree in gilding.
+To mercurialize with exactness is a nice point. If there
+is reason to suspect having timed rather short in the camera,
+reduce the time over mercury in a corresponding proportion.
+A dark impression will be ruined by the quantity of mercury
+which would only improve a light one.
+
+If practicable, it is most expedient that the plate be submitted
+to the action of mercury immediately on coming from the camera.
+I have frequently, however, carried plates for miles
+in the plate-holders and after exposing in the camera,
+brought them back to expose to mercury, and obtained fair proofs;
+but for the reason before given, it is advisable to carry
+along the bath, and bring out the impression on the spot.
+
+It is sometimes the practice of inexperienced operators to take
+the plate off the bath and examine the impression by solar light.
+This plan should be abandoned, as it is almost sure to produce
+a dense blue film over the shadows.
+
+This I am led to believe is occasioned by the action of light on the yet
+sensitive portions of the plate, and made to appear only by subsequent
+exposure to mercury, being equivalent to solarization.
+
+There has been little said by our professors upon the subject of
+the position of the plates while exposed to the mercurial vapour.
+Mr. Hunt, in referring to this subject, says: "Daguerre himself laid
+much stress upon the necessity of exposing the plate to the mercury
+at an angle of about 45 deg.. This, perhaps, is the most convenient
+position as it enables the operator to view the plate distinctly,
+and watch the development of the design; but beyond this, I am
+satisfied there exists no real necessity for angular position.
+Both horizontally and vertically, I have often produced equally
+effective Daguerreotypes." I presume from the last sentence of Mr. Hunt,
+that he has confined his experiments to the smaller sized plates.
+Hence he may not have thought of the effect of the vertical exposure
+of a large plate.
+
+In America this is a subject of no little importance. When an
+impression is to be developed upon a plate fifteen by seventeen inches,
+were we to use an angle of about 45 deg., it would be found
+to make a perceptible difference in the appearance of the image.
+By examining the wood tops of our baths as formerly made,
+it will be found that there is a great variation in the distance
+from the mercury to the different portions of the plate.
+By measuring one of these tops for the size plate above mentioned,
+I find the distance to the nearest point between the mercury
+and the plate, to be thirteen, and the middle point sixteen,
+and the furthest point twenty-one and a half inches:
+by this we see that one point of the plate is eight and a half
+inches further from the mercury than the nearest point;
+even this is not the variation there would necessarily be,
+were we to adopt the angle of 45 deg. as urged by Daguerre.
+
+Among our principal professors, the beveltop will not be found in use
+where the large plates are used. Should any one feel desirous
+to test more minutely the effect produced by a bevel top bath,
+I would suggest to them to place a frame, so constructed as to hold
+three sixth size plates, and fit it to the top of the bath,
+and so arrange it with openings that the plates may be placed,
+one at the nearest point of the mercury, the second midway,
+and the third to the greatest distance, and by placing the plates
+over at one and the same time, the experimenter will be enabled
+to judge if there exists a difference in the developing.
+In speaking of the above, reference is had to baths to the ordinary
+heights used by operators.
+
+We will now proceed to examine the effect produced by mercurial
+vapor upon the plate at different lengths of exposure.
+In some investigations which I have made upon the appearance
+of the Daguerreotype impressions when developed over mercury
+at 90 deg. C. (194 deg. F.), the following was the result.
+Plates, coated and exposed to light in our usual manner
+of operating, produced on exposure of
+
+1/2 minute, whole impression, deep blue.
+
+1 minute, ashy and flat; no shadows; linen, deep blue.
+
+1 1/2 minute, coarse and spongy; shadows, muddy; drapery, dirty reddish brown.
+
+2 minutes, shallow or watery; shadows, yellowish; drapery, brown.
+
+2 1/4 minutes, soft; face, scarcely white; shadows, neutral; drapery, fine
+dark brown linen somewhat blue.
+
+2 1/2 minutes, clear and pearly; shadows, clear and positive,
+of a purple tint; drapery, jet black, with the dark shades
+slightly frosted with mercury.
+
+2 3/4 to 3 minutes, hard and chalky; shadows, harsh; drapery, roughened,
+and misty with excess of mercury.
+
+The foregoing results will be found general.
+
+There are numerous opinions among our operators in regard to the quantity
+of mercury necessary for a bath. As regards this, I need only say,
+similar results occur when two pounds or two ounces are used,
+but the quantity generally employed is about a quarter of a pound.
+I am of the opinion that one ounce will answer as well as a larger quantity.
+I know of no better proof in favor of a small quantity than that
+presented in the following incident. Several years since, an operator
+(Mr. Senter, of Auburn, N.Y.) of my acquaintance, was requested to go
+several miles to take a Daguerreotype portrait of a deceased person.
+He packed up his apparatus and proceeded over a rough road for some
+distance to the house where he was to take the portrait, and arranging
+his apparatus, with all the expedition which the occasion required,
+after having everything in usual order (as was supposed),
+he proceeded and took some ten or twelve very superior impressions.
+They were fine, clear, and well developed. After taking the number ordered,
+he proceeded to repack his apparatus, and to his surprise, when he took
+up the bottle he carried the mercury in, he found it still filled,
+and none in the bath, except only such particles as had adhered to the sides,
+after dusting and being jolted for several miles over the rough road.
+From this it will be seen that a very little mercury will suffice to
+develop fine proofs. I saw some of the impressions referred to above,
+and they were certainly well developed, and very superior specimens
+of our art.
+
+Removing the Coating.--After the impression has been developed over
+the mercurial vapor, the next step is to remove the sensitive coating.
+For this purpose the following solution is used:
+
+Put about two ounces of hyposulphite of soda in a pint
+of water, which should always be filtered before using.
+A convenient way of doing this is to have two bottles,
+and a large funnel with a sponge pressed into the neck
+of it; or, what is better, some filtering paper folded in it.
+The solution in one bottle, the funnel is placed in the other,
+and the picture held over it; when the solution is poured
+on the plate, it runs from it into the filter, and is always
+ready for use.
+
+It is best that the washing be done immediately on the plate coming
+from the mercury bath. If allowed to stand long with the coating on,
+it assumes a very dark tint--as the operation of the light continues,
+though less active than while exposed in the camera, and destroys
+that brightness which would otherwise have been obtained.
+It is preferable to wash and gild a picture without it first
+being dried; yet when there are doubts of its giving satisfaction,
+there would sometimes be a saving by drying and getting the decision
+of the subject before gilding, as this last injures the plate for
+another impression. First, light your spirit-lamp, then with your
+plyers take the plate by the lower right-hand corner, holding it
+in such a manner that the plyers will form in a line with the upper
+left-hand corner; pour on, slowly, the hyposulphite solution,
+slightly agitating the plate, until all the coating is dissolved off;
+then rinse off with clean water, and if it is not to be gilded,
+dry by holding the plate perpendicular with the bottom left-hand
+corner lowest, and applying the blaze of the spirit-lamp to the back,
+at the same time blowing gently downward on the face of the plate.
+
+The hyposulphite solution should be often filtered through a sponge,
+and it will answer for a great number of washings. Yet it is observed that
+the mercury collects in this solution in small globules; these often come
+in contact with the plate, causing white spots, which spoil the impression.
+They should be guarded against, and the solution renewed. Again, in order
+to prevent streaks or scum on the surface of the plate, it is necessary
+that the coating should be removed with a good degree of uniformity.
+I find in practice that the hyposulphite of soda in our market varies much
+as regards strength, and consequently the rule to be adopted is to make
+a solution of sufficient strength to remove the coating in about ten seconds.
+I am aware that it may be said that this strong solution would have a tendency
+to injure the impression by destroying in a measure the sharpness of outline.
+To meet this, it need only to be said that the preventive is, to not let
+the solution rest on the surface of the plate for a longer time than is
+absolutely necessary, and then it should be drenched copiously with water;
+hence a chemical action upon the image is prevented and the general
+operation facilitated. This plan is adopted by our first operators with
+the greatest success.
+
+If the operator should allow the hyposulphite solution to run
+over the plate unevenly, it is quite likely that white or blue
+streaks would result. These it is impossible to remove without
+injury to the impression. Some, in order to prevent this,
+breathe over the surface, thus moistening it and putting it
+in a condition to receive the solution with greater uniformity.
+The plate should be well washed with water before gilding.
+
+Gilding, or Fixing the Image.--The next process to be given is that for fixing
+the image on the plate. This is done by precipitating a thin film of gold
+over the surface and is productive of the most brilliant effect when prepared
+immediately after the plate has been washed with water after the application
+of the hyposulphite solution, and before the plate has been allowed to dry.
+When, however, the plate has been dried and allowed to stand for any time,
+before gilding, the hyposulphite wash should be applied as at first,
+in order to destroy any chemical coating that may have been formed on exposure
+of the plate to the air. For gilding the larger plates, we have a gilding
+stand so constructed that the plate can be put on a perfect level.
+In practice, I prefer holding the plate with nippers, fastened at one corner.
+Hold the plate in the same manner as in removing the coating;
+pour on the gilding, newly filtered, until the surface is wholly covered,
+and with the blaze of the spirit lamp, at least three inches high, apply it
+to the back of the plate, moving it about, that the surface may be heated
+with as much uniformity as possible. Continuing this operation, the surface
+will generally become covered with small yellow bubbles which soon disappear,
+leaving the image clear and distinct.
+
+It is advisable to make use of a lamp having a sufficiently
+strong flame to produce the effect in a few minutes.
+If after a first heating, it is found that the impression can
+admit of a greater degree of intensity, it might be heated anew;
+but that is seldom necessary, and often by trying to do too,
+well, the operator, if he persists in heating certain parts
+of the plate, may find the liquid dry up just above the flame,
+and inevitably cause a stain*; or else the blacks are covered
+with a film, or even the coating of gold may suddenly exfoliate,
+when small particles are detached from the plate.
+The impression is then entirely spoiled, but the plate
+may be re-polished.
+
+* This can be remedied, however, if it is immediately
+washed over with the same solution that is on the plate,
+so that the surface shall not become cool; continue for a short
+time to apply the lamp under, and agitate the plate slightly,
+and it will soon be free from all imperfections and give
+a fine clear tone.
+
+It is not unfrequent that the surface assumes a dark, cloudy appearance.
+This is generally the best sign that the gilding will bring
+out the impression with the greatest degree of distinctness.
+Soon, the clouds gradually begin to disappear, and, "like a thing
+of life" stands forth the image, clothed with all the brilliancy
+and clearness that the combined efforts of nature and art can produce.
+When in the operator's judgment the operation has arrived at the highest
+state of perfection, rinse suddenly, with an abundance of clean water,
+and dry as before described.
+
+When an impression is dark, the gilding process may be longer continued;
+but when light, it should be gilded quickly, as lengthening
+the time tends to bleach the impression and make it too white.
+The cause of this appears to be, that with a moderate heat the chlorine
+is merely set free from the gold, and remaining in the solution,
+instead of being driven off, with its powerful bleaching, properties,
+it immediately acts upon the shades of the picture. A dark impression
+can thus, by a low heat, long-continued, be made quite light.
+To procure the best effect, then, heat suddenly with a large blaze,
+and judging it to be at the maximum, cool as suddenly as possible.
+
+When the hyposulphite of gold is used instead of the chloride,
+a less heat should be employed.
+
+Coloring Daguerreotypes.--Of all the so-called improvements
+in the Daguerreotype, the coloring is the least worthy of notice.
+Yet the operator is often, in fact most generally,
+called upon to hide an excellent specimen under paint.
+I can conceive of nothing more perfect in a Daguerreotype than
+a finely-developed image, with clearness of lights and shadows,
+possessing the lively tone resulting from good gilding.
+Such pictures, however, are not always had, and then
+color may perform the part of hiding the imperfections.
+We present the following method as given in Willat's Manual:
+
+"Daguerreotype portraits are now commonly met with beautifully colored;
+but the coloring is a process requiring great care and judgment,
+and many good pictures are spoiled in fruitless experiments.
+Several different methods of coloring have been proposed.
+The simplest mode appears to be that of using dry colors prepared
+in the following manner: A little of the color required,
+very finely ground, is thrown into a glass containing water,
+in which a few grains of gum arabic have been dissolved.
+After standing a few moments, the mixture may be passed through
+bibulous paper, and the residue perfectly dried for use.
+The principal colors used are Carmine, Chrome Yellow,
+Burnt Sienna, Ultramarine and White; boxes fitted with sets
+of colors properly prepared, may be obtained of the dealers,
+and include Carmine, White, Lilac, Sky Blue, Pink, Yellow,
+Flesh color, Orange, Brown, Purple, Light Green, Dark Green
+and Blue. With a few colors, however, all the rest may be
+made thus: Orange, by Yellow and Red; Purple, with Blue
+and Red; Green, Blue and Yellow; Brown, with Umber,
+Carmine and Lamp Black; Scarlet, Carmine and Light Red.
+While it is true that a little color may relieve the dark
+metallic look of some Daguerreotypes, it must not be concealed
+that the covering of the fine delicate outline and exquisite
+gradations of tone of a good picture with such a coating,
+is barbarous and unartistic.
+
+"The prevaling taste is, however, decidedly for colored proofs,
+and the following directions will assist the amateur in
+ministering to this perverted taste, should he be so inclined.
+The coloring should commence with the face, and the flesh tint
+must be stippled on (not rubbed) with a small camel's-hair brush,
+beginning from the centre of the cheek, taking great care
+not to go over the outline of the face, and also not to have
+too much color in the brush; the eyes and eyebrows must not
+be touched with color. After the flesh color is applied,
+take a piece of very soft cotton and pass it very gently backwards
+and forwards over the face, so as to soften down the color,
+and then apply the carmine to give the required tint.
+For men, the darker tints should predominate, and for women
+the warmer. Very light hair may be improved by a slight
+tint of brown, or yellow and brown, according to the color.
+In coloring the drapery, the same care must be used.
+No rules can be laid down for all the different colors required,
+and the amateur had better obtain the assistance or advice
+of some one accustomed to the use of colors. A little
+white with a dash of blue or a little silver, will improve
+white linen, lace, etc. The jewelry may be touched with gold
+or silver from the shells, moistened with distilled water,
+and laid on with a fine-pointed sable-hair brush.
+
+"Brilliants may be represented by picking the plate with the point
+of a pin or knife."
+
+
+
+MISCELLANEOUS.
+
+CHAPTER II.
+
+
+Coloring Back Grounds--Transparent ditto--Gilding Dissolvent
+Solution for removing Specks--Solarized Impression--To Purify Water--
+Cleaning Mercury--Adhesive Paper--Black Stain for Apparatus--
+Sealing Wax for Bottles--Rouge--Rotten Stone--Potassa Solution--
+Hyposulphite Solution--Substitute for do.--Gilding Solution--
+Solution for increasing the Brilliancy of the Daguerreotype--
+Bleaching Solution;--Cold Gilding--Neutralizing Agents--
+Buff Dryer--Keeping Buffs in order--Cleaning Buckskins--
+Reflector for taking Views.
+
+To Color Back-grounds--To obtain a properly colored back ground
+is a matter of no little importance to the Daguerreotype operator.
+I had nearly exhausted all patience, and tried the skill of painters
+to obtain a back-ground that would be suitable to my purpose;
+but all to no avail. At last I adopted the following method,
+and at a cost of coloring of twenty-five cents, can now produce
+a back-ground far more valuable than those which had cost
+five dollars before.
+
+Take common earth paint, such as is used in painting roofs;
+mix this with water to about the consistency of cream;
+then to four quarts of this mixture add about one pint of glue water
+(common glue dissolved in water, also about as thick as cream).
+This last will cause the paint to adhere to the cloth,
+to which it is applied with a common white-wash brush.
+By applying the brush on the coating while it is wet,
+it may be so blended that not a line can be seen,
+and a perfectly smooth color of any shade can be obtained.
+The shade of color I use is a light reddish-brown. Tripoli,
+rotten-stone, or any earthy matter, may be applied in
+the same manner.
+
+Transparent or Invisible Back-ground.--I give this as originally
+published in my System of Photography, 1849:
+
+"Take a large woollen blanket with long nap, the longer
+and rougher it is the finer will be the effect produced;
+stretch it on a frame of sufficient size, and suspend the frame
+at the centre of the upper end by a string fastened to a nail
+in the ceiling, from three to five feet back of the sitter.
+Having arranged this, fasten another string to the side of
+the frame, and while the operation is going on in the camera,
+swing the back-ground from right to left, continuing this during
+the whole time of sitting, and you have a clear "transparent"
+back-ground, which throws the image out in bold relief,
+and renders the surface of the plate invisible.
+If equalled at all it is only by atmospheric back-ground. I
+consider it to be the best ever known, and think it needs
+but to be tried to afford satisfactory proof that it is so.
+Although used by few before, since the first edition of this
+work at least two thirds of the operators have adopted its use;
+for any one can at once understand the principle and the effect
+which it produces."
+
+It may be added that a motion imparted to to any back-ground
+where softness is desired, produces an excellent effect.
+
+Gilding Dissolvent.--To one quart of muriatic acid add as much
+oxide of iron (common iron rust) as it will dissolve in two days.
+This may be done by putting in the oxide in excess.
+It should be frequently shook, and when wanted for bottling
+it should be allowed to stand in order to settle. When this
+is done the solution may be poured off, and reduced by adding
+to it an equal quantity of water; then it is ready for use.
+This constitutes a gilding dissolvent now in our market.
+
+Solution for Removing Specks.--There is probably no one cause
+of complaint so general as "what makes those black specks?"
+There are several causes which produce them, and probably the most
+general are dust, rouge, or a spray of moisture on the plate.
+It this be the case, there is no solution which can remove them,
+as they have prevented a chemical action with the silver,
+and their removal would only expose the surface of the plate
+which in itself would afford a contrast with the impression.
+Another and less dangerous source of these specks is organic matter
+contained in the solution employed in dissolving the chemicals,
+or the water in washing. much of the hyposulphite of soda
+in market contains a sulphuret, which, coming in contact
+with the silver surface, immediately causes oxidation.
+Such spots, as well also as most all others found on the plate
+after it has been exposed in the camera, can be removed
+by the following, solution: To one ounce of water add a piece
+of cyanide of potassium the size of a pea; filter the solution
+and apply by pouring it on the surface of the plate.
+In all cases the plate should first be wet with water.
+Apply a gentle heat, and soon the spots disappear,
+leaving the impression clear and free from all organic matter.
+
+In the absence of cyanide of potassium, a solution of pure hyposulphite
+of soda will answer as a fair substitute.
+
+To Redeem, a Solarized Impression.--The Daguerreotype plate,
+prepared in the ordinary manner, should be exposed in the camera
+a sufficient time to solarize the impression. Then, before it
+be exposed to the vapor of mercury, expose it for a very brief
+period to the vapor of either chlorine, bromine or iodine.
+Then expose over mercury, as usual. I have produced singularly
+interesting results by this process.
+
+To Purify Water.--Filter the water well, and then add about three drops
+of nitric acid to the pint. This can be used as absolutely pure water,
+but I would recommend the use of distilled water as preferable.
+
+Cleaning Mercury.--Make a small bag of chamois skin,
+pour in the mercury, and squeeze it through the leather.
+Repeat this several times, and filter by means of a funnel made
+of paper, with a very small aperture, through which it will escape
+and leave the particles of dust, or other substances, in the paper.
+A paper with a pinhole through it will answer as well,
+and it is less difficult to make.
+
+Adhesive Paper.--Take gum arabic, four ounces, put it
+in a wide-mouthed bottle and pour on water about one-third
+above the gum. Add half ounce of isinglass, or fish glue,
+and a small piece of loaf sugar. Let all dissolve, and spread
+over French letter paper, with a brush or piece of sponge.
+If once spreading is not enough, perform the same operation
+a second time.
+
+Black Stain for Apparatus.--Dissolve gum shellac in alcohol,
+or procure shellac varnish at the druggists', stir in lampblack,
+and apply with a sponge or bit of rag. This will adhere to metal,
+as well as wood, and is used for the inside of camera, tubes, etc.
+
+Sealing Wax for Bottles.--Melt together six parts rosin and one beeswax,
+and add a small quantity of lampblack; or, if red is preferable,
+add red lead. Common white wax is best, as most chemicals act
+less upon it.
+
+When bottles containing bromine are to be sealed, it is well to grease
+the stopper. This, however, only when the bottle is in frequent use,
+for if it were to be sent by any conveyance it would be likely to fly out.
+
+Rouge.--The method employed by Lord Ross is probably unsurpassed
+in the production of rouge. He has given his process as follows:
+
+"I prepare the peroxide of iron by precipitation with water
+of ammonia, from a pure dilute solution of sulphate of iron;
+the precipitate is washed, pressed in a screw press till nearly dry,
+and exposed to a heat which in the dark appears a dull, low red.
+The only points of importance are, that the sulphate of iron should
+be pure, that the water of ammonia should be decidedly in excess,
+and that the heat should not exceed that I have described.
+The color will be a bright crimson inclining to yellow.
+I have tried both potash and soda, pure, instead of water of ammonia,
+but after washing with some degree of care, a trace of the alkali
+still remained, and the peroxide was of an ochrey color,
+till overheated, and did not polish properly."
+
+Care should be observed to apply rouge in a dry state to the surface
+of the plate.
+
+I would remark, that so far as my experience has gone,
+I consider good rouge fully equal to any other polishing,
+material for the last or finishing polishing; consequently I
+shall not take up my space in enumerating any of the great
+variety that find few advocates.
+
+Why Rouge is to be preferred.--"Because it burnishes better,
+and because it assists in fixing the layer of gold, rendering it
+less susceptible of being removed in scales when heated too much."
+
+Rotten Stone.--"Purchase the best ground rotten stone
+of the druggist, put a few ounces at a time in a wedgewood
+or porcelain mortar, with plenty of clean rain water.
+This should have about forty drops of nitric acid to the quart.
+Grind well, and after letting the mortar stand two minutes,
+pour into a third. After remaining undisturbed eight minutes,
+finally pour off into a fourth to settle. Rinse back the sediment
+in the second and third, and grind over with a new batch.
+Repeat the operation till you have all in the fourth vessel.
+Let this stand several hours, and pour off the water very carefully.
+Set the deposit in the sun, or by a stove to dry.
+When perfectly dry, pulverize, and it is ready for use.
+With a little trouble you will obtain in this way a much
+better article than can generally be bought of dealers.
+For the last washing, alcohol, or a mixture of alcohol
+and water, is preferable."
+
+Potassa Solution.--The use of a solution of potassa in the preparation
+of the plate was suggested in the early history of the Daguerreotype.
+It was thought to possess some peculiar property for improving the tone
+of the impression. It is used for moistening the rotten stone in polishing
+the plate, and may be prepared by putting about an ounce and a half
+of alcohol in a close bottle, and add half a stick of caustic potash.
+This will soon become of a deep red color. For use, fill your small bottle,
+having a quill in the cork, with alcohol, and add a few drops of the above,
+or enough to change it to a bright orange or saffron color.
+
+A Substitute for the Hyposulphite Solution.--M. DAGUERRE recommends the use
+of a solution of salt water for removing the coating off the plate.
+I found this of some service at one time during my travels.
+My hyposulphite bottle got broke and its contents lost, so as only to leave
+enough for preparing gilding. I resorted to the use of salt solution,
+and found it to answer well. Make a saturated solution of salt in water.
+First wash the plate with clear water; then immerse it in the saline solution,
+when it should be agitated, and the coating will soon disappear.
+Another process with a salt solution of half the strength of the above
+is very interesting and effectual. The plate having been dipped into
+cold water, is placed in a solution of common salt, of moderate strength;
+it lies without being acted upon at all; but if it be now touched
+on one corner with a piece of zinc, which has been scraped bright,
+the yellow coat of iodine moves off like a wave and disappears.
