IMPROVEMENTS IN TREATING MASSICOTT, LITHARGE, AND OTHER COM- POUNDS OF LEAD, FOR THE PURPOSE OF OBTAINING THEREPROM SILVER AND CERTAIN OTHER PRODUCTS
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
CHISHOLM and MARIN HYPPOLITE BELLEMOIS, of Pomeroy Street, Old Kent
Road, in the County of Surrey, Manufacturing Chemists, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster the Sixth day of December, in the second year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto us, the said John
Chisholm and Marin Hyppolite Bellemois, Her especial licence, full power,
sole privilege and authority, that we, the said John Chisholm and Marin
Hyppolite Bellemois, our exors, admors, and assigns, or such others as we,
the said John Chisholm and Marin Hyppolite Bellemois, our exors, admors,
and assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein expressed, should and law-
fully might make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, the Isle of Man, Guernsey, Jersey, Alderney,
aud Sark, and all Her. said Majesty's Colonies and Plantations abroad, our
Invention of IMPROVEMENTS IN TREATING MASSICOTT, LITHARGE, AND OTHER COM-
POUNDS OF LEAD, FOR THE PURPOSE OF OBTAINING THEREPROM SILVER AND CERTAIN
OTHER PRODUCTS;" in which said Letters Patent is contained a proviso, that
we, the said John Chisholm and Marin Hyppolite Bellemois, by an instru-
ment in writing under our or one of our hands and seals, particularly to
describe and ascertain the nature of our said Invention, and in what manner
the same is to be performed, and to cause the same to be enrolled in Her said
Price Sal

page_text: Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as in
and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
John Chisholm and Marin Hyppolite Bellemois, do hereby declare the nature
of our said Invention as follows, that is to say:-
Our Invention relates, first, to a mode of obtaining silver from massicott
and other compounds of lead by treating such compounds of lead in a suitable
manner to obtain them in solution, and then by filtration or precipitation to
separate the insoluble products therefrom, which separated products will
contain silver, which may be obtained by well-known processes.
And, secondly, our Invention relates to a mode of making carbonate of
lead (and from such carbonate of lead, when desirable, pure lead,) by the
ordinary and well-known means from solutions of compounds of lead, when
such solution is obtained by means of acetic acid or acetate of lead. In dis-
solving massicott and other compounds of lead as heretofore practised, when
for making acetates of lead, the same has been for the most part performed by
the use of acetic acid, by acetate of lead, and also nitric acid, and nitrate of
lead. Our Invention does not so far as the first part thereof depend on the
means employed for obtaining the compounds of lead in solution, but in
separating silver from the insoluble products obtained from solutions of lead.
And the second part of our Invention relates to a mode of treating basic
acetate of lead for the purpose of making white lead or carbonate of lead. It
is well known that litharge and other compounds of lead contain silver, but in
many cases the quantity of silver is so small in comparison with the quantity
of litharge that to separate it by known processes would not answer.
Now, the object of our Invention, so far as relates to the obtaining silver
from compounds of lead, is to obtain the same in an acid, soluble, and by
filtration or other convenient means, separate the insoluble matter, which
will contain the silver. Such products being separated by the known means of
obtaining silver from refuse matters, will, conjoined with the employing the
solutions of lead, to obtain carbonate of lead, produce a more beneficial
treating or working of the massicott and other compounds of lead containing
silver than by simply treating the same for the single purpose of obtaining
silver only, or white lead only. And in order to give the best information in
our power, we will proceed to describe the process pursued by us.
The description of lead which is considered too poor of silver to repay the
-expence of separation should be converted into litharge, in which state the

