THE MANU- PACTURE OF SUB OR OXI-SULPHATE OF LEAD
Year: 1861

page_text: LETTERS PATENT to Augustus Leidemann and Theodore Lange, both of
Newcastle-upon-Tyne, Merchants, for the Invention of "THE MANU-
PACTURE OF SUB OR OXI-SULPHATE OF LEAD."-A communication from abroad
Mr Ludwie Brumlen of New York
Sealed tho 6th August 1861, and dated the 9th February 1861.
PROVISIONAL SPECIFICATION left by the said Augustus Leidemann and
Theodore Lange at the Office of the Commissioners of Patents, with
their Petition, on the 9th February 1861.
We, AUGUSTUS LEIDEMANN and THEODORE LANGE, both of Newcastle-upon-
Tyne, Merchants, do hereby declare the nature of the Invention for "THE
MANUFACTURE OF SUB OR OXI-SULPHATE OF LEAD," to be as follows:-
In order to make oxi-sulphate of lead we take a solution of acetate or sub-
acetate of lead, and precipitate the same, half by sulphuric acid and half by
muriatic acid, forming thereby sulphate and chloride of lead mixed together.
After the acetic acid, now become free to be used over and over again
for the purpose of making acetate of lead, is withdrawn from the precipitate,.
lime water or a solution of caustic alkali is brought on it till litmus paper
will not be discolored any more, whereby all the chloride of lead is decomposed
to oxide of lead, combining with the sulphate of lead to oxi-sulphate of lead,
whereas the muriatic acid of the chloride goes to the lime water, forming
chloride of lime in solution.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Augustus Leidemann and Theodore Lange in the Great
Seal Patent Office on the 9th August 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, AUGUSTUS
LEIDEMANN and THEODORE LANGE, both of Newcastle-upon-Tyne, Merchants,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of February, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fourth year of Her reign,
did, for Herself, Her beirs and successors, give and grant unto us, the said
Augustus Leidemann and Theodore Lange, Her special licence that we, the 'said
Augustus Leidemann and Theodore Lange, our executors, administrators, and
assigns, or such others as we, the said Augustus Leidemann, and Theodore
Lange, 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 "THE MANUFACTURE OF SUB OR
OXI-SULPHATE OF LEAD," a communication to us from abroad by Mr. Ludwig
Brumlen, of New York, upon the condition (amongst others) that we,
the said Augustus Leidemann and Theodore Lange, our executors or adminis-
trators, by an instrument in writing under our or their hands and seals,
or under the hand and seal of one of us or them, 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 Augustus Leidemann and Theodore
Lange, 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 thereof, that is to say :-
To manufacture the sub or oxi-sulphate of lead we use the sulphate of
lead obtained as a refuse in the cotton printworks or other works, and after
mixing it with about an equal quantity of chloride of lead, submit it to
the action of lime water till a further addition of lime water no longer
produces any precipitation of lead, or till blue litmus paper no longer changes
its color.
When sulphate of lead cannot be had in sufficient quantity or of good

page_text: quality, we make acetate of lead by dissolving litharge or lead in a diluted
acetic acid, and precipitate therefrom about one-half its contents of oxide of
lead by the introduction of sulphuric acid, and the other half by muriatic
acid, till a further addition of acid does not produce any more precipitate.
The precipitate then consists of sulphate of lead and chloride of lead in about
equal proportions; after a sufficient time, in order to collect the precipitate at
the bottom of the vessel, the clear liquid consisting of acetic acid with some
chloride of lead in solution is drawn off; the precipitate is brought on filters
in order to collect all the acetic acid as much as possible, to be used over and
over again for the production of new quantities of acetate of lead, and the
white precipitate is then treated with lime water or a weak solution of caustic
alkali, till all the chloride of lead is decomposed, and blue litmus paper does
not change its color. The precipitate then consists of sulphate of lead and
oxide of lead, and forms a white lead about equal in its contents of oxide of
lead to carbonate of lead, which is thereupon washed out and prepared in the
usual way for the market.
It is clear that the quantities of sulphate of lead and chloride of lead may
be altered to any proportion, and that consequently the contents of oxide of
lead in the precipitate may be changed to any variety. We therefore do not
specify any proportions. We claim the Invention of, and wish to secure by
Letters Patent,―
First, the composition of a white lead precipitate which we call oxi or sub-
sulphate of lead, and which consists of sulphate of lead and oxide of lead in
different proportions.
And, second, the method of manufacturing the same according to the fore-
going description.
In witness whereof, we, the said Augustus Leidemann and Theodore
Lange, have hereunto set our hands and seals, this Eighth day of
August, in the year of our Lord One thousand eight hundred and
sixty-one.
AUGUSTUS LEIDEMANN. (L.S.)
THEODORE LANGE.
(L.B.)