+It is a very pretty process. The zinc and silver forming together
+a voltaic pair, with the salt water intervening, oxidation of the zinc
+takes place, and the silver surface commences to evolve hydrogen gas;
+while this is in a nascent condition it decomposes the film of iodide
+of silver, giving rise to the production of hydriodic acid, which is
+very soluble in water, and hence instantly removed.
+
+This process, therefore, differs from that with hyposulphite.
+The latter acts by dissolving the iodide of silver, the former
+by decomposing it. It is necessary not to leave the zinc
+in contact too long, or it deposits stains, and in large plates
+the contact should be made at the four corners successively,
+to avoid this accident.
+
+Gilding Solution.--To one pint of pure rain or distilled
+water add fifteen grains of pure chloride of gold,
+and to another pint add sixty grains of hyposulphite of soda.
+When dissolved, pour the gold solution into the hyposulphite
+by small quantities, shaking well after each addition.
+The soda solution must not be poured into the gold, as the gold
+would be immediately decomposed, and the solution turn black,
+and be unfit for use.
+
+Some operators add muriate of potash and other substances,
+but these do not possess any advantage except in cases where it
+is necessary to bleach the solarized portions of the impression,
+and when such is the case, chloride of sodium (common salt)
+is probably as effective and is the most convenient.
+Add about a teaspoonful to two ounces of the gilding.
+
+Solution, for Increasing the Brilliancy of the Daguerreotype.--This solution
+will have the effect to thoroughly cleanse the surface of the gilded plate
+and excite a powerful influence on the general character of the impression.
+To a solution of three ounces of water, in which is dissolved a quarter of an
+ounce of cyanide of potassium, add one teaspoonful of a solution containing
+six ounces of water and half an ounce of each pure carbonate of potash,
+alum, common salt, gallic acid, sulphate of copper, and purified borax.
+While the plate is wet, pour on a little, and heat it with a powerful blaze.
+The effect will be quickly produced, in from three to fifteen seconds.
+Rinse and dry, as in the gilding.
+
+Bleaching Solution.--Make a saturated solution of muriate of ammonia
+(sal ammoniac) in pure water, and filter through paper.
+Reduce with an equal quantity of water when used. When the linen
+or any other portion of the impression is badly solarized,
+after removing the coating, rinse with water; then pour this
+upon the surface in the same manner as the gilding solution.
+If the solarization be very deep, apply the lamp beneath,
+and warm the plate a trifle. Now pour off, and, without rinsing,
+apply the gilding. The whole operation must be quickly performed,
+or the chlorine soon attacks the shades of the picture.
+When properly done, however, the solarized parts are restored
+to a clear, transparent white.
+
+Electro, or Cold Gilding.--This process I have adopted, and it
+produces exceedingly beautiful impressions for the stereoscope,
+adding a great charm to the pleasing effect of that instrument.
+It also possesses a pretty and curious effect on views.
+It is easy of trial, and may be used by dissolving one gramme
+of chloride of gold in half a litre of ordinary water, and thirty
+grammes of hyposulphite of soda in another half litre of similar water;
+then pour the solution of chloride of gold into that of soda,
+by little and little, agitating it exactly as in M. Fizeau's preparation,
+of which there is but a variation.
+
+When you wish to use it, pour some into a plate, or any other vessel
+of the same kind, sufficient to cover the proof; then, after having
+added to it a drop of ammonia, immerse the plate in it as soon
+as you take it out of the mercury-box, after having wiped its back
+and edges, and agitate the mixture quickly from right to left,
+so as to dissolve rapidly the coating of iodide of silver as usual.
+As soon as the plate appears white, cease all rapid motion,
+but continue to give it a slight undulating one; for if it were allowed
+to remain still for only a few minutes, the proof would be clouded.
+By little and little, the surface of the plate takes a yellow tint,
+which darkens more and more, approaching to bistre. You stop therefore,
+at the color you wish; and when the proof has been washed and dried,
+in the manner previously explained, it will be found to be fixed,
+without any stain, with a limpid surface, and an extraordinary warm tone.
+If you were to augment the proportions of the ammonia or chloride
+of gold, the operation would progress much quicker, but then the middle
+of the proof would be always much clearer than towards the border.
+The mixture may be used several times without being renewed.
+It does not, however, give such a beautiful color to the impression
+as when it is newly prepared. By communicating to the vessel containing
+the solution a continual motion, the impression, when once immersed,
+will be fixed. During that time, and while attending to anything else,
+watch its color; and at the end of ten minutes or a quarter of an hour,
+take it out of the bath and dry it.
+
+Agent for Neutralizing Bromine, Chlorine, and Iodine Vapors.--
+Aqua ammonia, sprinkled about the chemical or coating room,
+will soon neutralize all the vapor in the atmosphere
+of either chlorine, bromine, or iodine. No operator should
+be without, at least, a six-ounce bottle filled with ammonia.
+A little of its vapor about the camera-box has a decided and
+happy effect. Burnt coffee, pulverized, has also the property
+of destroying the vapors of the above chemicals, as also almost
+any other agent employed about the Daguerreotype room.
+Its deodorizing properties are such that if brought in
+contact with air filled with the odor of decomposing meat,
+it will instantly destroy all disagreeable smell.
+It can easily be used in the Daguerreotype room by placing
+a little of the raw bean, finely pulverized, on an old plate,
+and roasting it over the spirit-lamp.
+
+Buff Dryer.--There are various methods for keeping buffs dry and free
+from dust. Some place a sheet of iron against the wall at an angle
+sufficient to put a lamp between it and the wall, and then let
+the buff rest against the top of the sheet. By this method the buff
+is for its full length close to the heated iron, and at the same time
+exposed to the heated atmosphere and any dust that may be free.
+I would recommend some arrangement by which the buff would be inclosed.
+I have found the following to answer the purpose well, which is
+a box of sheet iron twenty inches long, eight wide and five high,
+with one end left open and the other closed; the cover is made
+of the same material, with the edges bent over to go on and off.
+There are several wires running through the centre of the sides,
+which it is necessary to cover with cloth or paper to absorb
+all the moisture that may be made by applying the heat,
+and the buffs are put in and taken out at the open end.
+In order that the heat may be as nearly uniform as possible, an iron
+bar one inch wide, eighteen inches long and one half inch thick,
+is so bent that the centre is one quarter inch from the bottom
+of the box, and that at least two inches of each end come in contact
+with the bottom; this being riveted on the bottom, and a lamp
+with a small blaze applied to the centre of the bar of iron.
+This will constitute one of the best and cheapest buff dryers in use.
+It may be suspended from the wall by placing wires around it,
+or it may stand upon legs. Perhaps a more convenient plan is to
+place it under the workbench in a similar position to a drawer.
+One precaution is necessary: when first heating the dryer,
+apply but a very gentle heat. This will prevent an accumulation
+of moisture, which would otherwise pass off in steam, coming in
+contact with the buff, thus causing a dampness. Another caution:
+never have the temperature of the air in the heater more than ten
+degrees above that which surrounds it.
+
+When wheels are used, they should be encased in a sheet iron or wood case.
+All those made for our market are provided in this respect.
+
+Keeping Buffs in Order.--This is one of the most important objects to arrest
+the attention of the operator. Every buff is more or less liable to get
+out of order by dust falling upon or coming in contact with the polishing
+powder employed in cleaning the plate. The edge of every plate should be
+thoroughly wiped and freed from any material that may adhere while cleaning.
+I have adopted the following method, which proves highly successful:
+
+Rub the buff leather, holding the face down, with the sharp
+edge of a pair of shears or a piece of glass. This brings
+out any portion of the skin which may have become matted from
+any moisture, and also takes out any substance imbedded in it,
+and prevents it from scratching. Then, with a stiff brush,
+rub the buff well, and it will be found to work well.
+This same process employ on wheels and hand buffs every morning,
+or oftener, as occasion requires.
+
+Preparing Buffs.--Two of these are necessary. That part of the stick to be
+covered should be about eighteen or twenty inches long, and three wide,
+and made crowning on the face from one end to the other, about one half inch.
+Before covering, these are to be padded with two or three thicknesses of
+Canton flannel. The buff should not be too hard, but padded with flannel,
+so that by drawing it over the plate, it may touch across the surface.
+The only proper material for buffs is prepared buckskin; and if prepared
+in a proper manner, this needs nothing but to be tacked upon the stick.
+There are several varieties of wheels employed; the one most generally
+adopted is Lewis' patent, which consists of several varieties of wheels.
+Any operator can make a suitable wheel on the same plan of a turning lathe.
+
+To Clean Buckskins.--When the operator is compelled to purchase an
+unprepared buckskin, the following is a good process for cleaning it:
+There is always in the buckskin leather that is purchased,
+more or less of an oily matter, which is acquired in its preparation,
+sometimes even amounting, to a third of its weight.
+The following is the mode of ridding it of this noxious ingredient:
+Dissolve, in about six or seven quarts of filtered water,
+about five ounces of potash; when dissolved, wash with the solution
+an ordinary buckskin; when it has been well stirred in the liquid,
+the water becomes very soapy, owing to the combination of the potash
+with the oily matters contained in the skin. Throw away this
+solution and use some fresh water without potash and rather tepid;
+change it several times until it remains quite limpid.
+Then gently stretch the skin to dry in an airy shaded place.
+When thoroughly dried, rub it well between the hands.
+It thus becomes very pliant and velvet-like.
+
+Reflectors for Taking Views.--There have been excellent cameras
+introduced for taking views, but the time of exposure,
+which is increased in proportion to the focal length,
+is considered an objection; consequently many adhere to the old
+plan of using the speculum, or rather, substitute a mirror.
+I now have one which I have used for several years and find
+it equal to any article of the kind have ever tried.
+One is easily made by a tin man, at a trifling expense.
+Procure a piece of best plate looking-glass, two and a half by five
+inches for a quarter, or four by eight for a half-sized camera;
+put a piece of pasteboard of the same size on the back,
+to protect the silvering, and stick around the edge in
+the same manner as in putting up a picture. Take a sheet
+of tin for the large size, or a half sheet for the other;
+place the glass crosswise in the centre; bend the ends of the tin
+over the edge of the glass and turn them back so as to form a groove
+to hold the glass, and still allow it to slide out and in.
+These ends of the tin must be turned out flaring, that they
+may not reflect in the glass.
+
+Have a tin band about an inch wide made to fit close on the end
+of the camera tube; place it on, and taking the tin containing
+the glass, bring it to an angle of forty-five degrees with the tube,
+extending nearly the whole length of the glass in front of the lenses;
+lap the loose ends of the tin on each side of the tin rim,
+and having your camera turned on the side to throw the view lengthwise,
+arrange the exact angle by examining the image on the ground-glass. When
+you have it exactly right, hold it while it is soldered fast to the band.
+Take out your glass and stain the tin black, to prevent reflection.
+
+
+
+CHEMICALS.
+
+CHAPTER III.
+
+Bromine and its Compounds--Iodine and its Compounds--
+Chlorine and its compounds--Cyanide of Potassium--
+Hyposulphite of Soda--Hyposulphite of Gold--Nitric Acid--
+Nitro-Muriatic Acid--Hydrochloric Acid--Hydrofluoric Acid--
+Sulphuric Acid--Accelerating Substances--Liquid Sensitives--
+Dry Sensitives, etc., etc.
+
+BROMINE.
+
+An article so extensively used in the practice of the Daguerreotypic art
+as Bromine, is deserving of especial attention, and accordingly every person
+should endeavor to make himself familiar with its properties and applications.
+
+History.--This element was discovered in 1826 by M. Balard,
+in the mother-liquor, or residue of the evaporation of sea-water.
+It is named from its offensive odor (bromos, bad odor). In
+nature it is found in sea-water combined with alkaline bases,
+and in the waters of many saline springs and inland seas.
+The salt springs of Ohio abound in the compounds of bromine,
+and it is found in the waters of the Dead Sea. The only use which has
+been made of bromine in the arts is in the practice of photography.
+It is also used in medicine In a chemical point of view it
+is very interesting, from its similarity in properties,
+and the parallelism of its compounds to chlorine and iodine.
+
+Dr. D. Alter, of Freeport, Pa., is the only American manufacturer,
+and furnishes all of the "American Bromine." Yet we understand
+much purporting to be of German manufacture is prepared from
+that made in Freeport. This is done by individuals in this city,
+who get well paid for the deception.
+
+For the successful application of bromine as an accelerating agent,
+we are indebted to Mr. John Goddard of London, who at the time was
+associated with Mr. John Johnson, now a resident of this city.
+
+Preparation.--The mother-liquor containing bromides is treated with a current
+of chlorine gas, which decomposes these salts, setting the bromine free,
+which at once colors the liquid to a reddish brown color. Ether is added
+and shaken with the liquid, until all the bromine is taken up by the ether,
+which acquires a fine red color and separates from the saline liquid.
+
+[page 74]
+
+Solution of caustic potash is then added to the ethereal solution,
+forming bromide of potassium and bromate of potash. This solution
+is evaporated to dryness, and the salts being collected are heated
+in a glass retort with sulphuric acid and a little oxide of manganese.
+The bromine is distilled, and is condensed in a cooled receiver,
+into a red liquid.
+
+Properties.--Bromine somewhat resembles chlorine in its odor,
+but is more offensive. At common temperatures it is a very
+volatile liquid, of a deep red color, and with a specific gravity
+of 3, being one of the heaviest fluids known. Sulphuric acid
+floats on its surface, and is used to prevent its escape.
+At zero it freezes into a brittle solid. A few drops in a large
+flask will fill the whole vessel when slightly warmed, with blood
+red vapors, which have a density of nearly 6.00, air being one.
+It is a non-conductor of electricity, and suffers no change
+of properties from heat, or any other of the imponderable agents.
+It dissolves slightly in water, forming a bleaching solution.
+
+Chloride of Bromine.--This as an accelerating agent is by
+many considered superior
+
+[page 75]
+
+to the other Bromide combinations. It can be readily prepared by
+passing a current of chlorine through a vessel containing bromine.
+A mixture of two parts muriatic acid and one of black oxide
+of manganese, should be put into a flask having a bent tube
+to conduct the chlorine vapor into the bromine in another vessel.
+This last vessel should also be supplied with a bent tube for
+conducting the combined vapors with a third vessel or receiver.
+On the application of the heat from a spirit lamp to the bottom
+of the flask, a current of chlorine gas will be disengaged,
+and pass into the bromine, when it readily combines, and gives
+off a vapor, which, when condensed in the third vessel,
+forms a volatile yellowish-red liquid. It is best, even at
+ordinary temperature, to place the receiver in an ice bath.
+For manner of using, see farther on, under head of Accelerators.
+
+Bromides.--A bromide treated with oil of vitriol, disengages
+chlorohyadic acid; but vapors of bromine are constantly disengaged,
+at the same time imparting a brown color to the gas.
+If the bromide be treated with a mixture of sulphuric acid,
+and peroxide of manganese, bromide is only disengaged.
+A solution of a bromide gives, with of nitrate
+
+[page 76]
+
+silver, a light yellowish white precipitate of bromide of silver,
+which is insoluble in an excess of acid, and readily dissolves in ammonia.
+The precipitated bromide is colored by light like the chloride, but is
+immediately tinged brown, while the chloride assumes at first a violet hue.
+The bromides, in solution, are readily decomposed and chloride being set free,
+colors the liquid brown.
+
+In the whole range of heliographic chemicals there is probably
+not another collection less understood and being so productive
+of interesting investigation as the bromides.
+
+Bromide of Iodine.--M. de Valicours furnishes us with the best
+method for preparing this mixture:
+
+"Into a bottle of the capacity of about two ounces, pour thirty or forty drops
+of bromine, the precise quantity not being of importance. Then add, grain
+by grain, as much iodine as the bromine will dissolve till quite saturated.
+This point is ascertained when some grains of the iodine remain undissolved.
+They may remain in the bottle, as they will not interfere with the success
+of the preparation.
+
+"The bromide of iodine thus prepared, from its occupying so small a space,
+can very easily be carried, but in this state it is much too concentrated
+to be used. When it is to be employed, pour a small quantity,
+say fifteen drops, by means of a dropping-tube, into a bottle
+containing about half an ounce of filtered river water.
+It will easily be understood that the bromide of iodine can be
+used with a greater or less quantity of water without altering
+the proportion which exists between the bromine and iodine."
+
+This article forms a very good dry accelerator, and is by some persons
+thought superior to all others, as it works with great uniformity,
+and is less liable to scum the plate in coating at high temperatures,
+or when the thermometer indicates a heat above 60 deg.
+
+Bromide of Potassium--Is prepared by mixing bromine and a
+solution of pure potass together, and evaporating to dryness;
+it crystallizes in small cubes, and dissolves readily in water.
+This agent is extensively employed in the paper and glass processes.
+
+Bromide of Lime. This the principal accelerator used in the American
+practice, and is the best of all dry combinations at present employed.
+There are many reasons why the dry is advantageous; these are too
+familiar to repeat.
+
+"The bromide of lime may be produced by allowing bromine vapor to act
+upon hydrate of lime for some hours. The most convenient method of doing
+this is to place some of the hydrate at the bottom of the flask, and then
+put some bromine into a glass capsule supported a little above the lime.
+As heat is developed during the combination, it is better to place
+the lower part of the flask in water at the temperature of about 50 deg.
+Fah.; the lime gradually assumes a beautiful scarlet color, and acquires
+an appearance very similar to that of the red iodide of mercury.
+The chloro-iodide of lime may be formed in the same manner; it has a deep
+brown color. Both these compounds, when the vapor arising from them
+is not too intense, have an odor analogous to that of bleaching powder,
+and quite distinguishable from chlorine, bromine, or iodine alone."
+
+Farther on, I have given, in connection with accelerators, a process I adopt,
+which is far less tedious and equally reliable.
+
+Bromide of Silver--May be formed by pouring an alkaline bromide
+into a solution of nitrate of silver, in the shape of a white,
+slightly yellowish precipitate, which is insoluble in water and nitric acid,
+but readily dissolves in ammonia and the alkaline hyposulphites.
+Chlorine easily decomposes bromide of silver, and transforms
+it into chloride.
+
+M. Biot has expressed his opinion, that it is not possible to find
+any substance more sensitive to light than the bromide of silver.
+This is true to a certain extent, but in combination with
+deoxidizing agents, other preparations have a decided superiority
+over the pure bromide of silver.
+
+Bromide of Gold--Is readily prepared by adding a little bromide
+to the brown gold of the assayers, and allowing it to remain
+some time under water, or assisting its action by a gentle heat.
+It forms a salt of a bright crimson color, but in its general
+properties is precisely similar to the chloride used in gilding.
+
+Bromide of Magnesia--Is prepared in the same manner as bromide of lime.
+
+This mixture is particularly adapted for hot climates,
+and is used in this country by some few who regard its use
+as a valuable secret.
+
+Bromide of Starch.--This preparation is much used, but not alone.
+It is combined with lime by putting about one part in measure
+of starch to four of lime. It is prepared by adding bromine to
+finely pulverized starch, in the same manner as bromide of lime.
+(See Accelerators.)
+
+Experiments with Bromine.--Place in a very flaring wine glass
+a few drops (say ten) of bromine, then place a small piece
+of phosphorus about one-twentieth of an inch in diameter.
+Place the latter on the end of a stick from five to ten feet in length.
+So place it that the phosphorus can be dropped into the glass,
+and in an instant combustion giving a loud report will be the result.
+
+b. Expose a daguerreotype plate to the vapor of bromine, it assumes
+a leaden-grey color, which, blackens by light very readily.
+Exposing this to mercury will not produce any decided action upon the lights.
+Immerse it in the solution of the muriate of soda, and the parts unacted
+upon by light becomes a jet black, while the parts on which the light
+has acted will be dissolved off, leaving a clean coating of silver.
+This will be a most decided black picture on a white ground.
+
+c. Expose an impressioned plate, that has been sufficient time
+in the camera to become solarized, to the vapors of bromine,
+and the impression will be fully developed and exhibit no signs
+of solarization. The exposure over the bromine most be very brief.
+Chlorine or iodine will produce the same result.
+The latter is preferable.
+
+Again, should the impressioned plate be exposed too long over the vapor
+of bromine, the impression would be rendered wholly insensitive to
+the mercurial vapor. Hence this method is resorted to for restoring
+the sensibility of the plate when there is reason to believe
+that the impression would not be a desirable one; as, for example,
+if a likeness of a child be wanted, and it had moved before the plate
+had been sufficiently long exposed in the camera, the plate may be
+restored to its original sensitiveness by re-coating over bromine,
+as above, thus saving the time and labor of re-preparing the plate
+for the chemicals.
+
+d. If by accident (we would not advise a trial to any extent
+of this), you should inhale a quantity of the vapor of bromine,
+immediately inhale the vapor of aqua ammonia, as this
+neutralizes the dangerous effect of the bromine vapor.
+every operator should be provided with a bottle of ammonia,
+as a little sprinkled about the chemical room soon disinfects
+it of all iodine or bromine vapor, and also tends to facilitate
+the operation in the camera.
+
+
+IODINE.
+
+History of Iodine.--This is one of the simple chemical bodies
+which was discovered in 1812 by M. Courtois, of Paris, a manufacturer
+of saltpetre, who found it in the mother-water of that salt.
+Its properties were first studied into by M. Gay Lussac.
+It partakes much of the nature of chlorine and bromine.
+Its affinity for other substances is so powerful as to prevent
+it from existing in an isolated state. It occurs combined with
+potassium and sodium in many mineral waters, such as the brine
+spring of Ashby-de-la-Zouche, and other strongly saline springs.
+This combination exists sparingly in sea-water, abundantly in many
+species of fucus or sea-weed, and in the kelp made from them.
+It is an ingredient in the Salt Licks, saline, and brine springs
+of this country, especially of those in the valley of the Mississippi.
+It is sparingly found in fresh-water plants, as well also in coal,
+and in combination with numerous other bodies.
+
+Fermented liquors contain iodine; wine, cider, and perry
+are more iodureted than the average of fresh waters.
+Milk is richer in iodine than wine; independently of the soil,
+with which it varies, the proportion of iodine in milk is
+in the inverse ratio of the abundance of that secretion.
+Eggs (not the shell) contain much iodine. A fowl's egg weighing
+50 gr. contains more iodine than a quart of cow's milk.
+Iodine exists in arable land. It is abundant in sulphur,
+iron, and manganese ores, and sulphuret of mercury:
+but rare in gypsum, chalk, calcareous and silicious earths.
+Any attempt to extract iodine economically should be made
+with the plants of the ferro-iodureted fresh waters.
+Most of the bodies regarded by the therapeutists as pectoral
+and anti-scrofulous are rich in iodine.
+
+It is probably to the application of this body that we owe the discovery
+of the daguerreotype. There is no record of thep recise date when Daguerre
+commenced experimenting with iodine, but by the published correspondence
+between him and M. Neipce, his partner, it was previous to 1833.
+There is no doubt, however, that the first successful application was made
+in 1838, as the discovery was reported to the world early in January, 1839.
+
+Preparation.--Iodine is mostly prepared from kelp, or the half
+vitrified ashes of seaweed, prepared by the inhabitants of the
+western islands, and the northern shores of Scotland and Ireland.
+It is treated with water, which washes out all the soluble salts,
+and the filtered solution is evaporated until nearly all the
+carbonate of soda and other saline matters have crystallized out.
+The remaining liquor, which contains the iodine, is mixed with successive
+portions of sulphuric acid in a leaden retort, and after standing
+some days to allow the sulphureted hydrogen, etc., to escape,
+peroxide of manganese is added, and the whole gently heated.
