ton. It can also be used
for wool and silk, and gives a fine rich brown. It is obtained from
the wood of various species of Areca, Acacia and Mimosa trees. Bombay
Catechu is considered best for dyeing purposes.

Catechu is soluble in boiling water. It is largely used by the cotton
dyer for brown, olive, drab, grey and black. (See pp. 46, 47, 48.)

LIGHT GREY

(For 6 lbs.) 1 oz. cutch, 1 oz. iron. Boil for 1/2 an hour in the
cutch, then put into boiling iron, being very careful to stir well.
Wash very thoroughly.

These proportions can be varied according to the shade of grey
required; the more iron makes the colour browner, the more cutch the
bluer grey.

CATECHU BROWN

The wool is boiled for 1 to 1-1/2 hours, with 10 to 20 per cent
catechu, then sadden with 2 to 4 per cent of copper sulphate, ferrous
sulphate, or chrome, at 100 deg.C., in a separate bath for 1/2 hour.

_ALDER BARK_

The bark and twigs of alder are used for dyeing brown and black. For 1
lb. wool use 1 lb. alder bark. Boil the wool with it for 2 hours, when
it should be a dull reddish brown. Add 1/2 oz. copper as for every
pound of wool for black.

_SUMACH_

Sumach is the ground up leaves and twigs of the _Rhus coraria_ growing
in Southern Europe. It dyes wool a yellow and a yellow brown, but it
is chiefly used in cotton dyeing.

_WALNUT_

The green shell of the walnut fruit and the root are used for dyeing
brown. The husks to be used for dyeing must be collected green and
fresh, then covered with water and kept from the light to prevent them
oxidizing. In the walnut tree there is an astringent colourless
substance which gives a greenish yellow dye. This has the property of
absorbing oxygen from the air and turning dark brown. It is only the
unoxidized pale greenish stuff that can act as the dye, the dark brown
itself has no affinity for the wool. Acids should be added to the dye
bath to prevent oxidization. Without a mordant the colour is quite
fast, but if the wool is mordanted with alum a brighter and richer
colour is got. When used they are boiled in water for 1/4 hour, then
the wool is entered and boiled till the colour is obtained. Long
boiling is not good as it makes the wool harsh. It is much used as a
"saddening" agent; that is, for darkening other colours.

"The best and most enduring blacks were done with this
simple dye stuff, the goods being first dyed in the indigo
or woad vat till they were a very da