IMPROVEMENTS IN PREPARING COLORING MATTERS
Year: 1870

page_text: LETTERS PATENT to Richard Samuel Dale and Carl Schorlemmer, of
the City of Manchester, in the County of Lancaster, Chemists, for
Sealed the 22nd July 1870, and dated the 24th January 1870.
PROVISIONAL SPECIFICATION left by the said Richard Samuel Dale
and Carl Schorlemmer at the Office of the Commissioners of
Patents, with their Petition, on the. 24th January 1870.
We, RICHARD SAMUEL DALE and CARL SCHORLEMMER, of the City of
Manchester; in the County of Lancaster, Chemists, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN PREPARING COLORING
MATTERS," to be as follows:-
Our Invention consists of improvements in the manufacture of
alizarine from anthracene, and for this purpose we take one part of
anthracene and heat it with from four to six parts of strong sulphuric
acid at boiling point for some time. We then dilute with water and
neutralize the solution with a carbonate, such as lime or barytes, or
with an alkali, such as caustic soda or potash, and remove the sulphates
thus formed by filtration or crystallization. The resulting liquid we
7--

page_text: heat between 180° and 260° centigrade with caustic soda or caustic
potash mixed with nitrate of soda or nitrate of potash or chlorates of
the same bases as long as a bluish purple color is produced. Instead
of nitrates or chlorates other suitable oxydizing agents may be employed.
We obtain the alizarine from this product by precipitation with an acid
in the usual manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent;
filed by the said Richard Samuel Dale and Carl Schorlemmer in
the Great Seal Patent Office on the 22nd July 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, RICHARD
SAMUEL DALE and CARL SCHORLEMMER, of the City of Manchester, in
the County of Lancaster, Chemists, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of January, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Richard Samuel Dale and Carl Schorlemmer,
Her special license that we, the said Richard Samuel Dale and Carl
Schorlemmer, our executors, administrators, and assigns, or such others as
we, the said Richard Samuel Dale and Carl Schorlemmer, our 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
PREPARING COLORING MATTERS," upon the condition, amongst others, that
we, the said Richard Samuel Dale and Carl Schorlemmer, by an in-
strument in writing under our hands and seals (or under the hand
and seal of one of us) 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 Richard Samuel Dale and Carl
Schorlemmer, do hereby declare the nature of our said Invention, and in

page_text: what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement (that is to say) :-
Our Invention consists of improvements in the manufacture of
alizarine from anthracene, and for this purpose we take one part of
anthracene and heat it with from four to ten parts of strong sulphuric
acid at boiling point for some time. We then dilute with water and
neutralize the solution with a carbonate, such as lime or barytes, or
with an alkali, such as caustic soda or potash, and remove the sulphates.
thus formed by filtration or crystallization. The resulting liquid we
heat between 180° and 260° centigrade with caustic soda or caustio
potash mixed with nitrate of soda or nitrate of potash or chlorates of
the same bases as long as a bluish purple color is produced, and
of these salts we use about the same quantities as of the anthracene
originally acted upon. We obtain the alizarine from this product by
precipitation with an acid in the usual manner.
Having now described the nature and particulars of our said In-
vention, and the manner in which the same is to be performed; we
desire it to be understood that we claim, the manufacture of alizarine by
treating the body produced by the action of sulphurio acid on anthracenc
after all excess of sulphuric acid has been removed with caustic soda or
potash in presence of nitrates or chlorates of the same or similar bases,
substantially as herein described.
In witness whereof, I, the said Richard Samuel Dale, for and on
behalf of myself and the said Carl Schorlemmer, have hereunto
set my hand and scal, this Twenty-first day of July, in the year
of our Lord One thousand eight hundred and seventy.