A Manual Of Photography

sasses’" 236 PRACTICE OF PHOTOGRAPHY. from the glass. Wash it in two or three waters for a few hours, dry with blotting-paper, and immerse each separately for ten minutes in a bath of the following solution : then wash and dry. “ The iodide may be removed by means of hyposulphite of soda in the usual way ; twelve months afterwards, or when convenient. If,” says Mr. Thomas, “the process has been carefully conducted, four beautiful negatives must be the result. I was ten days working incessantly at Pompeii, and scarcely ever knew what a failure was.” Section VI.—Mr. Muller’s Process. This gentleman has been practising photography with great success at Patna, in the East Indies. His process is as follows :— A solution of hydriodate of iron is made in the proportions of eight or ten grains of iodide of iron to one ounce of water ; this solution is prepared in the ordinary way, with iodine, iron turnings, and water. The ordinary paper employed in photography is washed on one side with a solution of nitrate of lead (15 grains of the salt to 1 ounce of water) ; when dry, this paper is iodized either by immersing it completely in the solution of the hydriodate of iron, or by floating the leaded surface on the solution. It is removed after a minute or two, and lightly dried with blotting- paper. The paper now contains iodide of lead and proto-nitrate of iron: while still moist it is rendered sensitive by a solution of nitrate of silver (100 grains to the ounce of water) and placed in the camera. After the ordinary exposure it may be removed to a dark room ; if the image is not already developed, it will be found speedily to appear in great sharpness without any further application. It may then be fixed with the hyposulphite of soda in the usual manner.