AN INVENTION FOR THE USE OF TANNERS, BEING CERTAIN TUT COMPOSITIONS OF MATTER TO BE USED IN THE TUT NUFACTURE OF LEATHER
Year: 1854

page_text: LETTERS PATENT to David Kennedy, of the City of Reading, in the
State of Pennsylvania, in the United States of America, Manufacturer
of Leather, for "AN INVENTION FOR THE USE OF TANNERS, BEING CERTAIN
TUT
COMPOSITIONS OF MATTER TO BE USED IN THE
TUT
NUFACTURE OF LEATHER,"
PROVISIONAL SPECIFICATION left by the said David Kennedy at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
January 1854.
I, DAVID KENNEDY, do hereby declare the nature of the said "INVENTION
FOR THE USE OF TANNERS, BEING CERTAIN COMPOSITIONS OF MATTER TO BE USED IN
THE MANUFACTURE OF LEATHER," to be as follows:-
In the manufacture of leather according to my Invention, I use, instead of
lime water for the depilatory process, a composition consisting of fresh slacked
lime, fresh wood ashes, carbonate of soda, and water. This composition should
be mixed in a vat and kept at the temperature of about summer heat. The
hides when immersed therein must be kept in a state of agitation by constant
handling until the operation is complete, which can only be determined by
actual inspection, as differences in the character and state of the hide hasten or
retard the process.
On the completion of this depilatory process, the hide should be thoroughly
cleansed by washing it in a copious supply of water, when it will be ready for

page_text: tanning, or to undergo the bating process, according to its nature and quality,
or the purpose to which it is to be applied.
The tanning of the hides is effected by immersing them in a liquor prepared
by a solution of my new tanning composition in water or in bark water; this
composition consists of valonia or divi divi, sulphate of soda, sulphate of mag-
nesia, sulphate of alumina, and soda (soda alum), carbonate of soda, borax or
boracic acid, and liquid ammonia. These ingredients" should be dissolved
separately in hot water, or in a hot decoction of bark (whichi is preferable), and
then poured into a tank and thoroughly stirred together to form the tanning
liquor, which may be drawn off as required to supply the vats or vessels in
which the hides are to be tanned..
The materials above, enumerated may be replaced by others possessing
similar properties, as for example, instead of the valonia or divi divi, terra japo-
nica, blood-root, nutgalls, cutch,-gambiers,-sumach,-quercitron bark, catechu,
or other like concentrated tannin material may be employed, but I prefer the
valonia; and next to that; the divi divi.
The other ingredients of the composition may be replaced by any of their
known equivalents.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Kennedy in the Great Seal Patent Office on the
3rd July 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
KENNEDY, of the City of Reading, in the State of Pennsylvania, in the
United States of America, Manufacturer of. Leather, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of January, in the year of our Lord One
thousand eight hundred and fifty-four, in the seventeenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
David Kennedy, Her special license that I, the said David Kennedy, my
executors, administrators; and assigns, or such others as I, the said David
Kennedy, 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 THE USE OF TANNERS, BEING CERTAIN
COMPOSITIONS OF MATTER TO BE USED IN. THE MANUFACTURE OF, LEATHER," upon the

page_text: condition (amongst others) that I, the said David Kennedy, by an instrument
in writing under my hand and seal, should particularly describe and ascer-
tain 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 David Kennedy, 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 statement
(that is to say)-
In manufacturing leather according to the plan now generally adopted, the
bides after having been properly soaked in water (and softened by breaking,
when necessary), the hair or wool, fat, mucous, and other matter, which would
retard the process of tanning and injure the quality of the leather, is commonly
removed by treating the hides with lime mixed with water to about the con-
sistency of whitewash. The liming, especially when the process is slow, has a
tendency to impair the strength of the fibres of the hide and render the leather
produced from it by subsequent tanning harsh and stiff. To prevent this, I
treat it with a composition which acts with greater energy, is more effective
than lime alone, and does not impair the strength of the fibre.
This composition consists of fresh slacked lime, one bushel; of fresh wood-
ashes, one bushel; of sal-soda (also called carbonate of soda), eight pounds;
and sufficient water to mix these materials into a liquid of the proper con-
sistency and strength, using one and a half bushels of this composition with
the same quantity of water, and to perform the same duty for which two
bushels of lime is ordinarily used. The composition should be mixed in a vat of
the proper size, and kept at the temperature of about summer heat, say from
seventy-six degrees to eighty-four degrees Fahrenheit. The hides must be kept
in a state of agitation by being constantly handled from the time they are
placed in the vat with this composition until the operation is complete, which
can only be determined by actual inspection, as differences in the character
and state of the hide hasten or retard the process. On the completion of this
depilatory process the hide should be thoroughly cleansed by washing it in a
copious supply of water, after which it will be ready for tanning, or to undergo
the bating process, according to its nature and quality, or the purpose to
which it is to be applied.
Bating the hide, so called, consists in immersing it in a mixture of the clung
of domestic fowls with water or any of the other well known bating liquors, but
I prefer that made from the dung of domestic fowls. The object of bating is

