Silver—pale gold.Bismuth—not apparently changed.Silver—deep gold, blue.Bismuth—yellow, blue.Silver—blue, yellow.Bismuth—dull colorless film.
Chlorine with Bismuth and Silver.
Bismuth is slowly attacked with chlorine gas, much in the same way as with iodine and bromine in vapor.
Bromine with Lead.
At the common temperature neither bromine nor chlorine forms colored films upon this metal, which it is very difficult besides to bring to any high state of polish on account of its softness. But when lead is heated, as over the flame of a spirit-lamp, the vapors of bromine then form very fine colored films, which are in succession gold, deep blue, &c.
Iodine with Iron.
These two may be made to form colored films when combined rapidly together, but generally a dull coating without any spectral color is obtained, on account of the deliquescence of that salt.
Until we know the index of refraction of the different films enumerated, it would be impossible to give a correct table of the combining powers in the experiments that have been detailed; nor is the table of the relative thickness of transparent plates as it has been transmitted to us by Newton, sufficient in the present instance, if any great degree of precision be required. Besides these objections, it is necessary before leaving this subject to pass in review several others inseparable from the mode of performing the experiments themselves. The principal circumstances complicating these experiments and liable to vary in different observations, are,—
First, the hardness of the metal acted upon; 2ndly, the obstacle opposed to the continuation of chemical action by the inert film formed upon the metal; 3rdly, the force of the vapors that attack the metal. The influence of the texture of the metallic surface on chemical action is most evident when bismuth is the metal employed. Here the chemical action may be seen to commence on small isolated portions of the surface, which have already assumed a deep gold color, before other parts are in the least changed, from the natural appearance of the metal. To determine how far this might influence the formation of the iodide of silver, a silver coin was exposed to iodine with a piece of pure silver; as the former was so much the harder of thetwo, it was naturally supposed that the chemical action would be slower in exerting itself on it than on the latter. This, however, was not the case, as may be seen by the following statement of the result of the experiment:
Silver coin—pale gold color.Pure silver—pale gold.Silver coin—deep gold.Pure silver—deep gold.Silver coin—light blue.Pure silver—light blue.Silver chin—yellow.Pure silver—blue, white, yellow not visible.Silver coin—yellow, red at edges.Pure silver—yellow, no red edges.Silver coin—red, blue at edges.Pure silver—yellow, no red apparent.
The intensity of the resistance offered by the different films of iodide of silver to a continuation of the chemical combination, may be determined by noting the moment at which the various spectral tints make their appearance.
By comparing the thickness of the colors with the space of time required for their production, it will be found, however imperfect the table given by Newton may be when applied to this subject, that towards the end of the experiment above given, the chemical combination is retarded by the presence of the inert film, and that to obtain the same thickness of film as at the commencement, about double the time is required.
The third cause of error may be avoided by operating with vapors of about the same force. In those described, the average time employed in passing to the maximum was generally about half an hour; if that were not taken into consideration, different results might be obtained.
In regard to chlorine, there exists another cause of complication—the affinity which it possesses for water; for when disengaged in the ordinary manner, chlorine carries with it a certain quantity of water which may very much alter the results of the experiment.—Philosophical Magazine,1842.
In each of the countries of Europe where the Electric Telegraph is established, viz.: Britain, France, Germany, and Russ a, the people seem anxious to claim for one or more of their own countrymen some merit in connection with the invention. The English speak of Wheatstone and Bain; the French of Le Sage; the Germans of Steinheil and Siemen; and the Russians of Schilling or Jacobi. Most of these inventors have their agents or representatives in different countries, ready on every suitable occasion to speak or write in behalf of their principal.
The inventor of the American Electric Telegraph has, we believe, no agent in Europe; and no person there who has any special interest in promoting the introduction of his system. The adoption of it by the Prussian government for great distances, as decidedly the best which it could obtain, after advertising extensively in Europe, is, therefore, the more remarkable; and especially, as the only knowledge which thePrussians possess of the American system seems to have been derived from one imperfectly acquainted with its powers; for we can account in no other way for the fact that Siemen's needle apparatus is adopted for short distances; Morse's instruments being clearly superior to Siemen's, or to any other needle apparatus, for short as Well as for long distances; since they are much more rapid in their motion, and have, besides, the advantage of making a permanent record on paper, instead of merely indicating to the eye by an evanescent sign. No one using the telegraph in America, would think of employing a needle apparatus in any of its operations.
