IMPROVEMENTS IN TANNING DISCLAI MEMORANDUM OF ALTER
Year: 1878

page_text: Filed 11th June 1880.
In the Matter of the Letters Patent granted to FRANK WIRTH, of the Firm
of Wirth and Company, Patent Solicitors, at Frankfort on the Main,
in the Empire of Germany, for the Invention of "IMPROVEMENTS IN
TANNING," a communication from Christian Henizerling, Doctor of
Philosophy, of Biedenkopf, in the Empire of Germany, bearing date the
Twenty third day of December 1878.
DISCLAIMER AND MEMORANDUM OF ALTERATION proposed to be
entered and filed by the said Frank Wirth and the Eglinton Chemical Com-
pany, Limited, of Scottish Amicable Buildings, St. Vincent Place, Glasgow, in
the County of Lanark, to portions of the Specification of the said Letters
Patent, according to the Statutes in that case made and provided.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, the said
FRANK WIRTH and the said EGLINTON CHEMICAL COMPANY, Limited, send greeting:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Royal Letters
Patent, bearing date the Twenty third day of December 1878, did grant unto the
above mentioned Frank Wirth, his executors, administrators, and assigns, the sole
privilege to make, use, exercise, and vend the Invention of "IMPROVEMENTS IN
TANNING" within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and the Isle of Man, during the term of fourteen years then next ensuing :.
And whereas the said Frank Wirth, on the Nineteenth day of June 1879, within
the time prescribed by the said Letters Patent, caused a Specification in writing
under his hand and seal to be filed in the Great Seal Patent Office:
And whereas the said Frank Wirth has assigned a portion of the rights conferred
by the said Letters Patent to the said Eglinton Chemical Company, Limited:
And whereas after the date of the application for the said Letters Patent and
since the filing of the Specification in pursuance thereof, we, the said Frank Wirth
and the said Eglinton Chemical Company, Limited, have ascertained or been advised
that the description of the said Invention therein contained is too broad and contains
matter that is unnecessary to the process, not new at the date of the application for
the said Letters Patent or not covered by the Provisional Specification:

page_text: And whereas we are desirous of making the alterations and disclaimers therein
hereinafter specified:
NOW KNOW YE, therefore, that we, the said Frank Wirth and the said
Eglinton Chemical Company, Limited, by and with the leave of Her Majesty's
Attorney General, do hereby, for the reasons aforesaid and in order to more clearly
define and limit the true nature of the said Invention and the means for carrying
it into practical effect, make the following alterations and erasures in the said
Specification, that is to say :-
Page 3, line 10 of the blue book, we strike out the word “natron” and insert its
more common name "soda."
Line 11, after the word "and" we insert "preferably."
Line 14, we strike out from the word "thickness" up to and including the word
"manipulated," line 22.
Line 25, we strike out from the word" treatment" up to and including the word
"treatment," line 26.
Line 28, we strike out the words " with a solution of alum and zinc and."
Line 33, we strike out from the words "damp hides" down to and including the
word "hides" in line 35, substituting for them the words "are then dipped."
Line 31, we insert the word "preferably" after the words "hides are.'
Line 36, we correct the spelling of the words "naphthaline" and "resin."
Lines 38 and 39, we strike out the word "perfectly" and substitute for it the
word "practically."
"
Line 39, after the word "watertight "-we-insert-the-words. "and when required
is made."
Strike out lines 44 and 45.
Line 46, for "2nd" read "1st," and we strike out the words "in tanning" and
substitute for them the words "substantially as and for the purposes described."
Strike out lines 47, 48, and 49.
Line 50, for the word "4th" read "2nd," and we strike out the words "and
chrome alumis."
"
Line 51, we insert after the word "sodium the words "as above described."
Page 4, line 3, for the word "5th" we read " 3rd"; line 1, correct the spelling
of the word "resin."
Line 4, for the word "6th" read "4th."
And we do hereby declare that the said Specification, as amended by the present
Disclaimer and Memorandum of Alteration, shall read as follows:
The hides are unhaired and soaked in the usual manner, after which they are placed
in a solution of from one half to five per cent. of acid or neutral chromate of potash,
or else acid or neutral chromate of soda, or acid or neutral chromate of magnesia, and
preferably from one to ten per cent. of alum, or a corresponding quantity of sulphate of
alumina, and with or without from one to ten per cent. of chloride of sodium, in which
they are left a longer or a shorter time, according to their texture and thickness. After
the hides have been some days in the solution of chromate salts, alum, and the like,
a small per cent. of yellow or red prussiate of potash is added; these, however, can
also be added at the commencement of the operation. The treatment with yellow
or red prussiate of potash is preferable for leather which afterwards is to be blacked.
In other cases the treatment with yellow or red prussiate of potash can be dispensed
with. In order to fix the tanning stuffs in the leather, manipulated in the manner
as above described, the hides are preferably placed for a short time in a solution of
one to two per cent. of chloride of barium, or one to two per cent. of acetate of lead,
or of one to two per cent. of soap. The hides can be dried in the usual manner.
The smoothed damp hides are then dipped for a short time in stearine, paraffine,
chrysene or naphthaline, resin, or the like stuffs, the same having been dissolved in
benzine, photogen, or the like dissolving stuffs. To the above can be added some
carbolic acid or thyme oil; the greasing can be effected as usual. The new leather
is practically watertight, and when required is made much softer and more lasting