+Iodine distills over in a purple vapor, and is condensed in a receiver,
+or in a series of two-necked globes.
+
+Properties.--Iodine is solid at the ordinary temperature,
+presenting the appearance of dark-grey or purple spangles, possessing a
+high degree of metallic lustre. It somewhat resembles plumbago,
+with which it is sometimes diluted, particularly when it is fine.
+Operators should endeavor to secure the larger crystals.
+It melts at 224.6 deg., forming a brown or nearly black liquid.
+It boils at about 356 deg., and emits a very deep violet colored vapor.
+It gives off a very appreciable vapor, sufficient for all purposes
+of forming the iodide of silver on the daguerreotype plate, at a
+temperature of 45 deg. or even lower. Iodine crystallizes readily.
+Every operator has found upon the side of the jar in his coating-box,
+perfectly regular crystals, deposited there by sublimation.
+
+Water dissolves but a small proportion of iodine, requiring 7000
+parts of water to dissolve one of iodine,
+
+[page 85]
+
+or one grain to the gallon of water. Alcohol and ether dissolve it freely,
+as does a solution of nitrate or hydrochlorate of ammonia and of iodides.
+
+The density of solid iodine is 4.95; that of its vapor 8.716. It greatly
+resembles chlorine and bromine in its combinations, but its affinities
+are weaker. It does not destroy the majority of organic substances,
+and vegetable colors generally resist its action. It combines
+with several organic substances, imparting to them peculiar colors.
+It colors the skin brown, but the stain soon disappears.
+
+Chloride of Iodine--Is formed by passing chlorine into
+a bottle containing some iodine. This can be readily done
+by pouring one ounce and a half of muriatic acid upon a quarter
+of an ounce of powdered black oxide of manganese, and heat it
+gradually in a flask, to which is adapted a bent glass tube.
+This tube must connect with the bottle containing the iodine,
+and the yellowish-green gas disengaged will readily combine with
+the iodine, forming a deep red liquid, and the operation is complete.
+The use of chloride of iodine will be referred to in connection
+with the Accelerators.
+
+[page 86]
+
+Iodides.--The iodide treated with the oil of vitriol,
+instantly produces a considerable deposit of iodine; and if
+the mixture be heated, intense violent vapors are disengaged.
+The reaction is due to the decomposition of oil of vitriol
+by iodohydric acid, water and sulphurous acid being formed,
+and iodine set free. The iodides in solution are decomposed
+by chlorine, iodine being precipitated, the smallest quantity
+of which in solution is instantly detected by its imparting
+to starch an intensely blue color.
+
+Iodide of Potassium.*--This compound is easily made in the following manner:
+Subject to a moderate heat a mixture of 100 parts of iodine,
+75 of carbonate of potash, 30 of iron filings, and 120 parts of water.
+This mass must be thoroughly dried and then heated to redness;
+the resulting reddish powder is to be washed with water,
+and the solution obtained filtered, and evaporated to dryness.
+It is found that 100 parts of iodine yield 135 parts of very white,
+but slightly alkaline, iodide of potassium.
+
+* I shall present the preparation of only a few iodides,
+and such as are more intimately connected with the Daguerreotype.
+
+Experiment.--On projecting dry pulverized iodide of potassium
+into fused anhydrous phosphoric acid, a violent disengagement
+of iodine takes place, attended by a transient ignition;
+fused hydrate of phosphoric acid liberates iodine abundantly
+from iodide of potassium; this reaction is accompanied
+by the phenomenon of flame and formation of a considerable
+quantity of hydriodic acid.
+
+Iodide of Mercury.--For the preparation of iodide of mercury,
+Dublanc recommends to cover 100 grms. of mercury with 1 kilogrm.
+of alcohol, to add 124 grms. of iodine gradually in portions of ten
+grms., and agitating between each fresh addition, until the alcohol
+becomes colorless again. After the addition of the last 4 grms.
+the alcohol remains colored, the whole of the mercury having become
+converted into iodide. The resulting preparation is washed with alcohol;
+it is crystalline and of a hyacinth color.
+
+Iodide of Silver.--This compound is formed upon every plate
+upon which a Daguerreotype is produced. The vapor of iodine
+coming in contact with the silver surface, forms an iodide
+which is peculiarly sensitive to light.
+
+The various colors produced are owing to the thickness of the coating,
+and the maximum sensibility of the coating, as generally adopted,
+is when it assumes a deep yellow, or slightly tinged with rose color.
+
+This compound is largely employed in most photographic processes
+on paper, and may be easily prepared by the following formula:
+By adding iodide of potassium to a solution of nitrate of silver,
+a yellowish-white precipitate of iodide of silver is obtained,
+which is insoluble in water, slightly soluble in nitric acid,
+and soluble in a small degree in ammonia, which properties seem
+easily to distinguish it from the chloride and bromide of silver.
+Chlorine decomposes it and sets the iodine free, and chlorohydric
+acid converts it into a chloride. It fuses below a red heat.
+Although the effect of light on the iodide is less rapid than on
+the chloride, the former sooner turning black, assuming a brown tinge;
+but when in connection with gallic acid and the ferrocyanate of potash,
+it forms two of the most sensitive processes on paper.
+
+Iodide of silver dissolves easily in a solution of iodide of potassium,
+and the liquid deposits in evaporation crystals of a double iodide.
+
+Iodide of Gold.--If a solution of potassium be added
+to a solution of chloride of gold, a precipitate of iodide
+of gold takes place, soluble in an excess of the precipitate.
+A little free potash should be added to combine with any iodide
+that may chance to be set free by the chloride of gold.
+
+Iodide of Lime is prepared by adding iodine to hydrate of lime
+(which will be referred to farther on) until the mixture assumes
+a light yellow shade, when wanted for combinations with accelerators,
+or to a dark brown when employed for the first coating.
+This latter mixture has been sold in our market under the name
+of "Iodide of Brome."
+
+Iodide of Bromine.--(See page 76.)
+
+Experiments with Iodine.--Place a plate which bas been exposed in the camera
+over the vapor of iodine for a very brief period, and it will present
+the appearance of the impression having been solarized.
+
+b. Upon a Daguerreotype plate, from which an impression has
+been effaced by rubbing or otherwise, the picture may be made
+to reappear by merely coating it over with iodine.
+
+c. Place in a vessel a little water, into which put the smallest
+possible quantity of free iodine and add a little starch, and the liquid
+will instantly assume a blue color. Advantage is taken of this fact
+in the laboratory to detect the presence of iodine in liquids.
+The starch should be dissolved in boiling water and allowed to cool.
+There are numerous other interesting experiments that can be performed
+by the aid of iodine, but it is unnecessary here to consume more space.
+
+
+CHLORINE.
+
+History.--The Swedish chemist, Scheele, in 1774, while examining the action
+of hydrochloric acid on peroxide of manganese, first noticed this element.
+He called it dephlogisticated muriatic acid. It was afterwards,
+by the French nomenclaturists, termed oxygenated muriatic acid,
+conceiving it to be a compound of oxygen and muriatic acid.
+This view of its notice was corrected by Sir H. Davy (in 1809), who gave
+it the present name. In 1840-41, this gas vas employed for accelerating
+the operation of light upon the iodized Daguerreotype plate.
+John Goddard, Wolcott & Johnson, Claudet, Draper, Morse and others,
+were among the first made acquainted with its use. Count Rumford,
+Ritter, Scheele, Seebert and others, experimented with chlorine in regard
+to its effect when exposed to the action of light in combination with silver.
+In 1845, M. Edward Becquerel announced that he had "been successful
+in obtaining, by the agency of solar radiations, distinct impressions,
+of the colors of nature."
+
+On the 4th of March, 1851, Neipce, St. Victor, a former partner of DAGUERRE,
+announced that he had produced "all the colors by using a bath of bichloride
+of copper, and that a similar phenomenon occurs with all salts of copper,
+mixed with chlorine."
+
+Preparation.--This is easily accomplished by putting about
+two parts of hydrochloric (muriatic) acid on one of powdered
+black oxide of manganese, and heating it gradually in a flask
+or retort, to which may be adapted a bent glass tube.
+A yellowish-green gas is disengaged, which being conducted
+through the glass tube to the bottom of a bottle, can readily
+be collected, being much heavier than the air, displaces it
+completely and the bottle is filled (which can be seen by
+the green color); a greased stopper is tightly fitted to it,
+and another bottle may be substituted.
+
+In all experiments with chlorine, care should be taken not to inhale the gas!
+
+Properties.--Chlorine is a greenish-yellow gas (whence its name, from chloros,
+green), with a powerful and suffocating odor, and is wholly irrespirable.
+Even when much diluted with air, it produces the most annoying irritation
+of the throat, with stricture of the chest and a severe cough,
+which continues for hours, with the discharge of much thick mucus.
+The attempt to breathe the undiluted gas would be fatal; yet, in a very
+small quantity, and dissolved in water, it is used with benefit by patients
+suffering under pulmonary consumption.
+
+Under a pressure of about four atmospheres, it becomes a limpid
+fluid of a fine yellow color, which does not freeze at zero,
+and is not a conductor of electricity. It immediately returns
+to the gaseous state with effervescence on removing the pressure.
+
+Water recently boiled will absorb, if cold, about twice its bulk
+of chlorine gas, acquiring its color and characteristic properties.
+The moist gas, exposed to a cold of 32 deg., yields beautiful yellow crystals,
+which are a definite compound of one equivalent of chlorine and ten of water.
+If these crystals are hermetically sealed up in a glass tube, they will,
+on melting, exert such a pressure as to liquefy a portion of the gas,
+which is distinctly seen as a yellow fluid, not miscible with the water
+which is present. chlorine is one of the heaviest of the gases,
+its density being 2.47, and 100 cubic inches weighing 76.5 grains.
+
+Chlorine Water.--This combination, which is used in conducting
+M. Neipce's process, can be readily prepared by conducting
+the gas into a bottle containing distilled water.
+One part water dissolves two parts of chlorine.
+
+Chlorides.--The metallic chlorides are nearly all soluble in water;
+that of silver and protochloride of mercury being the only exceptions.
+A metallic chloride, treated with oil of vitriol, disengages
+chlorohydric acid. Heated with a mixture of peroxide of manganese
+and sulphuric acid, chlorine is given off, which is easily recognized
+by its odor and other physical properties.
+
+The chlorides dissolve in water; give with nitrate of silver,
+a white precipitate, even in highly diluted solutions, becoming violet
+colored and finally black when exposed to the light. The rapidity
+of the change of color is proportioned to the intensity of the light.
+It is insoluble in nitric acid, but readily soluble in ammonia;
+it fuses without decomposition, forming, when cold, a tough, horny mass,
+and is reduced by hydrogen and by fusion with carbonate of soda,
+or with resin.
+
+Chloride of Bromine. (See page 74.)
+
+Chloride of Iodine. (See page 85.)
+
+Chloride of potassium.--or (Muriate of Potassa).--Dissolve half an ounce
+of carbonate of potassa in water, and neutralize with muriatic acid.
+Upon concentrating the solutions, cubic crystals will be obtained, having a
+taste similar to common salt. They consist of potassium and chloride,
+and when dissolved in water they may be regarded as muriate of potassa.
+
+Chloride of Lime.--Mix half an ounce of slacked lime (hydrate of lime)
+with six ounces of water, and conduct into this milk of lime,
+with frequent agitation, as much chlorine gas as will evolve from two
+ounces of muriatic acid and half an ounce of black oxide of manganese.
+The liquid clarifies by standing; may be regarded as a solution
+of chloride of lime, and must be protected from the air and light.
+It may also be made without putting in the water with the hydrate
+of lime, by merely passing the chlorine into the hydrate of lime.
+This last is by some used in preparations for accelerating the operation
+of taking Daguerreotypes, but when used for this purpose it is
+in small quantities.
+
+Chloride of Calcium.--To one part of water add two parts of muriatic acid,
+and add pieces of common chalk until effervescence ceases; then filter
+through cotton cloth and evaporate it by placing it in all earthen
+or porcelain dish, over a slow fire, to the consistency of a syrup.
+When cooling, large prismatic crystals of chloride of calcium are formed.
+These must be quickly dried by pressing between folds of blotting paper
+and kept carefully excluded from the air, as it readily attracts hydrogen.
+For most daguerreotype purposes, the syrup may be at once evaporated
+to dryness. This is frequently placed in the iodine coating box
+for the purpose of keeping the atmosphere dry. It is so easily made
+that every operator can provide himself with it in a short time,
+and at little expense.
+
+Chloride of Gold.--Is prepared by dissolving gold in aqua regia,
+a composition of one part of nitric to two parts of muriatic acid.
+Gold foil is the best for our purposes; coin, however, answers,
+in most cases, for the daguerreotype operator, as the alloy,
+being so slight is not noticed in the gilding process.
+When the latter is used, it will facilitate the operation to beat
+it out, forming a thin sheet, and then cutting in small strips.
+Where purity is required, foil is better. The gold is placed
+in three or four times its own weight of the above acids.
+For this purpose, an evaporating dish is best (a common saucer
+will do); a moderate heat may be applied to favor the action.
+The mixture should be stirred often with a glass rod;
+care should be observed not to apply too much heat,
+for at a temperature of about 300 deg. the chlorine would be
+expelled and leave a metallic precipitate, which would require
+re-dissolving. Acid may at any time be added if necessary
+to dissolve the gold, but it is advisable to add as little
+excess as possible, as it would require more time to evaporate.
+After all the gold has dissolved, and the liquid assumes a deep
+red color, the solution should be allowed to cool, being stirred
+nearly all the time. This salt is of a reddish-brown color.
+It is rarely we find in our market good chloride of gold,
+as common, salt is used for the bulk; and when the bottles
+are labelled "15 grains," "20 grains," nine-tenths do not
+in reality contain exceeding five grains of chloride of gold.
+The salt is mixed with the above solution when it is cooling,
+and gives bright yellow crystals, which some of our uninformed
+operators conceive to be the best quality.
+
+Chloride of Silver.--(Oxide of Silver.)--Take any quantity of silver
+coin or other silver, roll or hammer it thin; cut in small pieces.
+This in order to save time. Put the silver in a glass or earthen vessel
+(Florence flask is best); pour in nitric acid and water, about three
+parts of the former to one of the latter. The operation of cutting
+up the silver may be facilitated by applying a gentle heat.
+This blue solution consists of oxide of silver and oxide of copper,
+both combined with nitric acid. Should the operator wish a pure
+solution of silver, which, however, is not always used, he may obtain
+it in the following manner:
+
+To separate the two metals contained in the above solution from each other,
+put some bright copper coins into the solution and set it aside in a warm
+place for three or four days, occasionally giving it a circular motion.
+The separated laminae are pure silver, which is to be digested with ammonia
+until it ceases to be colored blue. The silver, after being washed and dried,
+is again dissolved in nitric acid, and the liquid, diluted with water,
+is kept as solution, of silver.
+
+Either of the above solutions (the one of oxide of silver and copper,
+and the pure silver solution) may be prepared for use by putting them
+in a bottle, with a quantity of water, and adding common fine salt,
+you obtain a white curdy precipitate of chloride of silver.
+No matter how much salt is used, provided enough be added to throw
+down all the chloride of silver. This solution should be well agitated
+and then allowed to stand for a few minutes; thus the white precipitate
+is in the bottom of the bottle. When the water has become clear,
+pour it off with care, leaving the sediment behind, then add a fresh
+quantity of clean water, shake, let settle, and pour off as before.
+Repeat the same for several times, and the excess of salt will disappear,
+leaving the white precipitate, which may be drained of the water
+and dried in the dark, and kept free from light and air.
+
+
+CYANIDE OF POTASSIUM.
+
+Cyanide of Potassium.--This important article is worthy
+the undivided attention of every Daguerreotypist.
+I here give Mr. Smee's process for its preparation.
+This is from that author's work entitled, "Electro Metallurgy,"
+American edition:
+
+"The cyanide of potassium, so often alluded to while treating
+of the metallo-cyanides, may be formed in several ways.
+It may be obtained by heating to a dull redness the yellow ferrocyanate
+of potash, in a covered vessel, filtering and rapidly evaporating it.
+The objection to this method, however, is that without great care
+the whole of the ferrocyanate is not decomposed, a circumstance
+which much reduces its value for electro-metallurgy. By boiling,
+however, the ignited residue with spirits of wine this difficulty
+is said to be overcome, as the ferrocyanate is absolutely insoluble
+in that menstruum, while the cyanuret, at that heat, freely dissolves,
+and is as easily re-deposited on cooling.
+
+"There is, however, a much better process by which this salt may
+be formed, viz. by simply transmitting hydrocyanic acid through potassium.
+Although the modes of making this acid are very numerous, there is but
+one which is likely to be employed on a very large scale, and that is
+its formation from the yellow ferrocyanate by means of sulphuric acid.
+This process is performed as follows: any given weight of the yellow
+salt is taken and dissolved in about five times its weight of water;
+this is placed in a retort, or some such analogous vessel, to which is
+then added a quantity of strong sulphuric acid, twice the weight of
+the salt, and diluted with three or four times its quantity of water.
+A pipe is carried from the neck of the retort to the receiving bottle,
+which should be kept as cool as possible.
+
+"For small operations, those invaluable vessels, Florence flasks,
+answer well: a bent tube being connected at one end to its month,
+the other passing into the second vessel; heat should be cautiously
+applied by means of an Argand lamp, a little vessel of sand being
+placed under the flask, which helps the acid to decompose the salt.
+Prussic acid is then generated and passes through the tube to
+the recipient vessel, which is to be charged with liquor potassae.
+
+"When the potash is saturated, the operation is completed.
+The Germans recommend a strong, alcoholic solution of potassa
+to be used in the second vessel, for in this case, the hydrocyanic
+or prussic acid combines with the potassa, forming a hydrocyanate
+of potassa, or, the water being abstracted, the cyanuret
+of potassium, which spontaneously precipitates, on the saturation
+of the fluid, the cyanuret, being insoluble in strong alcohol.
+The ferrocyanate of potash may be considered as containing
+three equivalents of hydrocyanic acid, two of potash and one
+of iron; but, unfortunately, we can only obtain half the acid
+from the salt, owing to the formation of a compound during
+its decomposition which resists the action of the acid.
+The decomposition of this salt taking 2 equivalents or 426 grains
+(to avoid fractions) would afford 3 equivalents or 81 grains
+of hydrocyanic, or prussic acid, capable of forming 198 grains
+of cyanuret of potassium, while in the retort there would
+remain 384 grains or 3 equivalents of bisulphate of potash,
+and 1 equivalent or 174 grains of a peculiar compound,
+said to contain 3 equivalents of cyanogen, 1 of potassium,
+and one of iron (Pereira). It is manifest that, but for this
+later compound, we might double the quantity of hydrocyanic
+acid from the yellow salt."
+
+The decomposition just described is the one usually received;
+but too much reliance must not be placed on its accuracy,
+for the analysis of the several compounds is too difficult
+for the results to be fully admitted. The residue left in
+the retort speedily turns to one of the blues, identical with,
+or allied to, Prussian blue. This is at best a disagreeable
+process to conduct, for the hydrocyanic acid formed
+adheres so strongly to the glass, that, instead of being
+freely given off, bubbles are evolved suddenly with such
+explosive violence as occasionally to crack the vessel.
+This may be remedied as far as possible by the insertion
+of plenty of waste pieces of platinum--if platinized,
+so much the better, as that facilitates the escape of the gas.
+The heat should be applied to every part of the vessel, and the flame
+should not be allowed to play upon one single part alone.
+Large commercial operations are performed in green glass
+or stone-ware retorts.
+
+"Now for one word of advice to the tyro: Remember that you are working
+with prussic acid; therefore, never conduct the process in a room,
+the fumes being quite as poisonous as the solution of the acid itself;
+moreover, have always a bottle of ammonia or chlorine by your side,
+that should you have chanced to inhale more than is pleasant,
+it will be instantly at hand to counteract any bad effects.
+It is stated by Pereira, that a little sulphuric acid or hydroferrocyanic
+acid passes to the outer vessel, but probably the amount would be of no
+consequence for electro-metallurgy, otherwise, it might be as well to use
+a Woulfe's apparatus, and discard the salt formed in the first vessel.
+To the large manufacturer it may be worth considering whether some other
+metallo-cyanuret, formed in a similar manner to the ferrocyanuret,
+might not be more advantageously employed, because the residue
+of the process last described contains a large quantity of cyanogen
+which the acid is unable to set free.
+
+"There are other modes of procuring prussic acid, besides the one which has
+been so tediously described; but these are found to be more expensive.
+The only one which I shall now notice is the process by which it is
+obtained from bicyanide of mercury. The bicyanide of mercury itself
+is formed when peroxide of mercury is digested with Prussian blue,
+the peroxide of mercury abstracting the whole of the cyanogen from
+the blue, and leaving the oxides of iron at the bottom of the vessel.
+The solution may be evaporated to dryness, and one part of the salt
+dissolved in six of water; one part of muriatic acid, sp. gr. 1.15, is
+then added, and the solution distilled, when the whole of the hydrocyanic
+acid passes over, and by being conducted into a solution of potassa,
+as in the former process, forms cyanuret of potassium. This process,
+though easier than the first described, is rather given as a resource under
+peculiar circumstances than as one to be adopted by the large manufacturer.
+The expense is the only objection, but in a small quantity this cannot
+be a consideration.
+
+"In giving this very rough outline of the general mode of forming salts,
+the minutiae necessary for chemical work have altogether been avoided,
+and those parts alone are entered upon which are more immediately
+necessary for the electro metallurgist to know and practice for himself.
+This will account for the long description of the cyanuret of potassium,
+while the preparation of the equally important and even more used acids,
+the sulphuric, muriatic, etc., commonly found in commerce,
+are altogether neglected.
+
+"In using solutions of cyanide of potassium, the workman should not immerse
+his arms into them, otherwise it occasionally happens that the solution
+produces very troublesome eruptions over the skin."
+
+
+HYPOSULPHITE OF SODA.
+
+Hyposulphite of Soda.--This salt forms one of the important chemicals
+for the Daguerreotype operator. Its application to this art is
+of an interesting nature. It is used to dissolve the sensitive salt
+of silver which remains unchanged during the exposure in the camera.
+It has the property of readily dissolving the chloride, bromide and
+iodide of silver. It should be pure and free from sulphuret of sodium;
+should this last be present, it will cause brown spots of sulphurated
+silver upon the Daguerreotype impression. This annoyance is a
+great source of complaint from many operators, and ever will be,
+so long as it is prepared by men who have no reputation to lose,
+and whose eyes are blinded by the "Almighty Dollar."
+
+A good article may be prepared as follows:
+
+"Mix one pound of finely pulverized carbonate of soda with ten ounces
+of flowers of sulphur, and heat the mixture slowly in a porcelain dish till
+the sulphur melts. Stir the fused mass, so as to expose all its parts
+freely to the atmosphere, whereby it passes from the state of a sulphuret,
+by the absorption of atmospheric oxygen, into that of a sulphite,
+with the phenomenon of very slight incandescence. Dissolve in water,
+filter the solution, and boil it immediately along with flowers of sulphur.
+The filtered concentrated saline liquid will afford, on cooling, a large
+quantity of pure and beautiful crystals of hyposulphite of soda."
+
+Hyposulphite of Gold.--This compound salt is by a few considered preferable
+to the chloride of gold, but our experience has induced us to use the latter,
+believing we are enabled to produce a more brilliant and warm-toned
+impression with it. When the hyposulphite of gold is used in gilding,
+it requires less heat and a longer application, as there is some danger
+of producing a glossy scum over some parts of the surface of the plate.
