DARK YELLOW.
Bleached grays answer for this color as well as naturally white feathers. Scour and rinse them well. Prepare a bath, feebly acidulated with sulphuric acid, and add the filtered solution of two and one-half per cent. of the weight of feathers, dark yellow, (manufactured by the Leipziger Anilin Fabrik, formerly Bayer & Kegel). Enter the feathers in the cold and work them diligently until the color is well up, then raise the temperature slowly to 170° F., dye to shade, lift, rinse in clear cold water, starch and dry.
II. A new light yellow, which is fast to light and air, is obtained by products of Leonhardt & Co., at Manheim, viz: redarine and acme yellow. Add to a hot bath of 170-190° F., a quite small quantity of redarine and still less acme yellow; enter the feathers, manipulate for one-half hour, take out, rinse and dry them with starch, and beat well out. This color being extremely sensitive, the purification of the water for the bath is as necessary as the most scrupulous cleanliness of utensils and workshops.