B.

Regarding the best methods of dyeing, that in neutral baths yields the
most satisfactory results in practical working. It is done in a boiling
hot or in a slightly boiling bath, with the addition of 6-1/4 oz.
crystallised Glauber's salt per gallon water for the first bath, and
when the baths are kept standing 20 per cent. crystallised Glauber's
salt, reckoned upon the weight of the goods, for each succeeding lot.

In dyeing unions, the dye-baths must be as concentrated as possible, and
must not contain more than from 25 to 30 times as much water as the
goods weigh. In this respect it may serve as a guide that concentrated
baths are best used when dyeing dark shades, while light shades can be
dyed in more diluted baths. The most important factor for producing
uniform dyeings is the appropriate regulation of the temperature of the
dye-bath. Concerning this, the dyer must bear in mind that the direct
colours possess a greater affinity for the cotton if dyed below the
boiling point, and only go on the wool when the bath is boiling,
especially so the longer and more intensely the goods are boiled.

The following method of dyeing is perhaps the best one: Charge the
dye-bath with the requisite dye-stuff and Glauber's salt, boil up, shut
off the steam, enter the goods and let run for half an hour without
steam, then sample. If the shade of both cotton and wool is too light
add some more of the dye-stuffs used for both fibres, boil up once more
and boil for a quarter to half an hour. If the wool only is too light,
or its shade different from that of the cotton, add some more of the
dye-stuff used for shading the wool and bring them again to the boil.
If, however, the cotton turns out too light, or does not correspond in
shade to the wool, add some more of the dye-stuffs used for dyeing the
cotton, without, however, raising the temperature. Prolonged boiling is
only necessary very rarely, and generally only if the goods to be dyed
are difficult to penetrate, or contain qualities of wool which only with
difficulty take up the dye-stuff. In such cases, in making up the bath
dye-stuffs are to be selected some of which go only on the wool and
others which go only on the cotton (those belonging to the second
group).

The goods can then be boiled for some time, and perfect penetration and
level shades will result. If the wool takes up the dye-stuff easily (as
is frequently the case with goods manufactured from shoddy), and are