In addition to the evidence of the high estimation of the American Telegraph by Europeans, furnished by this adoption of it in Prussia, we learn also from an elaborate work on Telegraphs by Dr. H. Schellen, recently published in Dusseldorf, that it is now introduced into other countries on that continent. Dr. S. says: "Of late the Morse Telegraphs are much used in Europe, viz: in England; between Hamburg and Cuxhaven; between Bremen and Bremer-haven; in Prussia, Austria, Bavaria and Hanover." Dr. S. might have added also that it is used in Turkey. Among the advantages of the American Telegraph, Dr. S. says, is its "quickness in making and marking the signs upon paper. * * *It records under the hand of a skilful operator 100 to 120 letters, in the same time in which the best needle telegraphs are able to indicate 20."
While the superiority of the American Electric Telegraph to all others is thus acknowledged by Europeans, they do not seem to be aware that the date of the American invention is also prior in point of time to that of any of their own electric telegraphs. They very naturally regard the date of the patent as the date of the invention, because in every country in Europe the patent is given to the person who first promulgates the invention in that country; and it is not safe, therefore, in Europe, for an inventor to permit others to know any thing of his invention until he has patented it. But in America, where the law permits no one to take out a patent but the inventor, he is perfectly safe in communicating the knowledge of what he has done, and even in publicly exhibiting his invention, before he takes out his patent, provided he secures himself by a caveat, and does not offer it for sale, or permit it to go into common use.
The inventor of the American Electric Telegraph, it is well known, exhibited his instruments in operation in the N. Y. University, in the presence of hundreds of our citizens in September, 1837, and privately to his friends at various times as far back as November 1835, although his first patent was not secured until 1838. No one claims for the inventions of either Wheatstone or Steinheil a date prior to 1837; and when European writers on the telegraph come to understand our laws, and the error into which they have fallen, by confounding the date of the American invention with the patent, they will no doubt do our country the justice to admit its claims to priority as well as tosuperiority.—N. Y. Observer.
Iron Pavement.—Iron is daily coming into more general use for almost every purpose. A letter from Paris, of a late date says:
"A new pavement, to upset the Macadam and other inventions of the kind, has been proposed by Mr. Tobard, who intends paving, in this way, the streets and boulevards of Paris. This gentlemen has proved, by figures, that melting iron is only worth 11 francs in Paris, 7 francs in Belgium, and 4½ francs by 100 kilogrammes in England, whilst the stone costs 25 francs in London, 15 francs in Paris, and 8 and 10 francs in Belgium. This new mode of pavement will be grooved, in order not to become slippery, and it is said that the electricity occasioned by the rolling of the carriages will prevent rust. Here is a new field open to industry."
Sealed 21st November, 1843.
Wegive the following as copied at the Patent Office in London. Many of our Daguerreotypists have enquired of us in relation to the patents on the Daguerreotype in England.
To Autoine Jean Claudet, of High Holborn, in the county of Middlesex, glass merchant, for an invention of improvements in the process and means of obtaining the representation of objects of nature and art,—being a communication.[Sealed 21st November, 1843.]
These improvements consist in rendering the Daguerreotype picture susceptible of producing, by printing, a great number of proofs or copies; thereby transforming it into a complete engraved plate.
The process is established on the following facts, which have come to the knowledge of the inventor:—
1st. A mixed acid, composed of water, nitric acid, nitrate of potassa, and common salt, in certain proportions, being poured upon a Daguerreotype picture, attacks the pure silver, forming a chloride of that metal, and does not effect the white parts, which are produced by the mercury; but this action does not continue long. Then, by a treatment with ammonia (ammonia containing already chloride of silver in solution, is preferable for this operation), the chloride of silver is dissolved, and washed off, and the metal being again in its naked state, or cleansed from the chloride, it can be attacked afresh by the same acid. This acid acts better warm than cold.
2d. As all metallic surfaces are soon covered (when exposed to the atmosphere) with greasy or resinous matters, it is necessary, in order that the action of the acid upon the pure silver should have its full effect, for the surface to be perfectly purified; this is effected by the employment of alcohol and caustic potash.
3d. When a Daguerreotype picture is submitted to the effects of a boiling concentrated solution of caustic potash, before being attacked by the acid, the state of its surface is so modified that the acid spares or leaves, in the part which it attacks, a great number of prints, which form the grain of the engraving.
4th. When the effects of the acid are not sufficient, or, in other words, it is not bitten deep enough, the effect is increased by the following process:—Ink the plate as copper-plate printers do, but with a siccative ink; when the ink is sufficiently dry, polish the white parts of the plate, and gild it by the electrotype process; then wash it with warm caustic potash, and bite it in with an acid, which will not attack the gold, but only the metal in those parts which having been protected by the ink, have not received the coating of gold. By these means the engraving is completed, as by the acid alone it is not generally bitten in deep enough.
