NAVY BLUE.
I. For this color naturally gray or semi-bleached feathers may be used. It requires a mordant, like wool. For this purpose prepare a bath of forty per cent. (of the weight of feathers) tannin at 167° F., enter the feathers and agitate them from time to time for three hours. Then take them up, drain and squeeze them out, enter a cold bath of pyrolignite of iron (black liquor) marking 5° B., and work them for half hour; take them out, drain and squeeze, and then expose them, well spread out upon the strings, for one hour to the action of the air. Then rinse and dye upon a fresh warm bath with a mixture of aniline blue and a little methyl violet, using about twenty per cent. of the weight of feathers. Add the dyestuff in the beginning only in small doses and slowly in order to prevent the production of a bronzy, undesirable lustre upon the stem, as is often the case in dying with aniline dyestuffs if they are added to the bath in too large doses.
II. Prepare a hot bath, to which add as much indigo carmine as to bring the color of the bath pretty near the shade to be produced. Enter the feathers and agitate them in the bath for one hour. Then take up the feathers, add alum and a solution of cloth-blue S. to the bath, re-enter the feathers and work them while raising the temperature to boiling point, when the steam or gas is turned off, or the pan removed from the fire, and the feathers allowed to lie for fifteen or twenty minutes longer in the bath. They are then taken out, rinsed, starched and dried and beaten.
III. Have the feathers properly cleaned and well rinsed from the soap, respectively soda. Gray feathers may be used unbleached, but a purer color is obtained upon them when bleached. Prepare a hot bath, to which so much sulphuric acid is added, that it has a feeble sour taste; add the solution of two per cent. (of the weight of feathers), navy blue, one per cent. fast blue or black, and one-eighth per cent. acid fuchsine. Stir well, enter the feathers, manipulate while raising the temperature to boiling point, but not to actual boiling, continue at this temperature for one half hour; then stop off the steam, lay the feathers down in the bath until cool, lift and dry as usual.