AN IMPROVED DEPILATORY PROCESS FOR HIDES AND SKINS
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "AN IMPROVED
DEPILATORY PROCESS FOR HIDES AND SKINS." A communication from
abroad by Charles Jules Pierre Desnos, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 23rd March 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "AN IMPROVED DEPILATORY PROCESS FOR HIDES AND SKINS."
[A communication from abroad by Charles Jules Pierre Desnos, of Paris, France.]
This Invention relates to an improved process for unhairing all kinds of skins,
but more particularly sheep skins. The depilatory solution or bath employed is
composed of limestone 500 grammes, and orpiment 100 grammes, made into a
paste in the following manner :-The lime is placed in a copper with water at a
high temperature; the lime is slaked immediately it begins to split, and the arsenic
is then added and also more water, the whole being stirred for about 5 minutes so
as to form a paste. I then add about one kilogramme of American potash, together
with a sufficient quantity of water (10 litres about), to render the mixture perfectly
homogeneous. The mixture is then exposed to a moderate heat until it marks
10° Beaumé, after which it is allowed to settle and the liquid decanted off. The
liquid forms the depilatory composition, and it is applied with a brush to the flesh
side of the skin. At the end of 2 hours on turning the skin the entire fleece,
consisting of wool, down, &c., can be removed with the greatest facility.
All kinds of skins may be unhaired by the above process, the advantages of
which are that it is economical, very expeditious, and enables the whole of the
fleece or hair to be removed without injury to the skins, which are left in a con-
dition fit for undergoing the subsequent operations of tanning and tawing. The
skins are moreover ungreased simultaneously with the depilation without injury
either to the skins or to the wool or hair.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on
the 22nd September 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"AN IMPROVED DEPILATORY PROCESS FOR HIDES AND SKINS.".
A communication from abroad by Charles Jules Pierre Desnos, of Paris, France.
This Invention relates to an improved process for unhairing all kinds of hides
and skins, but more especially sheep skins.
According to this Invention I employ a depilatory solution or bath prepared as
follows: I take of limestone 500 grammes, and orpiment 100 grammes, which I
make into a paste in the following manner: The lime is placed in a copper with
water at a high temperature; the lime is slaked immediately it begins to split, and
the orpiment is then added and also more water, the whole being stirred for about
5 minutes so as to form the paste. I then add about 3 kilogrammes of American
potash (if sheep skins are to be treated), or 6 kilogrammes of American potash
(if hides are to be treated), together with a sufficient quantity of water (10 litres
about), to render the mixture perfectly homogeneous. The mixture is then exposed
to a moderate heat until it marks 10° Beaumé, after which it is allowed to settle
and the liquid decanted off. This liquid forms the depilatory solution or
composition.
It will be understood that the proportions above named may be varied according
to the nature and quality of the hides or skins to be treated, and the quality of
the materials employed. The depilatory composition or solution is applied with a
brush to the flesh side of the skin. At the end of two hours on turning the skin
the entire fleece consisting of wool, down, &c., can be removed with the greatest
facility.
All kinds of skins may be unhaired by the above process, the advantages of
which are that it is economical, very expeditious, and enables the whole of the
- fleece or hair to be removed without injury to the skins, which are left in a con-
dition fit for undergoing the subsequent operations of tanning and tawing. The
skins are moreover ungreased simultaneously with the depilation without injury
either to the skins or to the wool or hair.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is,-
The unhairing of hides and skins by the employment in the manner described
of a depilatory solution or composition prepared of the ingredients and in the
manner, substantially as specified.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
.
my hand and seal, this Twenty first day of September, A.D. 1881.