+I prepare this salt as follows:
+
+Dissolve one part chloride of gold and four parts
+hyposulphite of soda in equal quantities of distilled water:
+pour the gold into the hyposulphite solution, in the same
+manner as in mixing the gilding solution; let it stand
+until it becomes limpid; filter and evaporate to dryness.
+Re-dissolve and add a few grains of burnt alum.
+
+After standing a few hours, filter and evaporate again. If not
+sufficiently pure, repeat the crystallization until it is so.
+For gilding, dissolve in water and use in the same manner
+as the common gilding solution.
+
+N.B.--The four following mixtures were employed in Neipce's
+process in his earliest experiments:
+
+Aqueous Solution of Bichloride of Mercury.--Eight grains of bichloride
+of mercury in 10,000 grains of distilled water.
+
+Solution of Cyanide of Mercury.--A flask of distilled water is
+saturated with cyanide of mercury, and a certain quantity is decanted,
+which is diluted with an equal quantity of distilled water.
+
+Acidulated White Oil of Petroleum.--This oil is acidulated by mixing
+with it one tenth of pure nitric acid, leaving it for at least 48 hours,
+occasionally agitating the flask. The oil, which is acidulated,
+and which then powerfully reddens litmus paper, is decanted.
+It is also a little colored, but remains very limpid.
+
+Solution of Chloride of Gold and Platinum.--In order not to
+multiply the solutions, take the ordinary chloride of gold,
+used for fixing the impressions, and which is composed of 1
+gramme of chloride of gold and 50 grains of hyposulphate of soda,
+to a quart of distilled water.
+
+With respect to chloride of platinum, 4 grains must be dissolved in 3 quarts
+of distilled water; these two solutions are mixed in equal quantities.
+
+Acids.--I shall not go into the preparations of the various acids
+employed in the Daguerreotype. This would be useless to the operator,
+as there are few, if any, that it would be advisable to prepare.
+It is only necessary for the experimenter to be made acquainted with
+their properties, and this in order to prevent any haphazard experiments,
+which are too common among operators. Any person who may be desirous
+to try an experiment, should first study the agents he wishes to employ.
+By so doing much time and money will be saved; while the searcher after
+new discoveries would rarely become vexed on account of his own ignorance,
+or be obliged to avail himself of the experience of others in any
+department of science.
+
+Nitric Acid--Exists in combination with the bases, potash, soda,
+lime, magnesia, in both the mineral and vegetable kingdoms,
+and is never found insoluble. It has the same constituents
+as common air, but in different proportions. The strongest nitric
+acid contains in every pound, two and a quarter ounces of water.
+Pure nitric acid is colorless, with a specific gravity of 1.5,
+and boiling at 248 deg.. It is a most powerful oxidizing agent,
+and is decomposed with more or less rapidity, by almost all the metals,
+to which it yields a portion of its oxygen.
+
+The nitric acid of commerce, is generally the article used by
+the Daguerreotypist. This usually contains some chlorine and sulphuric acid.
+It is obtained by the distillation of saltpetre with sulphuric acid.
+It is employed in the Daguerreotype process for dissolving silver,
+preparing chloride or oxide, nitrate of silver, [the former used
+in galvanizing,] and in combination with muriatic acid for preparing
+chloride of gold, used in gilding. It is also used by some for
+preparing the plate.
+
+Acidulated Solution.--This solution is used for cleaning
+the surface of the Daguerreotype plate. It has the property
+of softening the silver, and bringing it to a state in which it
+is very susceptible of being either oxidized or iodized,
+hence it contributes to increase the sensibility of the plate.
+The proportions are to one drop of acid add from 15 to 20
+drops of water, or make the solution about like sharp vinegar
+to the taste.
+
+Nitro-Muriatic Acid.--Aqua Regia is a compound menstruum invented
+by the alchemists for dissolving gold. It is composed of colorless
+nitric acid (aqua-fortis) and ordinary muriatic acid; the mixture
+is yellow, and acquires the power of dissolving gold and platinum.
+These materials are not properly oxidized; it nearly causes their
+combination with chlorine, which is in the Muriatic acid.
+
+Hydrochloric Acid (Muriatic Acid).--This acid forms a valuable
+addition to the chemicals employed by the practical Daguerreotypist.
+This acid is formed by acting upon common salt (which is chloride
+of sodium) by concentrated sulphuric acid. The water of the acid
+is decomposed, and its hydrogen combines with the chloride of the salt
+to form muriatic acid, and this unites with the sulphuric acid
+to form sulphate of soda; 60 parts of common salt and 49 parts
+of concentrated sulphuric acid, afford, by this mutual action,
+37 parts of muriatic acid and 72 parts of sulphate of soda.
+The muriatic acid of commerce has usually a yellowish tinge,
+but when chemically pure it is colorless. The former is commonly
+contaminated with sulphurous acid, sulphuric acid, chlorine, iron,
+and sometimes with arsenic.
+
+Muriatic acid, from the fact of the presence of the chlorine, is used
+in the Daguerreotype process for dissolving gold, and in combination
+with various accelerators. Its presence can be detected by ammonia.
+A strip of paper dipped in this and waved to and fro will emit
+a thick white smoke if the acid vapor be in the atmosphere.
+The ammonia neutralizes the acid fumes. By reversing the experiment we
+can determine whether vapor of ammonia be in the air, and also deprive
+these suffocating and dangerous gases of their injurious properties,
+and remove them from the air. Every Daguerreotype operator should
+be furnished with, at least, a six ounce bottle of aqua ammonia.
+Its operation is very nearly the same on bromine and iodine vapor.
+
+Hydrofluoric Acid (Fluorohydric Acid).--This acid is used to form some of
+the most volatile and sensitive compounds employed in the Daguerreotype.
+It is one of the most dangerous bodies to experiment with:
+it is volatile and corrosive, giving off dense white fumes
+in the air. It combines with water with great heat. At 32 deg.
+it condenses into a colorless fluid, with a density 1.069. It is
+obtained from decomposition of fluorspar by strong sulphuric acid.
+It readily dissolves the silica in glass, and consequently cannot be
+kept in a vessel of that material. It is prepared and kept in lead.
+It is employed in accelerators on account of its fluorine.
+
+One small drop on the tongue of a dog causes death.
+The operator who wishes to use it should pour some
+of the liquid for which he intends it into a graduate,
+or other vessel, and then add the desired quantity of acid.
+If by accident any of the spray should fall upon the skin,
+it should at once be copiously drenched with water.
+
+Sulphuric Acid.--There are two sorts of this acid:
+one is an oily, fuming liquid; this is made in Nordhausen,
+in Saxony, and is commonly called "Nordhausen sulphuric acid,"
+or oil of vitriol. The other which is the kind used in
+connection with the Daguerreotype, is common sulphuric acid.
+It is somewhat thinner, and when undiluted is not fuming.
+This acid may be obtained in a solid and dry state,
+called anhydrous sulphuric acid.
+
+The common sulphuric acid is made by burning sulphur, which forms
+sulphurous acid. To convert this into sulphuric acid and gain
+more oxygen, nitric acid, which is rich in that body, is added.
+It forms a limpid, colorless fluid, of a specific gravity
+of 1.8. It boils at 620 deg.; it freezes at 15 deg.
+It is acrid and caustic, and intensely acid in all its characters,
+even when largely diluted.
+
+Its attraction for basis is such that it separates or expels all
+other acids, more or less perfectly, from their combinations.
+Its affinity for water is such that it rapidly absorbs it from
+the atmosphere, and when mixed with water much heat is evolved.
+It acts energetically upon animal and vegetable substances,
+and is a poisonous, dangerous substance to get on the skin.
+It is a powerful oxidizing agent; hence its use in the galvanic battery,
+for which purpose it is mostly used by the Daguerreotypist.
+The fumes of this being so much more offensive than nitric acid,
+the latter is sometimes used. It is also employed in some of
+the more sensitive accelerators.
+
+
+ACCELERATING SUBSTANCES.
+
+Remarks on the Accelerating substances Used in the Daguerreotype.--
+I have now arrived at a point in this work, where the eye of
+the Daguerreotype public will intently search for something new.
+This search will prove in vain, at least so far as regards
+those who have enjoyed and embraced the opportunities for studying
+the principles of our art. Every experienced operator has in a degree
+become familiar with the mechanical uses of all the agents employed,
+while I fear but few understand the properties, and laws governing
+those properties, which are so indispensable to produce an image
+impressed upon the silver surface.
+
+There are three substances which form the bases for
+producing a Daguerreotype; silver, iodine and bromine.
+Each forms a separate body which is indispensable to the
+operators success as the art is now practiced in America.
+With these three, compounds of great variety are formed.
+
+The silver surface is first thoroughly cleaned and freed from all organic
+matter, then exposed to vapor of iodine, producing an iodide of silver.
+The plate upon which is this salt, is again exposed to the vapor of bromine,
+forming a bromo-iodide of silver, a salt also.
+
+As most of the various accelerators are compounds of bromine, with either
+chlorine or fluorine combination, they partake somewhat of the nature of these
+latter, giving results which can be detected by the experienced operator.
+Thus muriatic acid is added for its chlorine, which can generally be
+detected by the impression produced, being of a light, soft, mellow tone,
+and in most cases presenting a brilliant black to that colored drapery.
+Those who wish to experiment with agents for accelerating substances,
+should first study to well understand their peculiar nature and properties;
+as well, also, to endeavor to find out what will be the probable changes
+they undergo in combination as an accelerator. This should be done before
+making the experiments. From the foregoing it will be seen that numerous
+compounds are formed from the same basis, and, consequently, it would
+be a waste of time and a useless appropriation to devote more of our space
+than is necessary to give the principal and most reliable combination.
+
+In America, the words "Quick" and "Quick Stuff," are more generally used for
+and instead of the more proper names, "Sensitives," or "Accelerators," etc.
+As it has by use become common, I frequently use it in this work.
+
+Liquid Accelerator, No. 1.--This mixture was used by me in 1849,
+and is given as it appeared in my "System of Photography,"
+published at the above date:
+
+Take pure rain or distilled water, one quart, filter through
+paper into a ground stopper bottle, and add, for warm weather,
+one and a half ounce chloride of iodine; or for cold,
+one ounce; then add one ounce bromine, and shake well.
+Now with care not to allow the vapor to escape, add drop by drop,
+thirty drops of aqua ammonia, shaking well at each drop. Care must
+be taken not to add more at a time, as it evokes too much heat.
+This mixed, in equal proportions with John Roach's quick,
+forms an excellent chemical combination. For this purpose,
+take one and a half ounce of each, to which add ten ounces water,
+for warm weather, or from six to seven for cold. Pour the whole
+into a large box, and it will work from two to four months.
+I am now using (l849) one charged as above which has been
+in constant use for three months, and works uniformly well.
+The above is right for half or full size boxes, but half of it
+would be sufficient for a quarter size box.
+
+Coat to the first shade of rose over iodine, change to a deep
+rosy red over quick, and black about one tenth the first.
+
+I would not now recommend the addition of "John Roach s quick,"
+as I believe equally good results can be produced without it.
+This liquid is now used by many, and is very good for taking views.
+
+Lime Water Quick.--This mixture is more used at present than
+all the other liquids ever introduced. It produced the most
+uniform results, giving the fine soft tone so characteristic
+in pictures produces from accelerators containing chlorine.
+To one quart of lime water (this can be had of any druggist)
+add one and a half ounce of pulverized alum.
+This should be shook at intervals for twenty--four hours;
+then add one ounce of chloride of iodine and three fourths
+ounce of bromine.
+
+Lime Water.--This is easily prepared by putting lime into water,
+say a piece of quick-lime about the size of an egg into one quart of water.
+This should be shook occasionally for two or three days and allowed to settle,
+when the water can be poured off and used.
+
+Use.--To one part of quick add six parts of water; coat to a light yellow
+over the iodine, to a rose color over the quick, and recoat about one tenth.
+The above coating may be increased or diminished, it matters not,
+so that there is not too much, and the proper proportions are preserved.
+Some add to the above a small quantity of magnesia, say about a teaspoonful
+to the quart of liquid.
+
+Liquid Accelerator, No. 2.--The following was for a long
+time used by one of the first houses in the United States,
+and probably was one of the first liquids ever used.
+It produces a fine-toned picture, but is not considered as sure
+as the lime water quick:
+
+Take rain water one quart, add pulverized alum until it is a little sour
+to the taste, and a small piece, say one half inch square, of magnesia.
+Filter through paper, and add chloride of iodine one half ounce,
+bromine sufficient to take it up, which is a little less than half an ounce.
+
+Charge with one of quick to six of water; coat over iodine
+to a soft yellow, nearly, but not quite, bordering on a rose;
+over quick to a dark purple, or steel, and back one sixth
+to one tenth.
+
+Wolcott's American Mixture.--Van Loan Quick.--This mixture was first
+formed and used by T. Wolcott & Johnson and gained great celebrity for
+its productions. I have now a bottle hermetically sealed that contains
+about a half ounce of this mixture prepared in 1841 by John Johnson,
+now a resident of this city, and the former partner of Mr. Wolcott.
+The preparation of this mixture, as furnished by Mr. Johnson himself,
+is given as follows:
+
+"One part of bromine, eight parts of nitric acid,
+sixteen parts of muriatic acid, water one hundred parts.
+This mixture should be allowed to stand for several days;
+it improves by age.
+
+"Use.--A few drops say, 6 to 12, of this mixture, should be put
+into about 6 or 8 ounces of water; it will require frequent
+replenishing by the addition of a few more drops. The plate should
+be coated over the dry iodine to a red just bordering on a slate.
+and then exposed to the mixture only sufficiently long to change the color.
+If this is not done in less than six seconds it is not strong enough.
+Re-coat over the iodine full one fourth as long as first coating."
+
+This exceedingly volatile compound is difficult to control
+from its instability; it is but little used. The impressions
+successfully produced by this mixture are very brilliant,
+and possess a pleasing peculiarity.
+
+
+DRY SENSITIVES.
+
+Hydrate of Lime.--The operation by which water is combined
+with lime is called slaking. Take a piece of quick lime,
+common lime used in mortar, and immerse it in warm water for
+about fifteen seconds; then place it in an iron or tin vessel.
+It will soon begin to swell, evolving a great deal of heat and
+emitting steam, and soon falls into a fine powder, hydrate of lime.
+This should be well stirred and allowed to cool, and then
+bottled in order to prevent it from giving off the hydrate
+and recovering the carbonic acid from the atmosphere.
+The last is detrimental to its use with bromine, and is one
+cause of the complaint that "it will not take bromine."
+The hydrate of lime should, not be dried over a heat,
+as has been supposed by many, for in that case
+the hydrogen is expelled and it returns to a carbonate.
+It is advisable to cool it in a damp place like a ground cellar.
+Much of the lime in our market will not, except it be quite damp,
+combine with the bromine. This is owing to impurities.
+Nothing is equal to oyster-shell lime, which I use altogether.
+
+Bromide of Lime.--In preparing large quantities of this, we adopt
+the following method: Fill a four-quart bottle about two-thirds full
+of hydrate of lime; pour into this about one or two ounces of bromine;
+then shake well, add more of the bromine, shake well and let it stand
+for a few hours, adding sufficient bromine to give it a fine red color.
+It is better when kept in the large bottles, as it forms a more
+perfect combination: in other words it improves by age.
+
+Use.--Coat over the iodine to a rose red and then over this mixture
+to a purple or slate; recoat over the first about one fourth as long
+as first coating.
+
+Gurneys American Compound.--Of this compound there are two combinations,
+one for use, when the temperature of the atmosphere is above 65 or 70
+deg., and the other at a lower temperature. The first is called No. 1,
+the second No. 2.
+
+No. 1 is prepared by placing hydrate of lime in a bottle,
+say to three quarts of the hydrate of lime, add one ounce
+of pulverized burnt alum, and as much chloride of lime as can
+be put on a quarter of a dollar, and from l5 to 30 grains
+of dry pulverized iodine, or enough to change the color of
+the hydrate of lime, to the slightest possible tinge of yellow.
+There had better be less than carry the color to a deeper shade.
+The object of using the iodine is to form a compound with
+bromine that is not so volatile as the bromine itself.
+No matter how little iodine is combined with the bromine,
+the vapors possess their relative proportion; hence, only enough
+iodine to prevent "flaring," or as it is often termed
+a "scum-coating," is used. The iodine should be thoroughly
+combined with the lime, which will take about one or two days.
+Should add bromine the same as in bromide of lime,
+until the compound assumes a light red color.
+
+No. 2 is prepared in the same manner as No. 1, except the addition
+of the iodine, which is omitted.
+
+Use.--No. 1. Coat over the iodine to a bright yellow color,
+then over the compound, No. 1, to red color, recoat over iodine,
+about one sixth as long, as the time occupied in first coating.
+
+No. 2. Coat over iodine same as above, except recoat over the iodine
+about one fourth to one half as long as first coating.
+
+Dry Quick, No. 1.--Bromide of Lime and Starch.--The following
+compound forms an excellent accelerator, and is used by many.
+It is claimed for this preparation, that it will hold
+the bromine longer than others where starch is not employed.
+As regards this claim we do not think it can be substantiated.
+Our experience in practice has led us to the conclusion
+that there is no great difference as respects durability,
+but there is some little difference as regards the tone
+of the impressions produced by its use.
+
+To one quart of hydrate of lime add one quart of finely pulverized starch.
+To this mixture add bromine, until it assumes a deep yellow or pink color.
+
+Starch may be added to any of the dry mixtures.
+
+Use.--Coat over the iodine to a deep yellow, then over this quick
+to a red color, recoat about one sixth of the time of first coating.
+
+I will here again remark, that the exact color of the coating
+is not essentially provided a proper proportion is preserved.
+
+I have never seen it stated, though it be a fact worthy of note,
+that a proportionate time for coating over the iodine and accelerator,
+will not answer. For example: if a plate exposed to the vapor
+of iodine be perfectly coated in sixteen seconds, and then
+exposed to an accelerator, (not having iodine in its combination)
+receives its coating in four seconds, it will be found that a proper
+proportionate coating cannot be preserved by adopting, a proportion
+of time, but on the contrary, the time will diminish; for exposure
+over the accelerator, as in the above example, if it be desired to coat
+the plate with twice as much iodine as in the above example, the time
+would be, over iodine thirty-two seconds, and over the accelerator
+(to possess a proper proportion) from six to seven seconds.
+Hence it is that many inexperienced operators, when wishing to vary
+their usual manner of coating, fail in producing a favorable result.
+They coat calculating a proportion of time when they should not.
+
+Dry Quick, No. 2.--Bromide of Lime and Magnesia.--To one quart of hydrate
+of lime add one quart of magnesia, and mix them well together; add bromine
+same as in preparing bromide of lime; coat the same as over dry quick No. 1.
+This combination produces very uniform results, and is worked with much
+success by beginners.
+
+Chloro-Bromide of Lime.--To the bromide of lime add chloride of bromine
+until the mixture becomes a pale yellow color, resembling sulphur.
+It should be shook well, and enough of the chloride of bromine added
+to bring the compound to a deep blood red color.
+
+Use.--Coat over the iodine to a pink color, and then over the above to a red,
+or just changing the color. It should be remembered that accelerators
+containing chlorine do not admit of a great change of color of coating
+on the plate.
+
+Iodide of Starch.--This mixture can be employed for coating over in
+warm weather, and prevent the flashing resulting at high temperatures.
+It may be used the same as the iodide alone.
+
+To six ounces of finely pulverized starch, add one fourth ounce
+of dry iodine.
+
+Use.--Same as the dry iodine alone.
+
+The same combination may be made with lime, magnesia and other substances.
+
+Concentrated Solution of Iodine for First Coating.--It may appear
+strange to some of our old operators that an aqueous solution of iodine
+can be used for coating the plate and forming the iodide of silver.
+It has long been a cry among most operators that it is impossible to succeed
+when the iodine box contains dampness. Now this is a great mistake,
+and we will here state that in all cases where dampness appears
+upon a properly prepared Daguerreotype plate, it is the result of a
+different temperature of the metal from the air which surrounds it.
+Mr. Senter, of Auburn, was the first of our operators who used a solution
+of iodine for coating the plate, and we several years since saw
+his results, which would rival the production of any other operator.
+A concentrated solution of iodine is prepared by putting into a common
+bottle two thimblesful of hyposulphite of soda and a rather larger
+quantity of iodine, so that there may be more than sufficient.
+Add to it about 40 ounces of common water (heated to 60 or 70 degrees),
+by little and little, moving, the bottle to warm it, for fear of breaking.
+After shaking it a short time, the water is rapidly and strongly colored.
+The solution should be poured into a bottle with a ground stopper,
+and when cool used for iodizing.
+
+A solution of sufficient strength can be made by moistening
+or just covering the iodine with water.
+
+Chloride of Iodine as an Accelerator.--This is probably one of the best
+accelerators that can be used for coating the plate for taking views;
+it works too slow, however, to meet the wants of the operating room,
+yet its use was formerly, for a long time, adhered to by some of our
+best professors. In producing views with this, we are successful in
+obtaining well-developed impressions, with a depth of tone and richness
+of appearance not to be met with in the productions of any other substances.
+I give its use as furnished me by an old and experienced operator,
+and published in Humphrey's Journal, vol. i. p. 180:
+
+"As the process of using chloride of iodine may be of interest to some
+of our subscribers, I take pleasure in giving the following manipulation.
+To one ounce of chloride of iodine add two ounces of water;
+place this mixture in a coating-box, the same as quick stuff;
+coat the plate with dry iodine to a light yellow, or lemon color;
+then bring the coating to a deep pink over the chloride.
+The plate must be recoated over the dry iodine."
+
+This combination has been very successfully used in one of our
+most extensive establishments in this city, and the superiority
+of the pictures produced by it was considered as an equivalent
+for the additional time required to bring out the impressions.
+
+Chlorine as an Accelerator.--I shall here refer to but a single
+experiment in which I employed chlorine gas for coating the plate.
+I was provided with a retort, the neck of which was fitted to the jar
+of my coating-box, through a hole drilled for its reception.
+This was fitted perfectly tight in my coating-box. I placed
+some pure undiluted bromine water and the agents necessary
+for producing chlorine gas (in small quantity) in the retort.
+The result was that my first experiment produced an impression
+completely solarized in all its parts by an exposure of four seconds
+of time, which would have required an exposure of twenty seconds
+to produce a perfectly developed impression by the usual process.
+
+Another trial immediately produced one of the finest toned impressions
+I ever saw, perfectly developed in one second of time.
+
+My next two or three experiments proved total failures.
+I was unable to produce even a sign of an impression.
+By accident my retort was broken, and not being in a
+locality convenient to obtain another, my experiments
+were necessarily suspended.
+
+My attention was not called to this subject again for several years,
+when I noticed an account of some similar experiments by F. A. P. Barnard
+and Dr. W. H. Harrington, the latter of whom is now of the firm of Dobyns
+& Harrington, of New Orleans.
+
+From reading this article, I found my own difficulties explained.
+Too much of the chlorine gas was present in my coating jar.
+I would like to see some of our enterprising operators
+investigate this combination.
+
+It is a singular fact, that the vapors of bromine and chlorine combining
+upon the iodide of silver, produce a more sensitive coating than when
+the two are combined in solution, as in chloride of bromine solution.
+Those having Humphrey's Journal at hand, can refer to vol. i. p. 142.
+
+To use Bromine Water or other Accelerators in Hot Weather.--
+An excellent plan for using bromine water is as follows:
+
+Fill a two-ounce bottle quarter full of it, and then fill the bottle
+with fine sand, which serves to preserve a low temperature;
+then place the bottle in a porous cup, same as used in the battery;
+fill this also with sand, and close the end with plaster of Paris.
+Place this in a coating-box, and it will be found to act with great
+uniformity and be quite permanent.
