A Manual Of Photography

222 PRACTICE OF PHOTOGRAPHY. judge of the time required, which will vary from a few seconds to three or four minutes. The subject ought, if possible, to have a strong and decided effect ; but extreme lights, or light-coloured bodies, in masses, are by all means to be avoided. When the paper is taken from the camera, very little, or more commonly no trace whatever, of a picture is visible until it has been subjected to the fourth process, which is 13. The Bringing-out of the Picture, which is effected by again applying the “gallo-nitrate” in the manner directed in §°9. As soon as the paper is wetted all over, unless the picture appear immediately, it is to be exposed to the radiant heat from an iron, or any similar body, held within an inch or two by an assistant. It ought to be held vertically, as well as the paper; and the latter ought to be moved, so as to prevent any one part of it becoming dry before the rest. As soon as the picture is sufficiently brought out, wash it immediately in clean water to remove the gallo-nitrate, as directed in’§ 10; it may then be placed in a dish by itself, under water, until you are ready to fix it. The most perfect pictures are those which “ come out” before any part of the paper becomes dry, which they will do if sufficiently impressed in the camera. If the paper be allowed to dry before washing off the gallo-nitrate, the lights sink and become opaque ; and it exposed in the dry state to heat, the paper will embrown, the drying, therefore, ought to be retarded, by wetting the back of the paper, or the picture may be brought out by the vapour from hot water, or, what is better, a horizontal jet of steam. The fifth and last process is 14. The Fixing of the Picture, which is accomplished by removing the sensitive matter from the paper. The picture, or as many of them as there may be, is to be soaked in warm water, hut not warmer than may be borne by the finger ; this water is to be changed once or twice, and the pictures are then to be well drained, and either dried altogether, or pressed in clean and dry blotting-paper, to prepare them to imbibe a solution of the hyposulphite of soda, which may be made by dissolving an ounce of that salt in a quart (forty ounces) of water. Having poured a little of the solution into a fiat dish, the pictures are to be introduced into it one by one ; daylight will not now injure them; let them soak for two or three minutes, or even longer if strongly printed, turning and moving them occasionally. The remaining unreduced salts of silver are thus thoroughly dissolved, and may now, with the hyposulphite, be entirely removed by sealing in water and pressing in clean white blotting-paper alternately : but if time can be allowed, soaking in water alone will have the