THE PROCESSES OF PURE PHOTOGRAPHY.
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Gives good, warm tones, but must be used at once, as it will not keep. It is, above all, important to keep toning solutions alkaline, distinctly, but not violently, so, and ammonia will be found as snituable as any alkali for the purpose. If the prints tone very rapidly to a blue color, the gold is, probably, in too great quantity; the prints will lose their tone in the fixer, and the result will be fugitive. If the prints tone unevenly, the cause is either acidity, too much gold, or too high temperature. If patches refuse to tone, probably they have been touched with greasy fingers. The toning should take at least ten minutes, we prefer it to take fifteen or twenty. The prints must be kept in constant motion, and on no account be allowed to stick together, or to the side of the dish. The prints should be removed from the toner when by transmitted light they appear about the color finally desired ; by reflected light there will be a trace of blue beginning to appear on the high lights. Practice alone can teach to what degree prints
FIG. 23.
should be toned; some workers tone by dull, diffused daylight, others prefer artificial light. So long as the same kind of light is used, and the color carefully noted, it is immaterial what light is used. After toning is finished, the prints are placed in clean water, but unless a little common salt is put into this water, toning is apt to continue. Fixing is done in a solution of sodic hyposulphite one part, to water five or six parts, and the solution muat be alkaline, and should be about 60 deg. Fahr., certainly not cooler. The prints should be moved about in the fixing solution as in the toning, and fifteen minutes at least should be allowed for the