A Manual Of Photography

CALOTYPE PROCESS ON WAXED PAPER. 231 Section IV.—Calotype Process on Waxed Paper. The most successful operator with waxed paper has been M. Le Gray, to whom we are indebted for this and several other im- provements. In a work lately published by this photographer, he has entered into the question of the physical agencies which are active in producing the chemical changes on the various preparations employed. Throughout the essay, he evidently labours under an entire misconception of the whole of the phenomena, to which, indeed, it is clear he cannot have directed his attention. His manipulatory details are very perfect, but his scientific explanations are not to be received as correct expressions of the facts. First Process : To Wax the Paper.— This process divides itself into several parts, waxing the paper being the first. For this purpose he takes the paper prepared by Lacroix d’Angouleme, or, that of Canson brothers of Annonay. A larwe plate of silvered copper, such as is employed for the daguerreotype, is obtained and placed upon a tripod, with a lamp underneath it, or, upon a balneum mariæ. The sheet of paper is spread upon the silver plate, and a piece of pure white wax is passed to and fro upon it until, being melted by the heat, it is seen that the paper has uniformly absorbed the melted wax. When this has thoroughly taken place, the paper is to be placed between some folds of blotting paper, and then an iron, moderately hot, being passed over it, the bibulous paper removes any excess of wax, and we obtain a paper of perfect trans- parency. Second Process : To Prepare the Negative Paper. — In a vessel of porcelain or earthenware capable of holding 5 pints and a quarter of distilled water, put about 4000 grains of rice, and allow them to steep until the grains are but slightly broken, so that the water contains only the glutinous portion. In a little less than a quart of the rice solution thus obtained dissolve :— Sugar of Milk............................620 grains. Iodide of Potassium .... 225 “ Cyanide of Potassium . . . 12 “ Fluoride of Potassium ... 7 “ The liquid, when filtered, will keep for a long time without alte- ration. When you would prepare the paper, some of this solution is put into a large dish, and the waxed paper, sheet by sheet, is