page_text: than ordinary leather. The cost of tanning by this process is much lower than by
the bark process.
Having now described my Invention, and the best mode known to me of carrying
it into effect, I wish it to be understood that what I believe to be new and desire
to protect under the herein before in part recited Letters Patent is,-
1st. The use of yellow and red prussiate of potash, substantially as and for the
purposes described.
2nd. The use of the above named acid or neutral chromates in connection with
alum and chloride of sodium, as above described, and subsequent working the thus
tanned hides with tallow, paraffine, stearine, resin, and the like stuffs, dissolved in
benzine, photogen, or the like, substantially as set forth.
3rd. The method of tanning, substantially as described and set forth.
4th. As an article of manufacture, a leather prepared in the manner essentially
set forth.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this 75th day of April in the year our Lord One thousand
FRANK WIRTH. (L.S.)
28th day of
In witness whereof, the said Eglinton Chemical Company, Limited, have
hereunto caused their common seal to be affixed, this
April
'
One thousand eight hundred and eighty.
I hereby grant my fiat, giving leave to the above named Frank Wirth and
the Eglinton Chemical Company, Limited, to file in the Great Seal Patent Office,
with the Specification to which the same relates, the above written Disclaimer
and Memorandum of Alteration.

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company,
"
Patent Solicitors, at Frankfort on the Main, in the Empire of Germany, for
the Invention of IMPROVEMENTS IN TANNING." A communication from
Christian Heinzerling, Doctor of Philosophy, of Beidenkopf, in the Empire of
Germany
Sealed the 23rd May 1879, and dated the 23rd December 1878.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 23rd December 1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN TANNING."
(A communication from Christian Heinzerling, Doctor of Philosophy, of Biedenkopf,
in the Empire of Germany.)
The hides are unhaired and soaked in the usual manner, after which they are
placed in a solution of acid chromate of potash, or else acid chromate of natronium,
or acid chromate of magnesia and alum, or sulphate of alumina and chloride of
sodium, in which they are left longer or shorter, according to their texture and
thickness. In place of putting the hides direct in this solution they may be placed
in a 5 to 10 per cent. solution of alum to which zinc dust or cuttings are added.
The action of the zinc on the alum produces amorphous alumina, which precipitates
on the fibre.
After the hides have been soaked in the alum zinc solution a sufficient time, this
being regulated by the texture of the same, they are removed to the solution first
named, that is, acid chromate of potash or natronium, et cetera, the strength of such
solution being determined by the nature of the hides being manipulated. After
the hides have been some days in the solution of chromate, salts, alum, and the
like, a small per cent. of yellow prussiate of potash (ferro cyanide of potassium) or
red prussiate of potash (sesquiferrocyanate of potassium) is added; these however
Prics A31

