IMPROVEMENTS IN THE PREPARATION OF A COLOURING MATTER FOR DYEING TEXTILE MATERIALS AND FABRICS AND OTHER SUBSTANCES."
Year: 1860

page_text: LETTERS PATENT to John Dale, of Manchester, in the County of Lan-
caster, Manufacturing Chemist, for the Invention of "IMPROVEMENTS IN
THE PREPARATION OF A COLOURING MATTER FOR DYEING TEXTILE MATERIALS
AND FABRICS AND OTHER SUBSTANCES."
PROVISIONAL SPECIFICATION left by the said John Dale, at the
Office of the Commissioners of Patents, with his Petition, on the
24th March 1860.
I, JOHN DALE, of Manchester, in the County of Lancaster, Manufacturing
Chemist, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE PREPARATION OF A COLORING MATTER FOR DYEING TEXTILE
MATERIALS AND FABRICS AND OTHER SUBSTANCES," to be as follows:-
My Invention refers to the preparation of a colouring matter from barwood,
camwood, redwood, and other such woods.
It is well known that these substances when treated with alkaline solutions
afford a coloured substance, but all attempts to use it as a dye, have, so far as
I know, failed, the extracted material having lost or having been injured in
its dyeing property.
According to my Invention I treat barwood, camwood, redwood, and
other similar woods with alkaline solutions, but in such manner as to preserve
the dyeing quality.
The principle upon which my Invention is founded, I assume to be this:-

page_text: The colouring principle of barwood, I suppose to be a definate substance
capable of combining chemically with alkalies in certain proportions, and when
so combined is deprived (in that state) of its dyeing power, and if submitted to
an excess of alkali is permanently injured. I therefore treat barwood, cam-
wood, redwood, and other similar woods with such strengths of alkaline solu-
tions as will yield extracts of a red color in contradistinction to those hitherto
obtained which have been purple, and thus obtain the extract without an
excess of alkali. I subsequently precipitate the colouring matter by sulphuric
acid or other suitable substance. This precipitate being placed in a bath will
be found to afford the required dye, or the materials to be dyed may be placed
in a bath of the alkaline extract and sulphuric acid then added.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Dale, in the Great Seal Patent Office on the
24th September 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN DALE,
of Manchester, in the County of Lancaster, Manufacturing Chemist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of March, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Dale, Her special license that I, the said John Dale,
my executors, administrators, and assigns, or such others as I, the
said John Dale, 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 THE PREPARATION OF A COLORING MATTER FOR DYEING TEXTILE
MATERIALS AND FABRICS AND OTHER SUBSTANCES," upon the condition, amongst
others, that I, the said John Dale, by an instrument in writing under
my hand and seal, 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 John Dale, do hereby declare
the nature of my 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)
My Invention refers to the preparation of a coloring matter from barwood,
camwood, redwood, and other similar woods.
It is well known that these substances when treated with alkaline solutions
afford a colored substance, but all attempts to use it as a dye, have, so far as I
know, failed, the extracted material having lost or having been injured in its
dyeing property.
According to my Invention, I treat the above woods with alkaline solutions,
but in such manner as to preserve the dyeing quality.
The principle upon which my Invention is founded I assume to be this:-
The coloring principle of the above woods is a definite substance capable of
combining chemically with alkalis in certain proportions, and when so com-
bined is deprived in that state of its dyeing power, but if submitted to an excess
of alkali is permanently injured.. I therefore treat these woods with definite
strengths of alkaline solutions, by which I get extracts of a red color in con-
tradistinction to those hitherto obtained, which have been purple, and so as to
obtain an extract without excess of alkali, and I subsequently precipitate the
coloring matter by sulphuric acid or other suitable substance, this precipitate
being placed in a bath will be found to afford the required dye, or the materials
to be dyed may be placed in a bath of the alkaline extract, and sulphuric acid
added.
As an example of carrying my Invention into effect I place one ton of bar-
wood within a close vessel, and pass through it by means of pump or other
pressure one hundred and twenty pounds of caustic alkali of 25 per cent, pre-
viously deluted with 500 to 800 gallons of water and heated to the boiling
point. This operation extracts the coloring matter from the barwood, and
affords a pure red solution; this solution is now allowed to cool, and a
sufficient quantity of sulphuric or other acid is added to combine with the
alkali left in the solution. The coloring matter being then precipitated may be
washed and collected in any ordinary manner. The principle of this operation
depending upon using such a quantity of alkali as will be neutralized by
the acid property of the coloring matter in the wood; the said quantity will be
varied in some measure by the quality of the wood, and in all cases by the
description of wood, camwood, for instance, containing a larger amount of
acid will require more alkali; the object being to gain an extract as nearly
neutral as possible, for if it be on the alkaline side the coloring property is so

page_text: far injured as to render it useless for dyeing purposes, and if on the acid side,
the whole of the coloring matter will not have been extracted. The precipi
tated coloring matter obtained as above may be used to dye with or without
the mordaunts usually employed, for the woods from which it is derived, or the
neutral solution, that is, without precipitation of the coloring matter, may be
used as a dyeing bath, sulphuric or other acid being added while the goods are
immersed.
Having thus described and ascertained the nature of my said Invention, and
the manner in which the same is to be performed, I desire it to be understood
that I claim as secured to me under the above in part recited Letters
Patent.
Firstly, obtaining extracts of coloring matter from barwood, camwood;
and other similar woods by means of alkali, and in such manner that
the said extract shall be neutral or nearly so, and of a red color..
Secondly, precipitating a coloring matter from fluid extracts of barwood,
camwood, and other similar woods.
In witness whereof, I, the said John Dale, have hereunto set my
hand and seal, this Twenty-second day of September, in the year of our
Lord One thousand eight hundred and sixty.