+
+Bromide of Lime, another accelerator, can be used in the same manner,
+except it is, only necessary, when a solid sensitive is used,
+to mix it with the sand without placing it in a bottle.
+This method is employed with great success by a few, who have
+regarded it as a secret worth keeping.
+
+A Combination, requiring the Use of only One Coating-box.--
+It is often wondered by beginners, why some solution requiring only
+one coating cannot be employed. This can be done, but the results
+are not so satisfactory as when two or more are employed.
+Such an accelerator may be produced by adding alcoholic
+solution of iodine to a solution of chlorate of potash,
+until the latter will take up no more of the former,
+and to each ounce, by measure of this solution, ten drops
+of a saturated solution of bromide in water are added.
+The solution of chlorate of potash is made by diluting, one part
+of a saturated solution of the salt with ten parts of water.
+The use of the chlorate is simply as a solvent of iodine.
+
+Fats as Accelerators.--The use of fats, oils, or greasy substances,
+has been one of the most emphatic prohibitions about the
+Daguerreotype plate. Yet it has been proved that its presence
+in a small quantity upon the silver surface has the effect
+of reducing the time of exposure in the camera from two-thirds
+to three-fourths. An application may be made as follows:
+Pour sweet oil, or rub beef or mutton fat, on a common buff,
+which is free from all polishing powders. With this, buff a
+well-cleaned plate, and it will leave a scum, which should be
+mostly removed by using another buff, which should be clean.
+Coat the plate in the usual manner, and the result will be
+a great reduction in the time of exposure in the camera.
+The impression produced upon a plate so prepared presents,
+when coming from the vapor of mercury, a grey, scummy appearance,
+which, on the application of heat in gilding, does not improve;
+hence its use is not generally adopted.
+
+We have instituted some investigations upon this subject,
+and in the present volume, we shall not refer to it further.
+Those wishing to learn more fully the effect of light upon
+organic substances will find Robert Hunt's "Researches on Light"
+an invaluable work.
+
+
+
+
+LIGHT AND OPTICS.
+
+CHAPTER IV.
+
+
+Light--Optics--Solar Spectrum--Decomposition of Light--Light, Heat,
+and Actinism--Blue Paper and Color for the Walls of the Operating Room--
+Proportions of Light, Heat, and Actinism composing a Sunbeam--
+Refraction--Reflection--Lenses--Copying Spherical Aberration--
+Chromatic Aberration.
+
+It is advisable that persons engaging in the Daguerreotype art should have
+at least a little knowledge of the general principles of light and optics.
+It is not the author's design here to give a full treatise on these subjects,
+but he only briefly refers to the matter, giving a few facts.
+
+It has been well observed by an able writer, that it is impossible to trace
+the path of a sunbeam through our atmosphere without feeling a desire
+to know its nature, by what power it traverses the immensity of space,
+and the various modifications it undergoes at the surfaces and interior
+of terrestrial substances.
+
+Light is white and colorless, as long as it does not come
+in contact with matter. When in apposition with any body,
+it suffers variable degrees of decomposition, resulting in color,
+as by reflection, dispersion, refraction, and unequal absorption.
+
+To Sir I. Newton the world is indebted for proving the compound
+nature of a ray of white light emitted from the sun.
+The object of this work is not to engage in an extended theory
+upon the subject of light, but to recur only to some points
+of more particular interest to the photographic operator.
+
+The decomposition of a beam of light can be noticed by exposing
+it to a prism. If, in a dark room, a beam of light be admitted
+through a small hole in a shutter, it will form a white round spot
+upon the place where it falls. If a triangular prism of glass
+be placed on the inside of the dark room, so that the beam
+of light falls upon it, it no longer has the same direction,
+nor does it form a round spot, but an oblong painted image of
+seven colors--red, orange, yellow, green, blue, indigo, and violet.
+This is called the solar spectrum, and will be readily understood
+by reference to the accompanying diagram, Fig. 1.
+
+[page 133]
+
+To those who are unacquainted with the theory of light
+(and for their benefit this chapter is given), it may be a matter
+of wonder how a beam of light can be divided.
+
+[amdg_1.gif]
+
+This can be understood when I say, that white light is a bundle
+of colored rays united together, and when so incorporated,
+they are colorless; but in passing through the prism
+the bond of union is severed, and the colored rays come
+out singly and separately, because each ray has a certain
+amount of refracting (bending) power, peculiar to itself.
+These rays always hold the same relation to each other,
+as may be seen by comparing every spectrum or rainbow;
+there is never any confusion or misplacement.
+
+There are various other means of decomposing
+
+[page 134]
+
+white light besides the prism, of which one of the principal
+and most interesting to the Daguerreotypist is by reflection from
+colored bodies. If a beam of white light falls upon a white surface,
+it is reflected without change; but if it falls upon a red surface,
+only the red ray is reflected: so also with yellow and other colors.
+The ray which is reflected corresponds with the color of the object.
+It is this reflected decomposed light which prevents the beautifully-colored
+image we see upon the ground glass in our cameras.
+
+[amdg_2.gif]
+
+A sunbeam may be capable of three divisions--LIGHT, HEAT, and ACTINISM;
+the last causes all the chemical changes, and is the acting
+power upon surfaces prepared to receive the photographic image.
+The accompanying illustration, Fig. 2, will readily bring
+to the mind of the reader the relation of these one to another,
+and their intensities in the different parts of a decomposed sunbeam.
+
+The various points of the solar spectrum are represented in the order
+in which they occur between A, and B, this exhibits the limits of the
+Newtonian spectrum, corresponding with Fig. 1. Sir John Herschel and Seebeck
+have shown that there exists, beyond the violet, a faint violet light,
+or rather a lavender to b, to which gradually becomes colorless;
+similarly, red light exists beyond the assigned limits of the red ray to a.
+The greatest amount of actinic power is shown at E opposite the violet;
+hence this color "exerts" the greatest amount of influence in the formation
+of the photographic image.
+
+(Blue paper and blue color have been somewhat extensively used by
+our Daguerreotype operators in their operating rooms and skylights,
+in order to facilitate the operation in the camera. I fancy, however,
+that this plan cannot be productive of as much good as thought by some,
+from the fact, that the light falling upon the subject, and then reflected
+into the camera, is, coming through colorless glass, not affected
+by such rays as may be reflected from the walls of the operating room;
+and even if it were so, I conceive that it would be injurious,
+by destroying the harmony of shadows which might otherwise occur.)
+The greatest amount of white light is at C; the yellow contains less
+of the chemical power than any other portion of the solar spectrum.
+It has been found that the most intense heat is at the extreme red, b.
+
+Artificial lights differ in their color; the white light
+of burning charcoal, which is the principal light from candles,
+oil and gas, contains three rays--red, yellow, and blue.
+The dazzling light emitted from lime intensely heated,
+known as the Drummond light, gives the colors of the prism
+almost as bright as the solar spectrum.
+
+If we expose a prepared Daguerreotype plate or sensitive paper
+to the solar spectrum, it will be observed that the luminous power
+(the yellow) occupies but a small space compared with the influence
+of heat and chemical power. R. Hunt, in his Researches on Light,
+has presented the following remarks upon the accompanying illustration:
+
+"If the linear measure, or the diameter of a circle which shall
+include the luminous rays,
+
+[amdg_3.gif]
+
+is 25, that of the calorific spectrum will be 42.10, and of the chemical
+spectrum 55.10. Such a series of circles may well be used to represent
+a beam from the sun, which may be regarded as an atom of Light,
+surrounded with an invisible atmosphere of Heat, and another still
+more extended, which possesses the remarkable property of producing
+chemical and molecular change.
+
+A ray of light, in passing obliquely through any medium of uniform density,
+does not change its course; but if it should pass into a denser body,
+it would turn from a straight line, pursue a less oblique direction,
+and in a line nearer to a perpendicular to the surface of that body.
+Water exerts a stronger refracting power than air; and if a ray of light
+fall upon a body of this fluid its course is changed, as may be seen
+by reference to Fig. 4.
+
+[amdg_4.gif]
+
+It is observed that it proceeds in a less oblique direction
+(towards the dotted line), and, on passing on through, leaves the liquid,
+proceeding in a line parallel to that at which it entered. It should be
+observed that at the surface of bodies the refractive power is exerted,
+and that the light proceeds in a straight line until leaving the body.
+The refraction is more or less, and in all cases in proportion
+as the rays fall more or less obliquely on the refracting surface.
+It is this law of optics which has given rise to the lenses in our
+camera tubes, by which means we are enabled to secure a well-delineated
+representation of any object we choose to picture.
+
+When a ray of light passes from one medium to another, and through that into
+the first again, if the two refractions be equal, and in opposite directions,
+no sensible effect will be produced.
+
+The reader may readily comprehend the phenomena of refraction,
+by means of light passing through lenses of different curves,
+by reference to the following diagrams:--
+
+[amdg_5.gif]
+
+Fig 5 represents a double-convex lens, Fig. 6 a double-concave, and Fig.
+7 a concavo-convex or meniscus. By these it is seen that a double-convex
+lens tends to condense the rays of light to a focus, a double-concave
+to scatter them, and a concavo-convex combines both powers.
+
+If parallel rays of light fall upon a double-convex lens, D D, Fig.
+8, they will be refracted (excepting such as pass directly through the centre)
+to a point termed the principal focus.
+
+[amdg_8a.gif]
+
+The lines A B C represent parallel rays which pass through the lens,
+D D, and meet at F; this point being the principal focus,
+its distance from the lens is called the focal length.
+Those rays of light which are traversing a parallel course,
+when they enter the lens are brought to a focus nearer
+the lens than others. Hence the difficulty the operator
+sometimes experiences by not being able to "obtain a focus,"
+when he wishes to secure a picture of some very distant objects;
+he does not get his ground glass near enough to the lenses.
+Again, the rays from an object near by may be termed diverging rays.
+This will be better comprehended by reference to Fig.
+9, where it will be seen that the dotted lines, representing
+
+[amdg_9.gif]
+
+parallel rays, meet nearer the lenses than those from the point A. The
+closer the object is to the lenses, the greater will be the divergence.
+This rule is applicable to copying. Did we wish to copy a 1/6
+size Daguerreotype on a l/l6 size plate, we should place it in
+such a position to the lenses at A that the focus would be at F,
+where the image would be represented at about the proper size.
+Now, if we should wish to copy the 1/6 size picture, and produce
+another of exactly the same dimensions, we have only to bring it
+nearer to the lenses, so that the lens D E shall be equi-distant from
+the picture and the focus, i. e. from A to B. The reason of this is,
+that the distance of the picture from the lens, in the last copy,
+is less than the other, and the divergence has increased, throwing,
+the focus further from the lens."
+
+These remarks have been introduced here as being important
+for those who may not understand the principles of enlarging
+or reducing pictures in copying.
+
+I would remark that the points F and A, in Fig.
+9, are termed "conjugate foci."
+
+If we hold a double-convex lens opposite any object, we find that an
+inverted image of that object will be formed on a paper held behind it.
+To illustrate this more clearly, I will refer to the following woodcut:
+
+[amdg_10.gif]
+
+"If A B C is an object placed before a convex lens, L L, every point
+of it will send forth rays in all directions; but, for the sake
+of simplicity, suppose only three points to give out rays,
+one at the top, one at the middle, and one at the bottom;
+the whole of the rays then that proceed from the point A, and fall
+on the lens L L, will be refracted and form an image somewhere on
+the line A G E, which is drawn direct through the centre of the lens;
+consequently the focus E, produced by the convergence of the rays
+proceding from A, must form an image of A, only in a different
+relative position; the middle point of C being in a direct line
+with the axis of the lens, will have its image formed on the axis F,
+and the rays proceeding from the point B will form an image at D;
+so that by imagining luminous objects to be made up of all infinite
+number of radiating points and the rays from each individual point,
+although falling on the whole surface of the lens, to converge again
+and form a focus or representation of that point from which the rays
+first emerged, it will be very easy to comprehend how images are formed,
+and the cause of those images being reversed.
+
+"It must also be evident, that in the two triangles A G B
+and D G E, that E D, the length of the image, must be to A B,
+the length of the object, as G D, the distance of the image,
+is to G B, the distance of the object from the lens.
+
+It will be observed that in the last cut the image produced
+by the lens is curved. Now, it would be impossible to produce
+a well-defined image from the centre to the edge upon a plain surface;
+the outer edges would be misty, indistinct, or crayon-like. The
+centre of the image might be represented clear and sharp on
+the ground glass, yet this would be far from the case in regard
+to the outer portions. This is called spherical aberration,
+and to it is due the want of distinctness which is frequently
+noticed around the edges of pictures taken in the camera.
+To secure a camera with a flat, sharp, field, should be the object
+of every operator; and, in a measure, this constitutes the great
+difference in cameras manufactured in this country.
+
+Spherical aberration is overcome by proper care in the formation of the lens:
+"It can be shown upon mathematical data that a lens similar to that given
+in the following diagram--one surface of which is a section of an ellipse,
+and the other of a circle struck from the furthest of the two foci of
+that ellipse--produces no aberration.
+
+"At the earliest period of the employment of the camera obscura,
+a double-convex lens was used to produce the image; but this form
+was soon abandoned, on account of the spherical aberration so caused.
+Lenses for the photographic camera are now always ground of
+a concavo-convex form,
+
+[amdg_11.gif]
+
+or meniscus, which corresponds more nearly to the accompanying diagram."
+
+Chromatic Aberration is another difficulty that opticians have to contend with
+in the manufacturing of lenses. It will be remembered, that in a former page
+(133) a beam of light is decomposed by passing through a glass prism giving
+seven distinct colors--red, orange, yellow, green, blue, indigo and violet.
+
+Now, as has been said before, the dissimilar rays having an unequal degree
+of refrangibility, it will be impossible to obtain a focus by the light
+passing through a double-convex lens without its being fringed with color.
+Its effect will be readily understood by reference to the accompanying cut.
+
+If L L be a double convex-lens, and R R R parallel rays of white light,
+composed of the seven colored rays,
+
+[amdg_8b.gif]
+
+each having a different index of refraction, they cannot be refracted
+to one and the same point; the red rays, being the least refrangible,
+will be bent to r, and the violet rays, being the most refrangible, to v:
+the distance v r constitutes the chromatic aberration, and the circle,
+of which the diameter is a l, the place or point of mean refraction,
+and is called the circle of least aberration. If the rays of the sun
+are refracted by means of a lens, and the image received on a screen
+placed between C and o, so as to cut the cone L a l L, a luminous circle
+will be formed on the paper, only surrounded by a red border, because it
+is produced by a section of the cone L a l L, of which the external
+rays L a L l, are red; if the screen be moved to the other side of o,
+the luminous circle will be bordered with violet, because it will be
+a section of the cone M a M l, of which the exterior rays are violet.
+To avoid the influence of spherical aberration, and to render the phenomena
+of coloration more evident, let an opaque disc be placed over the central
+portion of the lens, so as to allow the rays only to pass which are at
+the edge of the glass; a violet image of the sun will then be seen at v,
+red at r, and, finally, images of all the colors of the spectrum in
+the intermediate space; consequently, the general image will not only
+be confused, but clothed with prismatic colors."
+
+To overcome the difficulty arising from the chromatic aberration,
+the optician has only to employ a combination of lenses of opposite
+focal length, and cut from glass possessing different refrangible powers,
+so that the rays of light passing through the one are strongly refracted,
+and in the other are bent asunder again, reproducing white light.
+
+To the photographer one of the most important features, requiring his
+particular attention. is, that he be provided with a good lens.
+By the remarks given in the preceding pages, he will be enabled, in a measure,
+to judge of some of the difficulties to which he is occasionally subjected.
+We have in this country but two or three individuals who are giving their
+attention to the manufacture of lenses, and their construction is such,
+that they are quite free from the spherical or chromatic aberration.
+
+
+
+CHAPTER V.
+
+To make Plates for the Daguerreotype--Determining the Time of Exposure
+in the Camera--Instantaneous Process for Producing Daguerreotype--
+Galvanizing the Daguerreotype Plate--Silvering Solution--
+Daguerreotype without Mercury--Management of Chemicals--
+Hints and Cautions--Electrotyping--Crayon Daguerreotypes--
+Illuminated Daguerreotypes--Natural Colors in Heliography--
+Multiplying Daguerreotypes on one Plate--Deposit in Gilding--
+Practical Hints on the Daguerreotype.
+
+
+TO MAKE PLATES FOR THE DAGUERREOTYPE.
+
+I do not give the method employed by our regular plate manufacturers;
+this is not important, as the operator could not possibly profit
+by it from the fact of the great expense of manufacturing.
+The following will be found practical:
+
+Procure a well planished copper plate of the required size,
+and well polish it, first with pumice stone and water,
+then with snake stone, jewelers' rouge. Plates can be
+purchased in a high state of preparation from the engravers.
+Having prepared the copper-plate, well rub it with salt and water,
+and then with the silvering powder. No kind answers better
+than that used by clock-makers to silver their dial-plates.
+It is composed of one part of well washed chloride of silver,
+five parts of cream of tartar, and four parts of table salt.
+This powder must be kept in a dark vessel, and in a dry place.
+For a plate six inches by five, as much of this composition
+as can be taken up on a shilling is sufficient.
+It is to be laid in the centre of the copper, and the figures
+being wetted, to be quickly rubbed over every part
+of the plate, adding occasionally a little damp salt.
+The copper being covered with the silvering is to be speedily
+well washed in water, in which a little soda is dissolved,
+and as soon as the surface is of a fine silvery whiteness,
+it is to be dried with a very clean warm cloth. In this state
+the plates may be kept for use. The first process is to expose
+the plate to the heat of a spirit flame, until the silvered
+surface becomes of a well-defined golden-yellow color;
+then, when the plate is cold, take a piece of cotton,
+dipped in very dilute nitric acid, and rub lightly over it
+until the white hue is restored, and dry it with very soft
+clean cloths. A weak solution of the hydriodate of potash,
+in which a small portion of iodine is dissolved, is now passed
+over the plate with a wide camel's hair brush. The silver
+is thus converted, over its surface, into an ioduret of silver;
+and in this state it is exposed to light, which blackens it.
+When dry, it is to be again polished, either with dilute acid
+or a solution of carbonate of soda, and afterwards with dry cotton,
+and the smallest possible portion of prepared chalk:
+by this means a surface of the highest polish is produced.
+The rationale of this process is, in the first place,
+the heat applied dries off any adhering acid, and effects more
+perfect union between the copper and silver, so as to enable
+it to bear the subsequent processes. The first yellow surface
+appears to be an oxide of silver with, possibly, a minute
+quantity of copper in combination, which being removed leaves
+a surface chemically pure.
+
+Another Method.--The best and simplest mode with which we are
+acquainted is to divide an earthenware vessel with a diaphragm:
+one side should be filled with a very dilute solution of sulphuric acid,
+and the other with either a solution of ferroprussiate of potash,
+or muriate of soda, saturated with chloride of silver. The copper plate,
+varnished on one side, is united, by means of a copper wire,
+with a plate of zinc. The zinc plate being immersed in the acid,
+and the copper in the salt, a weak electric current is generated,
+which precipitates the silver in a very uniform manner over
+the entire surface.
+
+Another Method.--A piece of brass or of polished copper, brass is preferred,
+is perfectly planished and its surface made perfectly clean.
+A solution of nitrate of silver, so weak that the silver is
+precipitated slowly, and a brownish color, on the brass, is laid
+uniform]v over it, "at least three times," with a camel's hair pencil.
+After each application of the nitrate, the plate should be rubbed gently
+in one direction, with moistened bitartrate of potassa, applied with buff.
+This coat of silver receives a fine polish from peroxide of iron and buff.
+Proofs are said to have been taken on it, comparable with those obtained
+on French plates.
+
+
+M. SOLIEL'S PROCESS FOR DETERMINING THE TIME OF EXPOSURE IN THE CAMERA.
+
+M. Soliel has proposed the use of the chloride of silver to determine the time
+required to produce a good impression on the iodated plate in the camera.
+His method is to fix at the bottom of a tube, blackened within, a piece
+of card, on which chloride of silver, mixed with gum or dextrine, is spread.
+The tube thus disposed is turned from the side of the object of which we wish
+to take the image, and the time that the chloride of silver takes to become
+of a greyish slate color will be the time required for the light of the camera
+to produce a good effect on the iodated silver.
+
+
+INSTANTANEOUS PROCESS FOR PROCURING DAGUERREOTYPES.
+
+The following method of producing Daguerreotypes has by some been named
+as above. Most experienced operators have been long acquainted with
+the effect of the vapor of ammonia upon the chemically coated plate.
+I will here insert Mr. W. H. Hewett's plan of proceeding.
+This gentleman, in referring to it (published in 1845), says:
+
+"This improvement consists in using the vapor of ammonia,
+as an object to accelerate the action of light upon the plate.
+The effect is produced upon a simple iodized plate, but still more upon
+a plate prepared in the ordinary way, with both iodine and bromine.
+By this means, the author obtained impressions instantaneously
+in the sunshine, and in five to ten seconds in a moderate light;
+and he hopes to be able to take moving objects. It can be applied
+by exposing the prepared plate over a surface of water, to which a few
+drops of ammonia have been added (sufficient to make it smell of ammonia);
+or the vapor can be introduced into the camera during the action.
+In fact, the presence of ammonia, in the operating-room, appears
+to have a good effect, as it also neutralizes the vapors of iodine
+and bromine that may be floating about, and which are so detrimental
+to the influences of light upon the plate."
+
+
+GALVANIZING THE DAGUERREOTYPE PLATE.
+
+In consideration of the importance of galvanized plates, I shall endeavor
+to give as plain and concise a manner of manipulation as possible.
+For some time it was a question among the operators generally,
+as to the beneficial result of electrotyping, the Daguerreotype plate,
+but for a few years past our first operators have found it a fact,
+that a well electro-silvered surface is the best for producing a portrait
+by the Daguerreotype.
+
+From my own experiments, I have found that a plate, by being galvanized,
+can be rendered more sensitive to the operation of the light
+in proportion of one to five, viz.: if a plate as furnished by
+the market, be cleaned, polished, coated and exposed in the camera,
+if the required time to freely develop an impression be ten seconds,
+a similar plate prepared in like manner and galvanized,
+will produce an equally well-defined image in eight seconds.
+In connection with this subject, there is one fact worthy of notice;
+a plate with a very heavy coating of pure silver, will not produce
+an equally developed image, as a plate with a thinner coating, hence the
+thin coating, providing it entirely covers the surface, is the best,
+and is the one most to be desired. The experiment is plain and simple.
+Let the slate receive a heavy or thick coating by the electrotype,
+then polish, coat, expose in the usual manner, and the result will
+be a flat, ashy, indistinct impression; when, on the other hand,
+the thin coating will produce a bright, clear and distinct image,
+with all the details delineated.
+
+The style of battery best for the purpose has been, and now is,
+a question of dispute among operators; some preferring the Daniell
+battery to Smee's. Some claim the superiority of the first from its
+uniformity of action; others, of the latter, for its strength.
+I consider either good, and for the inexperienced would prefer the Daniell.
+This is more simple in its construction, while it has certainty in action.
+The more skillful electrotyper would prefer Smee's, and this is the one
+most generally in use. I would remark that the plan of galvanizing plates
+should be followed by every operator, and when once thoroughly tested,
+no one will abandon it.
+
+
+SILVERING SOLUTION.
+
+To any desired quantity of chloride of silver in water add,
+little by little, cyanide of potassium, shaking well at each addition,
+until all the cyanide is dissolved. Continue this operation,
+and add the cyanide, until all the precipitate is taken up
+and held in solution.
+
+This solution is now ready for the plate-cup. Enough water may be
+added to cover any sized plate when held perpendicular in the cup.
