A PROCESS OF THICKENING, STRENGTHENING, & IMPROVING TANNED HIDES
Year: 1858

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer & Patent Agent, for the Invention of "A PROCESS
OF THICKENING, STRENGTHENING, & IMPROVING TANNED HIDES."-A com-
munication from Antoine Louis Adolphe Favier, residing at Nancy, in
the Empire of France.
Sealed the 3rd May 1859, and dated the 17th November 1858.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with bis Petition, on the
17th November 1858.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex;
Engineer & Patent Agent, do hereby declare the nature of the said Invention
for "A PROCESS OF THICKENING, STRENGTHENING, & IMPROVING TANNED HIDES,"
to be as follows:-
This Invention relates to a process for thickening, strengthening, and
improving tanned bides. Leather, although tanned, is often unsubstantial and
light in weight; it may be thickened, strengthened, and improved by pro-
ceeding in the following manner:-The deficient hide of leather is soaked in
a bath of gelatine which is extracted from refuse hides, and allowed to remain
about two or three hours; the leather after it has absorbed a certain
quantity of the gelatine is withdrawn from this first bath for the purpose
of being steeped in a solution of tannic acid, suitably concentrated.
A

page_text: portion of this acid combines with the gelatine which has been absorbed
by the hide in the previous operation; the leather is thereby rendered more
uniform than before, and at same time perfectly tanned. By repeatedly
steeping the hide or leather alternately in baths of gelatine and tannic acid, its
weight may be sensibly increased, and the desired consistency imparted to it
without its losing any of its original qualities.
According to this method of proceeding, hides of inferior quality in the
market may be improved at little cost, and their value considerably increased.
Hides which have been tanned by the ordinary processes may also be perfected
by means of the above-described process, and their weight increased from
twenty-five to forty per cent. without being deprived of their original qualities.
The value of this improved process will be understood from the above
description, for by it the gelatine furnished from refuse animal matters is
utilized, this animal matter being of itself of far inferior value to the first-
class hides or leather which may be manufactured by that means.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
18th May 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of Novr., in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-second year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Clark, Her special licence that I, the said William
Clark, my executors, administrators, and assigns, or such others as I, the
said William Clark, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all tinies
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "A PROCESS
OF THICKENING, STRENGTHENING, AND IMPROVING TANNED HIDES," a communi-
cation from Antoine Louis Adolphe Favier, residing at Nancy, in the Empire
of France, upon the condition (amongst others) that I, the said William

page_text: Clark, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should. particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed, in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Clark, my do hereby declare
the nature of the said Invention, and in what manner the same is to be
'performed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto, annexed
and to the letters and figures marked thereon (that is, to say):-
Leather, although tanned, is often unsubstantial and light in weight; it may
be thickened and strengthened by proceeding in the following manner :-The
deficient hide of leather is soaked in a bath of gelatine, which is extracted
from refuse hides, and allowed to remain about two or three hours; the
leather after it has absorbed a certain quantity of the gelatine is withdrawn
from this first bath for the purpose of being steeped in a solution of tannic
matter, suitably concentrated. A portion of this acid combines with the gelatine
which has been absorbed by the hide in the previous operation; the leather is
thereby rendered more uniform than before, and at the same time perfectly
tanned.. By repeatedly steeping the hide or leather alternately in baths of
gelatine and tannic acid, its weight may be sensibly increased, and the desired
consistency imparted to it without its losing any of its original qualities.
. According to this method of proceeding, hides of inferior quality in the
market may be improved at little cost, and their value considerably increased.
Hides which have been tanned by the ordinary processes may also be perfected
by means of the above-described process, and their weight increased from
twenty-five to forty per cont. without being deprived of their original qualities.
The value of. this improved process will be understood from the above
description, for by it the gelatine furnished from refuse animal matters is
utilized; this animal matter being of itself of far inferior value to the first-
class hides or leather which may be manufactured by that means. During
the successive immersions of the hide in the gelatine and in the tanning
liquid, the latter may be fulled or manipulated for the purpose of causing the
liquids to penetrate more into the pores.
The apparatus herein described and used for strengthening and otherwise
improving the leather referred to is the same as that described for tanning
hides according to the process secured by the Inventor in a Patent granted to

