IMPROVEMENTS IN DYEING AND PRINTING
Year: 1857

page_text: LETTERS PATENT to Barnard Barcroft, of Radcliffe Hall, near Manchester,
in the County of Lancaster, Manufacturing Chemist, for the Invention
of "IMPROVEMENTS IN DYEING AND PRINTING."
Sealed the 9th October 1857, and dated the 30th April 1857.
PROVISIONAL SPECIFICATION left by the said Barnard Barcroft at the
Office of the Commissioners of Patents, with his Petition, on the
30th April 1857.
I, BARNARD BARCROFT, of Radcliffe Hall, near Manchester, in the County
of Lancaster, Manufacturing Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN DYEING AND PRINTING," to be as
follows:-
This Invention has for its object the production of a chemical mixture to be
used instead of tartaric acid in the process of dyeing and printing, which
chemical mixture is produced by mixing sulphuric acid and water with
solutions of chloride of ammonium, of white arsenic, and of oxymuriate of tin,
the whole together forming the chemical mixture stated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Barnard Barcroft in the Great Seal Patent Office on the
27th October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BARNARD
BARCROFT, of Radcliffe Hall, near Manchester, in the County of Lancaster,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of April, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Barnard Barcroft, Her special licence that I, the said Barnard Barcroft,
my executors, administrators, and assigns, or such others as I, the said
Barnard Barcroft, 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 "IMPROVEMENTS IN DYEING
AND PRINTING," upon the condition (amongst others) that I, the said Barnard
Barcroft, 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 Barnard Barcroft, 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).:-
This Invention has for its object the production of a chemical mixture to be
used in dyeing and printing, which chemical mixture is produced by mixing
sulphuric acid and water with solutions of chloride of ammonium, of white
arsenic, and of oxymuriate of tin, the whole together forming the chemical
mixture stated.
Having thus stated the nature of my Invention, I will proceed to describo
the manner in which it is to be performed.
The chemical mixture is produced by first mixing fourteen quarts of
sulphuric acid of the specific gravity 170° Twaddell with twelve quarts of
cold water, allowing it to stand till cold. 1 then take a largo vessel and place

page_text: it in a water bath and pour into the said vessel twenty quarts of boiling water
and mix therewith forty-eight pounds of muriate of ammonium and six
pounds of white arsenic, allowing the whole to hoil till the solid portions are
dissolved, after which the solution is allowed to cool down to about 70°
Fahrenheit. I then add the first mixture, and allow the whole to stand till
cold, after which I add three quarts of oxymuriate of tin of the specific
gravity 120° Twaddell; in a few days it will be ready for use.
This chemical mixture is used in the place of and as a substitute for tartaric
acid in producing blues and reducing the shades of pink in dyeing and
printing.
I do not tie myself to the exact proportions herein named, although they
appear to me best adapted for the purpose set forth, nor do I make any claim
to the individual parts seperately; but what I claim is the chemical mixture
herein described as a substitute for tartaric acid in dyeing and printing.
In witness whereof, I, the said Barnard Barcroft, havo hereunto set
my hand and seal, this Twenty-first day of October, in the year of
our Lord One thousand eight hundred and fifty-seven.
Witness,
THOMAS BALDWIN, C.E.,
Corn Market Buildings,
Bury, Lancashire.
BARNARD BARCROFT. (L.S.)