, and work for half an hour; then lift, rinse lightly, and
pass into a weak sour bath, with sulphuric acid to raise to the
colour.

Soda may be used in place of borax, but the latter salt maintains the
softness of the wool fibre better.

By using various brands of Alkali Blue (3 R to 7 B), various shades of
blue from a reddish with the 3 R to a pure blue with the 6 B and 7 B
brands may be dyed. The Alkali Blues are fairly fast to light.

_Dark Blue_.--Prepare a dye-bath with 2 lb. Serge Blue, 10 lb.
Glauber's salt, and 2 lb. sulphuric acid, working at the boil (p. 153)
for one hour. This is a very common way of dyeing blues on serges,
cashmeres and worsted goods. In place of serge blue, what are known as
Blackley blues, or Dewsbury blues, may be employed. These have a
similar composition, but vary a little in the tint of blue they give.

_Navy Blue_.--Prepare a dye-bath with 2 lb. Induline A, 10 lb.
Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one
hour.

The Indulines are very useful colouring matters for dyeing navy or
dark blues on wool. They have the defect of being liable to give
uneven shades. This may be remedied by omitting the acid when first
making up the bath, entering the wool, working for half an hour to
thoroughly impregnate the material with the dye-liquor, then adding
the acid, and continuing the working for another half-hour. Or the
wool may be treated to a weak chlorine bath before it is dyed, by
first passing it through a weak hydrochloric acid bath and then
through a bath of bleaching powder. By using acetic acid in place of
sulphuric acid more even shades are obtained.

_Blue_.--Prepare a dye-bath with 1 lb. Acid Blue 1 V, 9 oz. Acid
Violet 1 V, 10 lb. Glauber's salt and 2 lb. sulphuric acid, working at
the boil for one hour.

_Blue Black_.--For this the dye-bath is made with 8 lb. Acid Blue 1 V,
10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil
for one hour.

_Deep Navy Blue_.--A very good shade is dyed with 5 lb. Acid Blue 1 V,
3 lb. Acid violet 1 V, 10 lb. Glauber's salt, and 2 lb. sulphuric
acid, working at the boil for one hour.

_Deep Navy_.--Prepare a dye-bath with 1 lb. Fast acid Magenta B, 3 lb.
Wool Blue B X, 4-3/4 oz. Orange I I, 5 lb. sulphuric acid, and 10 lb.
Glauber's salt, working at the boil for one hour.

The Patent Blues work exceedingly well on wool, giving good bright
shades of a fair degree of fastness. The following reci