(I) The feathers should be soaked in solution of ammonium or sodium carbonate, whereby they are rendered less liable to break or bend; after being dyed, they should be dried in a current of warm air. Feathers may be dyed black in the following baths: - (a) 100 pints water, 1 lb. ignited sodium carbonate; (6) ferric nitrate at 70° B.; (c) 2 lb. logwood, 2 lb. quercitrine. 1/2 lb. feathers is digested in a at 30°; the feathers are then washed with warm water, and soaked in 6. After another washing they are boiled in c, until of a deep black colour; they are then dipped in an emulsion formed by agitating oil and potassium carbonate together, and dried by gently swinging them in warm air.
(2) Feathers may be dyed brown by first treating them with catechu and then with potassium chromate; they can be dyed directly with aniline colours, and can be bronzed by painting with aniline violet dissolved in alcohol at 90 per cent. (Ding. Pol, Jl.)