AN IMPROVED PROCESS OF TANNING SKINS
Year: 1877

page_text: LETTERS PATENT to Lucien Gaulard, of Boulevard Saint Denis, No. 1, at Paris,
Engineer and Chemist, for the Invention of "AN IMPROVED PROCESS OF
TANNING SKINS."
Sealed the 15th March 1878, and dated the 19th September 1877.
PROVISIONAL SPECIFICATION left by the said Lucien Gaulard at the Office
of the Commissioners of Patents on the 19th September 1877.
LUCIEN GAULARD, of Boulevard Saint Denis, No. 1, at Paris, Engineer and
Chemist. AN IMPROVED PROCESS OF TANNING SKINS."
"
Various observations on the tanning of skins having demonstrated that the
re-action produced has been the decomposition of the watery juice by the tannin
which seizes the oxigen, whilst the hydrogen acts on the azotic matter and destroys
it in changing it into ammoniacal salts; it is concluded that for causing a rapid
tanning it suffices to oxidise the tannin and destroy the azotic matter by causing
to intervene an electric current into the juice, which decomposes the water of disso-
lution into oxigen and hydrogen, and determines at the same time with rapidity
the re-action above mentioned.
The oxigen and hydrogen introduced into the watery juice can be either produced
as described, or by any other agent or chemical means capable of giving birth to
these two gases; or the oxidising of the tannin may be effected by a current of oxigen,
and the change of the azotic matters into insoluble azotic matters by every agent
capable of developing the fermentation.
In carrying out this Invention the hides or skins are disposed in a tub with a
double bottom, according to the ordinary mode of tanning, that is to say, with
alternate layers of the hides or skins and tannin. In the space between the double
bottom are placed two parallel charcoal blocks fixed by the aid of copper presses or
clamps. It then suffices to put these two charcoal blocks into communication with
the two poles of any electric source for obtaining the phenomenon of the decompo-
sition of the watery juice into its two elements, oxigen and hydrogen, by which the
rapid assimilation of the tannin and the hides or skins is effected.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Lucien Gaulard in the Great Seal Patent Office on the 19th March
1878.
LUCIEN GAULARD, of Boulevard Saint Denis, No. 1, at Paris, Engineer and
Chemist. "AN IMPROVED PROCESS OF TANNING SKINS."
Various observations on the tanning of skins having demonstrated that the
re-action produced has been the decomposition of the watery juice by the tannin
which seizes the oxygen, whilst the hydrogen acts on the azotic matter and destroys
it in changing it into ammoniacal salts. I have concluded that for causing a rapid
tanning it suffices to oxydise the tannin and destroy the azotic matter by causing
to intervene an electric current into the juice, which decomposes the water of disso-
lution into oxygen and hydrogen, and determines at the same time with rapidity
the re-action above mentioned.
The oxygen and hydrogen introduced into the watery juice can be either pro-
duced as described, or introduced in a gaseous state produced by any other
known agent or chemical means capable of giving birth to these two gases; or the
oxydising of the tannin may be effected by a current of oxygen and the change
of the azotic matters to be destroyed into insoluble azotic matters by every agent
capable of developing the fermentation.
In carrying out my Invention the hides or skins are disposed, as shown on the
accompanying Drawing, Figure 1, in a tub A on the upper floor B of the double
bottom B, BI, according to the ordinary mode of tanning, that is to say, with
alternate layers of the hides or skins and tannin. In the space between the two
floors of the double bottom B, B¹, are placed two parallel charcoal blocks C, C,
fixed by the aid of copper presses or clamps D, D. It then suffices to put the two
charcoal blocks C, C, into communication by means of the wires a and b with the
two poles of any electric source whatever for obtaining the phenomenon of
the decomposition of the watery juice into its two elements, oxygen and
hydrogen, by which the rapid assimilation of the tannin and the hides or skins
is effected.
Having now described the nature of my said Invention, and the manner in which
the same is or may be used or carried into effect, I would observe in conclusion
that what I claim as my Invention is, producing the re-action necessary for the
rapid assimilation of the tannin and skins for the conversion of the latter into
leather, by the application and use of all known physical or chemical means
capable of determining that re-action, substantially as herein-before described, and
illustrated by the accompanying Drawing.
In witness whereof, I, the said Lucien Gaulard, have hereunto set my hand
and seal, this Fourteenth day of March. in the vear of our Lord 1878
Witness,
ALBERT CAHEN,
Civil Engineer,
of Boulevard St. Denis, 1,
at Paris.
L. GAULARD. (L.S.)