: A cold bath is prepared with 10 lb. to 12 lb.
alizarine, 3 lb. sumac extract, and 2 oz. lime. The cotton is entered
into the cold bath, worked from fifteen to twenty minutes so as to get
it thoroughly impregnated; then the heat is slowly raised to the boil
and the dyeing carried on at that heat until the full shade is obtained,
which usually takes about an hour. According to the brand of alizarine
used so will the shade that is obtained vary, as will be mentioned later
on.

Operation 11. First clearing: The dyed cotton is placed in a boiler and
boiled for four hours with 3 lb. soda crystals and 3 lb. palm oil soap,
afterwards washing well.

Operation 12. Second clearing: The dyed cotton is again boiled for two
hours with 2-1/2 lb. soap and 1/2 lb. tin crystals, then give a good
washing and dry.

This process is a long one--indeed, some dyers by repeating some of the
operations lengthen it--and it takes at least two weeks, in some cases
three weeks, to carry out.

The first idea is to get the cotton thoroughly impregnated with the oil,
and this oxidised to some extent on the fibre, and to this end the oil
treatments are carried out. In this process experience has shown that
olive oil is the best to use, although other oils have been tried from
time to time. The sumacing enables the alumina to be more firmly fixed
on to the cotton. The alumina combines with both the oil and the sumac,
and the resulting mordant produces a better and more brilliant red with
the alizarine. The clearing operations serve to remove impurities, to
brighten the colour, and to more fully fix it on the cotton.

_Process_ 2.--Operation 1. The cotton is well bleached or scoured with
soda in the usual way.

Operation 2. Oiling or preparing: A liquor is made from 10 lb. alizarine
oil or Turkey-red oil in 10 gallons water. This oil is prepared from
castor oil by a process of treatment with sulphuric acid, washing with
water and neutralising with caustic soda. The cotton is thoroughly
impregnated with this oil by steeping, then it is wrung out and dried.

Operation 3. Steaming: The cotton is put into a steaming cottage or
continuous steaming chamber and steamed for from one to one and a half
hours at about 5 lb. pressure.

Operation 4. A bath of red liquor (acetate of alumina) at 8 deg. Tw. is
prepared. Some dyers use basic alum at the same strength. In this bath
the cotton is steeped at 100 deg. F. for two hours; then it is wrung out and
dri