4 parts of water to 1 of silicate of soda
at 100 deg. Tw., to make the bath alkaline. Into this bath the goods are
entered and are then exposed to the air as before, after which they
may be passed through a weak bath of sulphurous acid, being next well
washed in water and dried.

The advantage of bleaching with peroxide is that, as it leaves only
water in the goods as the result of action, there is no danger of
their becoming tendered by an after development of acid due to
defective washing, as is the case with the sulphur bleach. The goods
never alter in colour afterwards, because there is nothing left in
that will change colour. Some bleachers add a little magnesia to the
bath, but this is not at all necessary.

#Bleaching with Peroxide of Soda.#--Peroxide of soda has come to the
front of late for bleaching wool. With it a stronger bleaching bath
can be made, while the product itself is more stable than peroxide of
hydrogen, only it is needful to keep it in tightly closed metal
vessels, free from any possibility of coming in contact with water or
organic matter of any kind, or accidents may happen. In order to
bleach 100 lb. of wool, a bath of water is prepared, and to this is
added 6 lb. of sulphuric acid and then slowly 4 lb. of peroxide of
sodium in small quantities at a time. Make the bath slightly alkaline
by adding ammonia. Heat the bath to 150 deg. F., enter the wool and allow
to remain five to six hours, then rinse well and dry. If the (p. 037)
colour does not come out sufficiently white repeat the process.

THE CHLORINATION OF WOOL.

The employment of chlorine in wool dyeing and wool printing has of
late years received an impetus in directions previously little thought
of. The addition of a little chlorine to the decoction of logwood has
been recommended as increasing the dyeing power of the wool. Treating
the wool with chlorine has a material influence in increasing its
capacity for taking dye-stuffs, and although but little attention has
been paid to this circumstance by wool dyers, yet among wool printers
it has come largely into use, and enables them to produce fuller and
faster shades than would otherwise be possible.

The method involves the treatment of the wool first with an acid, then
with a solution of a hypochlorite. The staple becomes soft and supple
and assumes a silky character; in dyeing it shows a greater affinity
for the dyes than it did previously. Although not deteriorated in