IMPROVE- MENTS IN THE MANUFACTURE OF 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 "IMPROVE-
MENTS IN THE MANUFACTURE OF MUREXIDE."-A communication.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
28th October 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
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF MUREXIDE," to be as
follows:-
The production of murexide has long been known as a chemical experiment,
but hitherto its introduction for commercial purposes has been in a great
measure barred by the difficulty of the manufacture, arising from uncertainty
in its production, even as a laboratory experiment, inasmuch as the least
variation from the exact proportions, temperature, or time, spoils the whole
result.
After long and extensive experiments the conditions of success have been-
discovered for the manufacture of murexide on a scale sufficiently extensive to
adapt it for commercial purposes, by treating a solution of alloxan while cold
with ammonia, and observing the following conditions:-
First, previously prepare, in a cold state, the alloxan with the neutralizing
substance, ammonia, soda, potash, lime, or their carbonates. The smallest
proportion of them should be more than half that which gives an alkaline
action, but should never attain an alkaline state.

page_text: Secondly, adding this neutralizing substance in portions, in order not only
to avoid the heating, but also to give the alloxan time to resume its acidity.
This last condition is established on this observation, that an equal quantity of
base added to the alloxan at several times, or at once, will give in the latter
case an impure alkaline compound; while in the former case-the compound
will remain acid, which is indispensable as a vehicle for the murexide. A
solution of alloxan rendered slightly alkaline becomes slightly acid some
moments after. In processes which operate by heat this retrograde effect is
lost.
Thirdly, raising this mixture of alloxan, suitably saturated, to the tem-
perature of from one hundred and forty to one hundred and fifty-eight
degrees Fahrenheit, letting it crystallize by cooling, and filtering it; or-the
murexide may be deprived of the acid salts with which it is impregnated, by
washing, and then be put to dry. in stoves of attempered heat..
The product can thus be obtained in quantities at a time in great purity.
These conditions are the more imperative as the quantities operated on become
greater. The following proportions are for example:-One hundred parts of
alloxan, at thirty degrees Beaumé, to which is added from twenty-three to
thirty per cent. of their volume of ammonia, at eighteen degrees Beaumé;
with all the precautions indicated; it may be by thirtieths, or about that
quantity, but slowly. The mixture being completed, heat it up to one
hundred and fifty-eight degrees Fahrenheit, by means of steam tubes traversing
it, then let it cool, and gather the crystallized deposit on the filters. The
mother waters are taken a, second time, sometimes even a third time, as long
as they can yield murexide, to undergo a similar treatment as regards' tem-
perature, but with a weaker and weaker neutralizing agent, say, for the
second time one-fourth of the strength of the first, and for the third, one
sixteenth of the first. I prefer this mode of exhaustion to obtaining it at
once, for the sake of safety.
1
.. For the purposes of dyeing and printing, it is useless to wash and dry the
product on the filters; may therefore be collected in a state of green paste.
The alloxan I use, and which I designate alloxan throughout my process,
arises from nitric acid diluted in an equal quantity of water at nearly ninety-
seven degrees Fahrenheit, saturated with' uric acid, from one hundred and
forty to one hundred and forty-nine degrees Fahrenheit, and consequently an
'alloxan mixed with alloxantine. I can substitute chromic or chloric acids,
either wholly or partially; for-the nitric acid....
74
2:23

page_text: SPECIFICATION in
pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
24th April 1858.
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.
:
+1
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of October, in the year of our
Lord One thousand eight hundred and fifty-seven, in the twenty-first 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 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 "IMPROVEMENTS IN THE
MANUFACTURE OF MUREXIDE," a communication, upon the. condition (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, thé said William Clark, 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 fol-
lowing statement (that is to say):-
The production of murexide has long been known as a chemical experiment,
O but hitherto its introduction for commercial purposes has been in a great
measure barred by the difficulty of the manufacture, arising from uncertainty
in its production, even as a laboratory experiment, inasmuch as the least varia-
tion from proper proportions, temperature, or time, spoils the whole result.
After-long and extensive experiments the conditions of success have been
5 discovered for the manufacture of murexide on a scale sufficiently extensive
to adapt it for commercial purposes; by treating a solution of alloxan, while
cold, with ammonia, observing the following conditions:
First, previously preparing, in a cold state, the alloxan with the neutralizing