page_text: silver will be retained mechanically. Such litharge should be preferred in
manufacturing the products hereafter described, butany litharge may be used,
as the usual desilverising operation seldom completely separates the silver
from the lead. In producing the products from litharge, as hereafter de-
scribed, the litharge as dissolved, and the residuum (trifling in quantity in pro-
portion to the litharge used) consists of a few insoluble impurities, together
with all the silver the litharge will have contained. Thus, one ton of lead
containing only four ounces of silve would not repay the expence attending
the separating it from so large a body; but by converting the one ton of lead
into litharge, the litharge again into a solution to be operated on to produce
white lead, the four ounces of silver. would be contained in comparatively
small quantity of residuum, from which it may be extracted in the usual well-
known modes at a very trifling expence. And it is well known that by dis-
solving the oxides of lead (by preference litharge in water with acetic acid or
acetate of lead) so as to form a solution of basic acetate of lead, and by
causing currents of carbonic acid gas to be passed through such solution, that
the excess of lead contained in such solution beyond the proportion of lead
contained in the neutral acetate of lead will be precipitated and thrown down
in the form of carbonate of lead or white lead; and the proportions of acetic
acid and lead forming the neutral acetate of lead will remain combined as
neutral acetate of lead, and will again take up further quantities of lead,
which will be again precipitated by carbonic acid gas when the same is
brought into contact therewith. But heretofore solutions of acetate of lead
have been used, and submitted to the action of carbonic acid gas in the cold
state, and unaided by artificial heat. The application of artificial heat, not
only for making the solution, but also during the action of carbonic acid gas,
has been found to be a material improvement in the process of making white
lead (carbonate of lead) by precipitation from solutions of lead dissolved by
acetate of lead or acetic acid. The temperature preferred to be used both
during the solution, and submitting the same to the action of carbonic acid gas,
is about 165° Fahrenheit or 60° Reaumer, as from repeated experiments we
have found that to be the best, but the advantageous use of artificial heat is
not confined to this particular temperature. The strength of the solution
should be kept up to about the following proportions:-Thirty pounds of
acetate of lead (commercial sugar of lead), or the equivalent of lead and acetic
or pyroligneous acid; sixty-three pounds of litharge; four hundred pounds of
But it is not absolutely necessary to adhere to these particular pre-
portions; and artificial heat may also be advantageously employed whatever
acid is employed, as the solvent when the process for obtaining the insoluble
water.

page_text: products is pursued. But no claim is made for the application of artificial
heat when making carbonate of lead from the solution when nitric acid or
nitrate of lead is used, as the solvent litharge, massicott, or other compounds
of lead, from which carbonate of lead is made, as above stated, generally
contain some portions of silver which will not be dissolved by the acid used as
a solvent in making white lead by precipitation at the degree of strength at
which acidsare used for the purpose; and these portions of silver, with other
matters and impurities left undissolved, may be readily taken from the solu-
tion by filtration or otherwise; and the silver being combined with foreign
matters very small in quantity as compared with the massicott, litharge, or
other compounds used in the manufacture of white lead, inay be easily (and
at small expence) extracted by any of the well-known methods employed for
extracting silver from foreign substances. We do not, therefore, confine
ourselves to any particular mode, the first part of our Invention relating to the
obtaining and treating the insolube products (from solutions of lead) to obtain
silver.
Having thus described the nature of our Invention, and the manner of
performing the same, we would have it understood that we do not claim any
right to the dissolving compounds of lead; nor do we claim the making of
white lead therefrom by submitting such solutions to the action of carbonic
acid gas, other than as herein-after stated. But what we claim is, first, the
obtaining silver from massicott, litharge, or other compounds of lead), by
treating the soluble products obtained from solutions of compounds of lead, as
above explained.
And, secondly, we claim the process above described in which artificial
heat is applied to basic acetates of lead when converting the same into
carbonate of lead.
In witness whereof, we, the said John Chisholm and Marin Hyppolite
Bellemois, have hereunto set our hands and seals, this Sixth day of
June, One thousand eight hundred and thirty-nine.
(L.S.)
попол.
M. HTE (L.S.) BELLEMOIS.
Signed, sealed, and delivered by the within-
named John Chisholm and Marin Hyppo-
lite Bellemois, in the presence of

page_text: AND BE IT REMEMBERED, that on the Sixth day of June, in the
year of our Lord 1839, the aforesaid John Chisholm and Marin Hyppolite
Bellemois, came before our said Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing therein
contained and specified, in form above written. Andalso the Specification
aforesaid was stamped according to the tenor of the Statute made for that
purpose.