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478 HE PHOTOGRAPHIC NEWS. [October 2, 1868. prints three or four times to free them from any free nitrate before being brought into the toning bath, to treat them in a mixture of equal parts of spirits of wine and water, to which, for every twenty parts, one part of caustic ammonia is added. The pictures are immersed in this mixture for a few minutes, then washed again in water, and afterwards toned and fixed in the ordinary manner. If this treatment is omitted the pictures are not capable of being perfectly fixed—that is to say, they become altered in direct sunlight.* Although, however, the omission of the spirit bath does not allow of their being perfectly fixed, the prints so produced do not undergo any alteration in diffused light, at least as far as my experience goes, which now renges over a period of nearly two years. (To be continued.) - Oorresponence. INDIA-RUBBER, ENCAUSTIC PASTE, ETC. Sib,—Some very important articles in your paper lately, respecting the use of india-rubber in photography, and also the application of encaustic preparations for improving the appear ance of the finished picture, induce me just to trouble you with a few lines on these subjects. In a paper I read early in this year before the South London Society, I expressed my belief that photographers who used india-rubber as a mountant would find it to their loss, and I have had abundant further evidence, since that time, that such is really the case. Vignettes are speedily stained and spoiled, and other pictures, within periods varying from a few months to a few years. I doubt if anything else is equal to Glenfield starch for mounting pictures on cards; and a very few drops of carbolic acid added to it when made will cause it to keep a considerable time. I also adverted in the same paper to the use of encaustic paste, expressing a belief that whilst greatly enhancing the beauty of the print, it gave every hope of increased longevity. Wax is one of the most permanent and most unchangeable substances from atmospheric influence, and not only does it contain no element of decomposition within itself, but, from its repulsion of fluids, it acts strongly as a preservative from any deleterious substances from without. It is also unaffected by most chemicals. Previous to Mr. Blanchard’s formula of bees'- wax in benzole, the encaustic paste made for sale to photo graphers was far too hard and brittle, often quite chippy. I adopted Mr. Blanchard’s suggestion at once, and after adding a few drops of an essential oil, to give a little more elasticity and prevent the preparation drying up too quickly, it was found all that could be desired. You have now given us M. Adam-Salomon’s recipe, and a very capital one it is. I made up a supply at onco, and had a large number of pictures done with it. Whether it is superior to our former one when properly made with essential oil of lavender is a matter of difference of opinion ; those who are employed in doing the pictures say they have no choice, that one applies to the prints just as well as the other. On looking over a hundred pictures of various sizes which have been finished indis criminately with the two preparations, there is nothing to lead one to a preference, although I confess that on carefully scru tinizing prints done with M. Salomon’s encaustic I certainly fancied there was a little more depth given, just a soupcon more of liquid transparency than with the other; but after repeated trials of the fairest nature, it was not found that it was possible to pick out from the bulk pictures treated with either preparation, on account of any difference in their appearance. There is no inducement on the part of dealers to adulterate bee’s-wax ; but it is believed that white wax, from its price, is, to a considerable extent, mixed with other and cheaper substances. I have made up M. Adam-Salomon’s for mula, substituting dees'wax for the white article, and from the result of the last few days’ use am rather inclined to look to it as the right thing. If this is manufactured for sale, a good * Professor Freund’s experience here is exceptional. We have prints in our possession produced at the time we first introduced the process, toned and fixed in the usual manner, which have been exposed to sunlight for months without change.—Ed. Photo. News. large bottle should be sold for a shilling, and in a convenient shaped bottle too. In conclusion, I most strongly advise the use of encaustic paste; those who have begun it are not likely to discontinue, whilst those who have not, have a pleasure in store. Samuel Eby. WET COLLODION WITHOUT WATER. Dear Sib,—In the News of September 25th you give a method of working wet plates without water, and as I have, by a different method, been doing the same thing for more than a year past, perhaps the result of some experiments may interest some of your readers. I bad just invented and completed a new dark tent upon small (11-inch) wheels, having the follow ing advantages1st. It is so light—only about two pounds upon each hand—that a boy twelve years old can get along as fast with as without it. 2nd. It can bo taken to pieces for rail way travelling in about one minute, is about the size of a child's perambulator, and can be set up as a dark tent in less than thirty seconds. Having completed the tent, I thought what a useful thing it would be if the wet process could be worked with out water, and I set about trying it. Knowing that a negative may remain in contact with hypo soda for many hours without injury, I poured hypo soda solution containing a little golden syrup upon a developed but unwashed plate, and I obtained a negative clear in the shadows, and without any stains; but the decomposition between the hypo and the pure nitrate of silver created a few minute floating particles, which adhered to the plate, and were difficult to remove in the after washing, which was generally postponed until the next day. I next tried chloride of calcium applied to the developed but unwashed plate. This converted the free nitrate into chloride, stopped further developing action, and kept the plates moist. The negatives were clean and bright, but if the chloride of calcium was used too strong, it sometimes produced a little discolouration of the white parts of the negative. I finished my efforts in this direction by trying a strong solu tion of common salt, with sufficient alcohol to prevent its running greasy upon the plate, and have used it ever since with perfect success. It stops developing action, and keeps the plates moist for several hours, merely with the addition of a pad of wet blotting-paper at the bottom of the plate-box.— Yours truly, W. Callaway. Lucerne Villa, Torquay, Sept. 26th, 1868. PS.—The salt produces a quantity of chloride of silver upon the plate, every trace of which dissolves in the hypo. Sir,—With reference to your article, in last week’s Journal, on •' Wet Collodion without Water,” allow me to make a few remarks. Being myself a landscape and architectural photo grapher, I have for my convenience a cab or portabio laboratory, fitted with racks that swing to and fro, so that it answers every purpose of a dark room. I think we are greatly indebted to Mr. Robinson, who has brought out the use of golden syrup. I may mention that I always take a 10 by 12 plate, proceed to my laboratory, and develop it with iron deve loper as follows:— Iron 120 grains Liquid ammonia 1 to 2 drops Glacial acetic acid } ounce. As soon as I find the picture sufficiently out in detail I pour over a mixture of equal parts of golden syrup and water. I find the syrup stops the action of the developer altogether, and by placing the negative on a rack inside your dark room while you are preparing another plate, you will find it sufficiently drained to place in your negative box, the bottom of which I always keep wet. In this way I have kept plates for a week, and obtained some splendid enlargements, of which you are aware plates must be very clear and transparent to obtain a direct enlargement without any working up. I shall be happy to forward you one of the enlargements from plates a week old, should you wish it. All that the above requires, after getting home, is to carefully wash, and, if necessary, you may intensify and fix without injury to the plate. I shall be glad to furnish you with further particulars as I proceed.
