American Hand Book of the Daguerreotype Part 3

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 const.i.tute 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 acc.u.mulation of moisture, which would otherwise pa.s.s 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 polis.h.i.+ng 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 gla.s.s. 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, subst.i.tute 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-gla.s.s, 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 gla.s.s crosswise in the centre; bend the ends of the tin over the edge of the gla.s.s and turn them back so as to form a groove to hold the gla.s.s, 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 gla.s.s.

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 gla.s.s, bring it to an angle of forty-five degrees with the tube, extending nearly the whole length of the gla.s.s 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-gla.s.s. When you have it exactly right, hold it while it is soldered fast to the band. Take out your gla.s.s 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 Pota.s.sium--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 G.o.ddard of London, who at the time was a.s.sociated 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.

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Solution of caustic potash is then added to the ethereal solution, forming bromide of pota.s.sium and bromate of potash. This solution is evaporated to dryness, and the salts being collected are heated in a gla.s.s 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 pa.s.sing 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 pa.s.s 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 a.s.sumes 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 quant.i.ty 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 s.p.a.ce, 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 quant.i.ty, 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 quant.i.ty 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 sc.u.m the plate in coating at high temperatures, or when the thermometer indicates a heat above 60 deg.

Bromide of Pota.s.sium--Is prepared by mixing bromine and a solution of pure pota.s.s together, and evaporating to dryness; it crystallizes in small cubes, and dissolves readily in water. This agent is extensively employed in the paper and gla.s.s processes.

Bromide of Lime. This the princ.i.p.al 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 gla.s.s 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 a.s.sumes 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 a.n.a.logous 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 a.s.sayers, and allowing it to remain some time under water, or a.s.sisting 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 gla.s.s 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 gla.s.s, and in an instant combustion giving a loud report will be the result.

b. Expose a daguerreotype plate to the vapor of bromine, it a.s.sumes 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.