+The strength of the solution may be kept up by occasionally
+adding the chloride of silver and cyanide of potassium.
+There should alway be a very little excess of the cyanide.
+
+The plate should be well cleaned and buffed, and the solution
+well stirred before it is immersed. Care should be
+observed to keep the solution clean, and allow no particle
+of dust to come in contact with the surface of the plate.
+The plate is now to be attached to the pole of the battery.
+
+After remaining a short time, it assumes a blue color; take it out,
+rinse freely with pure water, then dry with a spirit lamp,
+and it is ready for buffing. Buff and coat in the usual manner.
+Some operators are in the practice of immersing the plate
+in the solution and buffing twice. This additional silvering
+is no improvement wherever there has been a proper first coating.
+
+Sometimes the operator is troubled with streaks or scum on the plate.
+This may arise from three causes, all of which experience must teach
+the experimenter to avoid; first, too great an excess of cyanide in
+the solution; second, a lack of silver; third, the current too strong.
+Another annoyance arises from the solution being dirty and the dirt
+collecting on the surface. When this is the case, the dirt is sure
+to come in contact with the surface of the plate as it is plunged into
+the solution, and the result is a scum that it is difficult to dispose of.
+This can be prevented only by frequent filtering. One thing should always
+be borne in mind in electrotyping Daguerreotype plates--that in order to
+secure a perfectly coated surface, the plate should be perfectly cleaned.
+In this point, many who have tried the electrotype process have failed,
+attributing their ill success to other than the proper cause.
+
+
+
+DAGUERREOTYPES WITHOUT MERCURY.
+
+The following process possesses some interest, and is
+worthy a trial from operators. M. Natterer, of Vienna,
+discovered a process for obtaining proofs on iodized plates
+with the chloride of sulphur, without the use of mercury.
+A plate of silver is iodized in the usual manner, and then placed
+on the top of a vessel six or eight inches high, having at
+the bottom, in a small cup, a few drops of chloride of sulphur;
+it should remain exposed to the action of the vapor until
+the sombre yellow color is changed to a red, after which it
+is brought to a focus m the camera, where it is exposed
+to the light in the camera, for about the time necessary
+to produce an ordinary daguerreotype. The plate is then taken
+out and examined in the camera by the light of a candle.
+It often occurs that no trace of the image is as yet perceptible,
+but if the plate is heated by placing over a spirit lamp
+the unprepared side, or if left for some time in the dark,
+or, lastly, if exposed only a few seconds to a weak, dimmed light,
+the positive picture then appears with all its shades.
+Of these three modes of bringing out the image, the second
+is superior to the others.
+
+
+MANAGEMENT OF CHEMICALS.
+
+It is necessary, first of all, to know that you have a chemical
+which is capable of producing good results when in skillful hands.
+For this reason it is best to prepare your own quick, after some formula
+which is known to be good. Those quick-stuffs which contain chloride
+of iodine are noted for their depth of tone while they probably
+operate with less uniformity than those which are destitute of it.
+For operating under ordinary circumstances, especially with an
+inferior light, probably no accelerator is more quick and sure than
+Wolcott's. It also produces a very fine, white pleasing picture,
+though lacking that depth of impression so much to be desired.
+The dry quick operates with surety, and its use is simple and easy,
+producing an impression much like Wolcott's. For those having a good
+and permanent light, however, we would recommend a chemical giving
+more body to the impression.
+
+There is a class of accelerators called sensitives, claiming to
+work in from three to ten seconds, which, however, will be found
+very little, if any, more sensitive than this. We frequently
+work it with the ordinary coating in twelve and fifteen seconds.
+The manner in which the sensitives are worked is by coating very light.
+In this way, a flat, shallow picture is obtained in a few seconds;
+and the same can be done with any of the more volatile quicks.
+
+It is a fact not generally known, that a plate coated in a light
+chemical room is more sensitive than when coated in darkness.
+By admitting a free, uniform light, and exposing the plate to it a few
+seconds after coating, then timing short in the camera, a very light,
+clear impression is obtained. The time in the camera is reduced
+in proportion to the previous action of light. The shades, of course,
+are destroyed, and the tone injured; still, for taking children,
+we have succeeded better by this method than by the use of "sensitives."
+The discovery of this principle was accidental, while operating where
+the direct ray s of the sun, entering the window just before sunset,
+fell on the curtain of our dark room, rendering it very light within.
+
+The selection of iodine is not unimportant. Reject, at once,
+that which has anything like a dull, black, greasy appearance;
+and select that which is in beautiful large crystalline scales,
+of a purple color, and brilliant steel lustre.
+
+Solarization, and general blueness of all the light parts
+of the picture, were formerly great obstacles to success,
+though now scarcely thought of by first-class artists. Beginners in
+the art, however, are still apt to meet with this difficulty.
+It is occasioned by dampness in the iodine box, which causes
+the plate to become coated with a hydro-iodide of silver,
+instead of the iodide. The remedy is in drying your iodine.
+If in summer, you can open your box and set it in sunshine
+a few minutes; or if in winter, set it under a stove a short time.
+The true method, however, is to dry it by means of the chloride
+of calcium. It has such a remarkable affinity for water, that a
+small fragment placed in the open air, even in the dryest weather,
+soon becomes dissolved.
+
+Take one or two ounces of this chemical, heat it in the drying bath,
+or in a hot stove, to perfect dryness; place it in a small glass toy dish,
+or large watch crystal, and set it in the centre of your iodine box.
+Take this out and heat to dryness every morning. Adopt this process,
+and with your mercury at a high temperature, you will never be troubled
+with blue pictures.
+
+Young operators are apt to impute all want of success in operating to
+their chemicals, even though the cause is quite as likely to be elsewhere.
+Failure is quite likely to occur from dampness in the buffs, or in the polish;
+it is therefore necessary to be constantly on the guard in this quarter.
+With a view to this, always scrape your buffs with a dull knife,
+or with one blade of your shears, the first thing in the morning,
+and after brushing them thoroughly, dry them, either in the sun, by a stove,
+or in the buff-dryer. It is equally important that the polish and the brush
+should be kept dry.
+
+Want of success may arise from vapors of iodine or bromine in the camera box,
+mercury bath, or even in the buffs. It is incredible how small
+a quantity of these vapors will affect the effect of light when coming
+in contact with the plate, after or during the exposure in the camera.
+It is therefore necessary to be cautious not to mix chemicals,
+nor open your boxes or bottles in your room, but take them out to do it.
+Never hurry the operation through from lack of confidence in the result.
+The fact of anything being out of order, forms no excuse for slighting
+the process. If unsuccessful, do not pursue the same course every trial,
+but vary with a view to detect the cause of the difficulty.
+
+In case of a long series of failures, institute a regular course
+of investigation, after this manner, commencing where the trouble
+is most likely to occur:
+
+1. Are the plates well cleaned?
+
+2. Is the iodine dry? If the impressions come out blue,
+you may rest assured it is not. Take out the iodine,
+wipe and dry the box, and dry the calcium.
+
+3. Is the quick battery of the right strength? If dry,
+it must change the plate in from six to fifteen seconds.
+If any of the chloride of iodine class, it may vary
+from five seconds to a minute. Begin by coating light,
+and increase on each trial, observing the effect.
+If the light side of the picture seems loth to come out,
+and shows no contrast with the dark side, it is to be inferred
+that your battery is too strong, and must be reduced with water
+or set out in the open air for a few minutes, with the lid off.
+If working an old battery, never renew very strong,
+or it will work dark and heavy. A battery, to work well,
+should be gradually losing strength, but never gaining.
+An old battery, however, may be quickened up and made to work
+well for some time, by adding five of six drops of sulphuric acid,
+repeating the quantity as often as necessary, providing always
+that acid be not used in manufacturing the quick.
+
+4. Have the plates lost their sensitiveness by being many times
+exposed to mercury? Clean and burn them; but if French plates,
+burn light, or you spoil them.
+
+5. Are the buff s dry and clean? Examine the plate critically
+after buffing to detect any appearance of scum or film on
+the surface. If so, the longer you buff the more it shows.
+Scrape and dry the buffs thoroughly.
+
+6. Is the mercury free from scum and dirt? If not, filter.
+Is it also far enough from the coating boxes? Should be at least
+three feet, and kept covered.
+
+7. Is the mercury sufficiently heated? This is important.
+Long exposure, however, will answer the same purpose.
+
+8. Are your lenses clean, and in proper place?
+
+9. Are the tablets in focus with the ground-glass? If you can attribute
+the failure to none of these, mix a new box of some other kind of quick,
+say the dry, for instance. If you fail in the same manner here,
+take time, wash your buffs, overhaul all the chemicals, and start anew.
+Do not be discouraged.
+
+There is no day so dark but that the sun will shine again.
+We will close with this brief summary of advice:
+
+Clean your plates. Keep everything dry. Keep the mercury hot.
+Follow these instructions carefully, and you must succeed.
+
+
+HINTS AND CAUTIONS.
+
+First of all, cleanliness should be observed. When there is dust or dirt
+about your room, particularly about the work-bench, failures will be frequent;
+for the smallest particles of rotten-stone, when allowed to come in contact
+with the buffs, will produce scratches on the surface of the plate,
+which very much injures the operation, and often causes failures.
+
+Dust flying about the room is injurious, if allowed to fall
+on the plate, either before or after it has been coated,
+as it causes black spots which cannot be removed.
+
+The polished plate should not be allowed to come in contact with
+a strong current of air, for it tends to oxidize the surface.
+Breathing on the surface should also be avoided, for the same reason.
+
+The plate should, in all cases, be buffed immediately
+before using, and not allowed to stand any length of time.
+It should be held with the polished face downward.
+
+It is always best that the plate should be of the same temperature
+of the atmosphere in the room.
+
+Keep the camera and mercury-bath perfectly free from the vapors
+of iodine and bromine; for the presence of the slightest degree
+of either of the above will injure the impression in no small degree.
+As a preventive, let the camera be exposed to the sun or fire
+for a few minutes in the morning.
+
+Filter your mercury often, to keep the surface free from film and dust.
+
+The hyposulphite solution should be filtered through sponge every
+time it is used.
+
+The direct rays of light must not enter the camera in conjunction
+with those reflected from the object; or the picture will be veiled,
+and the color of the plate changed to a thick green.
+
+If the plate be iodized only to a light-yellow, the result might
+be of a bluish or grey tinge: and this is generally the case,
+when the quick is new and strong, and there is an excess of it on
+the plate, and yet not enough to form the bromide iodide of silver;
+in which case it would wholly spoil the impression.
+
+Your iodine will be found to operate more successfully, when the time
+required for coating the plate does not fall short of fifteen seconds,
+or exceed one minute.
+
+Too quick coating can be avoided by using less iodine in your box.
+In the summer months, when the weather is 80 deg. and over,
+one quarter of an ounce, or even less, will work to advantage.
+
+
+ELECTROTYPING.
+
+I am indebted to Mr. J. H. Fitzgibbons for the following process,
+which he employed in producing the excellent specimens he exhibited
+at the Crystal Palace:
+
+"I shall endeavor to lay down in as comprehensive a manner as possible the
+method by which I have been enabled to produce the most satisfactory results.
+I use a Smee's battery (another kind will do). After filling the cell,
+of common size, nearly full with water; add about quarter of an ounce
+of sulphuric acid. Mix this well, and let it stand for about three hours,
+or until the action of the battery becomes weak, when it is in order to work
+with a very uniform action. Put one pound of sulphate of copper in one quart
+of water; stir it until the sulphate of copper is all dissolved, and then add
+one half ounce of sulphuric acid and a quarter of an ounce of nitric acid.
+This solution, well mixed, should be filtered, and it is ready for use.
+It is very important that the solution should be kept clean, clear, and free
+from all foreign substance. The above quantity of this solution will be
+found sufficient for electrotyping a dozen of the sixth-size plates.
+When it is required to be strengthened, it is only necessary to add a little
+of the sulphate of copper.
+
+"With the battery prepared as above, and the solution of sulphate
+of copper in a vessel of proper dimensions to receive your plate,
+connect the galvanic current, and immerse the impressioned plate,
+letting it remain until a thin film of copper has been formed,
+then the battery can be strengthened, and the impression will be
+of sufficient thickness to be removed in from eight to twelve hours.
+An old Daguerreotype plate attached to the opposite pole of the battery
+(copper side towards the face of the plate to be electrotyped),
+will answer the same purpose as the silver-plate.
+
+"The great difficulty in taking an electrotype impression, and preserving
+the original, has been attributed to the battery being too powerful.
+I am led to believe from practice that the principal difficulty has been
+in the Daguerreotype plate itself, for if we use an impression that has
+been taken but a few days, and taken in the usual way, we will find
+it difficult to succeed without spoiling both the copy and original,
+and so also with an old impression.
+
+"I have found the most certain method to be as follows:--
+Coat the Daguerreotype plate as usual, except use less of
+the accelerators, the proportion of iodine coating being greater,
+of course the time of exposure in the camera will be lengthened.
+Mercurialize it at about a temperature requiring to develop the image,
+from six to eight minutes, at least. Gilding the Daguerreotype
+has much to do towards producing a good electrotype copy.
+This should be done by applying a little heat, and gilding very slowly,
+giving a coating of gold with the greatest possible uniformity.
+By this method, I have been enabled to produce any number of proofs.
+I have produced a dozen from one impression, and it remains
+as perfect as when first taken.
+
+"By a little judgment and care the operator will be enabled to produce
+the electrotype copy of the Daguerreotype plate without any difficulty.
+The electrotype copy should be immediately put under a glass and sealed
+in the same manner as the ordinary Daguerreotype."
+
+
+CRAYON DAGUERREOTYPES.
+
+This process is patented in the United States, by J. A. Whipple, of Boston,
+and of course no honorable person will use it for his own benefit without
+purchasing a right.
+
+A white back-ground is generally employed, the object being to blur
+the lower portion of the plate, leaving the head of the subject in relief.
+Every Daguerreotypist is familiar with the fact that a motion
+of any body between the camera and the sitter will cause a "blur."
+Cut a piece of thin paper and scallop it, making a semicircle.
+This is kept straight by means of a wire frame, and it is to be moved
+in front of the lower part of the body of the sitter during the time
+of exposure of the plate in the camera. Develop over mercury as usual,
+and the result will be a crayon Daguerreotype.
+
+Another method is to have a wheel with a hole cut through
+it of a diameter of about 12 inches. This hole is so cut
+as to leave teeth resembling those of a large saw.
+This wheel is so arranged that it can be turned around,
+which should be done during the time of exposure in the camera.
+It must be placed between the camera and the sitter, and at such
+a distance from the camera as to allow such proportion of the body
+of the sitter be seen upon the ground-glass as is desired.
+It will be readily seen that by turning this wheel during
+the operation will produce the same result as the paper being
+moved in the other method. The teeth make the "blur."
+The side of the wheel towards the camera may be black, by which
+means the result will be a dark instead of a light border.
+
+
+ILLUMINATED DAGUERREOTYPES.
+
+This process is also patented, and the remarks on the preceding subject
+will apply in this case. The plate is prepared and exposed as in the
+usual method of the Daguerreotype. A white back-ground is employed.
+Let the head of the sitter come in the middle of the plate, and before
+exposing it to the vapors of mercury, put a small mat or diaphragm,
+having a small hole through it, over or directly on the surface of the plate.
+This diaphragm should be bevelled, and the bevel should be towards the surface
+of the plate; this, in order to prevent too sharp a line on the impression.
+It will be readily seen that if an impressioned plate so covered is placed
+over the mercury, it will be developed on such portions only as are exposed.
+The principle is so familiar that further explanations are unnecessary.
+
+
+NATURAL COLORS IN HELIOGRAPHY.
+
+This subject is worthy the attention of every operator. The following
+process is so plain and easy of trial that any Daguerreotypist can try it.
+This is as given by Mr. James Campbell, and was published in Humphrey's
+Journal of the Daguerreotype and Photographic Arts, vol. 5, page 11.
+Mr. Campbell has done much to further the process announced by M. Neipce,
+and his experiments have proved highly successful.
+
+The following is submitted as worthy of trial:
+
+"The proper preparation of the chloridated plate, to enable it to receive
+colored impressions is an object of the first importance to those wishing
+to experiment on it, and consequently requires particular notice.
+The plate may be prepared by making it the positive pole of a battery,
+and letting it at the same time be immersed in chlorine water.
+The negative pole should be a slip of platinum. All the colors may
+be produced from a plate so prepared if the chlorine and water are in
+the right proportions; but generally one color or the other predominates,
+according to the amount of chlorine in the liquid. By adding the chlorides
+of strontian, uranium, potassium, sodium, iron, or copper to the liquid,
+various effects may be produced, and these bodies will be found to produce
+the same color on the plate that their flame gives to alcohol.
+
+"The honor of this discovery is due to M. Neipce.
+Copper gives a variegated flame; hence many colors may be
+impressed on a plate prepared with a solution of its chloride.
+
+"M. Neipce recommends a solution of the mixed chlorides of copper
+and iron, and it is with these, that I have been most successful.
+As the chlorides of copper and iron are not much used in the arts,
+they are not generally found for sale in the shops; and it may be
+well to furnish those not much versed in chemistry with an easy
+method of preparing them.
+
+"They may be made directly from either metal by dissolving it
+in hydrochloric acid; but they may be formed by a cheaper method,
+and by which also the acid fumes are avoided.
+
+"Sulphate of iron or copper, or both together, may be dissolved
+in water and then neutralized with common crude potash, or its
+carbonate or bicarbonate--known commonly as pearlash and saleratus.
+If either of the latter be used, there will be formed sulphate
+of potash and a carbonate of the metal used, and there will also
+be a considerable effervescence of carbonic acid, which will,
+if care is not taken, cause the mixture to run over the vessel.
+After the copper or iron salt is neutralized, which is known
+by its ceasing to effervesce, the carbonate of the metal
+will settle slowly, and will at first nearly fill the vessel.
+The supernatant fluid, which is sulphate of potash in solution,
+may now be carefully poured off, and its place filled with water;
+this operation should be repeated several times until the water which
+passes off is tasteless. The carbonate of the metal rapidly changes
+to an oxide by contact with the air, and it will generally be found,
+when it is sufficiently washed, that it is at least half oxide.
+On adding hydrochloric acid cautiously to the mixture, a chloric
+of the metal will be formed, and carbonic acid will be evolved
+from the remaining carbonate. The chloride formed is soluble;
+but as there are two chlorides of these metals, and we wish
+to produce the one which contains the most chlorine, it is best
+to add the acid cautiously until the solution is decidedly acid.
+After filtering the solution, it is fit for use; and it should be
+preserved in well-stoppered bottles. The water used should be rain
+or distilled water.
+
+"About one part of the mixed chlorides should be used to three
+or four of water.
+
+"The battery may be either Smee's, Daniell's, or Grove's;
+if of either of the former, it should be of two series;
+if of the latter, one cup is sufficient.
+
+"The plate on being immersed in the liquid, almost instantly takes
+a violet color. It should be allowed to remain from two to five minutes,
+according to the strength of the battery, and until it becomes nearly black.
+It should now be carefully washed, and afterwards heated over a spirit
+lamp until it takes a cherry-red color, and it is then ready for exposure
+in the camera. Before speaking of exposing the plate, it may be well
+to speak of some difficulties which the inexperienced operator may find
+in preparing it. If the battery is not in good order, and a sufficient
+current is not passed through the solution, the plate will become coated--
+and apparently almost as well as when the battery is working well--
+but on exposure it will give a negative picture, and but little colored;
+while if the battery is in good order, the impression is invariably positive.
+
+"Sometimes on heating the plate after washing, the surface
+is covered with spots or assumes a variegated appearance.
+This indicates that the solution is impure, or that the plate
+have not been thoroughly washed and are still contaminated
+with the soluble chlorides which are contained in the solution.
+
+"From the fact that the plate if prepared with positive electricity gives
+a positive picture, while it prepared otherwise it gives a negative,
+it is evident that electricity plays an important part in this process.
+The same is true to some extent with the compounds formed
+with iodine, bromine. and fluorine.
+
+"On heating the plate, the brown coating of chloride melts into a translucent
+enamel, and the heat should be withdrawn when a cherry-red color is produced.
+It the heat is continued longer, the plate assumes a lighter color,
+and becomes less sensitive; and the enamel will finally scale off.
+To produce a picture by the ordinary process of M. Neipce, unaccelerated, it
+should be exposed for from three to five hours to sunlight in the camera,
+though pictures may be procured by contact, in from fifteen to thirty minutes."
+
+
+MULTIPLYING DAGUERREOTYPES ON ONE PLATE.
+
+I have produced some interesting specimens of the Daguerreotypic art,
+by exposing in the camera only a portion of the sensitive plate to
+the action of light. When on the exposed portion an image is formed,
+then taking the tablet into the dark room, change ends and expose
+the sensitive portion, and produce another image, developing as usual.
+This plan is adapted for taking likenesses for lockets.
+Two images can be presented as sitting side by side, by covering
+half the plate with black paper, and exposing as before.
+In this manner we have been enabled to surprise persons by exhibiting
+their portrait on the same plate with a stranger's. Daguerreotypists
+must be cautious in practicing this, as it might not be agreeable
+to the parties whose likenesses are together, by the above process.
+It is impossible to produce an impression without a line being seen
+where the edge of the paper prevented the operation of the light.
+
+I have recently seen a fine specimen produced by another plan,
+which far exceeds the above, there being no line, or any
+peculiarity denoting two exposures. The specimen referred to,
+was a gentleman represented on one plate by two full length portraits.
+This was produced by using a black velvet for the background.
+The plate was exposed sufficient time to produce one impression,
+and then the gentleman assumed another position, and is repeated
+as looking at himself. From the fact that the time required to develop
+black velvet being so much longer than that for producing a portrait,
+we are enabled to produce the above interesting results.
+
+
+DEPOSIT IN GILDING.
+
+Regarding specks from bad water, I would remark that gilding
+should be made only with distilled water. Thus made,
+it produces very little deposit, even by long keeping.
+It therefore preserves its original strength, and works
+with great uniformity.
+
+Every grain of deposit contains at least 7-10 its
+weight of gold, easily discoverable by the blowpipe.
+Such gilding is continually deteriorating, which with
+good chloride and distilled water may be prevented.
+Distilled water should also be used for the hyposulphite.
+and for cleaning plates. Any good, clear water may be
+afterwards used for washing off, with equally good results.
+I am very rarely troubled with specs, and deem this as
+the main reason.
+
+With a portable still attached to a cooking stove, I obtain
+half a gallon of water per hour, and with very little trouble.
+A small tin retort or still connected with a Leibig's condenser,
+would not add much to the "traps" of the travelling operator,
+and save him many a disreputable specimen.--T. J. BAILEY.--
+Humphrey's Journal.
+
+
+PRACTICAL HINTS ON THE DAGUERREOTYPE.
+
+The following is from Humphrey's Journal, vol. 5, and from the pen
+of Dr. WM. HARRINGTON, one of the most able writers upon the subject
+of the Daguerreotype in this country:
+
+
+THE CAUSE OF THE DIFFICULTY THAT SOMETIMES OCCURS TO PREVENT THE
+PRODUCTION OF A CLEAR IMPRESSION UPON A DAGUERREOTYPE PLATE.
+
+Beyond all doubt this is traceable to dampness.
+Truly this is not a new thought; but where does this dampness
+come from? How does it originate, and where is it located?
+Generally it has been referred to a point entirely remote
+from its real location.
+
+This dampness exists particularly upon the surface of the plate;
+is obviously derived immediately from the atmosphere;
+and is owing to a certain relative temperature of the plate
+with the hygrometric condition of the atmosphere.
