GRAY.
So unpretending this color appears, so difficult is it to produce, and it requires a considerable amount of practice and good judgment to bring out a good color from the beginning, as very little too much or too little will spoil a color either in tone or in shade. A very good logwood gray, which with proper attention seldom fails to turn out satisfactory, is made as follows: Prepare a hot bath, to which add a small quantity of decoction of logwood; enter the feathers and work them in the bath for fifteen or twenty minutes, according to shade desired. Then take them up, add to the bath very little pyrolignite of iron, that is, only as much as to turn the color of the bath; re-enter the feathers, agitate them again for fifteen or twenty minutes in the liquid; then lift, rinse and starch as usual. This color might be best described as dark ash gray. Instead of pyrolignite of iron, some solution of copperas may be used. It will be easily understood, that the more concentrated the decoction of logwood is, the darker turns out the color, and it is in that respect particularly that the dyer has to use good judgment in producing shades from silver gray to dark ash gray. This color, besides, presents the advantage, that by topping it with solutions of blue, brown, yellow or green coal-tar dyestuffs a great variety of mode colors can be produced.