IMPROVE- MENTS IN TANNING HIDES
Year: 1860

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County.
of Middlesex, Engineer and Patent Agent, for the Invention of "IMPROVE-
MENTS IN TANNING HIDES."-A communication from abroad by Mr. Wilhelm
LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County.
of Middlesex, Engineer and Patent Agent, for the Invention of "IMPROVE-
MENTS IN TANNING HIDES."-A communication from abroad by Mr. Wilhelm
Martz, Chemist, of 29, Boulevart St. Martin, Paris, in the Empire of
France.
Sealed the 12th September 1860, and dated the 19th March 1860.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
19th March 1860.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN TANNING HIDES," to be as follows:-
This Invention relates to an improved tanning process. After the raw
hides have been deprived of their hair by the ordinary processes, they are
plunged into a solution of water and chromate of potash or other alkaline
chromates, and there allowed to remain from six to twelve hours according to
the thickness of the hide. The hides are then to be completely washed in a
running stream, which deprives them of all extraneous matters. By this
means the greasy matters in the hides are so transformed as to cause them to
possess greater affinity for the tannin or other tanning matter, which allows
of the operation being much more rapidly effected, and also economizes the
quantity of tanning matter necessary.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
15th September 1860.
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 Nineteenth day of March, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third 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 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 "IMPROVEMENTS IN
TANNING HIDES," a communication from abroad by Wilhelm Martz, Chemist,
of 29, Boulevart St. Martin, Paris, in the Empire of France, upon the con-
dition (amongst others) that I, the said William 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, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
This Invention relates to an improved tanning process. The raw hides are
previously prepared as in ordinary, and immersed in lime or otherwise to
deprive them of their hair, and well cleaned. A solution of chromate of
potash (Cr 05, KO.) is then prepared in any suitable capacity in water, or
other kinds of alkaline chromates will answer the purpurpose. When the
solution is complete, as many skins are placed in the liquid as the capacity is
capable of holding, so that the said skins may be covered by the liquid;
notion is theu imparted to them. These skins are left in the solution from

page_text: six to twelve hours, according to their thickness. After this the skins are
submitted to a washing in as much running water as possible until they are
completely deprived of all extraneous matters which the solution might
contain, so that no impurities may be found either on the exterior or interior
of the skins. Skins thus washed regain their original whiteness, and are free
from all foreign matters.
By the above described process, the greasy matters in the skins undergo
transformation, which causes the skins to have a greater affinity for the tannin
or other substance, which thereby facilitates the saturation. The affinity of
the fibrous tissue of the hide to saturate itself with tannin is considerably
augmented by this process, and as regards the time employed in the operation,
permits in a short time, and with good tanning matters, of obtaining a superior
leather to that produced by other processes. This process is also applicable to
thick leather, sole leather, for example, as well as thinner varieties, and does
not alter in any way the qualities of the hides; on the contrary, hides which,
by the habitual application of milk of lime, have become stiff and hard, are
rendered supple, and their elasticity preserved by this process. Calves' skins
treated in this way, which by the ordinary processes require from two to three
months to be completely tanned, may be perfectly tanned in a space of from
eight to ten days at the ordinary temperature, without the use of artificial
beat, by employing good tanning matters, for example, the bark of oak, &c.
The thickest and heaviest hides which require by the ordinary process of
tanning from five to six months' treatment, may be prepared in from three to
six weeks, and those which require two years in ordinary, may be tanned in a
space of from three to five months. In this manner a very solid leather may
be obtained, distinguishing for its fine colour and elasticity, without requiring
much tanning matter. There is further an economy in these matters, because
in this short space of time the tannin does not precipitate too much in the
state of gallic acid.
.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Fifteenth day of September, in the year of our
Lord, One thousand eight hundred and sixty.