Chapter C: C. Harrison, (2)

Before submitting the plate to the operation of printing, in order to insure an unlimited number of copies, it is necessary, as before stated, to protect it by a slight coating of copper, which is obtained by the electrotype process; otherwise the printing would soon wear the plate. This coating must be kept very thin, but the fineness of the engraving, and the polish of the white parts, should be destroyed. In this state the plate can be delivered to the printer.

After a certain number of impressions have been obtained, it will be perceived that the coating of copper is worn in some places; then this coating must be removed, and a fresh one applied in its place. For this purpose, the plate must be purified and cleansed by warm potash, and plunged in a weak acid, composed as follows:--Water, 600 parts; nitric acid, 50 parts; nitrous acid of engravers, 5 parts; all in volume. This acid will dissolve the coating of copper, and the plate being coppered again, by the same means as before, may be again submitted to the operation of printing; and as nothing can prevent the success of a repetition of the same operation, any number of impressions may be obtained. The coating of copper can also be removed by caustic ammonia. The Daguerreotype plate engraved by this process, may also be reproduced and multiplied by the electrotype process, the same as any other engraved plate.

The essential points of this process, which constitute the present invention, consist,--

First,--in the discovery and employment of certain properties of a mixture composed of nitric acid, nitrous acid, and hydrochloric acid, in detrimental or fixed proportions. The two last mentioned acids may be employed either in a free state, or combined with alkaline or other bases. This mixed acid has the property of biting the pure silver, which forms the black parts of the Daguerreotype picture, without attacking the white parts formed by the amalgam of mercury.

The result of the action of the biting is, to form on the black part of the picture an insoluble chloride of silver; and this chloride of silver, which, when formed, stops the action of the acid, is dissolved by the ammonia, which allows the biting to continue.

Secondly,--In the discovery of certain properties of a warm solution of caustic potash, and in the employment of the said solution, by which the mercury forming the picture is better and deeper amalgamated with the silver under it, so that many imperceptible points of the amalgam are affected in such a manner that the action has no action upon them.

Thirdly,--In the discovery and employment of a process which produces a grain favourable to the engraving, by which the biting on the plate is rendered deeper. This is effected by filling the parts engraved with a siccative ink, or any other substance, and then gilding the plate by the electrotype process: the gold is not deposited on the parts protected by the ink. When the plate is gilded, the ink is cleansed by the caustic potash, and the plate may be submitted to the effect of an acid, which does not attack the coating of gold, but bites only on the silver in the parts already engraved by the first operation.

Fourthly,--In the employment of a process by which the plate is protected from the wear of the printing operation. This is effected by covering the plate before printing, with a slight coating of copper; by the electrotype process, and when the coating begins to wear, by printing, it is removed by a weak acid or by ammonia, which dissolves the copper without effecting the silver under it. The plate is coppered again, and after another printing, the same operation is repeated, so that a considerable number of copies may be printed without injury to the engraving.

Enrolled in the Pitty Bag Office, May, 1844.

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=INTERESTING EXPERIMENT WITH STRYCHNIA.=

An interesting experiment, illustrative of the poisonous effects of strychnia, was recently made by Professor Agassiz, at Cambridge. The subject was a large black bear, about eighteen months old. The animal was taken when young, and had been kept in captivity for a considerable period. Professor Agassiz being desirous of killing it for the purpose of dissection, about three grains of strychnia were administered. The poison, though extremely bitter was readily swallowed. At the expiration of ten minutes, no effect having been produced, a second dose of about the same quantity was also inclosed in a biscuit and offered. The cunning animal broke open and swallowed the biscuit, but rejected the poison. The first portion, however, had proved efficacious, and in exactly fifteen minutes from the time when first administered, the animal was seized with terrible convulsions, and soon died.

