IMPROVE- NENTS IN THE MANUFACTURE AND PRODUCTION OF MINIUM OR RED LEAD
Year: 1862

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
NENTS IN THE MANUFACTURE AND PRODUCTION OF MINIUM OR RED LEAD."-
A communication from abroad by Charles Louis Pierre Burton, of 45,
Rue St. Sebastien, Paris, in the Empire of France.
Sealed the 25th July 1862, and dated the 6th May 1862..
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
6th May 1862.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
IMPROVEMENTS IN THE MANUFACTURE AND PRODUCTION OF MINIUM OR RED LEAD,"
a communication from abroad by Charles Louis Pierre Burton, of 45, Rue
St. Sebastien, Paris, in the Empire of France, to be as follows":
-
The improvements consist in the conversion of oxide of lead, when free or
uncombined, and of certain basic salts of lead, into minium or red lead by

page_text: mixing the same with either nitrate of potash or soda, and with either
carbonate of potash or carbonate of soda, or mixtures of the same, and sub-
jecting such mixtures to the action of an elevated temperature, whereby the
oxide of lead is oxidised, and is converted into minium or red lead.
In carrying out this Invention it will be found that if oxide of lead, or a
certain number of its saline basic compounds be brought in contact with the
nitrates of potash or soda there will always result when the mixture shall have
been brought to and maintained at a dull red beat the following decomposition,
that is to say, one equivalent of alkaline nitrate is transformied to the state of
nitrite, and the two equivalents of oxygen which are liberated will be employed
for superoxydising six equivalents of oxide of lead, so as to form two equi-
valents of red lead 2 Pb O'. It is evident that we have nothing to do hero
with salts of leads, the acids of which would be destroyed and burnt before the
oxide became superoxydised, and that we are only treating of those salts
whose acids are permanent; as, for example, carbonates, hydrates, sulphates,
phosphates, arseniates, borates, nitrates, and chlorides of lead. The first
two are employed in their natural state, and the other five with the addition
of, for each equivalent of salt, one equivalent of carbonate of potash or
carbonate of soda, so as to give to each of them a basic character, which they
must possess in order that they may re-act as required in this decomposition.
In the treatment of sulphate of lead, for example, the mixture should be
as follows:
One equivalent of purified sulphate of lead, or 1-894 parts by weight,
One equivalent of carbonate of soda, or 0.665 parts by weight,
One-sixth equivalent of nitrate of soda, or 0.143 parts by weight.
This mixture when heated to a dull red heat in presence of an excess of
nitre would, after the re-action has ceased, form a mass of a beautiful red
vermilion colour containing the superoxyde of lead, and as this last is insoluble
it suffices to lixiviate this mass with water, which dissolves all the soluble
salts, (sulphates, nitrates, and nitrites,) and to allow the residuum to drain,
and subsequently to be dried.
In collecting the products of this process with care, we obtain within a
few fractions, the theoretical quantities of red lead, of soluble nitrates, and of
sulphates, which result from the above equation. We find in effect,-
Red lead-
Sulphate of soda
Nitrate of soda
1.427 parts by weight
0.800 "
0.143 "
The fusion or
TOLLTAL
am

page_text: made in vessels capable of resisting the action of heat, also that of the nitre
when in fusion, and of the lead compound.
In the process for the manufacture or production of minium, which I have
described, the product has a definite composition, represented by the formula
Pla O, and possesses properties that are peculiar to it, and which distinguish
it from red lead prepared by the old process.
I do not limit myself to the precise mixtures herein given, nor to the quan-
tities of such mixtures, but I reserve to myself the right of producing red lead
or iminium in accordance with the principles herein described, subject to
such modifications as may be found advisable in carrying out this Invention.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 6th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Henry Johnson, Fler special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I, the said
John Henry Johnson, my executors, administrators, or 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 MANUFACTURE AND PRODUCTION OF MINIUM OR RED LEAD," a communication
froin abroad by Charles Louis Pierre Burton, of 45, Rue St. Sebastien,
Paris; in the Empire of France, upon the condition (amongst others) that I,"
the said Jolin Henry Johnson, my exécutors or administrators, by an instru-
ment in writing under my hand and seal, or under the hand and seal of one
of them, should particularly describe and ascertain the nature of the said
Invention; and in what manner the same was to be performed, and 'cause

page_text: 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 John Henry Johnson, 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 following
statement:-
The said Invention consists in the conversion of oxide of lead, when free or
uncombined, and of certain basic salts of lead, into minium or red lead, by mixing
the same with either nitrate of potash or soda, and with either carbonate of
potash or carbonate of soda, or mixtures of the same, and subjecting such
mixtures to the action of an elevated temperature, whereby the oxide of lead
is oxidised, and is converted into minium or red lead.
.
In carrying out this Invention it will be found that if oxide of lead or a
certain number of its saline basic compounds be brought in contact with the
nitrates of potash or soda, there will always result, when the mixture shall
have been brought to and maintained at a dull red heat, the following decom-
position, that is to say, 1 equivalent of alkaline nitrate is transformed to the
state of nitrite, and the two equivalents of oxygen which are liberated will be
employed for superoxydising six equivalents of oxide of lead, so as to form
two equivalents of red lead 2 Pbs 0. It is evident that we have nothing to do
here with salts of lead, the acids of which would be destroyed and burnt
before the oxide became superoxydised, and that we are only treating of those
salts whose acids are permanent; as, for example, carbonates, hydrates,
sulphates, phosphates, arseniates, borates, nitrates and chlorides of lead. The
first two are employed in their natural state, and the other five, with the
addition of, for each equivalent of salt, one equivalent of carbonate of potash or
carbonate of soda, so as to give to each of them a basic character, which
they must possess. in order that they may re-act as required in this decom-
position.
In the treatment of sulphate of lead, for example, the mixture should be as
follows:-
1 equivalent of purified and dried sulphate of lead, or 1.894 parts by weight,
1 equivalent of carbonate of soda, or
equivalent of nitrate of soda, or
-
0-665 parts by weight,
0.143 parts by weight.
This mixture when heated to a dull red heat in presence of an excess of
nitre would, after the re-action has ceased, form a mass of a beautiful red
vermillion colour, containing the superoxyde of lead; and as this last is
insoluble it suffices to lixiviate this mass with water, which dissolves all the

page_text: soluble salts, (sulphates, nitrates, and nitrites,) and to allow the residuum to
drain, and subsequently to be dried.
In collecting the products of this process with care we obtain within a few
fractions the theoretical quantities of red lead, of soluable nitrites, and of sul-
phates which result from the above equation. We find in effect,―
Red lead-
Sulphate of soda
Nitrite of soda
-
- 1.427 parts by weight
-
0.800
"
-
0.143
"
"
"
The fusion of the mixture from which the red lead is produced should be
made in vessels capable of resisting the action of heat, also that of the nitré
when in fusion, and of the lead compound.
In the process for the manufacture or production of minium which I have
described, the product has a definite composition represented by the formula
Pb O', and possesses properties that are peculiar to it, and which distinguish
it from red lead prepared by the old process.
I do not limit myself to the precise mixtures herein given, nor to the quan-
tities of such mixtures, but I reserve to myself the right of producing red lead
or minium in accordance with the principles herein described, subject to such
modifications as may be found advisable in carrying out this Invention.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, the Sixth day of November, One thousand
eight hundred and sixty-two.
J. HENRY JOHNSON. (L.S.)
J. HENRY JOHNSON. (L.S.)