A NEW OR IMPROVED PROCESS FOR ACCELERATING TANNING
Year: 1875

page_text: LETTERS PATENT to Thomas Christy, jn'., of 155, Fenchurch St.,
London, for the Invention of "A NEW OR IMPROVED PROCESS FOR
ACCELERATING TANNING."-A communication from abroad by Theodore
Sealed the 31st August 1875, and dated the 6th March 1875.
PROVISIONAL SPECIFICATION left by the said Thomas Christy at
the Office of the Commissioners of Patents, with his Petition, on
the 4th March 1875.
·I, TпомAS CHRISTY, jn'., of 155, Fenchurch St., London, do hereby
declare the nature of the said Invention for "A NEW OR IMPROVED PROCESS
FOR ACCELERATING TANNING," to be as follows:-
The fruit of the balsamocarpon brevifolium contains a bitter and
very astringent juice, this juice is of a vitreous yellow color, and like
yellow amber it is pulverised with great facility. This yellow substance
is very rich in tanning properties; it is almost pure tannin, it dissolves
in water, and when a piece of hide is put in a somewhat concentrated

page_text: solution of it the tanning action is so encretic that the hide is soaked
through in a few days.
To make use of this property and apply it to tanning hides I
mix this substance in dissolution with the juice of oak bark in the
proportion of 25% at an equal degree of density. It can also be
mixed with other tanning extracts or substances. With oak bark onc
obtains a leather of a very nice colour, but on the express condition of
using the mixture at the commencement of the operation. Used by
itself this juice gives the leather a yellow shade; mixed with extracts
it shortens the tanning considerably and gives very much lighter colors.
than the extracts bark and wood alone. The use of this substance, pure
or mixed, requires great care. It is necessary to begin with extremely
weak juice, to move the hides three times a day, and augment the
degrees of strength in an inappreciable manner and with great regularity,
at the most one degree a day, especially in the commencement of the
operation. Pure in the state of solution this substance is easily dete-
riorated by the contact of the air, the tanning substance is transformed and
disappears. To prevent this inconvenience I mix it with one or two per
cent. of oxalates, the antiseptic properties of which prevent or delay this
deterioration.
The proportion of 25% indicates for the mixture of the tauning
substance is that which I have adopted as giving good results, but I
reserve the right of altering this proportion according to the nature of
the hides to be treated and the quality of the leather required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 25
filed by the said Thomas Christy in the Great Seal Patent Office
on the 6th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
CHRISTY, junior, of 155, Fenchurch Street, London, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 30
Letters Patent, bearing date the Sixth day of March, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me; the said Thomas Christy, junior, Her special
licence that I, the said Thomas Christy, junior, my executors, adminis-
trators, and assigns, or such others as I, the said Thomas Christy,
junior, 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
"A NEW OR IMPROVED PROCESS FOR ACCELERATING TANNING," a communication
to me from abroad by Theodore Ramspacher, Engineer, 82, Boulevard
St. Marcel, Paris, upon the condition (amongst others) that I, the said
Thomas Christy, junior, 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 Thomas Christy, junior, 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:-
.
The fruit of the balsamocarpon brevifolium (which in the well known
work entitled the Treasury of Botany edited by John Lindley, and
published in 1874 is described in page 119, contains a bitter and very
astringent juice, the properties of which I utilize for the accelerated
tanning of skins or hides.
Before describing my method of operation I will give an exact and
detailed description of this fruit, as botanists are not always agreed upon
the names of fruits and plants.
The fruit of balsamo-carpon imported into this country under that
designation is nearly straight and about one inch long, rounded at the
extremities. Sometimes it is imported in a crushed form or in a powder,
the seeds and part of the husk having been removed. It is formed of a
very thin and corrugated epicarp, the colour of which various from orange
red to orange yellow, and even brown red. On the inside there is a
membraneous endocarp, the folds of which form from 2 to 4 imperfect
cells, each containing a smooth red seed.

