A NEW PROCESS FOR MANUFACTURING RED AND VIOLET COLOURING MATTER
Year: 1860

page_text: LETTERS PATENT to Georges de Laire and Charles Girard, Chemists, of
the Imperial Mint, Paris, in the Empire of France, for the Invention of
Sealed the 9th November 1860, and dated the 26th May 1860.
PROVISIONAL SPECIFICATION left by the said Georges de Laire and
Charles Girard at the Office of the Commissioners of Patents, with
their Petition, on the 26th May 1860.
We, GEORGES DE LAIRE and CHARLES GIRARD, Chemists, of the Imperial
Mint, Paris, in the Empire of France, do hereby declare the nature of the
said Invention for "A NEW PROCESS FOR MANUFACTURING RED AND VIOLET
COLOURING MATTER," to be as follows:-
By our new process we put into a distilling apparatus twelve parts arsenic
acid and twelve parts water, and the arsenic acid having become completely
hydrated, we add ten parts kyanol (the "aniline of French chemists); the
whole is then agitated or shaken, so as to produce a thorough mixture, forming
a homogeneous, clammy, or nearly solid mass. This mass is heated at a low
fire, so as to gradually raise its temperature, when liquefaction takes place.
By this modus operandi water and only a small quantity of kyanol (aniline)
is evaporated, provided the operation is carefully conducted at a temperature
of 248 degrees Fahrenheit, a great portion of the kyanol is already changed
into colouring matter, and care should be taken to keep the temperature at
that point for some time, after which it is further raised, but in no instance

page_text: above 320 degrees Fahrenheit. We thus obtain a perfectly homogeneous
and fluid mass above 212 degrees Fahrenheit. This operation may be made
to last from four to five hours. When cooled the mass solidifies and becomes
a hard brittle matter of a coppery hue similar to Florentine bronze. This
matter is highly soluble in water, and imparts it a fine pure red tint, having
no admixture of violet, the intensity of this colouring matter being so great
that when boiled and concentrated it appears altogether black.
This colouring matter may, without inconvenience, be directly applied to
dyeing fabrics, the fabric not retaining the slightest trace of arsenic.
It may
also be freed in an easy way from arsenic, by either of the following
processes
First process. The mass is pulverized and digested with either chlorhydric
or sulphuric acid, diluted with water. The clear solution thus obtained is
then saturated with a slight excess of soda. Thus the colouring matter preci-
pitates whilst the arsenic is dissolved in the alkali. The colouring matter is next
washed once or twice in cold water, when it may be filtered or decanted.
Second process. The coloring matter, after having been dissolved in
water, is digested with a quantity of lime corresponding with the portion of
arsenical compounds contained in it, the lime being slightly in excess. The
coloring matter is thus precipitated as well as the arsenical compounds, which
combine into insoluble calcareous salts. The precipitate both, and the solution
are then (without being separated) acted upon by either carbonic, tartaric, or
acetic acid, which dissolve the coloring matter, the whole of the arsenic
remaining insoluble.
There are also other means for purifying the colouring matter obtained,
such as sulphuretted hydrogen, any of which agents may be used as may be
found most advantageous.
We also obtain a violet coloring matter by changing the proportions of the
arsenic acid used. For preparing the said violet matter, we take twenty-four
parts arsenic acid, twenty-four parts water, and ten parts kyanol (aniline).
The process is precisely the same as for the red coloring matter herein-before
described, and the whole of the kyanol (aniline) is thus transformed into
soluble colour, which is fit for directly dyeing violet, pensée, and granate red,
but when used for silk stuffs, the coloring, matter should previously be purified.
The purifying process is easily performed by means of naptha (benzine), which
separates the violet matter from the remainder. There are also different other
ways of purifying the same, as for the red color herein-before described.
The red and violet coloring matters obtained by the process herein-before
described are nearly equal in quantity to the kyanol (aniline) employed.

