IMPROVEMENTS IN THE PREPARATION OF THE COLOURING MATTER CALLED MUREXIDE
Year: 1857

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, for the Invention
of "IMPROVEMENTS IN THE PREPARATION OF THE COLOURING MATTER CALLED
MUREXIDE." A communication.
Sealed the 6th November 1857, and dated the 20th May 1857.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 20th
May 1857.
**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 PREPARATION OF THE COLOURING MATTER CALLED
MUREXIDE," (a communication.)
This Invention relates to the production of the colouring matter called
murexidė, in a state more or less rich, by means of two processes.
First Process.-I treat in a dry state, or it may be a little damp, alloxantine,
or any other derivatives of uric acid, or any mixture of derivatives of uric acid
which may generate the murexide, by means of ammoniacal gas alone, or
by a mixture of ammoniacal gas with alcoholic vapour, (or any other gas or
vapour which is not prejudicial to the production of murexide,) for the
purpose of obtaining the murexide.
Second Process.-I treat alloxantine (or any other derivatives or mixtures of
derivatives of uric acid which will furnish the murexide) by ammonia dissolved

page_text: in alcohol, or by a mixture of ammonia dissolved in water, and mixed with
alcohol or any other chemical agent in which the murexide is insoluble, or but
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
18th November 1857.
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 Twentieth day of May, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth 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 execu-
tors, 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, 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 THE COLOURING MATTER CALLED MUREXIDE," a communication, upon the con-
dition (amongst others) that I, the said William Clark, 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 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 I, the said William Clark, do hereby declare the
nature of the 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:-
It has been known heretofore that by treating a solution of alloxane and
alloxantine with ammonia, or with carbonate of ammonia, in many cases
murexide is obtained of greater or less purity and in greater or less quantity,
according as the operation has been conducted with more or less care and
regularity.

page_text: The improved processes are as follows:-I submit alloxantine in a powdered
state or in crystals to contact with gaseous ammonia. It is according to
the concentration of the ammoniacal gas employed that the transformation of
the alloxantine into murexide is effected more or less rapidly. In order to
obtain a perfect result it is essential that humidity be excluded as much as
possible during the action of the ammonia on the alloxantine.
When alloxantine in solution or in a dry state is treated by ammonia
dissolved in water a stronger or weaker colouring is produced, which arises
from the formation of murexide; this colouring disappears simply by a more
or less prolonged exposure to the air. In order to preserve it and obtain
murexide of a pure character, I treat alloxantine either in a dry or humid.
state, or in solution with ammonia dissolved in alcohol, or with ammonia
dissolved in water and mixed with alcohol. After a contact of one or several
hours I filter and dry the product, in order to drive away at the same time
excesses of the. ammonia solution. I also obtain murexide by treating
alloxantine either in a dry or humid state with ammonia in a gaseous state
mixed with alcoholic vapours.
I may here remark that the nearly total exclusion of humidity during the
chemical action of the ammonia on alloxantine, herein-before mentioned, need
not be observed in presence of the alcoholic vapours, as murexide is insoluble
in alcohol, and hence is little susceptible of being attacked by a too prolonged
action of the ammonia.
I propose to substitute, when required, carbonate of ammonia for ammonia
in each of the processes herein-before described, and also to substitute ether or
vapours of ether for alcohol or vapours of alcohol.
In order to have the murexide perfectly pure, the product obtained by any
of the above-described processes must be dissolved in pure water, filtered and
crystallised or precipitated from the solution by carbonate of ammonia, or by
any other known process, but for commercial use the latter purification can
be avoided.
Having described the nature of the Invention, and the manner of performing
the same, I declare that what I claim as the Invention intended to be secured
by the herein-before in part recited Letters Patent, is,―
First, the process of treating in general all matters derived from uric acid
which will produce murexide, and principally alloxantine, in a dry state with
ammonia in a gaseous state.
Secondly, the process which consists of treating alloxantine, or any other
matter derived from uric acid, or mixture of matters derived from uric acid,
which can give rise to murexide in a dry or slightly humid state with

page_text: ammóniacal gas alone, or with a mixture of ammoniacal gas and alcoholic
vapours, or any other gas or vapours which are not hurtful to the formation of
murexide, in order to obtain murexide in a comparatively pure state.
Thirdly, the exclusive right of treating alloxantine, or any other matter
derived or mixture of matters derived from uric acid which will produce
murexide with ammonia dissolved in water, and mixed with alcohol or any
other chemical agent in which murexide is insoluble or only slightly soluble,
and which has no prejudicial action on the murexide. I also claim the
exclusive use of alcohol as a solvent or medium, either as a substitute for water
or for a portion of water, as a solvent of the chemical agents which assist in
the manufacture of murexide.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Eighteenth day of November, in the year of our
Lord 'One thousand eight hundred and fifty-seven.
WILLIAM CLARK. (L.S.)
Witness,
WILLIAM G. E. SWINNOCK.