AN IMPROVED BLACK DYE
Year: 1876

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "AN IMPROVED
BLACK DYE" A communication from abroad by Charles Rave, of Paris,
France.
Sealed the 8th December 1876, and dated the 19th June 1876.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 19th June 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Mid-
dlesex, Patent Agent. "AN IMPROVED BLACK DYE"
In the ordinary process of dyeing black logwood is applied to the materials to be
dyed after they have been previously impregnated with a mordant, which usually
consists of salts of iron, chromium, and copper.
The present Invention consists in forming a pure black coloring matter with log-
wood or its extract and the salts which oxidize it, which is then applied to the
materials to be dyed, more particularly wool and felt.
This Invention presents great advantages, the dyeing operation being effected in
a single bath without mordant, and wool dyed in this manner is not injured as
when dyed in the ordinary way. A considerable saving in time and fuel is also
effected, while the cost of the coloring matter is but little if any increased.
According to this Invention I make a decoction or extract of logwood, and by
adding thereto one of the mordants or salts used for changing it to a black I obtain
a precipitate which I collect on a filter and wash. I thus obtain a black homo-
geneous paste in condition for use. This black will also furnish fast grey colors.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the 18th
December 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Mid-
dlesex, Patent Agent. "AN IMPROVED BLACK DYE." A communication from
abroad by Charles Rave, of Paris, France.

page_text: dyed after they have been mordanted, the mordants ordinarily used being salts of
iron, chromium, and copper.
The present Invention consists in forming a pure black coloring matter (termed
by the Inventor a "direct black") with logwood or its extract, which is applied to
the materials to be dyed, more particularly wool and felt.
This Invention presents great advantages, the dyeing operation being effected in
a single bath without mordant, and wool dyed in this manner is not injured, as is
the case when dyed in the ordinary way, and neither stains or other blemishes are
produced. Moveover a considerable saving in time and fuel is effected, and the cost
of the coloring matter is but little if any increased.
According to this Invention I make a decoction or extract of logwood, and by
adding thereto one of the mordants or salts used for changing it to a black I obtain
a precipitate which I collect on a filter and wash. I thus obtain a black
homogeneous paste in condition for use. This black will also furnish fast grey
colors.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,―
The manufacture of a black dye or coloring matter (termed a direct black) with
logwood and the salts which serve to oxidize it, capable of being applied directly to
wool, felt, and other fabrics.
Also the employment thereof for dyeing grey, as herein specified.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Eighteenth day of December, in the year of our Lord
One thousand eight hundred and seventy-six.