page_text: Between the two above-named envelopes is a tissue consisting of
strong ligneous fibres which unite to either suture, forming a lace-like
tissue. The tissue contains a bitter and astringent juice of an amber
color which fills the space between the epicarp and the endocarp.
This astringent and vitreous juice when dry is so fragile that it often
breaks and is reduced to dust with the epicarp that covers it.
The substance which I have referred to as a juice of an amber colour is
extremely rich in tannin, it is soluble in water, and when a piece of skin
or hide is dipped into a strong solution its action upon a skin or hide is so
energetic that it effects penetration in a very short time. Balsamocarpon
not only contains tanning properties but it helps and quickens the
absorption by the skins of the tanning matters contained in the various
tanning substances with which it may be mixed. To utilize the
properties of balsamocarpon in tanning hides I treat it with water, or
when the juice alone is employed I dissolve it and mix it with a solution
made from say the oak bark in the proportion of 25% of equal degrees
of strength, balsamocarpon can also be mixed with different extracts and
other tanning substances used in the tanning process.
When balsamocarpon is used with oak bark a leather of a beautiful
shade is obtained provided that the same mixture is used from the com-
mencement of the operation. Employed alone it gives the leather a
yellow citron colour, mixed with other tanning substances it affects the
tanning and the leather obtained is of a much lighter shade. When
comparatively puro and in a soluble state balsamocarpon is quickly
affected by the air and its tanning properties are weakened if not lost, to
counteract this inconvenience I mix with it a small quantity of oxalates
which are antiseptic and so prevent this change.
The proportion of 25% indicated for the mixture of tanning matters
is that which I have adopted as giving very good results, but this pro-
portion may be varied according to the nature of the skins to be
treated and the quality of the leather that is desired to be produced.
Balsamocarpon either when used alone or mixed requires great care,
when it is used by itself for tanning skins or hides they should be treated
in the first instance with a very weak solution, and they must be turned
three times a day. During the first fifteen days the strength of the
solution should be gradually strengthened by about 1 degree Dring and
Fage's tannometer every two days, at the end of this time the skins are

page_text: to be turned once in every 24 hours, the strength of the solution being
increased 1 degree per day (Dring and Fage tannometor). When the
strength of the solution attains 26 degrees to 32 degrees (Dring and
Fage tannometer) the hides or skins are bedded, and care must be taken
to keep up the strength of the solution till the tanning is complete.
To use balsamocarpon mixed with other tanning matters very weak
liquors, say 1 to 2 degrees (Dring and Fage tannometer) must also be
used at the commencement and be gradually strengthened. When the
skins are unhaired and have been steeped in lime they should before
they are put into the tanning solution or mixture be freed from all the
lime that they contain. For this purpose they ought to be manipulated
for 2 or 3 days in clean water, to which should be added a small quantity
of glucose. The lime unites with the glucose. In this manner tho
water dissolves the glucose and forms a very soluble glucosate. In
this way water dissolves the glucosate, and the skin is completely
freed from the lime. In lieu of glucose other sacharine matters may be
employed:
In order more fully to explain my improved process I will describe by
way of illustration the mode in which I proceed in practice:-Supposing
100 hides are worked in a suitable pit, these unhaired hides weigh on an
average 33 lbs., they must be steeped for 2 or 3 days in a pit of very
weak liquor scarcely coloured (say 1 to 2 degrees Dring and Fago
tannometer, and they must be turned 2 or 3 times in the 24 hours.
After this first operation the skins must be turned regularly twice a day
in the morning and in the evening, and each time 22 lbs. of the powder
(balsamocarpon) in a dry state must be put in this pit, say 14 lbs. per
day per 100 hides. Before returning the skins to the pit the liquor
should be well stirred. This addition of balsamocarpon should be con-
tinued for about 15 days. At the same time that this balsamocarpon is
added the other substances used by tanners, such as valonia, mimosa
bark, hemlock, and any other tanning substances should also be added.
At the end of 15 days the balsamocarpon is no longer used, and tho
liquor is strengthened by any tanning substances such as before-named.
When the hides are penetrated they are put in very strong liquor between
each hide, a layer of bark or other tanning substance now in use by
tanners is placed, and they are left for a month or six weeks, according
to the nature of the hides and the quality of leather that is required.
Generally the hides are tanned in two months.

page_text: Having now described the nature of my said Invention, and the
manner in which the same is carried into effect, I therefore claim,-
First. The use of the improved process of tanning wherein is employed
the material herein designated balsamocarpon for the purpose of acccle-
rating the process, substantially as herein described.
Second. The use of the material herein designated as balsamocarpon,
in the manner and for the purposes substantially as herein described.
In witness whereof, I, the said Thomas Christy, junior, have here-
unto set my hand and seal, this Sixth day of September, in
the year of our Lord One thousand eight hundred and seventy-
five.