Book-bot.com - read famous books online for free

Scientific American Supplement, No. 447, July 26, 1884 by Various
page 57 of 141 (40%)
dyeing-copper. The indigo, in the frothy state in which it is skimmed
from the purifying barrels or tanks, is then added, with sufficient lime
to dissolve it when it has been reduced. It is heated gently by a steam
coil, to about 90 deg. Fahr., and the goods are dyed in it. The colors
obtained by means of this indigo are light in shade, and the goods must
be dipped several times if dark shades are required. But it is found
better in practice not to attempt to dye dark shades by this process;
the ordinary indigo-vat is better adapted for such work. The object of
not wasting indigo is sufficiently attained by employing it for the
purpose to which it is best adapted. Of course the recovered indigo may
be used in the ordinary manner. I merely mention the most convenient way
of disposing of it in works where only a small quantity is recovered,
and which do not practice dyeing on an extensive scale.

I have now to ask you to turn to a different subject, namely, the
scouring of wool, not by the usual agent, water, but by a liquid,
bisulphide of carbon, made by the action of sulphur vapor on red hot
coke or charcoal.

This, again, is not wholly a new process, for various attempts have
been made to dissolve out the yolk, or _suint_, or greasy matter from
unwashed wool, as it comes from the back of the sheep. Fusel oil
has been patented for this purpose. Carbon disulphide has also been
patented, but, as will afterward be shown, the old method of removing it
from the wool injured the color and quality of the fiber, so as to make
the application of this scouring agent a failure.

Wool in its unwashed state contains a considerable proportion of what is
termed _suint_. This consists of the fatty matter exuded as perspiration
from the sheep, along with, or in some form of combination with, potash
DigitalOcean Referral Badge