page_text: can also be added at the commencement of the operation. In the manufacture of
some kinds of leather the treatment with yellow or red prussiate of potash is
omitted. This part of the operation should however be used on leather intended
for uppers which is afterwards to be blacked.
In order to fix the tanning stuffs in the leather manipulated in the manner as
above described, the hides are placed for a short time in a solution of chloride of
barium, or acetate of lead, or of soap. The hides can be dried in the usual manner.
The smoothed damp hides can be greased or fatted like ordinary tanned leather.
This can either be effected by tramping or by dipping the hides for a short time in
stearine, paraffin, or the like stuffs, the same having been dissolved in chrysen,
naptha, benzin, photogen, or the like stuffs.
To the above can be added some carbolic acid or thyme oil; the greasing can
be effected as usual.
The new leather is perfectly water tight, much softer, and more lasting than
ordinary leather. The cost of tanning by this process is much lower than by the
bark process.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 19th June
1879.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN TANNING.'
A communication from Christian Heinzerling, Doctor of Philosophy, of Biedenkopf,
in the Empire of Germany.
The hides are unhaired and soaked in the usual manner, after which they are
placed in a solution of from one half to five per cent. of acid or neutral chromate of
potash, or else acid or neutral chromate of natron, or acid or neutral chromate of
magnesia, and from one to ten per cent. of alum, or a corresponding quantity of
sulphate of alumina, and with or without from one to ten per cent. of chloride of
sodium, in which they are left a longer or shorter time, according to their texture
and thickness. The above named neutral or acid chromates may also be sub-
stituted by chrome alum or sulphate of chrome oxide. In place of putting the
hides direct in this solution, they may be placed in a five to ten per cent. solution
of alum, to which zinc dust or cuttings are added. The action of the zinc on the
alum produces amorphous alumina, which precipitates on the fibre. After the hides
have been soaked in the alum zinc solution a sufficient time, this being regulated
by the texture of the said hides, they are removed to one of the solutions first
named, the strength of such solution being determined by the nature of the hides
being manipulated. After the hides have been some days in the solution of
chromate salts, alum, and the like, a small per cent. of yellow prussiate of potash or red
prussiate of potash is added; these however can also be added at the commencement
of the operation. The treatment by the solution of alum and zinc is especially
suited for sole-leather, heavy upper leather, or the like, whilst the treatment with
yellow or red prussiate of potash is preferable for leather which afterwards is to be
blacked. In other cases, the treatment with a solution of alum and zinc and with
yellow or red prussiate of potash can be dispensed with. In order to fix the
tanning stuffs in the leather manipulated in the manner as above described, the
hides are placed for a short time in a solution of one to two per cent. of chloride of
barium, or one to two per cent. of acetate of lead, or of one to two per cent. of soap.
The hides can be dried in the usual manner. The smoothed damp hides can be
greased or fatted like ordinary tanned leather. This can either be effected by
tramping or by dipping the hides for a short time in stearine, paraffin, chrysene, or
naphtaline, resine, or the like stuffs, the same having been dissolved in benzine,
photogen, or the like dissolving stuffs. To the above can be added some carbolic
acid or thyme oil; the greasing can be effected as usual. The new leather is per-
fectly watertight, much softer, and more lasting than ordinary leather. The cost
of tanning by this process is much lower than by the bark process.
Having now described my Invention, and the best mode known to me of carrying
it into effect, I wish it to be understood that what I believe to be new and desire
to protect under the hereinbefore in part recited Letters Patent is,-
Îd. The working raw hides with alum and zinc, producing a precipitate of
amorphous alumina on the fibre.
2nd. The use of yellow and red prussiate of potash in tanning.
3rd. The use of chloride of barium, or acetate of lead, or of soap, in combination
with chromates, solution of alum and zinc, and in case with yellow or red prussiate
of potash, essentially as and for the purpose set forth.
4th. The use of the above named acid or neutral chromates and chrome alums in
connection with alum and chloride of sodium, and subsequent working the thus

page_text: tanned hides with tallow, paraffine, stearine, resine, and the like stuffs dissolved in
benzino, photogen, or the like, substantially as set forth.
5th. The method of tanning, substantially as described and set forth.
6th. As an article of manufacture, a leather prepared in the manner essentially
set forth.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this Sixteenth day of June, in the year of our Lord One thousand
eight hundred and seventy nine.
FRANK WIRTH. (L.S.)