AN IMPROVED PROCESS OF TANNING
Year: 1856

page_text: LETTERS PATENT to Emile Constantin Fritz Sautelet, Chemist, of Paris,
in the French Empire, for the Invention of "AN IMPROVED PROCESS OF
TANNING."
Sealed the 27th May 1856, and dated the 12th January 1856.
PROVISIONAL SPECIFICATION left by the said Emile Constantin Fritz
Sautelet at the Office of the Commissioners of Patents, with his Petition,
on the 12th January 1856.
I, EMILE CONSTANTIN FRITZ SAUTELET, do hereby declare the nature of the
said Invention for AN IMPROVED PROCESS OF TANNING, to be as follows:―
The skin or hide is first cleansed from grease by means of soap and water, or
alcohol or other solvent which does not injure the fibres. A solution of bark,
tannin,.sumach, catechu, or other tanning material is then caused to filter or
soak through the skin, by means of pressure or suction produced by mechanical
or physical means. This filtration is continued from fourteen to forty-eight
hours, or for a shorter or longer time, according to the nature and thickness of
the skin,.and whether it be from the ox, calf, horse, or other animal. A
solution, of gelatine, or other måtter capable of precipitating the tanning
material, is then introduced by pressure or suction; this solution and the
tanning solution may be introduced repeatedly and alternately. By these
operations.the.skin may be tanned in a very short time. The skin is stretched
during the process in a double frame, which confines and clips the edges of the
skin, which is sustained by a trellis or open framework. The skin thus held

page_text: and supported is made to form the partition between two vessels or compart-
ments. Into one compartment the soap and water or other cleansing liquid is
introduced by a pump, and it is thus forced to pass through the skin into tho
other compartment. The pressure may also be given by a piston, acted on by
steam, water, or other fluid, or by forming a partial vacuum in the other com-
partment. Several skins may be fixed in the same apparatus and traversod
successively by the same solution, and several apparatus may be arranged in
stages, so as to operate upon a large number of skins. After thus removing
the grease, water is introduced to wash out the cleansing liquid. The tanning
solution is then introduced in a similar manner. A solution of gelatine, or
other substance capable of precipitating the tanning material in the interior or
pores of the skin, is then introduced in a similar manner, or the gelatine may
be introduced by immersing the skins in the solution, or by rubbing it in by
band, or by mechanical means, or otherwise... The density of..tho.leather,may
bo increased by introducing a solution of a salt of lead, or of baryta, or other
metallic salt.
SPECIFICATION in pursuance-of-the-conditions.of-the Letters Patent, filed
by the said Emile Constantin Fritz Sautelet in the Great Seal Patent
Office on the 5th July 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMILE
CONSTANTIN FRITZ SAUTELET, Chemist, of Paris, in the French Empire, send
greeting....
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of January, in the year of our Lord.Ono
thousand eight hundred and fifty-six,. in the nineteenth year of Her reign; did;
för Herself, Her heirs and successors; givo and grant unto me, the said. Emilo
Constantin Fritz Sautelet, Her special licenco that I the said Emile Con-
stantin. Fritz Sautelet, my executors, administrators; and assigns, or such
others as I, the said Emile Constantin Fritz-Sautelét, my executors; adminis-
trators, and assigns, should at any time agree with, and no others; from!.time
to timo and at all times 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 AN IMPROVED PROCESS OF TANNING, upon the condition: (amongst
others) that I,- tho said: Emile. Constantin Fritz Sautelet, my executors.or
administrators, by an instrument in writing under my, or their, or one of their

page_text: 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 Emile Coustantin Fritz Sautelet, 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 thereof, referenco being had to-the accompanying
Drawing, and to the figures and letters marked thereon, that is to say :-
The skin or hide is first freed from the hair in the ordinary manner, and it
is then cleansed from grease by means of soap and water, or alcohol or other
solvent which does not injure the fibres. A solution of bark, tannin, sumach,
catechu, or other tanning material is then caused to filter or soak through the
skin by means of pressure or suction, produced by mechanical or physical
means. This filtration is continued from fourteen to forty-eight hours, or for
a shorter or longer time, according to the nature and thickness of the skin.
The quality of the leather is improved by employing weak solutions and con-
tinuing the action from two to fifteen days. A solution of gelatine, or other
matter, capable of precipitating the tanning material, is then introduced by
pressure or suction. This solution and the tanning solution may be introduced
repeatedly and alternately. By these operations the skin may be tanned in a
very short time. The skin is stretched during the process in a double frame,
which confines and clips the edges of the skin, which is sustained by a trellis
or open framework. This frame prevents the skin from being forced out and
torn away from its attachments by the pressure of the liquid to which it is
subjected. The skin thus held and supported is made to form the partition
between two vessels or compartments. Into one compartment the soap and
water or other cleansing liquid is introduced by a pump or by a pipe from an
elevated cistern, and the liquid is thus forced to pass through the skin into the
other compartment. The pressure may also be given by a piston, acted on by
steam, or by water or other fluid, or by forming a partial vacuum in the other
compartment..Several skins may be fixed in the same apparatus, and traversed
successively by the same solution, and several apparatus may be arranged in
stages, so as to operate upon a large number of skins at the same time. After
5 acting upon the skins in this manner for three or four, hours, or more or less,
the cleansing. liquid. is drawn off, and water is introduced to wash out the
cleansing liquid. The water is then drawn off, and the tanning solution is then
introduced in a similar manner, and its action is continued for a period varying
from a few hours to fifteen days, or more or less, according to the nature and

