IMPROVEMENTS IN THE MANUFACTURE OF PIGMENTS AND WRITING INKS
Year: 1862

page_text: LETTERS PATENT to Thomas De la Rue, of 84, Westbourne Terrace, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF PIGMENTS AND WRITING INKS."
Sealed the 6th February 1863, and dated the 9th August 1862.
PROVISIONAL SPECIFICATION left by the said Thomas De la Rue at the
Office of the Commissioners of Patents, with his Petition, on the 9th
August 1862.
I, THOMAS DE LA RUE, of 84, Westbourne Terrace, in the County of
5 Middlesex, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF PIGMENTS AND WRITING INKS," to be as
follows:-
This Invention has for its object improvements in the manufacture of pigments
and writing inks. For these purposes glycerine is combined with gum
tragacanth which is first partially dissolved or softened with water, these
matters are then allowed to stand some days. With this mixture or compound
lamp black or other proper form of carbon is ground, to which is added a
solution of salep or gluten. or glutinous substance in acetic acid. In some
cases isinglass dissolved in acetic acid is also used. Colored pigments and inks
are similarly prepared, and other gums than the one mentioned are also in some
cases employed. The black bye-product or waste substance obtained in the
manufacture of anilino is also ground with glycerine prepared as above described
to produce a pigment or ink to which is added a solution of salep or glutén
of glutinous substance dissolved in acetic acid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas De la Rué in the Great Seal Patent Office on the
9th February 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
DE LA RUE, of 84, Westbourne Terrace, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of August, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas De la Rue, Her special licence that I, the said Thomas
Do la Rue, my executors, administrators, and assigns, or such others as I, the
said Thomas De la Rue, 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 "IMPROVE-
MENTS IN THE MANUFACTURE OF PIGMENTS AND WRITING INKS," upon the
condition (amongst others) that I, the said Thomas De la Rue, 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 per-
formed, 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 De la Rue, 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
pigments and writing inks. For these purposes glycerino is combined with
gum tragacanth which is first partially dissolved or softened with water, these
matters are then allowed to stand some days. I prefer to employ a quart of
water to one ounce of gum tragacanth, and to add to this when the gum is
softened, ten ounces by measure of glycerine; the compound should be well
stirred. With this mixture or compound lampblack or other proper form of
carbon is ground. I prefer to use the best lampblack, and to add it from time
to time during the process of grinding, until a paste of the consistence of strong

page_text: printing ink is obtained. Afterwards to obtain a writing ink, there is added
to this a solution of salep or gluten or glutinous substance in acetic acid.
I usually take twenty ounces by measure of water, eight ounces of a strong
and clear solution of salep (one ounce of ground salep, to one pint of water),
sixteen ounces of vinegar, and twenty-eight ounces of a solution of gluten in
vinegar (three ounces of dry gluten to a quart of vinegar). I add and
thoroughly mix the whole of these materials to the paste produced in the
manner already described, and in this manner I obtain an indelible ink. The
vinegar I employ is the strongest commercial pyroligneous acid diluted with
six times its bulk of water. In some cases isinglass dissolved in acetic acid
is also used in place of gluten, but gluten is preferable. Colored pigments
and inks are similarly prepared, and other gums, than the one mentioned are
also in some cases employed. Gum arabic for example may be employed,
but the gum tragacanth is preferable; I also use the black bye-product or
waste substance obtained in the manufacture of aniline, this is also ground
with glycerine prepared as above described, to produce a pigment or ink, to
which to render it sufficiently fluid for use is added a solution of salep or
gluten or glutinous substance dissolved in acetic acid; this dilution or mixture
may be made as part of the process of manufacture, but in many cases, as for
artists water colors, it is more convenient to send the product into the market
in the form of a paste produced as above described, and which may be packed
in bladder or in thin metal vessels, as is common with oil colors, and the user
will then reduce the paste to a proper working consistency by the addition of
a solution of gluten in vinegar.
What I claim is the grinding carbon, aniline waste and other pigments with
glycerine and gum tragacanth, or other gum as above described. Also the
use of a solution of salep and of a solution of gluten or glutinous material
in vinegar in the preparation of inks from pigments as above described.
In witness whereof, I, the said Thomas De la Rue, have hereunto set
my hand and seal, this Ninth day of February, in the year of our
Lord One thousand eight hundred and sixty-three.
THO. DE LA RUE. (L.S.)