The whole time which elapsed between the taking of the poison and the death of the animal, did not exceed twenty-five minutes. In order to alleviate its sufferings and hasten death, a quantity of hydrocyanic acid was poured upon the nose and mouth of the bear. It did not, however, produce any sensible effect, and was not apparently taken into the system, as the animal at the time was nearly dead. But the subsequent effects of the poison were most remarkable. Although the bear, at the time of death, was in perfect health and strength, twenty-four hours had not elapsed before the body was in an advanced stage of decomposition. Indeed the appearances indicated that the animal had been dead for nearly two months. The interior of the body, when opened about twenty hours after death, still retained its warmth in a considerable degree, while an offensive gas issued from every pore. The blood had not coagulated, the spinal marrow and nerves were in a semi-fluid state, and the flesh had assumed a leaden-gray color. The hair of the hide readily came out on being slightly pulled. No smell of the hydrocyanic acid could be perceived.

The origin of this singular and speedy decomposition is not fully known, though it is supposed to be due to the agency of the hydrocyanic acid. A chemical examination of the muscle, brain, nerves, liver and kidneys is now going on at the Cambridge laboratory, under the direction of Professor Horsford. One singular fact connected with the spontaneous decomposition of these parts is, that they all yielded or disengaged hydrosulphuric acid gas, with the exception of the liver, which did not.--_Annual of Scientific Discovery._

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=NOTICE.=

A few copies only of Volume I. of the Daguerreian Journal can be had by applying at this office. Price three dollars.

This is the most complete work ever published on the Daguerreian Art. Orders addressed to the publisher of this Journal.

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=THE DAGUERREIAN JOURNAL=

=NEW YORK, JUNE 1, 1851.=

The metal which the Daguerreotypists have most to deal with is silver. To obtain plates of this perfectly clean and keep them so is one of the most difficult parts of his art; in order to accomplish it he is obliged to have resource to circuitous mechanical processes, or to some chemical means whereby the old surface may be removed, or a new surface deposited. He uses tripoli and rotten stone, rouge and buffing, fatty matters, alcohol, ammonia, and nitric acid, for the first purpose; and electro-plating for the second. The operator must not mistake the object he has in view. By all his mechanical operations, where friction is concerned, he obtains a _polished_ surface; but it is not to _polish_ the plate that he uses the buff, and the other materials; the object is to clean the plate, and the _polish_ of the surface follows as a natural result. That a polished surface is not necessary for the formation of an image is evident from photography on paper, and Hyalotype. In these cases the surfaces do not reflect light; they are not polished; they are merely clean. The fact of a plate freshly taken out of a cell where silver has been deposited on it receiving beautiful images, is another proof that polish is unnecessary for success. What is wanted is a surface of pure silver, one not coated with the slightest trace of oxide, carbonate, or sulphuret of silver, or with any impurity derived by contact with foreign matter. The Daguerreotypist has, then, two objects in view.--1st, to get a clean surface on his plate; and 2nd, this once obtained, to keep it so without further alteration. Although silver is classed with gold and platinum, as one of those metals which do not tarnish or oxidize readily on exposure to the air, yet it is now well known in practice what a difference exists in the character of the picture brought out on a plate recently polished and one set aside even for a few hours. It is true that the atmosphere alone will not affect or oxidize a plate of polished silver, but that is only true of a very dry atmosphere; for an atmosphere which contains even a small amount of moisture in it, will in a short time dull the surface of the plate. In this instance the moisture is deposited first, and brings the air into closer contact with the surface of the metal, promoting the union of the latter with the oxygen of the air. This is exemplified every day in the case of iron, which does not rust in dry weather, but when the air begins to deposit its moisture it rapidly oxydizes. So is it with lead and zinc, but in a less degree. Pure water has no effect in tarnishing the surface of a silver plate, but if it contains even a very small quantity of animal or vegetable matter it darkens the surface in consequence of the presence of sulphur. The ordinary tarnish of silver is due to the fastening upon the surface of sulfurous vapors, which are constantly floating in the air. We are scarcely yet in possession of sufficient facts to justify the statement that sun-light materially aids in this alteration. We do know that oxidizement in any substance goes on much more rapidly in sunshine than under any other circumstances. In the vegetable kingdom it is of hourly occurrence; but the different effects of shade and shine upon the oxidizement of plates of metal has not been minutely studied. However this may be, after a time the silver surface does get coated with a film, of partly sulphuret, partly oxide, and a complete layer of air, which so closely attaches itself to the plate that water when poured on it rolls off and does not wet the surface. It is this film, of air which mechanical friction and bulling are so serviceable in removing. The tarnish of a sulphuret is not so readily removed by friction as by ammonia, for the sulphuret of silver is, to some extent, soluble in ammonia; but as the sulphuret when present gives a yellowish brown tint to the surface, it is only then that it is needful, and even a weak solution of commom salt or hydrodate of potash cleans the surface much quicker.