+
+Whenever this relation exists between the plate and atmosphere,
+a precipitation of moisture takes place upon the surface of
+the plate, which render all efforts at polishing impracticable.
+This interference is not confined to the buffing operation alone,
+but sometimes is discoverable even in the ordinary process of scouring.
+Every one at all experienced in this art will remember that it
+is not always an easy matter for him, by scouring, to bring his
+plate to the desired lustre. All his efforts become unavailing;
+the more he rubs, the duller the surface of his plate appears;
+and although he renews his cotton repeatedly, still he is obliged
+to content himself with an unsatisfactory finish.
+
+This relative condition is not confined to any particular season
+of the year, nor to any certain thermometric temperature;
+but may occur in summer as well as in winter; the weather being
+warm or cold, wet or dry, clear or cloudy, raining or shining.
+Under any of these circumstances, if the relation of the plate
+and atmosphere be such as to invite upon the plate a precipitation
+of humidity from the atmosphere, the prospect of producing a clear
+impression is quite problematical.
+
+It is reasonable to expect this occurrence from the fact that metal is a
+good radiator, and radiation reduces the temperature of a metallic body below
+that of the atmosphere. Consequently, if this relative condition happens,
+the result will be as I have stated.
+
+Bodies may be colder than the atmosphere and yet derive no moisture from it;
+while at the same time the driest atmosphere is not devoid of moisture,
+but will part with it under certain conditions.
+
+Assuming for granted that this relative condition between
+the plate and atmosphere, disposing the former to receive
+the humidity of the latter, constitutes the great obstacle
+the operator has to contend with in producing, a clear
+proof upon the plate, the remedy naturally suggests itself,
+and is very simple. It consists in merely heating the plate
+above the temperature of the atmosphere, previous to polishing,
+and retaining that temperature during the operation.
+Various measures might be devised to effect the desired object;
+one of which consists of a sheet-iron box, heated from the inside
+by a spirit-lamp, upon the top of which are to be kept
+the plates ready to undergo the process of being polished;
+the blocks of the swing or any other vice; or the iron bed
+belonging to Lewis's vice.
+
+In cold weather, when it is necessary to keep a fire in the preparation room,
+all of the above may be so arranged in the vicinity of the fire as to receive
+the requisite degree of heat for the purpose specified.
+
+This part of the subject, however, is left entirely for the ingenuity
+of the operator. No matter by hat means he accomplishes the object;
+all that is required is to heat the plate above the temperature of
+the atmosphere and retain that heat during the process of polishing.
+
+Since the adoption of this method. in connection with my partner,
+T. J. Dobyns, even in this humid climate of ours, when everything
+in the room is dripping with moisture, it has been attended
+with invariable success.
+
+
+CHOICE OF PLATES, ETC.
+
+In the great catalogue of complaints made by operators,
+none is more common than that alleged against the quality
+of plates in general use. Although the greatest diversity
+of opinion exists upon this subject, nevertheless the plates
+of every manufactory share in this universal condemnation.
+
+To be sure it cannot be denied but that this necessary article
+of utility in the photographic art has undergone a sad deterioration
+in quality owing to the increasing demand and great reduction in price--
+the plates of the present day being by no means so heavily coated
+with silver as formerly--but the complaint alluded to is not predicated
+so much upon the thinness of silver as upon a mysterious something
+which has conferred upon the plates the epithet of not good.
+
+That this complaint is in a great measure groundless appears evident
+from the fact that while, with the same brand of plates one operator can
+work successfully, another encounters the greatest difficulty; while one
+is able to produce beautifully clear and altogether satisfactory results,
+the other labors under the troublesome annoyance of innumerable specks,
+large dark insensitive patches and brown map-like portions, together with
+divers other blemishes, sufficient to prevent him from obtaining anything
+like a tolerable impression.
+
+From this wide difference in the results of the two operators using
+identically the same article, it is but reasonable to conclude
+that the complaint is founded in error; while the inference
+is no more than just, that the fault may be traced to a want
+of practical skill on the part of the complaining operator himself;
+rather than to the inferior quality of the plates.
+
+The question, then, whether the plates are unfit for use,
+or whether those who pronounce them so understand
+how to use them, appears to be satisfactorily answered.
+It therefore becomes a matter worthy of investigation,
+to ascertain what superior judgment and skill one operator
+possesses over another which enable him to work successfully
+a quality of plate, pronounced by the other entirely useless.
+
+Suppose we make a critical examination of one of the repudiated plates.
+From its external appearance we have little hesitation in pronouncing it
+to be French; indeed, this presumption is strongly corroborated by the fact
+that it is ornamented upon one of its corners with a brand to designate
+the manufactory from which it emanated.
+
+Upon close inspection we cannot fail to notice a striking peculiarity
+upon the surface; the roughness is very remarkable; the planishing
+hammer has left amazingly visible indications of its busy work.
+One would suppose the manufacturer intended the surface of the plate
+to represent the undulations of the sea, instead of that smooth
+and level character so strongly recommended by M. Daguerre.
+
+Such a plate necessarily requires at the hand of the operator
+considerable labor before the surface is in a proper
+condition to receive a suitable polish from the buffer.
+The least reflection in the world should teach any one that so long
+as the undulatory character continues upon the surface of the plate,
+it is in a very imperfect condition for buffing, because the buffer
+cannot touch every point equally; the elevated portions alone
+receiving a high degree of polish while the depressed portion,
+from their roughness acting as nuclei, gather dust, rouge,
+and other foreign bodies, so detrimental to sensitiveness.
+The secret of the superior judgment and skill of one operator
+over another, is intimately connected with this point:
+his success depends very much upon the first process of
+cleaning the plate.
+
+Let us examine the manipulation of the complaining operator.
+He takes one of these plates and gives it a careful scouring with
+rotten-stone and alcohol or any other liquid preferred for this part
+of the operation--that is, he gives it what he terms a careful scouring--
+very gently indeed because, from the frequent trials he is in
+the habit of making in the camera, he fears he will rub the silver
+entirely away before he succeeds in obtaining a good impression.
+The dark patches, specks, and granular appearance resulting entirely
+from the unevenness of the surface of the plate, look like copper to him,
+and he is surprised that he should have rubbed away the silver so soon,
+particularly by such delicate handling.
+
+The judgment and experience of the successful operator, however,
+teach him that scouring injures a plate less than buffing.
+He knows that unless the hammer marks be obliterated,
+he cannot by the buffer produce a surface of uniform polish
+and sensitiveness, without which a fair proof is extremely doubtful;
+he knows that the time employed in the preliminary operation
+of cleaning the plate properly is economy.
+
+There is a style of French plates in the market, denominated heavy,
+which are truly excellent, if properly managed. Much patience, however,
+is required to remove the marks of the hammer; but with tripoli and alcohol
+the surface is readily cut down, and the plate is then susceptible of a
+beautiful black lustre by polishing with the buffer. The complaining
+operator could not succeed by his own method with one of the plates;
+he would encounter all manner of clouds and other unaccountable phenomena;
+he would imagine this plate entirely worn out before it was half cleaned,
+and soon fix in his own estimation the reputation of the heavy plate.
+
+In making a choice of plates, therefore, it would appear to be a matter
+of perfect indifference with an experienced operator what kind he would use,
+except so far only as the labor required in cleaning them was to be
+taken into consideration.
+
+The distinction between a scale plate, a Scovill No. 1,
+S. F., heavy A, star, crescent, eagle, or any other brand,
+consists in the superior finish of some, and the thinness
+of the silver in the cheaper qualities.
+
+Consequently, let the complaining operator but employ the diligence
+inculcated in this article, to clean his plate thoroughly,
+so as to bring it to a perfectly even and level surface,
+and he will seldom be troubled with specks, clouds, dark patches,
+and the host of other obstacles which heretofore have tormented him.
+
+
+
+CHAPTER VI.
+
+AN ACCOUNT OF WOLCOTT AND JOHNSON'S EARLY EXPERIMENTS, IN THE DAGUERREOTYPE.
+BY JOHN JOHNSON.
+
+[From Humphrey's Journal, vol. ii 185l]
+
+As a general thing, however perfect any invention may be deemed
+by the inventor or discoverer, it falls to the lot of most,
+to be the subject of improvement and advancement, and especially
+is this the case with those new projects in science which open
+an untrodden field to the view of the artisan. Such has been,
+in an eminent degree, the case with the discovery first announced
+to the world by Mons. Jean Jaques Claude Daguerre, of Paris,
+in the year 1839, and which excited unbounded astonishment,
+curiosity and surprise. It may be questioned had any other
+than Daguerre himself discovered a like beautiful combination,
+whether the world would have been favored with details exhibiting
+so much care, patience and perseverance as the Daguerreotype
+on its introduction. Shortly after, these details reached
+the United States, by Professor S. F. B. Morse, of New York,
+who was, at the time of the discovery, residing in Paris.
+By this announcement, the whole scientific corps was set in operation,
+many repeating the experiments, following carefully the directions
+pointed out by Daguerre, as being necessary to success.
+Among the number in the United States, was Alexander S. Wolcott
+(since deceased) and myself; both of this city. On the morning
+of the 6th day of October, 1839, I took to A. Wolcott's residence,
+a full description of Daguerre's discovery, he being at
+the time engaged in the department of Mechanical Dentistry,
+on some work requiring his immediate attention, the work being
+promised at 2 P.M. that day; having, therefore, no opportunity
+to read the description for himself (a thing he was accustomed
+to do at all times, when investigating any subject). I read to him
+the paper, and proposed to him that if he would plan a camera
+(a matter he was fully acquainted with, both theoretically and
+practically), I would obtain the materials as specified by Daguerre.
+This being agreed to, I departed for the purpose, and on my
+return to his shop, he handed me the sketch of a camera box,
+without at all explaining in what manner the lens was to be mounted.
+This I also undertook to procure. After 2, P.M., he had
+more leisure, when he proceeded to complete the camera,
+introducing for that purpose a reflector in the back of the box,
+and also to affix a plate holder on the inside, with a slide to obtain
+the focus on the plate, prepared after the manner of Daguerre.
+While Mr. Wolcott was engaged with the camera, I busied myself
+in polishing the silver plate, or rather silver plated copper;
+but ere reaching the end preparatory to iodizing, I found I had
+nearly or quite removed the silver surface from off the plate,
+and that being the best piece of sliver-plated copper
+to be found, the first remedy at hand that suggested itself,
+was a burnisher, and a few strips were quickly burnished
+and polished. Meantime. the camera being finished, Mr. Wolcott,
+after reading for himself Daguerre's method of iodizing,
+prepared two plates, and placing them in the camera,
+guessed at the required time they should remain exposed
+to the action of the light; after mercurializing each in turn,
+and removing the iodized surface with a solution of common salt
+two successful impressions were obtained, each unlike the other!
+Considerable surprise was excited by this result, for each plate
+was managed precisely like the other. On referring to Daguerre,
+no explanation was found for this strange result; time, however,
+revealed to us that one picture was positive, and the other negative.
+On this subject I shall have much to say during the progress
+of the work. Investigating, the cause of this difference occupied
+the remainder of that day. However, another attempt was agreed upon,
+and the instruments, plates, etc., prepared and taken up
+into an attic room, in a position most favorable for light.
+Having duly arranged the camera, I sat for five minutes,
+and the result was a profile miniature (a miniature in reality,)
+or a plate not quite three-eighths of an inch square. Thus, with much
+deliberation and study, passed the first day in Daguerreotype--
+little dreaming or knowing into what a labyrinth such a beginning
+was hastening us.
+
+[Description of apparatus represented on pages 192 and 199:]
+
+ A.--The Box--about 4 inches long by about 2 outside diameter.
+ B.--The Reflector soldered to a brass screw, and mounted in the
+ rear of the box.
+ c.--The slide to regulate the focus to the plate holder.
+ d.--The standard to the plate holder screwed to the slide.
+ f.--The plate-holder frame having two small ledges, * *, for the
+ plate to rest upon.
+
+[page 192]
+
+ g.--The plate resting upon the ledge., * *, and kept against the
+ frame by the spring h. The plates used were about 3/8 of an inch
+ square.
+ A.--The window with the sashes removed.
+
+B and C (p. 199) are large looking-glasses mounted as plain reflectors,
+the lower one C having rotary motion upon the saddle, resting upon the sill
+of the window in order to direct the rays of the sun upon the reflector B,
+at any hour of the day--the vertical motion of the reflector C
+
+[amdg_12.gif]
+
+being necessary, the sun varying in altitude so much during
+the hours most favorable to the production of portraits.
+The reflector C was
+
+[page 193]
+
+kept up to the required position by the handle lever, upright post and bolts.
+Reflector B was hinged at its upper end at the top of the window frame,
+the only motion being necessary was that which would reflect upon the sitter
+the incident rays from reflector C--the reflector B being kept at the required
+angle by the connecting lever m, etc. Suitable back-grounds were placed
+behind the sitter.
+
+The reflector B and C, had frequently to be renewed, the heat of the sun
+soon destroying their brilliance or power of reflecting, light,
+before renewing them, however, we resorted to the springing of them,
+by which means their power was increased for a period.
+
+The camera or reflecting apparatus, invented by Mr. Wolcott,
+was, from the nature of the case, better adapted at that day
+to the taking of portraits from life, than any other instruments.
+After carefully examining the camera described by Daguerre,
+and the time stated as necessary to produce action for an image,
+it became evident to the mind of Mr. Wolcott at once, that more light
+could be obtained (as the field of view required was not large)
+by employing a reflector of short focus and wide aperture, than from
+a lens arrangement, owing to spherical aberration and other causes.
+Many experiments having been tried with the small instrument figured
+(p. 199), a reflector for taking portraits from life was determined on,
+having eight inches diameter, with twelve inches focal distance
+for parallel rays; this was to admit plates of two inches wide
+by two and a half long Mr. Wolcott having on hand reflectors
+of the right diameter, for Newtonian telescopes, of eight feet
+focal distance, resolved (as it was a matter of experiment)
+to grind down or increase the curve for the focal distance before named--
+this required time. In the mean time, many plans were pursued
+for making good plates, and the means of finishing, them. As the
+completion of the large reflector drew to a close, our mutual friend,
+Henry Fitz, Jr., returned from England, whither he had been on a visit,
+and when he heard what we were about, kindly offered his assistance;
+he being well versed in optics, and having been before engaged with
+Mr. Wolcott, in that and other business is offer was gladly accepted--
+Mr. Wolcott himself having frequent engagement; to fill as operator
+in the details of mechanical dentistry. Thus, by the aid of Mr. Fitz,
+the reflector was polished, and experiments soon after tried on
+plates of two by tow and a half inches, with tolerable success.
+Illness on my part quite suspended further trial for nearly four weeks.
+
+On my recovery, early in January, 1840, our experiments were
+again resumed with improved results, so much so as to induce
+Mr. Wolcott and myself to entertain serious thoughts of making
+a business of the taking of likenesses from life, intending to
+use the reflecting apparatus invented by Mr. Wolcott, and for
+which he obtained Letters Patent, on the 8th day of May, 1840.
+Up to January 1st, 1840, all experiments had been tried on
+an economical scale, and the apparatus then made, was unfit
+for public exhibition; we resolved to make the instruments as
+perfect as possible while they were in progress of manufacture.
+Experiments were made upon mediums for protecting the eyes from
+the direct light of the sun, and also upon the best form and
+material for a back-ground to the likenesses. The length of time
+required for a "sitting," even with the reflecting apparatus,
+was such as to render the operation anything but pleasant.
+Expedients were ever ready in the hands of Wolcott: blue glass
+was tried and abandoned in consequence of being, at that time,
+unable to procure a piece of uniform density and surface:
+afterwards a series of thin muslin screens secured to wire
+frames were prepared as a substitute for blue glass.
+The objections to these screens, however, were serious,
+inasmuch as a multiplication of them became necessary to lessen
+the intensity of the light sufficiently for due protection
+to the eyes, without which, the likenesses, other than profiles,
+were very unpleasant to look upon. Most of the portraits,
+then of necessity were profiles formed upon back-grounds,
+the lighter parts relieved upon black, and the darker parts upon
+light ground; the back-ground proper being of light colored
+material with black velvet so disposed upon the light ground,
+this being placed sufficiently far from the sitter, to produce
+harmony of effect when viewed in the field of the camera.
+Other difficulties presented themselves seriously to the
+working of the discovery of Daguerre, to portrait taking--
+one of which was the necessity for a constant and nearly
+horizontal light, that the shaded portions of the portrait
+should not be too hard, and yet, at the same time,
+be sufficiently well developed without the "high light"
+of the picture becoming overdone, solarized or destroyed.
+In almost all the early specimens of the Daguerreotype,
+extremes of light and shade presented themselves,
+much to the annoyance of the early operators, and seriously
+objectionable were such portraits. To overcome this difficulty,
+Mr. Wolcott mounted, with suitable joints, upon the top
+of his camera, a large looking-glass or plane reflector,
+in such a manner that the light of the sun (as a strong light
+was absolutely necessary), when falling upon the glass could
+be directed upon the person in an almost horizontal direction.
+
+Early in February, 1840, Mr. Johnson, Sen., (since deceased) sailed for
+Europe with a few specimen likenesses taken with the instruments
+completed as above, with the intention of patenting the invention.
+On his arrival a joint arrangement was effected with Mr. Richard Beard,
+of London, in patenting and working the invention in England.
+Up to February, 1840, but few friends had been made acquainted
+with the progress of the art in the hands of Mr. Wolcott and myself.
+From time to time reports reached us from various sources
+of the success of others, and specimens of landscapes,
+etc., were exhibited at Dr. James R. Chilton's laboratory,
+in Broadway, much to the gratification of the numerous visitors
+and anxious expectants for this most wonderful discovery.
+Dr. Chilton, Professor J. J. Mapes, Professor J. W. Draper.
+Professor S. F. B. Morse, all of this city; Mr. Cornelius,
+Dr. Goddard and others of Philadelphia; Mr. Southworth,
+Professor Plumbe, and numerous others were early in the field;
+all, however, using the same description of camera as that of Daguerre,
+with modification for light, either by enlargement by lens
+and aperture for light, or by shortening the focal distance.
+
+At a conversational meeting of the Mechanics' Institute, Professor J. J. Mapes
+being present, a question was asked if any one present could give
+information relative to portraiture from life by the Daguerreotype.
+Mr. Kells, a friend of Mr. Wolcott and a scientific and practical man
+(sinced deceased), at once marked out upon the black-board, the whole
+as contrived by Mr. Wolcott. This gave publicity to the invention
+of Mr. Wolcott. Shortly after, Professor Mapes, Dr. Chilton,
+and many others, sat for their portraits, and were highly gratified.
+Professor Morse also came and proposed to Mr. Wolcott to join him
+in the working of the invention, etc.
+
+From this time much interest was manifested by our friends in our progress.
+Rooms were obtained in the Granite Buildings, corner of Broadway
+and Chambers street, and fitted for business. The rooms being small,
+it was soon found impracticable to use the arrangement of looking-glass,
+as previously spoken of; a new plan became necessary, to introduce which,
+the sashes were removed,
+
+[page 199]
+
+and two large looking-glasses were mounted in proper frames, thus:--
+
+[amdg_13.gif]
+
+Just in front, and between the sitter and
+
+[page 200]
+
+the reflector, upon a proper stand, were used those paper
+muslin screen before described; also screens of tissue paper.
+These screens. however, when they were used, required so much
+time for a sitting, that some other medium, as a protection
+to the eyes, became absolutely necessary. The most plausible
+thing that suggested itself was blue glass; but, as this could
+not be found, numerous were the expedients proposed by the
+friends of the art, who from time to time visited our rooms.
+At the suggestion of Professor Mapes (who is ever ready to assist
+those in perplexity), a trough of plate glass s, about twenty-eight
+inches square in the clear, and from three to four inches thick,
+was filled with a solution of ammonia sulphate of copper,
+and mounted on the frame as in the sketch, which, for a time,
+answered extremely well; soon, however, decomposition of this
+solution became apparent from the increased length of time
+required for a sitting, although to the eye of an observer,
+no visible cause for such long sittings could be pointed out.
+Professor Mapes being appealed to, suggested that to the above
+solution a little acid be added which acted like a charm--
+shortening the time for a sitting from six, eight, or ten
+minutes to that of about one. Decomposition, however, would go
+on by the action of light and heat through the solution.
+New solutions were tried, when the whole were finally
+abandoned as being, too uncertain and troublesome.
+(The reflecting apparatus R, was placed upon the stand
+as in the sketch, with a wedge for elevating the camera,
+between it and the table, to obtain the image properly upon
+the plate.) A quantity of blue window glass was next obtained,
+and holes drilled through the corners of it, and several sheets
+were wired together to increase the size, and, when complete,
+was suspended from the ceiling in its proper place, and so arranged
+that when a person was sitting, this sheet of glass could be moved
+to and from, the object of which was to prevent shadows on the face
+of the sitter produced from the uneven surface of the glass.
+This latter contrivance was used until a perfect plate
+of glass was procured.
+
+The number of persons desirous of obtaining, their miniatures,
+induced many to entertain the idea of establishing themselves in the Art
+as a profession, and numerous were the applications for information;
+many persons paying for their portraits solely with the view of seeing
+the manner of our manipulations, in order that they might obtain
+information to carry on likeness-taking as a business.
+
+The reflecting camera being a very troublesome instrument
+to make, and difficulties besetting us from every source,
+but little attention could be given to teaching others;
+and, indeed, as the facts seemed to be at this time,
+we knew but little of the necessary manipulations ourselves.
+In course of time, several established themselves.
+The first one, after ourselves, who worked the discovery
+of Daguerre for portrait taking in this city, was a Mr. Prosch;
+followed soon after by many others, in almost all cases copying
+the reflecting arrangement for light, as figured above,
+many using it even after we had long abandoned that arrangement
+for a better one.
+
+Innumerable obstacles to the rapid advance of the daguerreotype,
+presented themselves almost hourly, much to the annoyance
+of ourselves, and those dependent upon our movements for
+their advancement. Among the most difficult problems of the day,
+was the procuring of good plates. Messrs. Corduran & Co.
+were among the first to supply the trade; at that early day,
+however, it was a very rare thing, to be able to procure an even
+perfect surface, from the fact that a pure surface of silver
+could scarcely be obtained, the manufacturers deeming it too
+much trouble to prepare silver plated copper with pure silver--
+the result was, that in attempting to polish perfectly
+such plated metal as could be procured, the plates would
+become cloudy, or colored in spots, from the fact of having
+more or less alloy, according as more or less of the silver
+surface was removed in polishing the plate fit for an impression.
+To explain more clearly, it was the practice of most silver
+platers to use an alloy for silver-plating. In the reduction
+of the ingot to sheet metal, annealing has to be resorted to,
+and acid pickles to remove oxides, etc. The number of times
+the plated metal is exposed to heat and acid in its reduction
+to the required thickness, produces a surface of pure silver.
+The most of this surface is, however, so rough as to be
+with difficulty polished, without in places removing entirely
+this pellicle of pure metal, and exposing a polished surface
+of the alloy used in plating. Whenever such metal was used,
+very unsightly stains or spots frequently disfigured the portraits.
+The portrait, or portion of it, developed upon the pure silver,
+being much lighter or whiter than that developed upon the alloy;
+it therefore appeared that the purer the silver, the more
+sensitive the plate became. Accordingly, we directed Messrs.
+Scovills, of Connecticut, to prepare a roll of silver-plated metal,
+with pure silver; it fortunately proved to be a good article,
+but, unfortunately, a pound of this metal (early in 1840)
+cost the round sum of $9. Like descriptions of metal,
+the same gentlemen would be glad to furnish, at this time,
+for $4. Soon after this, some samples of English plated metal,
+of a very superior quality, came to our possession, and relieved
+us from the toil of making and plating one plate at a time,
+an expedient we were compelled to resort to, to command material
+to meet the pressing demands for portraits.
