IMPROVE- MENTS IN THE MANUFACTURE OF COLORING MATTERS
Year: 1860

page_text: LETTERS PATENT to Williain Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF COLORING MATTERS."-A communication:
from abroad by Charles Emile Kopp, of 29, Boulevart St. Martin,
Paris, in the Empire of France, formerly Professor of Chemistry.
Scaled the 14th June 1861, and dated the 22nd December 1860.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
22nd December 1860.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF COLORING MATTERS," to be as
follows:-
This Invention relates to new methods of treating madder by which pure
coloring matters are easily separated and extracted. Madder, especially fresh
madder roots, after being ground to a coarse powder, are lixiviated with an
aqueous solution of sulphurous acid or other compound having anti-fermenting
properties. The solution, which is of a deep brownish orange color, after,
adding three per cent. of hydrochloric or sulphuric acids of commerce, is
heated to about 140 degrees Fahrenheit, when a red or yellowish brown
coloring matter, which I term purpurine, is precipitated, which is separated
from the liquor by filtration. The clear filtered liquor being now heated to a
boiling point, yields a new precipitate of a dark green color containing

page_text: alezarine & altered chlorogerin. The green alezarine being separated by
filtration the mother liquor can be used for preparing garancine, garenceous,
or alcohol, lactic acid; and other derivatives from.sugar. Instead of precipitating
the green alezarine by raising the heat of the mother liquor of purpurine to
the boiling point; the acid (in case hydrochloric acid has been used) can be
saturated by a small excess of milk of lime, which determines the precipitation
of alezarine of lime. This compound being collected in a filter, and washed
and decomposed by hydrochloric acid, yields yellow alezarine nearly insoluble
in water and easily separated by filtration. The clear solution obtained by
extracting madder with aqueous sulphurous acid can be used directly for
preparing lakes or combinations of coloring matters with suitable oxides.
The residue of madder after lixiviation with sulphurous acid is washed
several times with boiling water, and may then be used in dyeing as a kind
of madder flower (fleur de garance). The same residue. boiled with the
acid liquors from the preparation of green alezarine is converted into a
weak garancine.
The hot aqueous solution from the washing is super-saturated with lime or
other-oxides, in order to precipitate the coloring matters in the state of lakes;
by decomposing these lakes with acids the coloring matters are set free, and
can be separated from the salts formed by these acids and the oxides pre-
viously combined with the coloring matters.
SPECIFICATION in pursuance of the conditions of the Letters Patent; filed
by the said William Clark in the Great Seal Patent Office on the
21st June 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of December, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, 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,

page_text: 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 MANUFACTURE OF COLORING MATTERS," a communication from abroad. by
Charles Emiles Kopp, of 29, Boulevart St. Martin, Paris, in the Empire of
France, formerly Professor of Chemistry, upon the condition (amongst others).
that my, the said William Clark, my executors or administrators, by an instru
ment in writing under my, or their, or one of their hands and seals, should par-
ticularly 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 late of the said Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare
the nature of the said Invention, and in what manner the same is to ber
performed, to be particularly described and ascertained in and by the following
statement (that is to say):-
This Invention consists of a new manner of treating tinctural substances,
especially madder, in order to obtain therewith pure coloring extracts, pure
dyeing baths, & fine lakes.
In carrying out my Invention I proceed in the following manner.:
Madder, either in roots or in powder, is treated with an aqueous solution of.
sulphurous acid, to which are added very small quantities of hydrochloric or.
sulphuric acid, according to the amount of alkaline or carthy carbonates con-
tained in the madder. Instead of sulphurous acid the aqueous solutions of:
other bodies may be employed, having the property of preventing the peculiar
fermentation which takes place when the madder is treated with water, and.
renders the coloring matter insoluble in water, such as crude acetic acid,.
arsenious acid, creosote, &c.; however, I have found that sulphurous acid is
the most effective & economical, & that its use presents the greatest advantages.
After several hours standing in contact with the aqueous sulphurous acid, the
madder is strongly pressed in order to obtain a clear yellow or orange colored
liquor. The pressed madder is treated with a new aqueous solution of sul-
phurous acid as long as the liquor obtained by pressure contains sufficient
coloring matters; weak solutions can be used to extract new qualities of fresh
madder. The strong sulphurous solutions can be used directly either alone or
mixed with mordants for the treatment of steam colors upon textile fabrics,
which in the first case should be previously subjected to the mordant. The
weaker solutions are used either for dyeing, especially wool and cotton, or for
the preparation of earthy or metallic lakes, easily obtained by adding to the
cold or boiling solution the oxides or salts of the metals to be combined with