5th. To protect the plate from the effects of wear, produced by the operation of printing, the following process is employed: The surface of the plate is covered with a thin coating of copper, by the electrotype process, before submitting it to the operation of printing; and when that pellicle or coating of copper begins to show signs of wear, it must be removed altogether, by plunging the plate in ammonia, or in a weak acid, which, by electro-chemical action, will dissolve the copper, without effecting the metal under it; the plate is then coppered again, by the same means, and is then ready for producing a further number of impressions. This re-coating operation may be repeated as many times as may be required. The following is the description of the whole process, which is divided into two parts, consisting of a preparatory and printing process.
Preparatory Engraving.—For this operation which is the most delicate, it is necessary to have—1. A saturated solution ofcaustic potash. 2. Pure nitric acid at 36° of the barometer of Beaumé (spec. grav. 1·333). 3. A solution of nitrate of potassa, composed of 100 parts of water, and 5 parts of nitrate, by weight. 4. A solution of common salt, composed of water 100 parts, and salt 10 parts by weight. 5. A weak solution of ammoniacal chloride of silver, with an access of ammonia. The ammoniacal chloride of silver must be diluted with 15 or 20 parts of pure water. In the description of the process, this solution will be called ammoniacal chloride of silver. 6. A weak solution of ammonia, containing 4 or 5 thousandths of liquid ammonia. This solution will be called ammoniacal water. 7. A weak solution of caustic potash, containing 4 or 5 thousandths of the saturated solution, which will be called alkaline water. 8. A solution composed of water 4 parts, saturated solution of potash 2 parts, alcohol 1 part, all in volume. This solution will be called alcoholized potash. 9. Acidulated water, composed of water 100 parts, and nitric acid 2 parts, in volume. Besides, it is necessary to have three capsulæ or dishes, made of porcelain, large enough to contain the plate, and covered with an air-tight piece of ground plate glass, and two or three more capsulæ, which do not require to be covered; two or three glass funnels, to wash the plate; and two or three glass holders, in the shape of a spoon or shovel, by which the plate is supported when put in and taken out of the solution, without touching it with the fingers.
The Daguerreotype plate is submitted to the engraving process, after having been washed in the hyposulphate of soda, and afterwards in distilled water.
First process for biting in or engraving the plate.—The following solutions must be put in the capsulæ, in sufficient quantity, so as to entirely cover the plate:—1. Acidulated water. 2. Alkaline water. 3. Alcoholized potash, in covered capsulæ. 4. Caustic potash, in covered capsulæ. 5. Distilled water.
The plate being then put upon the glass holder or spoon, is plunged in the acidulated water, and agitated during a few seconds, then put into a glass funnel, and washed with distilled water. It is taken again with the glass spoon, and plunged in the capsulæ containing alcoholized potash. This capsulæ is covered with its glass cover, and then heated, by means of a spirit lamp, to about 140° Fahrenheit. The plate must remain in the capsulæ half an hour, during which the solution is heated now and then, and agitated. During that time the following acid solution, which will be callednomal acid, must be prepared: it is composed as follows:—Water 600 parts, nitric acid 45 parts, solution of nitrate of potassa 12 parts, solution of common salt 45 parts. These proportions are in volume. The nomal acid must be poured in a capsulæ, covered with its glass cover, and a sufficient quantity must be kept in the bottle.
When the plate has been immersed in the alcoholized potash during half an hour, it is taken out of the solution by means of the glass holder, and immediately plunged in the alkaline water, and agitated pretty strongly; from thence it is put in distilled water (A). This being done, the plate is plunged in the acidulated water, and moved about therein for a few seconds: it is then put into the nomal acid. When the plate has been immersed a few seconds in the acid, it is taken out by means of the glass holder, taking care to keep it as much as possible covered with the solution, and it is immediately placed horizontally upon a stand, and as much acid as the plate can hold is poured upon it from the bottle; it is then heated with a spirit lamp, but without attaining the boiling point. During this operation it is better to stir or move about the acid on the plate by pumping it, and ejecting it again, by means of a pipette or glass syringe; after two or three minutes theacid is thrown away, the plate is put in the glass funnel, and then well washed with water, and afterwards with distilled water (B).
Thus, without letting the plate dry, it is put upon the fingers of the left hand, and with the right hand some ammoniacal chloride of silver, which is moved about the surface by balancing the hand is poured upon it; the solution is renewed until the chloride, formed by the action of acid, is dissolved; the plate is then washed by pouring upon it a large quantity of ammoniacal water, and afterwards some distilled water. (C.)
