BISMARCK BROWN.
Bismarck brown is a product that is used in feather dyeing to a considerable extent, chiefly in a diluted form. It dissolves readily in boiling water. It comes in the form of a powder, of a dirty black hue, and in liquid it is a heavy yellowish red. It makes a fast color, alkali having but little effect on it. Oxalic or sulphuric acid will brighten the color, and turning it more on the red order. In giving a brownish hue to such light colors as beige, ecru, etc., it is invaluable. It is used by some in the topping of dark brown. It has such a great affinity for the fibre of feathers that it is very difficult to remove therefrom.
CONCENTRATED COTTON BLUE.
This blue appears to the consumer in the form of crystals or coarse powder of a purplish tint. It is not universally used among feather dyers, although it is the most reliable aniline blue in use. It is used in conjunction with oxalic acid to develop. It is fast to light, and possesses a great many advantages of value. It is soluble in water, either hot or cold, and is used in the production of the palest shades, as well as in the darkest navy blues.
ROCCELINE.
A patented product, that in feather dyeing is capable of taking the place of all other reds. It is the only dyestuff that satisfactorily takes the place of extract of safflower, producing, with the aid of a proportion of oxalic acid, the most beautiful shades of scarlet and cardinal. It is perfectly fast to light, dissolves readily in boiling water, and comes to us in the form of a dull red powder. Its adulterations, if it contains any, have never interfered with its success; in fact, to the feather dyer it contains virtues too manifold and valuable to enumerate.