Hyposulphite of soda, about 1 lb. to a gallon of water, constitutes the fixing solution; its function is to dissolve all the chloride of silver that may remain in the prints after their previous washing and toning.
The prints should be immersed one at a time, and kept in motion so that the solution may have an equal action. When there are a large number of prints the dish containing the fixing solution should be correspondingly large, so that the prints may not be massed together but kept separate and free for the more perfect action of the fixing solution; they should be kept in motion until the fixing is completed, which will be in about 15 or 20 minutes. Some printers ascertain that the action is complete by holding the print up and examining it by transmitted light; if it looks mottled and uneven it is not fixed, but if you can see the fibre of the paper and all is clear, then remove the prints from the hypo into a dish containing brine or common salt and water, one by one as before, and keep them in motion in this brine until all are well saturated with it; then let fresh water run into the dish, which will gradually change the brine to clear water.
The prints are put into the brine, and this gradually changed to clear water to prevent blisters or a separation of the albumen from the paper in the form of blisters. The water may be allowed to run into the dish, the prints being kept in motion, and in the course of an hour they will be sufficiently washed; they may then be taken out and placed between the' sheets of blotting paper to remain until next morning, when they can be overlooked, the blemished prints thrown out, and the perfect may be mounted.
The fixing solution should not be used a second time, but should be thrown into a large barrel with the washings, that at some future time the silver may be recovered; when the barrel becomes full, a small amount of saturated solution of protosulphite of iron may be thrown in, the water stirred well, and when the sediment has settled to the bottom the clear liquid may be drawn off and the barrel is ready to receive the next washings of hypo.
The selected prints are again placed in water and permitted to remain until they become saturated; in the meantime some starch paste should be prepared. The prints are then removed from the water and placed on a sheet of glass, face down; when all are thus placed, squeeze out all the water and they are ready to mount. Now with a wide bristle brush spread the paste evenly on the back of the print, carefully removing any lumps or dust or fibre of any kind, then insert under the edge of the print the point of a knife-blade, raise it until you can take it in the fingers, then place it pasted side down on the face of your mount, adjust it evenly and lay it on the table; now cover it with a piece of clean white paper, and with the palm of the hand rub it down until all parts are in contact and all air is expelled from between the print and mount. As the prints are mounted they should be placed in rows on clean white or blotting paper, one layer over the other; on the top place a clean sheet of paper and over that a board of the proper size with a weight on it to press the mounted picture flat; in the course of an hour they will be dry enough to spot.
With a fine pencil brush and Indian ink, go over the prints and carefully touch up all the white spots and other blemishes that may be found on the surface, so that they harmonize in color with the surrounding parts. When this is done the pictures may be lubricated for burnishing.