AN IMPROVEMENT IN PREPARING SKINS OR HIDES FOR THE APPLICATION OF TANNIN THERETO OR FOR BEING TANNED
Year: 1854

page_text: LETTERS PATENT to Samuel Sweetser, of the State of Massachusetts, of
the United States of America, for the Invention of "AN IMPROVEMENT IN
PREPARING SKINS OR HIDES FOR THE APPLICATION OF TANNIN THERETO OR FOR
BEING TANNED."-A communication from Warren A. Simmonds, of the
aforesaid State.
Scaled the 25th July 1854, and dated the 26th May 1854.
PROVISIONAL SPECIFICATION left by the said Samuel Sweetser at
the Office of the Commissioners of Patents, with his Petition, on the
26th May 1854.
I, SAMUEL SWEETSER, of the State of Massachusetts, of the United States of
America, do hereby declare the nature of the said Invention of "AN IMPROVE-
MENT IN PREPARING SKINS OR HIDES FOR THE APPLICATION OF TANNIN THERETO OR
FOR BEING TANNED," [which Invention was communicated to me by Warren A.
Simonds, of the aforesaid State,] to be fully described and ascertained in and
by the following Specification:-
In carrying out any improvement I make uso of soda ash in connection
with lime; and for preparing the alkaline vats sufficient for treating about
three hundred goat skins, about fifty pounds of soda ash may be dissolved in
about thirty wine gallons of hot water. When the solution has become
complete, about fifty pounds of quick lime may be added, when the mixture
should be well stirred and suffered to remain until it becomes cold, when to
the whole may be added, after or before it is poured into the vats, about

page_text: five hundred and fifty gallons of soft or rain water. The skins or hides can
be put into this liquor without the necessity of their being previously
soaked, scraped, or broken, and milled or fulled by the usual process. By
permitting them to remain about three weeks in the compound alkaline
solution, they are ready to have their hair removed by the beamsman, when
the remainder of the process of treating the skin preparatory to its immersion
in the vats or tannin liquor thereof is the same as that usually employed
by tanners.
When skins are prepared by my process they are found to be heavier.
stouter, and better, than the stock produced by the old process of tanning.
By using the soda ash in combination with the lime, thereby producing a
compound alkaline solution, I have found that there appears to be a specific
action upon the skins, such as swells or fulls them to such an extent as to
render the milling and beaming processes, generally required previous to
their immersion in a solution of lime, almost if not wholly unnecessary.
With my process, a poor, inferior, or what tanners term a "starved skin," is
rendered plump or full, is toughened, and made to have the appearance of a
good or mediam skin.
What I claim as my improvement in the treatment of skins by an alkaline
solution, and preparing them for the reception of tannin, is, the employment
of soda ash and lime in combination, substantially as specified.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Samuel Sweetser in the Great Seal Patent Office on the
27th October 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
SWEETSER, of the State of Massachusetts, of the United States of America,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her I.etters
Patent, bearing date the Twenty-sixth day of May, A.D. 1854, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Samuel Sweetser, Her special license that I, the said
Samuel Sweetser, my executors, administrators, and assigns, or such others as
I, the said Samuel Sweetser, 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

page_text: and Ireland, the Channel Islands, and Isle of Man, an Invention of "AN
IMPROVEMENT IN PREPARING SKINS OR HIDES FOR THE APPLICATION OF TANNIN
THERETO OR FOR BEING TANNED," [the same being a communication to me by
Warren A. Simonds, of the aforesaid State,] upon the condition [amongst
others] that I, the said Samuel Sweetser, by an instrument in writing under
my hand and seal, 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, or Office of Her
Majesty's Commissioners of Patents, within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Samuel Sweetser, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following Specifi-
cation :-
"All kinds of hides and skins have to be submitted to certain preliminary
operations before they are submitted to the action of the tanning agent;
the principal objects of which are the removal of any small portions of flesh
or fatty matter which may adhere to the cutis from imperfect flaying, the
removal of the hair, epidermis, and dirt, and the distention of the pores of the
hides and skins, whereby they are rendered more susceptible of the action of
the tanning principle."
"The first operations to which dried hides or skins are submitted are a
thorough soaking in water, and repeated rubbing and beating or treading under
feet, in order to soften and bring them as near as possible to the fresh state.
The beating is now commonly executed by a machine quite similar to the
fulling mill of the woolen manufacture, in which the hides are exposed to the
long continued action of two heavy wooden mallets or stocks."
"The next process to which the hides are submitted has for its principal
object the removal of the hair. Several different methods of accomplishing
this object have been practised, the oldest of which and that most extensively
followed in Europe and America consists in the application of a solution of
lime. The vessels in which the hides are impregnated with the solution of
lime are stone or brick built cisterns, sunk in the ground. Several of these
pits, containing lime water or very weak milk of lime, of three or four different
strengths, are arranged together in a series. The softened and washed hides
are introduced first into the weakest lime pits, and after having remained
there for a day or two are transferred to the next in gradation, and so on, until
the hair and epidermis readily yield to the touch, and the hides present certain
appearances indicative of a sufficient action of the lime. During the whole of