page_text: principally to remove from the skin the lime with which it became impreg
nated during the depilatory process previously described. This removal is
effected by the combination with the lime of some ingredient of the bating
liquor that will make a salt soluble in water. Such a salt of lime is formed
when the liquor prepared from the dung of fowls is used and washed away
when the hides are rinsed on the completion of the bating. In this manner the
lime is effectually removed.
The bating liquor should be kept at a temperature of eighty degrees
Fahrenheit, and the hides attentively watched and constantly handled during
immersion, which is necessary to expedite the process and prevent putre-
faction.
The hides being properly prepared by the before-mentioned processes are
ready for tanning, which I effect by immersing the hide in a liquor prepared
by a solution of my new tanning composition in water or bark water. This
composition consists of twenty-four pounds of valonia or divi divi, eight
pounds of sulphate of soda, four pounds of sulphate of magnesia, one pound of
sulphate of alumina and soda (soda alum), two pounds of sal soda (carbonate
of soda), one pound of borax or boracic acid, and one pound of liquid ammonia.
These ingredients should be dissolved separately in hot water or in a hot decoc-
tion of bark, which is preferable, and then poured into a tank and thoroughly
stirred together to form the tanning liquor, which may be drawn as required to
supply the vats or vessels in which the hides are to be tanned.
The tanning
liquor thus formed in the tank is in the most concentrated form, and only
suitable to apply, to hides in the advanced stages of the tanning process, and
must be largely diluted with water or bark water before it is applied to hides
at the commencement of this process, or else partially spent by having been
applied to hides in a more advanced state. The hides, as the tanning advances,
may be treated with liquor progressively stronger, care being taken to handle
the hides frequently in the early part of the process, while the liquor is weak;
but less handling will do as the process advances, so that the hides intended
for sole leather, near the close of the process, may be laid down in a vat
alternately with layers of ground bark, and then a liquor composed of three
parts of the composition before mentioned, and one of good bark liquor must
be poured into the vat until the hides are covered. In this condition they
may be from ten to fifteen days, when they will be completely tanned. Light
skins need not be laid down, as they will be thoroughly tanned by handling in
the liquor alone.
Fides may be tanned by this process, fast or slow, according to the amount
of handling, and the strength of liquor employed. When a tan, yard has

page_text: become impregnated thoroughly with the chemicals employed, it can be kept
with much less, expense than at first, and the quality of leather will bę
noticeably improved, and the time of tanning lessened;
When the before-mentioned tanning compound is employed with hemlock
bark, in the proportion of fifteen pounds of the compound to about one hundred
and twenty-eight cubic feet of the bark, the leather produced will have the
color, pliancy, and other desirable qualities of the best oak tanned leather: In
this way the expense of oak tanned leather will be greatly reduced, while the
quality will be fully maintained.
The materials employed in the before named tanning composition may be
replaced by others possessing similar properties, as for example, instead of the
valonia or divi divi, terra japonica, blood-root, nutgalls, cutch, gambiers,
sumach, quercitron bark, catechu, or other like concentrated tanning material
may be employed; but I prefer the valonia, and next to that, the divi divi.
The other ingredients of the composition may be replaced by any of their
known equivalents. I do not intend to confine myself to the precise ingre-
dients specified, although those above mentioned I believe to be the best;
neither do I intend to limit myself to the proportions before specified in which
the articles are combined; but I contemplate varying the articles and their
proportions to any extent that convenience or economy may render expedient,
so that the modifications and replacements do not change the essential
character of the compound.
Having now described my Invention of certain compositions of matter to be
used in the manufacture of leather, I wish it to be understood that under the
above in part recited Letters Patent, I claim the combination of valonia or the
equivalent thereof with the sulphate of soda, magnesia, and alumina, and sal
soda, and boracic acid or their equivalents dissolved in water, bark liquor or a
solution of tannin for the purpose of tanning hides and skins.
The sulphate of soda, or the equivalent thereof, I claim in the foregoing
composition, not because it aids in the tanning process, but because it gives
to the leather a clear, bright, and durable color, so that while the tanning
chemicals ensure a leather of good quality, this ensures a good color and
saleable appearance.
The sulphate of magnesia I claim for the purpose of inducing a more rapid
combination of the tannin with the skin, which is highly important when
expedition is desirable.
I claim the sal soda, because of its mild alkaline properties, which acting
upon the skin modifies the harsher action of the lime and ashes, so as to leave
the skin softer and in better condition for the reception of the tannin than any

page_text: other preparation I have tried or known, and by keeping this salt in due pro-
portions in the tanning liquor, it preserves the softness of the skins to the
completion of the tanning process.
I claim the employment of the borax for the purpose of giving increased
density and firmness to the leather, so that it may not be deficient in these!
qualities at the same time that it possesses great pliancy.
In witness whereof, I, the said David Kennedy, have hereunto set my
hand and seal, this Third day of June, in the year of our Lord One
thousand eight hundred and fifty-four.
DAVID KENNEDY. (L.S.)