The photographic news

• Bandzählung: 7.1863
• Erscheinungsdatum: 1863
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
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• PURL: http://digital.slub-dresden.de/id1780948042-18630000
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• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

THE PHOTOGRAPHIC NEWS. Vol. VII. No. 245.—May, 15, 1863. CONTENTS. PAGE Recovery of Waste Silver 229 Formic Acid in the Developer. By II. G. Cooper, Jun 229 Enamelled Photographic Paper. By L. M. Liesh 230 Landscape and Instantaneous Photography. By W. II. Warner 230 Scientific Gossip 231 Critical Notices 232 On the Action of Photographic Varnishes upon the Collodion Film. By Dr. D. Van 233 Recovery of Gold and Silver from Waste Photographic Materials. By William England... 234 PAGE A Short Lesson in Photography.—No. 13 235 Copyright in Engravings and Photographs 236 Photography in Tropical Climates 237 Fogging Nitrate Baths 238 Correspondence—Foreign Science, &c 238 Photographic Notes and Queries 239 Talk in the Studio 239 To Correspondents 240 Photographs Registered during the past Week 240 RECOVERY OF WASTE SILVER. Os another page will be found an interesting paper by Mr. England on recovery of silver from the various residues accumulating in photography. When it is remembered that little more than one and a half per cent, of the silver used in printing is actually to be found in the finished print, and that consequently upwards of £4 18s. Od. out of every £5 spent in silver, is waste, unless some steps be taken to recover it, the question becomes one of serious import. There will be of course a practical limit to the amount of silver possible to be recovered, and perhaps before that is reached, a limit to the amount it will be remunerative to recover, for it is quite possible in such operations for the cost of the effort to exceed the value of the result. But it is quite clear that with moderate effort a large proportion of the silver now wasted in too many establishments might be saved. Where the amount of work, especially of printing, is small, the trouble of recovering the silver as chloride and sulphide, and then of reducing it to a metallic state, seems somewhat formidable and the result is scarcely considered worth the constant attention necessary. It is to be regretted that a system of collecting argentiferous waste, in which photo- graphers might have confidence, is not established. Attempts have been made to establish such a system, we know; but, we believe, without much success. In other trades in which the precious metals are used the sweepings of the rooms, the dusters employed, &c., are regularly collected, and command a specific price remunerative to those who save and those who collect, and it is much to be regretted that a similar system docs not obtain for photographers. Refiners are prepared, we are aware, to purchase the various residues containing silver, or to reduce it, making a specific charge for the operation. But there is a want of confidence existing which makes photographers indifferent about availing themselves of the aid of the refiner. One photographer, we know, who took a large quantity of chlo- ride of silver for reduction, was coolly informed, on calling again for the reduced metal, that the crucible had unfortu nately cracked, and his silver was lost. It was not until after he had threatened legal proceedings he obtained any satisfaction ; and, finally, he received a small ingot of metal, Sot a third of the legitimate yield of the chloride he had taken. Mr. England informed us that a short time ago, after turning an accumulation of sensitive papers, he carefully Weighed out three parcels of the ashes, each weighing two Pounds, having well stirred and mixed the ashes first, to avoid any possible difference in their character. One parcel of two pounds he sent to one refiner for reduction ; a second parcel was sent to another refiner, and the third he reduced himself. The result was—eight ounces of metallic silver from the first refiner; nine ounces from the second; and ten ounces and a half from the parcel he reduced himself. „hus, if the silver were worth only five shillings an ounce, he was mulct, in one instance, of twelve shillings and six pence; and, in another, of seven shillings and sixpence, in addition to the legitimate charge for reduction. We do not wish to imply that dishonesty is an invariable, or even a common characteristic of refiners, we should be sorry to entertain such a notion; but the fact is, that a few such cases destroy confidence, either in the men employed, or the method adopted. Where it can be done, however, it is a very simple opera tion for the photographer to reduce his own residues. Where gas is available, and a moderate amount only of the metal has to be reduced, the small Griffin’s furnace, heated by gas, Mr. England informs us, answers admirably. There are similar small furnaces, costing but a few shillings, made for burning coke. We have seen a small stove, in which coke was burnt, used successfully for the reduction ; and it is possible, although difficult, to obtain sufficient heat in a kitchen fire. The London pots, recommended by Mr. Eng- and, are cheap and excellent, and the flux employed is also cheap. In Mr. England’s establishment, which we recently visited, the recovery of the waste silver is provided for in all the arrangements. In the sensitizing room the excited sheets are suspended on pins along two sides of the room, and beneath, to catch the droppings, are curved glasses placed at an incline so as to flow to a common point where a jar is placed. These curved glasses are each about two feet long, and are formed of parts of a cylinder of fourteen inches diameter which is cut into three sections. A cocoa-nut matting covers the floor, which, when worn out, will be burnt, and yield probably more than its original cost, in argenti ferous ashes. Pieces of waste blotting-paper or rag are at hand to wipe up small portions of spilled silver solutions. The kaolin is made to give up its silver and is used over and over again. The silver in washing waters is precipitated as chloride, and in old hypo baths as sulphide. All clippings of sensitive paper and waste prints are burnt, and even the ashes of waste fixed prints are made to yield something. We do not know whether Mr. England has made any exact calculation of the saving effected; but wo believe it is possible to recover from sixty to seventy per cent, of the silver used. This, even in small establishments, is, we think, worth saving. • FORMIC ACID IN THE DEVELOPER. BY H. G. COOPER, JUN. I have lately been making many experiments with formic acid in the developer; and as the subject of its use is now attracting considerable attention, the results which I have obtained may not be uninteresting to your readers. I took a nitrate of silver bath of the strength of 30 grains of pure fused nitrate to the ounce, and having made it perfectly neutral, added one drop of strong nitric acid to 20 ounces of it.