+
+Having it now in our power to obtain good plated metal,
+a more rapid mode of polishing than that recommended by Daguerre
+was attempted as follows:
+
+This metal was cut to the desired size, and having a pair of "hand rolls"
+at hand, each plate, with its silvered side placed next to the highly
+polished surface of a steel die, was passed and repassed through the rolls
+many times, by which process a very smooth, perfect surface was obtained.
+The plates were then annealed, and a number of plates thus prepared
+were fastened to the bottom of a box a few inches deep a foot wide,
+and eighteen inches long; this box was placed upon a table and attached
+to a rod connected to the face plate of a lathe, a few inches from
+its centre, so as to give the box a reciprocating motion. A quantity
+of emery was now strewn over the plates, and the lathe set in motion.
+The action produced wag a friction or rubbing of the emery over the surface
+of the plates.
+
+When continued for some time, a greyish polish was the result.
+Linseed, when used in the same manner, gave us better hope
+of success, and the next step resorted to was to build
+a wheel and suspend it after the manner of a grindstone.
+The plates being secured to the inner side of the wheel or case,
+and as this case revolved, the seeds would constantly keep to
+the lower level, and their sliding over the surface of the plates
+would polish or burnish their surfaces. This, with the former,
+was soon abandoned; rounded shots of silver placed in the same
+wheel were found not to perform the polishing so well as linseed.
+Buff-wheels of leather with rotten-stone and oil, proved to be far
+superior to all other contrivances; and, subsequently, at the suggestion
+of Professor Draper, velvet was used in lieu of buff leather,
+and soon superseded all other substances, both for lathe and
+hand-buffs, and I would add, for the benefit of new beginners
+that those who are familiar with its use, prefer cotton velvet.
+The only requisite necessary is, that the buffs made of cotton
+velvet should be kept dry and warm.
+
+The greater number of operators, with whose practice I am familiar,
+use, for polishing plates, prepared tripoli, imported from France,
+or Browne's rotten-stone. The former of these articles is
+very objectionable, inasmuch as there is no positive certainty of being
+enabled to procure or make the article of uniform grit--the nature
+of the substance rendering, it impossible to reduce it to varying degrees
+of evenness, by the well known process of washing, for that purpose,
+and the burning of rotten-stone changes its chemical nature somewhat,
+at the same time rendering, this invaluable article harsh and gritty.
+And especially, no reliance can be placed upon burned rotten stone
+if purchased from those who do not give very great attention and care
+to its preparation; and the same remarks apply to rouge.
+
+The best article for polishing Daguerreotype plates is
+rotten-stone, such as can be procured in any town, prepared after
+the following manner: Procure, say half a dozen wide-mouthed bottles,
+of suitable dimensions, numbering each from one to six.
+Put into No. 1 about half a pound of rotten-stone. and nearly fill
+the bottle with water. Then, with a proper stick or spatule,
+mix well the rotten-stone and water; after which, let No. 1 rest for,
+say one minute, then carefully pour off into bottle No. 2
+(or, what would be better, draw off by a syphon) as much of the
+floating particles of rotten-stone as is suspended in the water.
+Again fill bottle No. 1 with water, agitate it as before,
+and decant it to bottle No. 2, care being taken to draw off
+only the suspended particles of rotten-stone.
+
+When a sufficient quantity of washings from bottle No. 1 is collected into
+bottle No. 2, a similar process must be gone through. as above stated,
+for No. 1; the difference being in the care required, and in the time
+allowed between the stirring or mixing the rotten-stone and water.
+The floating particles of rotten-stone, after four minutes' subsiding, will be
+found fine enough for the finest Daguerreotype polishing required.
+
+A quantity of such washings may be collected in a large bottle,
+and allowed to stand a few hours, when all the rotten-stone will
+have settled. The water may be poured off and the rotten-stone put
+into an evaporating dish, and while being dried, must be constantly
+stirred to obtain an impalpable powder.
+
+Further washings may in like manner be resorted to for finer
+qualities of rotten-stone. In my practice, I have used
+the articles at two and four minutes' settling, and occasionally
+have prepared it after standing for eight minutes.
+So fine a quality as this, however, is seldom required.
+In using, rotten-stone, I mix with it, for polishing,
+fine olive oil, until I obtain a thin paste--and the best of all
+methods for polishing (well planished) Daguerreotype plates,
+is one like that used for glass by lens polishers; that is,
+by using a disc or buff-wheel, and having, a suitable holder
+by which to secure the plate, and then by pressing the plate
+against the revolving buff, well saturated with the mixed
+oil and rotten-stone, a very good surface is obtained.
+A quantity of plates may be prepared in this way, and all
+the adhering oil, etc., may be removed by a clean hand,
+or lathe buff, after which each plate must be heated to the point
+necessary to burn off the remaining oil great care being required
+not to overheat the plate. A very slight excess of temperature
+will at once destroy all the polish previously obtained.
+The test for ascertaining the right temperature is at hand;
+the adhering oil will be driven from the plate in the form
+of smoke when the right temperature is reached. The moment
+the smoke ceases to rise from the plate, the heat must he removed,
+and the plate quickly cooled upon a piece of iron.
+
+A quantity of plates thus prepared may be kept on hand for
+any required time, and the labor of one minute, with a lathe
+or hand-buff with dry charcoal, or rather, prepared lampblack,
+will perfectly polish the surface ready for indexing, etc.
+This lampblack also requires some care in preparing.
+Take a small-size crucible, properly temper it by a slow fire,
+that it may not be cracked after which, fill it with common lampblack,
+cover it over with a piece of soap-stone, and again replace it
+in the fire. Build a good hard coal fire around it continue the heat
+for two or three hours, being careful not to raise the cover
+till the crucible be quite cold. Pulverize when using it.
+It is very desirable to keep this lampblack dry and warm.
+Some operators use much rouge I would recommend the above in preference;
+but those who feel that they cannot dispense with the use of rouge,
+had better try a large addition of prepared lampblack to a small
+one of rouge, as this latter article, unless great pains
+be taken in its preparation, will adhere and work itself into
+the body of the surface, so that it cannot be removed therefrom;
+and I have seen many specimens of Daguerreotype very much
+injured in effect from this rouge tint disseminated throughout
+their shaded features, at the same time that the whole
+general effect of such pictures is that of a want of life.
+It is true that with the use of rouge a very high degree of polish
+may be obtained, but probably not higher than can be produced
+with many other substances of a less objectionable nature.
+
+From the announcement of the discovery by Daguerre to the beginning
+of the year 1840, I am not aware of any attempt to lessen the time for
+the action of an image, or an impression, other than that of the reflecting
+camera invented by Mr. Wolcott. Early, however, in 1840, Mr. Wolcott
+was desirous to be enabled to further shorten the time for a sitting,
+and having some knowledge of bromine and its action, by request,
+Dr. Chilton prepared a small quantity; but Mr. Wolcott did not succeed
+very well with it, he having invariably used too much in combination with
+iodine to produce that sensitive coating now well known to the profession.
+Professor Morse, of this city, Dr. Goddard, of Philadelphia, and others,
+in the years 1840 and 1841, were acquainted with the use of bromine.
+N. Griffing, of this city, or myself, used with tolerable success,
+iodine in large excess to nitric acid and water; and, subsequently, to nitro
+muriatic acid (which reacted and formed a peculiar chloride of iodine);
+this latter combination proved to be preferable to simple iodine,
+at the same time somewhat more sensitive, and was used by me in this city up
+to the time of my leaving for London (October 1, 1840). On arriving in London,
+I instituted a series of experiments in the various chemical combinations,
+solely with the view to be enabled to obtain more speedily a portrait
+than it was practicable to do with any known chemicals at that date.
+The high latitude, and the winter season of the year rendering but a
+feeble light at best, the greater the necessity for a more sensitive
+chemical preparation to the shortening the time for a sitting.
+Near the beginning of the year 1841, I discovered and practically applied,
+chloride of iodine to great advantage, and, as far as memory serves me,
+I believe the first used in this country was some made and shipped, Messrs.
+Harnden & Co., from London, to Mr. Wolcott, in New York.
+
+About the same time, Mr. John Goddard, of London (who was associated
+with myself), discovered a rather valuable combination of chemicals,
+consisting of a mixture of iodine, bromine, iodus, and iodic acid,
+and a proper combination of those bodies gave an action somewhat
+more sensitive than chloride of iodine--but the "high lights"
+of the portraits would become solarized or overdone, more frequently
+with this combination than with the chloride of iodine.
+Throughout the year 1841, I used, with great success, chloride of iodine,
+applied as one coating--occasionally in conjunction with Mr. Wolcott,
+attempting the use of iodine, bromine, and chlorine, and at times
+with more or less success. The difficulty of exactly combining,
+the three elements above mentioned, in order to produce a certainty
+of result with harmony of effect, was the work of many months,
+with great labor and study, the slightest modification requiring
+a long, series of practical experiments, a single change consuming,
+frequently, an entire day in instituting comparisons, etc., etc.
+
+Early in the year, 1842, I discovered a combination of chemicals
+(now known in London as "Wolcott's Mixture," in hermetically sealed bulbs)
+of exceeding uniform character, very sensitive to the action of light,
+and specimens produced in 1842-3, with this combination, will bear
+comparison with the best specimens produced at this late date.
+
+About the same time, I discovered that however much overdone a
+Daguerreotype might be, the means were at hand to save or redeem it.
+It has long, since been known to operators, that if a plate be
+exposed to light after being coated, unless it be again coated,
+a clear and distinct picture could not be obtained upon the same plate
+without first repolishing and recoating the same, care being taken
+that no light fall upon the prepared surface. To prevent solarization,
+coat a plate as usual, expose to the action of light any required time
+(according to circumstances), say from quarter to one half more
+time than would be required in the ordinary method of procedure;
+observe, before putting the plate in the mercury box, place it over
+the vapor of iodine, bromine, or chlorine, etc. (carefully excluding
+the light), for a very brief period, great care being required to have
+the selected vapor very much diluted with air, in order to success.
+Many experiments will be required ere arriving at satisfactory results.
+Specimens now unknown to general operators, for harmony of effect,
+have been, and may again be produced by the method pointed out above.
+I have found the best general effect, and the most certain result
+to follow from the use of the vapor of chlorine--but this requires
+more than ordinary care. I would, therefore, recommend the use
+of iodine. Thus: to a few grains of iodine, add an ounce of warm
+water (which will become tinged with iodine); when cold, to half a pint
+of pure water in a new and clean coating box, put, of the above,
+fifty drops; stir and mix well this small quantity of iodine
+in with the water; in ten minutes this box will be ready for use.
+Great care and judgment will be required in the application of this
+vapor to the plate; if the plate remain over the vapor too long.
+the developed picture will have a faint and misty appearance;
+if not exposed long enough, the "high light" will be solarized.
+I have great hope of the ultimate use of this process, as it is
+the only means yet discovered to be enabled to secure specimens
+of extremes of light and shade, yet producing harmony of effect;
+and I would call the attention of the profession to the fact,
+that a plate may be exposed to the action of light for any length of time
+(a thousand times longer than required to act for the lesser quantity
+of mercury to deposit itself, or that amount necessary to form a perfect
+specimen), and be restored by the application of any of the vapors
+above mentioned, remarking that for extremes for solarization,
+denser vapors will be required. Much remains to be done with this
+discovery to the application of the Daguerreotype.
+
+
+
+HUMPHREY'S JOURNAL OF THE DAGUERREOTYPE & PHOTOGRAPHIC ARTS.
+
+The above-named publication is well known as the best and most
+valuable one devoted to the Photographic Science in this country.
+Humphrey's Journal made its appearance November 1st, 1850, and consequently
+is the first and oldest serial offered to the Photographic world.
+
+The art of producing Portraits and Landscapes by means of Light,
+has recently taken a new and enlivening impulse, which will
+in all probability lead to important and interesting results.
+No practical Daguerreotypist, Photographer, or amateur,
+should be without the means at hand for securing all of
+the information upon this subject. Each should be ready to
+receive and apply the improvements as they may be developed.
+In order to accomplish this, it is a matter of great importance
+to the Practitioner or Experimenter that he should have
+a reliable medium through which he can obtain information.
+In what source can the inquirer better place his confidence than
+in a regular Journal, whose editor is literally a practical person,
+and familiar with the manipulations necessary for producing
+Portraits upon "Daguerreotype Plates," and upon glass and paper?
+Such is the conductor of Humphrey's Journal.
+
+This Journal is published once every two weeks, and contains all
+the improvements relating to the Art, and is the only American
+Journal whose editor is practically acquainted with the process
+for producing Daguerreotypes, Ambrotypes, and Photographs.
+The first No. of Vol. X. is dated May 1st, 1858. The terms
+(Two Dollars per annum) are trifling compared with the vast
+amount of information furnished.
+
+AMBROTYPES.--Humphrey's Journal contains everything novel which appears upon
+this subject, and has already presented more new, important, and original
+matter than can be found in any other place.
+
+Many are the letters we have received during the term of the last volume,
+in which the writer has stated that a single number of Humphrey's Journal has
+contained information of more value to him than "several times the amount
+paid for the entire volume."
+
+Our resources have grown up around us, and our facilities for procuring,
+as well as distributing, all such facts and improvements as will benefit
+as well as instruct all who have the progress of the Art at heart,
+are as ample as they can well be made.
+
+The future volumes will be abundantly furnished with original
+writings from persons of standing in the scientific world;
+and the practical Photographer will here find a full account
+of such improvements as may from time to time develop themselves.
+
+From the editor's long practical experience in the Heliographic Science,
+he will be enabled to present the subject in a plain, clear,
+and concise manner.
+
+Read what the Editors say of Humphrey's Journal:--
+
+"We have received a copy of a valuable Journal (Humphrey's) published
+in New York, which has reached the 18th number of Vol. VI.....We now
+have the pleasure of quoting from our trans-atlantic coadjutor."--
+Liverpool Photographic Jour.
+
+"Humphrey's Journal is practical as well as scientific in character."--
+American Journal of Science and Arts.
+
+"It treats the subject knowingly and with force."--New York Tribune.
+
+"It is both a popular and interesting publication."--Mechanics' Magazine.
+
+"It is highly useful to all who practice 'shadow catching.'"--
+Ohio State Journal.
+
+"The work is neatly gotten up, and contains many interesting
+varieties in this new field of science."--Times.
+
+"It should be hailed and encouraged, not only by Daguerreotypists themselves,
+but by every lover of Science and Art."--The Democrat.
+
+"We cannot too strongly urge all artists, and those persons
+who feel an interest in the Heliographic Arts and Sciences,
+to take a copy of the work."--Sentinel.
+
+"It is indicative of talent worthy of the important Art it is designed
+to elevate."--American.
+
+"This Art is entitled to its own organ, which could not have fallen into
+better hands than those of the editor of 'Humphrey's Journal.'"--Transcript.
+
+"It is a scientific work of interest and usefulness."--
+Star of the North.
+
+"This Journal answers many points heretofore regarded as inexplicable."--
+Hudson River Chronicle.
+
+"It is rich with interest."--North American.
+
+"It contains all the 'Improvements.'"--Delta.
+
+"It teaches us how to take our own portraits."--Bee.
+
+"It will cultivate a taste for Daguerreotypes."--Commercial Advertiser.
+
+"It should be in the hands of all."--Reveille.
+
+"It is the Daguerreotypist's friend."--London News.
+
+"It should be found in every library."--Evening Journal.
+
+
+From some of our Subscribers
+
+"Humphrey's Journal has been the means of saving much time and money,
+for by its instruction I have been enabled to produce some of the finest
+Paper Pictures I have ever seen." W. P.
+
+"Don't fail to send me the Journal, for I would not be
+without it for five times the amount of subscription.
+It is the only publication I can depend upon." A. G. R.
+
+"Your treatment of the humbugs and humbugging members of the profession,
+is of the most valuable importance to us practical Daguerreans. Go on.
+God speed! Here is the amount for the renewal of my subscription."
+E. F. S.
+
+"How can any Operator offord to be without it?"
+L. L. H.
+
+"Here are five dollars: send me Humphrey's Journal to this amount.
+I will not be without it." M. S.
+
+"It is my best friend." J. E. W.
+
+We might quote like commendatory extracts enough to more than ten
+times fill this page.
+
+Humphrey's Journal contains 16 octavo pages of reading matter.
+
+
+TERMS.
+
+ One copy per annum, in advance . . . . . . $2 00
+ Three copies, do. do. . . . . . . $5 00
+ Six copies, do. do. . . . . . . $9 00
+
+The thousands who read it cannot be induced to remain without it.
+All who desire to keep up with the improvements should subscribe
+for a copy.
+
+Subscription price Two Dollars per year.
+
+Don't fail to become a subscriber. Address S. D.
+ HUMPHREY
+ Office, 37 Lispenard Street, NEW YORK.
+
+
+
+ THE PRACTICAL MANUAL OF THE COLLODION PROCESS.
+ BY S. D. HUMPHREY.
+ THIRD EDITION
+
+This Edition contains all the Improvements in the Art made public
+up to the day of publication, and gives complete Practical
+Instructions for making Collodion Positives or Ambrotypes,
+Collodion Negatives, Printing, etc., etc. The quick, great and
+unprecedented sale of the first and second editions demonstrates,
+more than the strongest language could possibly do,
+the extraordinary and increasing popularity of this work.
+The Third Edition contains two hundred and sixteen 12mo.
+pages, of a larger size and in smaller type than either
+of the preceding editions, and is illustrated with numerous
+wood-cuts. It is intended to be the best practical work extant;
+substantially bound in cloth, price One Dollar; forwarded by mail
+(postage prepaid). Address
+
+
+S. D. HUMPHREY, New York
+
+
+
+A GUIDE TO PHOTOGRAPHY,
+
+Containing simple and concise directions for obtaining Views, Portraits,
+etc., by the chemical agency of Light, by W. H. Thornthwaite,
+author of "Photogenic Manipulations," etc. Illustrated with numerous
+wood-cuts. The Book contains more than one hundred 12mo pages,
+bound in board, and is sold at twenty-five cents per copy, or five
+copies for one dollar. Address
+
+S. D. HUMPHREY, New York
+
+
+
+ HOLMES, BOOTH & HAYDENS,
+ MANUFACTURERS OF
+ DAGUERREOTYPE CASES,
+ PLATES, CAMERAS,
+
+MATTINGS, PRESERVERS, ETC., ETC.
+
+MANUFACTURERS AND IMPORTERS OF EVERY VARIETY OF AMBROTYPE,
+AND PHOTOGRAPHIC GOODS,
+
+Of the Best and most approved Quality.
+
+ESPECIAL ATTENTION GIVEN T0 THE FURNISHING OF EVERY ARTICLE USED
+IN THE PRACTICE OF THE DAGUERREOTYPE
+
+Depot 81 Chambers and 63 Reade St., New York.
+
+Manufactory at Waterbury, Conn.
+
+
+
+HOLMES, BOOTH & HAYDENS' CAMERAS
+
+From 1/4 to the Mammoth size. These CAMERAS are of the most superior make,
+and all subjected to the most thorough test before being offered for sale.
+
+VIEW CAMERAS, made expressly for taking views: an entirely new article.
+
+DAGUERREOTYPE PLATES, OF EVERY VARIETY. AND WE WOULD CALI.
+PARTICULAR. ATTENTION TO THE
+
+Wreath, and H. B. & H. Eagle 40 Plates, AS HAVING NO EQUALS IN THE MARKET.
+
+SOLE AGENTS FOR THE CELEBRATED H. B. AND N. P. FRENCH PLATES.
+
+Always on hand a complete assortment of Ambrotype and Photographic goods.
+
+SOLE AGENTS FOR THE Patent solid glass corner Plate Holders.
+
+All orders will receive prompt attention, and be forwarded with dispatch.
+
+ HOLMES, BOOTH & HAYDENS,
+ 81 Chambers, and 63 Reade St.
+ New York.
+
+
+
+SCOVILL MANUFACTURING CO.
+
+ MANUFACTURER OF
+ DAGUERREOTYPE PLATES,
+ MATTINGS,
+ PRESERVERS, CASES,
+ APPARATUS, etc., etc.
+
+Importers and Dealers in every description of Daguerreotype,
+Photographic, AND AMBROTYPE GOODS,
+
+The SCOVILL MANUFACTURING COMPANY flatter themselves that an experience
+of nearly twenty years in the business and the most extensive
+variety of the above Goods in the United States, entitle them
+to the continuance of orders for the Domestic and Foreign trade,
+which will receive the most careful attention.
+
+Park Building, New York. Entrances--36 Park Row, 4 Beekman,
+and 141 Nassau Street.
+
+
+
+
+SCOVILL MANUFACTURING CO.
+
+Would call especial attention to their large variety of
+
+CASES,
+
+Embracing many Fancy Styles made only by themselves, and to which they
+are constantly adding New Designs.
+
+ Union Cases,
+ Of all sizes, with Riveted Hinges.
+ AGENTS FOR THE SALE OF
+ C. C. HARRISON'S CAMERAS,
+
+with improvements, which we are now prepared to sell at
+reduced prices, and warranted to give better satisfaction
+than ever before DAGUERREOTYPE PLATES, H. B.--N. P.--
+Star and other brands PLATE GLASS,
+
+embracing three-quarters white: Crown and all other varieties.
+We would call particular attention to our Black Glass,
+made expressly for Ambrotypes.
+
+ CHEMICALS,
+ for the Daguerreotype and Photographic Art.
+ Iodized and Plain COLLODION. Gun Cotton, etc., etc.
+ Tagliabue's Collodiometres and Actino-Hydrometres, for
+ testing Chemicals.
+
+APPARATUS OF EVERY VARIETY.
+
+Gutta Percha, Porcelain, and Glassware of all kinds used in the Art.
+
+A large assortment of Gilt Frames always on hand and made to order.
+
+Ambrotype Shields, with solid corners of a new style.
+
+All orders will meet with prompt attention
+
+ SCOVILL MANUFACTURING CO.,
+ PARK BUILDING
+ New York
+ 36 Park Row, 4 Beckman, and
+ 141 Nassau Street.
+
+
+
+
+ HARDWICH'S PHOTOGRAPHIC CHEMISTRY
+ AMERICAN EDITION.
+
+ A MANUAL of
+ PHOTOGRAPHIC CHEMISTRY,
+
+INCLUDING THE PRACTICE OF THE COLLODION PROCESS.
+
+BY
+
+T. FREDERICK HARDWICH,
+
+ LECTURER ON PHOTOGRAPHY IN KINGS COLLEGE, LONDON;
+ LATE DEMONSTRATOR OF CHEMISTRY IN KING'S COLLEGE.
+
+Last Edition,
+
+The above is the title of this new and valuable work.
+It is too well known to need any further comment in this place.
+This volume contains nearly 300 large duodecimo pages.
+bound in red cloth, $1.00. Copies to be forwarded by mail,
+$1.18, postage pre-paid.
+
+ S. D. HUMPHREY,
+ Photographic
+ Book Publisher,
+ 37 LISPENARD
+ STREET, NEW YORK,
+
+N.B. Postage stamps taken.
+
+
+End of the Project Gutenberg Etext of American Hand Book of Daguerreotype
+
+
+
diff --git a/old/amdag10.zip b/old/amdag10.zip
new file mode 100644
index 0000000..2b19b82
--- /dev/null
+++ b/old/amdag10.zip
Binary files differ
diff --git a/old/amdgf10.zip b/old/amdgf10.zip
new file mode 100644
index 0000000..ac05530
--- /dev/null
+++ b/old/amdgf10.zip
Binary files differ