d and 7-1/2 lb. soda, boiling with 50 gallons
of water. About 1-1/4 per cent. is required for developing full shades.

Developer B (Bayer) is ethyl beta-naphthylamine, in the form of its
hydrochloric acid compound. The bath is made from 10 lb. of the
developer and 50 gallons of water, 1-1/4 per cent. being used to obtain
full shades.

Developer D (Bayer) is dioxy-naphthalene-sulpho acid, and simply
requires dissolving in water to make the bath.

=Toluylene diamine= is a homologue of phenylene diamine and is used in
precisely the same way.

Generally the special developers issued by the various colour firms
simply require dissolving in water to form the developing bath.

The cotton, previously being passed through the diazotising bath, is
then run into the developing bath, in which it is kept for from twenty
to thirty minutes or until the required shade is fully developed, after
which it is taken out, rinsed and dried. The method of working is the
same for all the developers, and may be carried out in any kind of
vessels. As is indicated above, the developing baths may be kept
standing and be freshened up as required; they are used cold. Sometimes
two developers are mixed together, in which case care should be taken
that an alkaline developer naphthol or phenol be not mixed with an acid
developer (phenylene diamine, naphthylamine, etc.), unless the acidity
of the latter has been neutralised with soda; otherwise the developer
might be thrown out of the bath in an insoluble and hence useless form.

The advantages of the diazotising and developing process just described
may be summed as--easy and quick working, superior fastness to washing,
soaping and milling, increased fastness to light and softness of the
dyed fibre.

_Scarlet._--Dye with 3 lb. Primuline and 20 lb. salt, at the boil for
one hour, diazotise and develop with beta-naphthol.

_Crimson._--Dye with 3 lb. Primuline and 20 lb. salt, then diazotise and
develop with alpha-naphthol.

_Red Brown._--Dye with 4 lb. Primuline and 20 lb. salt, then diazotise
and develop with phenylene diamine.

_Deep Orange._--Dye with 3 lb. Primuline and 20 lb. salt, then diazotise
and develop with resorcine.

_Pale Orange._--Dye with 3 lb. Primuline and 20 lb. salt, then diazotise
and develop with phenol.

_Sage Brown._--Dye with 6 lb. Primuline, 3 lb. Titan ingrain blue and 20
lb. salt, then diazotise and develop with resorcine.

_Dark Maroon._--Dye with 6 lb. Primuli