IMPROVEMENTS IN THE MANUFACTURE OF COLORING MATTERS
Year: 1859

page_text: LETTERS PATENT to Thomas Dix Perkin, of King David Fort, St.
George's in the East, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF COLORING MATTERS."-A com-
munication from abroad by Rudolph Knosp, of Stutgart.
Sealed the 27th April 1860, and dated the 15th November 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Dix Perkin at
the Office of the Commissioners of Patents, with his Petition, on the
15th November 1859.
I, THOMAS DIX PERKIN, of King David Fort, St. George's in the East, in
the County of Middlesex, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF COLORING MATTERS," to be as
follows:-
This Invention has for its object improvements in the manufacture of
coloring matters. For this purpose aniline or its analogues, such as toluidine,
xylidine, cumidine, is combined with the per-nitrate, or the sub-nitrate, or the
per-sulphate, or the nitrite of mercury, and kept heated to ebullition until it
becomes red. The coloring matter is extracted from this by repeated boilings
with water, and may be obtained in a solid state by evaporating off the water,
or by precipitation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Dix Perkin in the Great Seal Patent Office on the
15th May 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
DIX PERKIN, of King David Fort, St. George's in the East, in the County of
Middlesex, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of November, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her beirs and successors, give and grant unto me, the
said Thomas Dix Perkin, Her special licence that I, the said Thomas
Dix Perkin, my executors, administrators, and assigns, or such others
as I, the said Thomas Dix Perkin, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and 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 Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF COLORING MATTERS," a com-
munication from abroad by Rudolph Knosp, of Stutgart, upon the condition
(amongst others) that I, the said Thomas Dix 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 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 Dix Perkin, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This. Invention has for its object improvements in the manufacture of
coloring matters. For this purpose aniline, or its analogues, such as toluidine,
xylidine, cumidine, is combined with the per-nitrate, or the sub-nitrate, or the
per-sulphate, or the nitrite of mercury, and kept heated to ebullition until it
becomes red. The coloring matter is extracted from this by repeated boilings
with water, and may be obtained in a solid state by evaporating off the water;
or by precipitation.
The following is the manner in which it is preferred to conduct the

page_text: process: To aniline, or one of its analogues (aniline is used by preference
both because it is easily obtained, and because the color it produces is perhaps
superior to that produced by any of its analogues,) there is added per-nitrate
sub-nitrate, per-sulphate, or nitrite of mercury, care being taken (whichever
salt is employed) that it is perfectly free from water; the salt is added
gradually, and until no further change of color or action is produced by it.
The sub-nitrate of mercury is used in preference to the other salts above
named, and from 6 to 8 parts of this salt will be required to be added to 10
parts of aniline or of one of its analogues. The mixture thus prepared is
heated, by preference, in an oil bath, and caused to boil, when metallic
mercury will be deposited; the boiling is continued until the mixture, which
is then an oil-like liquid, becomes of a bluish red color; this liquid is then,
while it is hot, separated from the mercury, and on cooling it will form a
crystalline paste. The oily matter or color may in this form be sent into the
market, and a dye bath may be prepared from it by simply boiling the oily
matter or color in water. It is, however, preferred to boil the oily matter
above mentioned in several successive waters until no more color is extracted
from it; these aqueous solutions are carefully filtered, and on cooling deposit
a great part of the coloring matter taken up, and by adding common salt to
the water, practically, the whole of the coloring matter may be precipitated.
The precipitate may be dissolved in alcohol or wood spirit, and in this form
it is very suitable for use in dyeing and printing on fabrics.
In witness whereof, I, the said Thomas Dix Perkin, have hereunto set
my hand and seal, this Fourteenth day of May, in the year of our
Lord One thousand eight hundred and sixty.
THOMAS DIX PERKIN. (L.S.)