est
solution.

Now take exactly 5 ozs. of freshly prepared sour of 2 deg. Tw., pour into a
jar, and add carefully some of the soda-test solution until a piece of
cloth dyed with turmeric is turned brown, when the acid is neutralised.
Now make a mark on the bottle of soda to show how much has been used. In
all subsequent tests of the sour 5 ozs. should always take the same
quantity of soda solution; if it takes less it is too weak, if more it
is too strong; the remedy in each case is obvious. It is worth while to
graduate the test bottle for 1 deg., 3 deg., 4 deg., 5 deg. Twaddell, as well as for 2 deg.
Tw. acid.

After the souring it is often the custom to pile the goods on to a
wooden stillage, but the goods should not be left too long so piled up
for they may become dry, either entirely or in parts. In any case, as
the goods dry the acid becomes concentrated and attacks them and makes
them tender, which is not at all desirable. Therefore, if it is not
convenient to proceed with them for some time after souring, they
should be moistened with water from time to time, but it is best to wash
them off at once, whereby they are made ready for the next operation.

(6) =Lye Boil.=--This is, perhaps, the most important operation in the
whole process of bleaching, especially if the cloths are going to be
printed in the so-called madder style with alizarine colours, or
otherwise stains are liable to occur in the final stage, and it is then
sometimes difficult to put the blame for these upon the right shoulders.

In principle the lye boil is simple, consisting in boiling the goods
with a solution of soda ash, or caustic soda. The quantity of ash used
varies in different works, as might naturally be expected; from 170 lb.
to 200 lb. of ash to 10,000 lb. of cloth is a fair proportion to use.
The length of boil averages about four hours, certainly not less than
three should be given, and it is not necessary to give more than five
hours in either ordinary kiers, with central puffer pipe, or in injector
kiers.

Care should be taken to see that the goods are well packed into the
kiers, not too tightly or the lye will fail to penetrate equally all
through, and this is important if a uniform bleach is desired; neither
should they be too loose, or they will float about and get torn. It is
not necessary to be particular about the quantity of water used, except
that it must be sufficient to keep the goods well covered, and still
have