As nitric acid is the best solvent of silver, so is it the best agent to remove films of oxide and carbonate from the surface; it does so readily, effectually, and leaves a clean new surface of silver, similar to a plate newly prepared, or one which has received a new coating in the electrotype cell. The acid, however, must be very much diluted, otherwise its local action is so immediate as to eat down the surface of the plate faster than it spreads, producing inequalities,--even when left long on, although diluted, it produces roughness; hence its use has not been happy in many hands. To such, the longer, but less failing processes of mechanical action are to be recommended in preference.

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Friend Humphrey:--

I have thought for some time past that I would furnish a few thoughts for the _Daguerreian Journal_, under the head of _General Rumors_. A fear of injuring the Daguerreian business, by giving an additional publicity to my discovery, for the present has kept me from this, as well as from furnishing several other articles.

A _very few_ persons (for the honor of humanity, I am glad the number is small) have made statements which reflect seriously upon the integrity and motives of myself and friends. By means of certain legal processes, of which I am not wholly ignorant, I could do _these gentry_ more simple justice than by dignifying them by a notice in our Journal, yet I bear them no ill will, and _for the present_ shall act on the principle that it is better to suffer wrong than to engage in a quarrel, especially with men who have so little regard for the feelings and reputation of their fellows, as to condemn, denounce, and accuse, without discrimination, and without the slightest knowledge of facts.

The "head and front of my offending" is this--that I _have_, by dint of unwearied pains and perseverance, succeeded in imprinting the colors of nature, in all their inimitable glory, upon the metallic surface. The process, when brought out, it is believed, by the best of judges, will be an astonishment to, the world, and a delight to our nation; and I have felt, from the first, that I am but an instrument in the hands of the Almighty, and am therefore bound in duty, as well as by inclination, to dispose of the secret in a way to accomplish the greatest amount of good. In this spirit I have frequently published my unalterable resolve that my process _shall never be monopolized, or used for the purposes of extortion_. If I had no other reason for this course, the fact that there are great numbers of worthy persons engaged in our art, who, like myself, are poor, this would be sufficient. Various plans have been suggested to me, for the best possible method of disposing of my discovery. Numerous gentlemen of high standing, have honored me with personal intercourse and friendly advice. I have even suffered the claims of courtesy to interfere with my experiments, and, I believe I have the good will and confidence of those who have honored me with their visits; but I have never swerved from my original determination, and have given no person the slightest reason to think otherwise.

In view of these _facts_, it is not strange that I should feel annoyed at the various rumors to which I refer, and some of the intimations which have been thrown out, I _feel_ are but poor pay for my having nearly, if not quite, ruined my health, by laboring from morn till midnight for the good of others. More especially have I been _grieved_ that _some of my best friends, and the best friends of the fraternity_, should be accused of having outwitted me, and drawn me into obligations to them which would compel me to pursue a grasping course. Now, it is true that certain gentlemen have, from the most honorable motives, made me very liberal offers of aid, and it is also true that my mind is about settled in regard to the parties with whom I shall act; but it is not true that I am under obligations to give notoriety to my _business affairs_, and it is certain that I shall not do so until I see fit. Neither is there the least foundation for the assertion that I am committed to any person. There confidence in me is not based on paper, but on a much surer foundation.

The process which I have been so fortunate as to discover, is _my property_. No man on earth has any claim, upon it, and I have a perfect right to dispose of it as I please, in case I do not interfere with the rights of others. This, I think, is the philosophy of _Professor Morse_, so admirably and clearly expressed in the last number of the Journal. This distinguished man recently favored me with a visit, and, in the course of the interview, shed much light on this subject for which I feel truly thankful.

My intention has been, and is, to _do right_, and I believe the majority approve of the course I have pursued thus far. The many marks of approbation I have received from eminent men, both in this profession and others, is truly encouraging to me in my poor health and arduous labors, and will never be forgotten. Those who seem to possess a different spirit, and who have apparently endeavored to hedge up my way by means of "rumors," "new discoveries," "threats," &c., have my forgiveness, and I trust that, in future, if they are not disposed to aid, they will do nothing to hinder me.