page_text: this process it is usual to "handle" the hides about once a day in order to
equalize the action.
This process of handling merely consists in taking the hides up out of the pits
and allowing them to drain in a heap for an hour or two, after which they are
returned to the pits.
.
T
It is a common practico to stir the liquid immediately before the intro-
duction of the hides, so that each hide may be in contact with some solid
particles of lime.
The time requisite for the liming of hides varies from one to three weeks,
and for the skins of sheep from two to five days, it being dependant on the
texture of the hide and the state of the atmosphere. Lime water does not
continue the action a sufficient length of time without a frequent renewal of
the solution; hence, it is always usual to have a little more liine present than
the water is capable of dissolving at once. It was formerly the practice of
some tanners to take the hides out of the lime pits after a few days'immersion,
and pile them in a heap on the ground; having remained in this state for
about a week, they were returned to the same pits from whence they were
taken, and after a short time again taken out and drained. These operations
were repeated until the hair and epidermis could be easily scraped off.
When taken out of the lime pits, the hides are laid singly upon an arched
wooden or stone bench, called the "beam," one end of which is raised. With
the assistance of a curved two-handled iron scraper, called the unhairing
knife, the beamsman then removes the loosened epidermis and hair, and
afterwards with a similar but sharper instrument, called the fleshing knife, ho
removes the flesh and fat adhering to the other side, unless they had been
separated before the hide was limed. After another slight scraping and a
thorough washing in water, in order to withdraw as much of the lime as
possible, the hides are ready to be exposed to the tanning infusions.
.
Thus, by the old process, as herein-above detailed, it will be seen that lime
alone has been used in preparing the skins.
In carrying out my Invention I make use of soda ash in connection with
the lime; and for preparing the alkaline vats sufficient for treating about three
hundred goat skins, about fifty pounds of soda aslı may be dissolved in about
thirty wine gallons of hot water.
When the solution has become complete, about fifty pounds of quick lime
may be added, when the mixture should be well stirred and suffered to remain
until it has become cold; when to the whole may be added, after or before
it is poured into the vats, about five hundred and fifty gallons of soft or rain
water.

page_text: The skins or hides can be put into this liquor without the necessity of their
being previously soaked, scraped, or broken, and milled or fulled by the usual
process.
By permitting them to remain about three weeks in the compound alkalino
solution they are ready to have their hair removed by the beamsman, when
the remainder of the process of treating the skin preparatory to its immersion
in the tan vats or the tanning liquor thereof is the same as that usually
employed by tanners.
When skins or hides are prepared by my process they are found to be
heavier, stouter, and better, than the stock produced by the old process of
tanning. By using the soda ash in combination with the lime, thereby pro-
ducing a compound alkaline solution, I have found that there appears to be a
specific action upon the skins, such as swells or fulls them to such an extent
as to render the milling and beaming processes, generally required previous to
their immersion in a solution of lime, almost if not wholly unnecessary. With
my process, a poor, inferior, or what tanners term a "starved skin," is ren-
dered plump or full, is toughened, and made to have the appearance of a good
or medium skin.
What I claim as my improvement in the treatment of skins by an alkaline
solution, and preparing them for the reception of tannin, is, the employment
of soda ash and lime in combination, substantially as specified.
In testimony whereof, I have hereunto set my hand and seal, this Fifth
day of September 1854