page_text: me, and dated 14th Octr. 1858, No. 2292. By this means the hides are
strengthened by causing the gelatinous liquor and the tanning matter to be
filtered alternately through the hides. This filteration is effected, 1st, by the
aid of the pressure of a column of gelatinous fluid and of tanning liquid;
2ndly, by means of a vacuum; the two processes being either employed
separately or in combination.
First process for improving hides by the pressure of gelatinous &
tanning liquids. Figs. 3 & 4 represent front and side views of the apparatus
employed. a, vat placed at a certain height, depending upon the amount of
pressure required to be obtained, which vat alternately contains the gelatinous
and tanning liquids; b, double frame, formed of a series of parts hinged
together, which may be arranged in any suitable position and fixed by means
of screws or locking joints; c, hide, the edges or borders of which being
brought in contact are securely fastened between the parts of the frame so as
to form a kind of bag; d, tubes, furnished with cocks for alternately con-
ducting the gelatinous and tanning liquids from vat a into the bag formed by
the hide under operation.
The whole being arranged as represented in the Drawing, it will be under-
stood that if the vat a be placed about twelve yards, for example, above the
hide, the gelatinous and tanning liquids placed therein will be allowed to pass
in succession out of the vat, and filter through the hide to be thickened or
improved, with a pressure of a little more than one atmosphere; those liquids
in being thus applied form in the hide an artificial tannate of gelatine, and
thereby increase the weight of the hide. The pumpe is for the purpose of
forcing the gelatinous liquid or tanning liquid into the bag formed by the hide
by means of pipe fin cases where an elevated vat is not made use of.
Second process for improving hides by means of the pressure of tanning
and gelatinous liquids and a vacuum combined.-Figs. 1 and 2 represent front
and side views of the apparatus. d, tube from an elevated vat which is
alternately charged with gelatinous fluid and tanning liquid; g, h, upper and
lower yats; c, hide, forming a diaphragm between the two vats, for which
purpose the edges are fastened between horizontal flanges of the vats, adapted
to the form of the hide; i, grating (whose position may be altered by means
of handle ) supporting the stretched hide; j, pump for producing a vacuum,
communicating with vat h by means of tube k.
All the parts being arranged as represented in the Drawing, if a vacuum
be obtained in vat h by the aid of pumpj, the gelatinous and tanning liquids
from vat will be filtered alternately through the hide by reason of the

page_text: difference of pressure, and will leave a tannate of gelatine in its pores. After
filtering the liquids separately for a certain time, the supporting grating i is
moved from its position for the purpose of treating the spaces covered by the
bars, and through which the liquids have not penetrated.
:
Thirdly, improving hides by means of a vacuum. Method of producing a
vacuum by means of a column of fluid.-Fig. 5 represents a vertical section
of an apparatus for this purpose. h, h, vat, the lower part of which is more
than twelve yards from the ground; c, hide, stretched between the horizontal
flanges of the vat h suitably shaped for the purpose; i, i, grating, supporting
the distended hide and capable of being moved when necessary; l, reservoir,
placed on the ground, communicating with the vat h by a tube m furnished
with a stop-cock; n, guage, indicating the height of the liquid placed above
the ground at a height of the column.
All the parts being arranged as represented in the Drawing, and supposing
the apparatus to be previously filled with water, by opening the stop-cock of
pipe m, the water will descend in this pipe, and thereby produce a vacuum in
the vat h, h; the gelatinous liquor and tanning liquid are then poured
alternately on the hide, which liquids filter through it by reason of the
difference of pressure, thereby forming a tannate of gelatine in combination
with the hide, which will greatly increase its weight.
The liquids, after being poured on to the hides, pass into tube m, hence
the vacuum is always maintained without any manipulation; the grating i
shifts also from its position, as in the preceding operation, for a similar object.
If the vat h is placed on the ground, the reservoir should be sunk to the depth
of more than twelve yards below the surface. Instead of a perfect vacuum,
a partial vacuum only may be obtained by shortening the pipe m. The
materials employed in the construction of these apparatus should be such as
cannot be injured by the action of the tanning substances.
By means of these improved methods, several hides may be perfected at.
one time by superposing them on each other. Fig. 6 represents an apparatus
for similar purposes furnished with a second vat, the hide being held between
the flanges of the vats. The same letters of reference in this Figure represent
like parts as in Fig. 5.
Having described the nature of the Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,―
First, the method of improving hides by subjecting them alternately to the
action of gelatinous liquor and tanning liquid, as herein described, so as to

page_text: leave in the pores of the hide a tannate of gelatine which increases its weight
and gives it greater solidity, and tends to improve and perfect it.
Secondly, improving hides by causing gelatinous and tanning liquids to
alternately filter through the hide at a certain pressure due to the column of
liquid, as herein-before described and as illustrated in Figs. 3 & 4 of the
Drawing annexed.
Thirdly, improving hides by causing the gelatinous and tanning liquids to
filter alternately through the hide at a certain pressure due to the column of
liquid, and in combination with a vacuum produced on the other side of the
hide, as herein-before described and as illustrated in Figs. 1 & 2 of the
Drawing annexed.
Fourthly, improving hides by causing the gelatinous and tanning liquids to
filter through the hide by means of a vacuum obtained on the other side of
the hide by means of a depending column of fluid, and the use of the apparatus
'for effecting the same, as herein-before described and represented at Figs. 5
& 6 of the annexed Drawing.
Fifthly and lastly, I claim the use of the apparatus for improving hides, as
herein-before described by means of pressure alone or by a vacuum and
pressure combined.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Seventh day of May, in the year of our Lord One
thousand eight hundred and fifty-nine.
Witness,
W. G. E. SWINNOCK,
53, Chancery Lane,
London.
W. CLARK. (L.S.)