Im- PROVEMENTS IN PRINTING OR IMPRESSING AND DYEING FABRICS AND TISSUES
Year: 1865

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "Im-
PROVEMENTS IN PRINTING OR IMPRESSING AND DYEING FABRICS AND TISSUES."
-A communication from abroad by Félix Dehaut, Doctor of Medicine,
of 29, Boulevart St. Martin, Paris.
Sealed the 10th April 1866, and dated the 19th October 1865.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
19th October 1865.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN PRINTING OR IMPRESSING AND DYEING FABRICS AND
TISSUES," to be as follows:-
This Invention relates to the application of soluble chromates for the direct
production on tissues and fabrics of chrome greens of various hues, either by
impressing, printing, or dyeing. This process is based on the possibility of
producing in the fabric itself insoluble salts with a base of oxide of chromium,
such as phosphate, borate, arsenite, arseniate, or silicate of chromium.
The following is a description of the process:-I, for instance, take phos-
phate of ammonia and chromate of potash in equivalent proportions, and
dissolve them together in cold water, adding a sufficient amount of glucose or
other substance capable of reducing chromic acid.
chromic acid. I apply this solution
properly concentrated either by way of impression, or by immersion, and I raise
the tissue to a temperature of two hundred and twelve degrees Fahrenheit,
whereby the reaction is determined and the green color made to appear.

page_text: This reaction may be likewise produced at a low temperature, but much more
slowly.
With a view to the commercial application of this process a 'further modi-
fication consists in mixing together, either dry or in solution, the two salts
that are to react in the tissue or fabric. It suffices to dissolve this mixture
in water, adding thereto the organic substance, and proceeding to apply it as
above specified. It is evident that if instead of producing the reaction which
generates the insoluble salt in the fabric itself, I produce it in a vessel, the
same salt may be obtained in the pulverulent state, and capable of being
employed or used as common chromium greens.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the 18th
April 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of October, in the year of our
Lord One thousand eight hundred and sixty-five, in the twenty-ninth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said William Clark, Her special licence that I, the said William
Clark, my executors, administrators, and assigns, or such others as I, the
said William Clark, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVEMENTS
IN PRINTING OR IMPRESSING AND DYEING FABRICS AND TISSUES," a communication
to me from abroad by Félix Dehaut, Doctor of Medicine, of 29, Boulevart
St. Martin, Paris, upon the condition (amongst others) that I, the said
William Clark, 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.

page_text: NOW KNOW YE, that I, the said William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
'formed, to be particularly described and ascertained in and by the following
statement (that is to say) :-
This Invention relates to the application of soluble chromates for the direct
production on tissues and fabrics of chrome greens of various hues, either by
impressing, printing, or dyeing. This process is based on the possibility of
producing in the fabric itself insoluble salts with a base of oxide of chromium,.
such as phosphate, borate, arsenite, arseniate, or silicate of chromium.
The following is a description of the process:-I take, for instance,
phosphate of ammonia and bichromate of potash or of ammonia in equivalent
proportions, and dissolve them together in cold water, adding a sufficient
amount of glucose or other substance capable of reducing the chromic acid.
I apply this solution properly concentrated either by way of impression, or by
immersion, and I raise the tissue to a temperature of two hundred and twelve
degrees Fahrenheit, whereby the reaction is determined and the green color
made to appear. This reaction may be likewise produced at a low tem-
perature, but much more slowly.
With a view to the practical or commercial application of this process a
further modification consists in mixing together, either dry or in solution, the
two salts that are to react in the tissue or fabric. It suffices to dissolve this
mixture in water, adding thereto the organic substance, and proceeding to
apply it as above specified. It is evident that if instead of producing the
reaction which generates the insoluble salt in the fabric itself, I produce it in
a vessel, the same salt may be obtained in a pulverulent state, and capable of
being employed or used as common chromium greens.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Seventeenth day of April, in the year of our
Lord One thousand eight hundred and sixty-six.
Witness,
53, Chancery Lane,
London.
W. CLARK. (L.S.)