page_text: substance, ammonia, soda, potash, lime, or the carbonates of these bases.
The smallest proportion of them should be more than half that which gives
an alkaline action, but should never attain an alkaline state.
Secondly, adding this neutralizing substance in portions; in order not only
to avoid the heating, but also to give the alloxan time to resume its acidity.
This last condition is established on this observation, that an equal quantity of
base added to the alloxan at several times, or at. once, will give, in the latter
case, an impure alkaline compound, while in the former case the compound
will remain acid, which is indispensable as a vehicle. for the murexide. A
'solution of alloxan rendered slightly alkaline beconies acid some moments
after. In processes which operate by heat this retrograde effect is lost. : .
Thirdly, raising the mixture of alloxan suitably saturated to the .tem-
perature of from sixty to seventy-seven degrees centigrade (one hundred
and forty to one hundred and seventy degrees Fahrenheit), letting it crystallize
by cooling, and filtering it; or the murexide may be deprived. of the acid
salts with which it is impregnated, by washing, and then be put to dry in
stoves of tempered heat...:
The product can be thus obtained in sufficiently large quantities at a timė,
and in great purity. These conditions are the more imperative, as the
quantities to be operated on are increased. The following proportions are
for example: One hundred quarts of alloxan at thirty degrees Beaumé, to
which is added from twenty-three to thirty per cent. of its volume of
ammonia, at eighteen degrees Beaumé; with all the precautions indicated it
may be by thirtieths, or about that quantity, but slowly. The mixture being
completed, it is heated up to about seventy-five degrees centigrade (one
hundred and sixty-six degrees Fahrenheit), then allowed to cool, and sub-
sequently the crystallized deposit on the filters is gathered. The niother
waters are taken a second time, sometimes even a third time, or as long as
they yield murexide, to undergo a similar treatment as regards temperature;
but at each time with a weaker and weaker neutralizing agent, say, for the
second time, one-fourth of the strength of the first, and for the third; one-
sixteenth of the first. I prefer this mode of exhaustion to obtaining it at
'once, for the sake of safety:"
For the purposes of dyeing and printing it is useless to wash and dry the
product gathered from the filters; it may therefore be collected in a state of
green paste.
The alloxan I use, and which I designate alloxan throughout this process,
arises from a nitric solution formed of nitric acid diluted in about an equal
quantity of water, and then saturated with uric acid at the temperature of at

page_text: least sixty degrees centigrade (one hundred and forty degrees Fahrenheit); it
consequently represents an alloxan mixed with alloxantine. I can substitute
chromic or chloric acids, either wholly or partially, for the nitric acid.
Having described the nature of this Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to be secured
by the herein-before in part recited Letters Patent is, the treatment of a
solution of uric acid in nitric acid diluted with water, and saturated sufficiently
to form a mixture of alloxan and alloxantine, by a neutralizing substance,
under the following conditions, in order to produce, in its crystallized state,
the colouring matter called murexide.
First, treating cold a solution of alloxan and alloxantine with a neutralizing
substance, principally with ammonia or carbonate of ammonia.
Secondly, adding the neutralizing substance in portions, and at intervals.
Thirdly, the subsequent heating of the mixture of alloxan and alloxantine,
after it has been suitably saturated by the neutralizing substance, to from
sixty to seventy-seven degrees centigrade (one hundred and forty to one
hundred and seventy degrees Fahrenheit), all as herein-before described.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Twenty-fourth day of April, in the year of our
Lord, One thousand eight hundred and fifty-eight.
Witness,
W. G. E. SWINNOCK.
W. CLARK. (L.S.)