The brotherhood have nobly aided me, by purchasing my book. My sales are exceeding my most sanguine expectations, and are placing me on a footing to make me _feel that I am free_. All may be assured that I shall not use my freedom "as a cloak," but to serve their interests, of which both myself and friends hope to give them _full proof_ hereafter.

Now that I have been compelled to close my doors against visitors, I would state that I am doing my utmost to bring out my process in a short time, and I will hereafter give, in the _Daguerreian Journal_, such notices of my success as will meet the wishes of the public, as well as the interest of our fraternity,

I am yours &c.,
L. L. Hill.

Westkill, Greene Co., N. Y.,
_May 30, 1851._

[Hand] The foregoing letter was addressed to me privately, and as it contains some of Mr. Hill's views in relation to the various rumors afloat, I have thought it best to insert it for the public.

S. D. H.

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We take pleasure in saying to our friends that, through the kindness of John Johnson, Esq., of this city, we have received many of the valuable letters and papers written by Mr. S. A. Wolcott, a former partner of the first named gentleman. Mr. W. is well and favorably known as one of our early and most successful investigators in the Photogenic Art. Many of the most valuable improvements had their origin in his hands. We were surprised to find so great an amount of information as is here presented.

Our Daguerreotypists of the present day may consider themselves fortunate, when looking back upon the difficulties experienced by those early engaged in putting a shadow on the silver plate. We find here many a mystery unravelled, and set forth in a light heretofore unexplained. As these letters, written by Mr. W. to his partner, Mr. J., (at the time they were written) were many of them confidential, and some few contain business matter of a foreign character, it will require some little time to prepare them for the press in the order in which they were written. We shall make no alteration in the manuscript, and exclude such matter only as relates to business of a foreign character. They present a team of investigation and research worthy the first in the scientific circle.

We would here take occasion to speak of a curious specimen of our art, which we saw while recently spending an evening with Mr. Johnson. This specimen is a profile view of a gentleman, and if not the _first_ likeness from life, it is said to claim age with the oldest Daguerreotype ever produced, and is no less interesting for its antiquity than for its size, it being on a plate _less than one quarter of an inch square_. To produce an impression on such a plate it would require the superior skill of the most successful operator of the present day. The outline is distinctly marked, the features remarkably well delineated, being in fact, one of the most interesting curiosities we have ever witnessed. The plate is cemented by means of Canada Balsam to a piece of plate glass about three-fourths of an inch square, and thus it has been preserved in its present state.

We saw many other specimens of Daguerreian antiquity, but as we intend to speak more fully of our evening visit at Mr. Johnson's, we will defer further notice for the present.

We would here say to such as may have Mr. Walcott's letters relative to the art, that we would consider ourselves especially favored if we could be allowed the perusal of them.

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=THE NATURAL COLORS IN PHOTOGRAPHY.=

The subscriber begs to request those interested in the above discovery _not to visit him_ until further notice, which will be given in the Daguerreian Journal. It is _absolutely essential_ that he should have his time, and be left undisturbed. Stern necessity, arising from the fact that I can never complete my process if disturbed as hitherto, compels me to say both to friends and strangers, that my doors are locked, and will continue to be until I have completed my experiments. As this notice is given with a regard to the general good, it is presumed no offence will be taken.

L. L. Hill.

Westkill, Green Co., N. Y.,
May 25, 1851.

Editors by inserting the above in their papers will confer a favor, and save many from spending their time and money to no purpose.

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=OUR DAGUERREOTYPES.=

Butler, of this city, is now producing fine likenesses in oil. This gentlemen calls these pictures "Daguerreotypes in Oil." We never have seen better likenesses transferred from a Daguerreotype, and in an economical point of view, they are the best oil paintings that can be had.

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E. Long, of St. Louis, Mo. In our last, we spoke of H. H. Long as the gentleman who had produced likenesses of Jenny Lind. This was incorrect; we should have said E. Long. However, they both are a _long_ ways from taking poor Daguerreotypes.

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