PRODUCING A NEW COLORING MATTER FOR DYEING WITH A LILAC, OR PURPLE COLOR STUFFS OF SILK, COTTON, WOOL, OB OTHER MATERIALS
Year: 1856

page_text: LETTERS PATENT to William Henry Perkin, of King David Fort, in the
Parish of Saint George in the East, in the County of Middlesex,
Chemist, for the Invention of "PRODUCING A NEW COLORING MATTER FOR
DYEING WITH A LILAC, OR PURPLE COLOR STUFFS OF SILK, COTTON, WOOL, OB
OTHER MATERIALS."
Scaled the 20th February 1857, and dated the 26th August 1856.
PROVISIONAL SPECIFICATION left by the said William Henry Perkin
at the Office of the Commissioners of Patents, with his Petition, on the
26th August 1856.
I, WILLIAM HENRY PERKIN, do hereby declare the nature of the said
Invention for "PRODUCING A NEW COLORING MATTER FOR DYEING WITH A LILAC
OR PURPLE COLOR STUFFS OF SILK, COTTON, WOOL, OR OTHER MATERIALS," to be
as follows:-
Equivalent proportions of sulphate of aniline and bichromate of potassa are
to be dissolved in separate portions of hot water, and, when dissolved, they are
to be mixed and stirred, which causes a black precipitate to form. After this
mixture has stood for a few hours it is to be thrown on a filter, and the pre-
cipitate to be well washed with water, to free it from sulphate of potassa, and
then dried. When dry it is to be boiled in coal-tar naptha, to extract a brown

page_text: substance from it, and this process must be repeated several times, until such
substance is entirely separated. The residuo is then to be boiled in methylated
spirit, to extract the coloring matter, and the spirit is afterwards to be sepa-
rated from the coloring matter by distillation. The coloring matter thus
obtained is a solid of a bronze color. The coloring matter, when required for
use, is to be powdered with a given quantity of oxalic or tartaric acid, and
moistened with a little methylated spirit, and is then thrown into boiling water.
The materials to be dyed are then to be immersed, the solution being kept
boiling, and when dyed they are to be washed with cold water, to cleanse them
from the acid. The materials thus dyed are of a lilac or purple color of a
very durable character, the tints or shades of which may be varied by the
quantity of coloring matter used.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Henry Perkin in the Great Seal Patent Office on
the 21st February 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY PERKIN, of King David Fort, in the Parish of Saint George in the
East, in the County of Middlesex, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of August, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Henry Perkin, Her special licence that I, the said William
Henry Perkin, my executors, administrators, and assigns, or such others as
I, the said William Henry Perkin, 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, usc, exercise, and vend, within the United Kingdom. of. Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for PRODUCING A NEW COLORING MATTER FOR DYEING WITH A LILAC OR PURPLE
COLOR STUFFS OF SILK, COTTON, WOOL, OR OTHER MATERIALS," upon the condition
(amongst others) that I, the said William Henry Perkin, 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

page_text: 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 William Henry Perkin, 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):-
The nature of my Invention consists in producing a new coloring matter for
dyeing with a lilac or purple color stuffs of silk, cotton, wool, and other mate-
rials in the manner following :-
I take a cold solution of sulphate of aniline, or a cold solution of sulphate
of toluidine, or a cold solution of sulphate of xylidine, or a cold solution of
sulphate of cumidine, or a mixture of any one of such solutions with any others
or other of them, and as much of a cold solution of a soluble bichromate as
contains base enough to convert the sulphuric acid in any of the above-
mentioned solutions into a neutral sulphate. I then mix the solutions, and
allow them to stand for ten or twelve hours, when the mixture will consist of a
black powder and a solution of a neutral sulphate. I then throw this mixture
upon a fine filter, and wash it with water till free from the neutral sulphate.
I then dry the substance thus obtained at a temperature of 100° centigrade,
or 212° Fahrenheit, and digest it repeatedly with coal tar naptha, until it is
free from a brown substance which is extracted by the naptha. Any other
substance than coal tar naptha may be used in which the brown substance is
soluble and the coloring matter is not soluble. I then free the residue from
the naptha by evaporation, and digest it with methylated spirit, or any other
liquid in which the coloring matter is soluble, which dissolves out the new
coloring matter. I then separate the methylated spirit from the coloring
matter by distillation, at a temperature of 100° centigrade, or 212° Fahren-
heit.
To produce the lilac or purple color in the material to be dyed, I add a
strong solution of the coloring matter (preferring an alcoholic solution) to a
dilute boiling solution of tartaric acid or oxalic acid, and work the silk, cotton,
or other material through it when cold.
For dyeing wool it is found advantageous to boil the wool with the above
solution and sulphate of iron, to rinse it in water, and afterwards wash it in
soap and water.
Having now described the nature of my Invention, and in what manner the
same is to be performed, I hereby declare that I claim as the Invention,
whereof the exclusive use is intended to be secured by the above-mentioned

page_text: Letters Patent, the producing in the manner above described a coloring
matter for dyeing silk, cotton, wool, or other materials with a lilac or purple.
color.
In witness whereof, I, the said William Henry Perkin, have hereunto
set my hand and seal, this Twenty-first day of February, in the year
of our Lord One thousand eight hundred and fifty-seven.
Signed, sealed, and delivered in the pre-
sence of
JAMES EDELL,
7, Crescent, Minories, Sol'.
W. H. PERKIN. (L.S.)