Vermont telegraph. [volume] (Brandon [Vt.]) 1828-1843, 1841-08-04
MIS- CELIA N Y.
- ,he Vavpe fN.Yl Standard.

|
and the principles upon which they are
based, recently made by Mr.. S. B. How'd,
Che inventor Of the celebrated "Howd's
Water Wheelsn) in the art Of tanning leath-
er, Of which you spoke in your last paper.
Leather is compound of gelatine and
vegetable astringent matter formed by steep
ing the skins of animals in the infusion of
certain banks. Before applying the astrin-
gent principles 10 the skins, they are usually
prepared by soaking in lime water, which
renders the cu,cle and hair easily separable
and discharges the albumen; and are after
wards softened by allowing them to enter
into degree of putrefaction. In this state
they are submitted TO the action of the Tan
min or astringent principle. And it is at
this point that How'd begins his experiment.
The next step in the process is TO bring the
Tannin in contact with every portion Of
every fibre Of the skin, or in other words
| with the Gelatine, in order to form the above
mentioned compound Of Tannin and Celia
|
min has been found to be the result of q
purely chemical combination. Tannin is
soluble in water, and when the solution is
brought in contact with the Gelatine of
which the skin is mainly composed, after
being lined, &C., the Tannin parts from The
water, preciptates, and combines with the
Gelatine by reason Of its greater affinity for
the latter than for the former.
To produce this compound, the most
speedily and completely, preserving at the
same time the greatest tenachy and fexi.
bility of the skin, has long been deemed &c
constitute the great art and mystery oil
Tanning; and numerous have been the
means and experiments resorted to for its
accomplishment. But hitherto from the
earliest period up to the time of Mr.. Howd's
experiments, almost every attempted i'm
provement in tanning has either signally
|, failed or has fallen far short Of that point OF
utility which would warrant a departure
from the old and long, firmly established pro
cess. That old process and the only one
by which what was called good Leather
). could be made, was, after the skins had beer
lined, &C., to steep them first in cold
lweak liquor, then in successively stronger
ones, until sufficient Tannin had entered
: into combination with the Gelatine of the
's hides in the mean time frequently moving
them about in the watts, raising them out ant
dripping them in the open atmosphere. b.
this process the time required TO effect a tai
was long, and varied according to the kim
of skins operated upon, and the kind o
leather intended to be made. To tan cal
skin required from two and half to fou
= months, COW hide for upper leather, from
= six to eight months, and hide of sole leath
n er from eight to thirtY-six months.
a By the attempted improvements of whic
e have spoken, and which have not total
le failed of their object, tan has been effecte
:. within shorter periods of time than thos
4 mentioned, but always at a sacrifice of som
81 valuable quality of the leather. Warm Ii
vi quors have been used, the effect Of whic
n is to impair the elasticity and tenacity of tn
e. individual fibre and to diminish the genera
!, adhesion of the several fbres TO each othe
rs Rollers and presses have been employed t
= expel from the pores Of the skin the waite
+. and gallo acid remaining there after partin
is with the Tannin which they held in solr
ne ton, the action of which breaks down III
ed natural arrangement of the ibres and yer
pc much diminishes the strength and durabilit
y Of the leather. Reels have been adapte
- to the vats in order to facilitate the movin
To- Of the skins, and numerous other appliar
IS ces have been had recourse TO, which hav
in some instances lessened the amount {
S, labor before necessary, but which can NJ
C. be deemed any Improvement. upon the form
ne er process of tanning.
es Experienced Tanners have repeatedly d.
- clared, and the. truth of the declaration
!, indisputable, that good leather could not
ed made by the use of warm liquor, Roller
es or Presses and yet they have always state
nd that they saw no reason why Tan migl
nd not be effected with cold liquor within
It. much shorter time than usual, provide
8 the Tannin could be brought in contac
= with the Gelatine without resorting TO th
m aid of caloric, orato the use of violent m'
10 chanical means. That contact Mr.. How
as actually sIecrs without the aid of caloric G
st the use Of Violent mechanical means, by th
Of application Of simple philosophical an
e chemical principles.
: I have said that Tannin or the astringen