page_text: In conclusion, we do not confine ourselves to any of the particular pro-
portions herein-before stated; but what we consider as novel in our process is
the use of arsenic acid for transforming kyanol (aniline) into red and violet
coloring matter.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Georges de Laire and Charles Girard in the Great Seal
Patent Office on the 22nd November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGES
DE LAIRE and CHARLES GIRARD, Chemists, of the Imperial Mint, Paris, in the
Empire of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, 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 us, the said Georges de Laire and Charles Girard, Her special licence
that we, the said Georges de Laire and Charles Girard, our executors,
administrators, and assigns, or such others as we, the said Georges de Laire
and Charles Girard, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "A NEW
PROCESS FOR MANUFACTURING RED AND VIOLET COLOURING MATTER," upon the con-
dition (amongst others) that we, the said Georges de Laire and Charles Girard,
our executors or administrators, by an instrument in writing under our, 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 we, the said Georges de Laire and Charles
Girard, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement: -
By our new process we put into a distilling apparatus twelve parts arsenic
acid, and twelve parts water, and the arsenic acid having become completely

page_text: hydrated, we add ten parts of kyanol (the "aniline of French chemists).
The whole is then agitated or shaken, so as to produce a thorough mixture,
forming a homogeneous, clammy, or nearly solid mass. This mass is heated
at a low fire, so as to gradually raise its temperature, when liquefaction takes
place. By this modus operandi water and only a small quantity of kyanol is
evaporated, if the operation is conducted with the proper care. At a tempera-
ture of 248 degrees Fahrenheit, a great quantity of the kyanol or aniline is
already converting into colouring matter, and care should be taken to keep the
temperature at that point for some time, after which it is further raised, but
in no instance above 320 degrees F. We thus obtain a perfectly homo-.
geneous and fluid mass above 212 degrees F. This operation lasts from four-
to five hours. When cooled, the mass solidifies and becomes a hard brittle
matter, of a coppery hue, similar to Florentine bronze. This matter is highly
soluble in water and other solvents, such as alcohol, and imparts them a fine
pure, red tint, having no admixture of violet, the intensity of this colouring
matter being so great that after having been boiled and concentrated it appears
altogether black.
This colouring matter may, without inconvenience, be directly applied to
dyeing or otherwise colouring fabrics and other substances, the substance thus
coloured not retaining the slightest trace of arsenic. The arsenic may also be
eliminated in an easy way by either of the following processes :-
First process. The mass is pulverized and digested with either chlorhydric
(bydrochloric) or sulphuric acid, diluted with water. The clear solution thus
obtained is then saturated with a slight excess of soda or carbonate of soda;
thus the colouring matter precipitates, whilst the arsenic is dissolved in the
alkali. The colouring matter is next washed once or twice in cold water,
when it may be filtered or decanted.
Second process. The colouring matter, after having been dissolved in
water, is digested with a quantity of lime corresponding with the portion of
arsenical compounds contained in it, the lime being slightly in excess. The
colouring matter is thus precipitated, as well as the arsenical compounds,
which combine into insoluble calcareous salts. The precipitates both, and the
solution, are then (without being separated) acted upon by either of the
carbonic, tartaric, or acetic acids, which dissolve the colouring matter,
the whole of the arsenic remaining insoluble.
There are also several other means for purifying the colouring matter
obtained, such as sulphuretted hydrogen "benzine," any of which agents may
be used as may be found most advantageous.
We also obtain a violet colouring matter, and also a combination of blue

page_text: and other colouring matter, by merely changing the proportions of the arsenic
acid used. Thus instead of employing the proportions above stated, if we act
with eighteen, twenty, and twenty-four parts of arsenic acid on ten parts of
aniline, or a quantity of any salt containing ten parts weight of aniline, a
colouring matter is produced that is more or less violet, tending towards the
pure blue, and the matter thus obtained may be used directly, as it is, or the
blue ingredient may be separated from it, and be used as such..
We now have to point out the following concomitant, but characteristic and
important features of our Invention, as herein-before specified, viz.,-
First, establishing the proper limits of temperature within which the
reaction has to be carried on, in order to prevent the production of secondary
substances differing from the colouring matter to be produced.
Second, the precise atomic proportions in which the reactive bodies must be
used, so as to prevent the production of resinous matter, and thus convert the
whole (or nearly so) of the aniline into a colouring matter of the shade
required.
And what we distinctly claim, either in connexion with or without the con-
comitant features above ascertained, as novel and secured to us, by the herein-
before in part recited Letters Patent, is the use of arsenic acid for converting
aniline or kyanol into colouring matter.
In witness whereof, we, the said Georges de Laire & Charles Girard,
have hereunto set our hands and seals, this Sixteenth day of
November, in the year of our Lord One thousand eight hundred
& sixty.
Witness,
F. TOLHAUSEN,
35, Boulevard Bonne Nouvelle.
(L.8.)
G. DE LAIRE.
CHARLES GIRARD. (L.S.)