page_text: coloring matter, or for the preparation of pure coloring matters in the
following manner :-To the cold sulphurous solution is added two or three per
cent., or more of a strong acid, p. ex. hydrochloric or sulphuric acid. In a
short time, especially in heating to about 140° Fahrenheit, the solution
deposits a red coloring matter which I call red extract of madder or purpurine.
This red extract or purpurine is collected upon a filter & washed with cold
water. It can be dried or kept in a pasty state; it dissolves with a beautiful
carmine color in ammonia. It can be used either for dyeing or printing, or
for the preparation of lakes of a bright and pure shade. The mother liquor of
the red extract being now heated to the boiling point & kept boiling for some
time, deposits a black greenish powder containing a large quantity of alizarine,
& for this reason I shall call it green alizarine or extract of madder. The
green alizarine can be used directly for printing and dyeing, or for the pre-
paration of lakes, or can be treated with spirit of wood, alcohol, &c., in general
with liquids which dissolve the pure alizarine, or can be strongly heated in
order to obtain pure crystallized yellow alizarine. Green alizarine as I am
aware has already been obtained in small quantities in laboratories, but never
in a manufacturing point of view, and in the manner above described, & has
never been used for printing & dyeing. The mother liquors of the green
alizarine are used for the preparation of garancine by boiling with these mother
liquors either fresh madder or residues of madder from the print works, or the
residue of madder already extracted with aqueous sulphurous acid & with
ordinary water. The same mother liquors can also after the saturation with
lime or chalk be submitted to fermentation, & afterwards to distillation in order
to obtain alcohol. The madder extracted with watery sulphurous acid can be
dried either alone or mixed with small quantities of chalk or alkaline carbonate
to be used for dyeing as a peculiar flower of madder, or it may be washed with
cold or hot water before being pressed and dried. The washing liquors which
possess drying properties being mixed with earthy and metallic oxides or salts
yield insoluble lakes of a pure shade. I prefer to make use of milk of lime
which produces an insoluble purple calcareous lake, easily collected by
filtration. This calcareous lake, decomposed by salts of alumine, iron, tin, &c.,
produces excellent solutions for the preparation of colors for printing. The
same calcareous lake being decomposed by boiling with bydrochloric acid yields
soluble chloruret of calcium & insoluble yellow alizarine, which after being
washed with cold water, is ready for dyeing or for the preparation of pure
Jakes & steam colors. The mother liquid of the calcareous lakes being finally
mixed with acetate of lead or other metallic salts yields a small quantity of
metallic lakes of various shades.

page_text: This improved manner of treating madder is capable of various modifications,
If, for instance, the formation of green alizarine is desired to be avoided, the
operation can be conducted in the following manner:-After having pre-
cipitated the red extract of purpurine from the sulphurous solution with a few
per cent. of hydrochloric acid, the mother liquors are not boiled, but imme-
diately mixed with earthy or metallic oxides or salts more or less neutralized
with alkalies, in order to precipitate the coloring matter in the state of
insoluble, earthy, or metallic lakes. In using milk of lime a strongly colored
calcareous lake is obtained, which being washed and afterwards boiled with
hydrochloric acid yields insoluble yellow alizarine in a sufficient state of purity
after the chloruret of calcium & the excess of hydrochloric acid have been com-
pletely eliminated by sufficient washing with cold water. The characteristic
features of this Invention are,
First, that in all the different stages of the treatment the residue of madder
is not altered or contaminated with obnoxious substances, and that any coloring
matter retained in the residue remains perfectly useful for dyeing purposes.
In consequence the preparation of the pure extracts & lakes can be combined
with the utmost facility with the manufacture of garancine.
Secondly, that perfectly clear & bright liquors are obtained rich in coloring
matters, very advantageous for many dyeing processes (especially for dyeing
wool), & with which fine lakes of various shades may be immediately
obtained.
Thirdly, that the liquors treated in the manner above described yield with
great facility and at little expense pure purpurine, pure alizarine, & green
alizarine.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Twentieth day of June, in the year of our Lord One
thousand eight hundred and sixty-one.
0 Witness,
W. G. E. SWINNOCK,
53, Chancery Lane.
W. CLARK. (L.S.)