Scour the white, respectively bleached feathers and rinse well. Prepare
a bath with five per cent., of the weight of feathers, bisulphate of
soda, to which add gradually and carefully the filtered solution of
acid violet, fast yellow and fuchsine S., making the additions from
the beginning in small quantities only, until the desired tone and
shade are obtained; then enter and work the feathers to sample at 173°
F.
It is for this dye particularly important that the bisulphate of soda
used be crystallized, that is, pure bisulphate free from surplus
sulphuric acid, while the commercial article is often nothing but a
mixture of Glauber salt (sulphate of soda) into sulphuric acid, answer
for this dye.
A good reseda is also easily obtained by adding to the acidulated bath
small quantities of decoction of logwood and turmeric, so as to give a
feeble bath. Enter the scoured and bleached feathers, after rinsing, at
170° F., work them for about fifteen minutes, until level, and sadden
with a little solution of blue stone. Rinse, starch and dry as usual.