page_text: thickness of the skin and the strength of the solution employed. A solution of
gelatine, or other similar substance capable of precipitating the tanning
material in the interior or pores of the skin, is then introduced in a similar
manner. By thus impregnating or nourishing the skin with gelatine, an
additional quantity of leather is formed or precipitated in the pores of the skin,
and the quality and density of the leather is thus improved. The alternate
filtration of the tanning liquid and the solution of gelatine may be repeated
several times, if desired. The nourishing of the skin with the solution of
gelatine may also be effected by simply immersing the skin in the solution, or
by rubbing it into the skin by hand, or by mechanical means. The density or
weight of the leather may be still farther increased, if required, by impreg-
uating it with a solution of a salt of baryta, or a salt of lead, or other suitable
metallic salt, and with another salt capable of forming an insoluble precipitate
with the first salt. Thus, the skin may be impregnated successively with solu-
tions of sulphate of soda and chloride of barium, which decompose each other,
and produce an insoluble sulphate of baryta, and also a soluble sulphate of
soda, which may be washed out by causing water to traverse or filter through
the skin as before.
The accompanying Drawing represents an apparatus adapted for carrying
out my Invention.
Figure 1 is an elevation; and Figure 2 is a horizontal section at the line
a, b, in Figure 1. The same letters refer to similar parts in both Figures.
A is a wooden frame or foundation, carrying two guides or tramways B, B,
in which run the rollers C, C, which support the frames D¹ and D. Each of
these frames carries two cars or flanges E, which receive the ends 9,9', of the
clamps K, K. Two skins G, G, are placed on the two sides of the central
frame D', and their edges are secured by the Interal frames D, D. A metal
plate L, or a piece of caoutchouc or waterproof cloth, or leather, or other
suitable material, is placed upon each lateral frame D, and a frame M with
cross bars is pressed upon it by means of a screw I passing through the
clamp K or K. The chambers O and O' are thus closed, and the skins G, G,
are thus protected from the external air, and form a chamber P, into which
the cleansing and tanning liquids and the solution of gelatine are introduced,
as herein-before described. Q is a three-way cock, having one branch R,
which communicates with the cistern containing the tanning liquid, and
another branch T which communicates with that containing the solution of
gelatine. Another similar cock may be used for introducing the cleansing
liquid and the water; or, the same cock may be used, and the cistern may be
successively filled with the different liquids. U is a cock for allowing of the

page_text: exit or entrance of air when required; and V is a cock for running out the
liquid into the channel S. This liquid is thus caused to filter through the skins
from their internal faces. In order to equalize the effect, the liquid is after-
wards passed in the opposite direction through the skin: For this purpose it
is sufficient to remove the plate or waterproof diaphragm L, and substitute a
new skin for it, and to fix and inclose this new skin by another plate or
diaphragm. The liquid is then introduced into the chamber O, and thus the
second side of the first skin is tanned while the first side of the new skin is
tanned. The first skin is then removed, and another new skin is submitted to
the operation. By proceeding successively or alternately in this manner the
skins are thoroughly and equally tanned.
Having now described the nature of the Invention, and in what manner the
same is to be performed, I wish it to be understood that I do not claim
generally the tanning of skins by causing the liquid to filter. or percolate through
them; but what I claim is,―
First, the tanning of hides or skins by exposing them to the filtration or
percolation of soap and water, or other cleansing liquid capable of removing
grease without injuring the fibre, and then exposing them to the filtration
or percolation of the tanning liquid, as herein-before described.
the
Second, the tanning of hides or skins by the successive or alternate
application of the tanning liquid and a solution of gelatine, as herein-before
described.
Third, the improved process of tanning by the successive operations of
cleansing and tanning by filtration or percolation under pressure, and nourishing
with a solution of gelatine, as herein-before described.
In witness whereof, I, tho said Emile Constantin Fritz Sautelet, havo
hereunto set my hand and seal, this Third day of July, in the year
of our Lord One thousand eight hundred and fifty-six.
0 Witness,
CH. ARMENGAUD, Civil Engineer,
No. 23, Boulev de Strasbourg,
à Paris.
E. C. F. SAUTELET. (L.S.)