Without allowing the plate to dry, it is then put in the caustic potash, and the capsula being then placed upon the stand, the potash is heated up to the boiling point; it is then left to cool (D); and beginning again the operations described from A, to D, a second biting is obtained; and by repeating again the operations described in A, and B, a third biting is produced. The plate is then dried; in this state the black parts of the plate are filled with chloride of silver.
The plate is then polished until the white parts are perfectly pure and bright. This polishing is soon done with cotton and ('ponce') (pumice stone); afterwards, the chloride of silver, filling the black parts, is cleansed by the means described in B, and C. The plate is dried, but before drying, it is well to rub the plate slightly with the finger, in order to take off from the black parts any remains of an insoluble body, which generally remains on it. The preparatory engraving is then finished, and the plate has the appearance of a very delicate acquatint engraved plate, not very deeply bitten in.
Nevertheless, if the operation has been well managed, and has been successful, it is deep enough to allow the printing of a considerable number of copies.
Note.—Sometimes, instead of treating the plate with the boiling potash in the capsula, a similar result may be obtained by placing the plate upon the stand, covering it with the solution, and heating it by means of a spirit lamp, until, by evaporation the potash becomes in a state of ignited fusion. By this means the grain is finer, but the white parts are more liable to be attacked.
Last operation of biting in: This operation requires some of the re-agents, before-named, and also,
1. A siccative ink, made of linseed oil, rendered very siccative by boiling it sufficiently with litharge; it may be thickened with calcined lampblack.
2. An electrotype apparatus, and some solutions of it to gild, and copper the plate.
Means of operating: The plate must be inked as copper-plate printers do, taking care to clean off the white parts more perfectly than usual; the plate is then to be placed in a room sufficiently warm, until the ink is well dried, which requires more or less time, according to the nature of the oil employed. The drying of the oil may be hastened by heating the plate upon the stand with the lamp, but the slow process is more perfect and certain.
When the ink is well dried, the white parts are cleaned again, by polishing the plate with cotton and ponce, or any other polishing powder; a ball of cotton, or any other matter covered over with a thin piece of caoutchouc or skin, can be used for this purpose. When polished the plate is ready to receive the electro-chemical coating of gold, which will protect the white parts.
Gilding.—The gilding is obtained by any of the various processes of electrotyping that are known. The only indispensable condition is, that the surface obtained by the precipitation must not be liable to be attacked by the weak acid; a solution answering this purpose is made of 10 parts, (by weight), of ferocganide of potassium; 1 part of chloride of gold, and 1,000 parts of water, used with a galvanic battery. During the gilding the plate must be turned in several positions, in order to regulate the metallic deposit. In some cases the gildingmay be made more perfect, if the plate is covered with a thin coating of mercury before putting in the gilding solution.
When the plate is gilded, it must be heated with the boiling caustic potash, by the process already indicated for the preparatory engraving, in order to cleanse it from all the dried oil or ink, which fills the hollow. The plate is then washed and dried, and when the oil employed has been thickened with the lampblack, the surface of the plate is rubbed with crumbs of bread, in order to cleanse and take off the black remaining; then, the white parts being covered and protected by varnish not liable to be attacked, and the black parts being uncovered and clean, the plate can be bitten in by aqua-fortis, according to the ordinary process used by engravers.
This operation must be used upon the stand, and not by immersing the plate in the solution.
Before this biting in, if the preparatory engraving has not succeeded well, and the plate still wants a sufficient grain, it can be given by the various processes of aquatint engraving.
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. Thisis 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.
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.
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.
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 apolishedsurface; but it is not topolishthe plate that he uses the buff, and the other materials; the object is to clean the plate, and thepolishof 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 completelayer 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.
Friend Humphrey:—
I have thought for some time past that I would furnish a few thoughts for theDaguerreian Journal, under the head ofGeneral 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.
Avery fewpersons (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 dothese gentrymore simple justice than by dignifying them by a notice in our Journal, yet I bear them no ill will, andfor the presentshall 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 Ihave, 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 processshall 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 thesefacts, it is not strange that I should feel annoyed at the variousrumors to which I refer, and some of the intimations which have been thrown out, Ifeelare 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 beengrievedthatsome 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 mybusiness 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, ismy 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 ofProfessor 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, todo 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 mefeel 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 themfull proofhereafter.
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 theDaguerreian 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.
HandThe 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.
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, whenlooking 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 thefirstlikeness 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 plateless 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.
The subscriber begs to request those interested in the above discoverynot to visit himuntil further notice, which will be given in the Daguerreian Journal. It isabsolutely essentialthat 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, Greene 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.