ken out, well washed and dried.

The quantity of Nitrazol C given will suffice for all shades dyed with
from 2 to 4 per cent, of dye-stuff, but when paler shades are dyed,
using less than say 1/2 per cent. of dye-stuff, about 4 lb. Nitrazol C,
with the soda and acetate of soda in proportionate quantities, may be
used.

Azophor red P N is also a preparation of diazotised paranitroaniline in
the form of a dry powder which keeps well.

To prepare the coupling bath there is taken 2 lb. of Azophor red P N,
which is dissolved in water and added to the bath along with 1 lb.
acetate of soda. The dyed goods are worked in the cold bath for half an
hour, then taken out, well washed and dried.

The quantities given are sufficient for shades dyed with 2 to 4 per
cent. of dye-stuff; for weaker shades half the quantities may be taken.

Benzo-nitrol developer is sold in the form of a yellow paste. To use it
take 5 lb., stir into a smooth paste with water, then add to the
coupling bath. There is then added 3 pints of hydrochloric acid, with
some stirring. Allow to stand for half an hour, add 1-1/2 lb. acetate of
soda and 6-1/2 oz. soda, when the bath is ready for use. The cotton is
entered and worked for half an hour, then lifted out, washed and dried.

It may be mentioned that solutions of the three couplers just named may
be kept for some time without decomposition, but as soon as soda and
acetate of soda are added they begin to decompose and then cannot be
kept more than a few hours in a good condition. It is a good plan
therefore not to add the acetate of soda until the bath is to be used.

An excess of coupler in the bath does no harm, but a deficiency may lead
to poor and weak shades being developed.

The following recipes show the dyes which may be applied by this method
and give some idea of the colours that can be got. Only the dye-stuffs
are given. Any of the above couplers can be used with them as may be
most convenient.

_Black._--Dye with 5 lb. Benzo-nitrol black B, 1 lb. soda and 20 lb.
Glauber's salt.

_Olive Green._--Dye with 6 lb. Primuline, 3 lb. Titan ingrain blue and
20 lb. salt.

_Black._--Dye with 4 lb. Dianil black C R, 2 lb. soda and 25 lb. salt.

_Dark Blue._--Dye with 2 lb. Dianil dark blue R, 1 lb. Dianil dark blue
3 R, 2 lb. soda and 25 lb. salt.

_Gold Brown._--Dye with 1 lb. Primuline, 8 oz. Dianil brown R and 20 lb.
salt.

_Chestnut._--Dye with 3 lb. Primuline, 3/4 lb. Dianil brown G O, 1