The Idaho Republican. [volume] (Blackfoot, Idaho) 1904-1932, 1911-01-13
in most cases are first suspended In
weak tanning infusions. before they

S The object of this Is to insure uni
! form absorption Of tarnin by tn
= skins, before subjecting them to tn
rough usage of handling" which il
the early stages of the process is liza
BILE to cause injury to the delicat
structure of the skin. During thi
suspension the skins are in continu
Gus agitation to cause the tannin tt
be taken up evenly. In all up-to
date tanneries both the suspension
and the agitation are accomplished
generally by electrically-driven ma
chinery. The treatment of the butts
in the handlers generally occupies
about six to eight weeks. They are
now removed to the layers" In
which they receive the treatment OF
bark, or tan liquor until the tanning
is complete. Here the butts are stra-
tilted with ground oak bark or valo-
mia, which is spread between each
butt to the depth of about one inch,
and a thicker layer finally on top.
The" pit is then filled up with ooze.
For heavy tannages six to eight lay
ers are required.
Many materials besides oak bark
are now used to make tanning in
fusion, and some of these, being
stronger, have fastened the tanning
process. Among the most important
of these valonia, the acorn of an ever
green oak found in Asia Minor and
Greece, which contains three times
as much tannin as the strongest oak
bark, the sumach, the divi-divi and
algarovilla, pods of South American
trees closely allied to logwood, and
the larch, spruce, pine and hemlock
banks.
Undressed leather, after it is tan
ned, needs simply to be rendered
smooth and compact, which is accom-
plished by securing and COMPRISING
the surfaces with stones, brushes, the
"striking-pin" and rollers-all of
which processes are now effected in
the best mills by electrically-driven
machinery Dressed leather must, in
addition, be stuffed" with oils to
increase their resistance to water and
their flexibility; they must frequent
ly be dyed or stained in black or
colors and grained" These process
es also require electrical apparatus
of some kind or another.
In 1860 a machine was invented
for splitting leather to any desired
degree of thinness. Electrically-dri-
ven splitting machines are now in
general use. The practise previously
was to shave the leather down, the
shavings being wasted. The process
of dressing tanned leather known as
currying was formerly separate in
dustry, but is now carried on as a
part of the general business of leath-
er manufacture. A favorite oil used
by curriers' for stuffing leather is the
degras, or superfluous oil pressed
from shamoyed leather
The possibility of tanning by the
use of chromium compounds, instead |
of the older tanning materials, was
discovered as early as 1856 by a |
German chemist, but the first process
which attained commercial success
was invented in 1884 by Augustus
Shultz. ChrOme-tanning consumes |
only few hours, as compared with |
weeks or months required by the
older method, and it produces lea
Their which is extremely soft and |
pliable, of close texture, and thor
oughly resistant to water. The lea
Their can also be dyed successfully If |
the dye is applied while the skin is
still wet, but so great is its water
repellent character that, once dried,
it cannot be wetted sufficiently to
dye properly.
Tawing, an essential feature in the
tanning industry, consists in dressing
the skins in antiseptic materials, so
as to preserve them from decay. At
ter thorough cleansing the pelts are
stepped in pit filled with. lime and
water, being taken out from time to
time and drained on sloping benches.
When removed finally from the lime
pit, the skins are worked with the
knife, to render them more supple,
and are then put into the branning
mixture. This consists of bran and
water in the proportion of two pounds
Of bran to a gallon of water. From
the mixture they are transferred to
an alum bath in a wooden .tumbler
or drum. After remaining in this
mixture about five minutes they un-
dergo what is called pasteing. The