CERTAIN. IMPROVEMENTS IN OXIDIZING LEAD AND CONVERTING, THE SAME. INTO PIGMENTS OR WHITE AND RED LEAD, AND MANUFACTURING PART OF THE PRODUCTS ARISING FROM THESE PROCESSES INTO SODA
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
HEARD, late of Bateman's Buildings, Soho Square, in the County of Middlesex,,
but now of Clifton Street, Wandsworth Road, in the County of Surrey,.
Manufacturing Chemist, send greeting.
'
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her.
Royal Letters Patent under the Great Seal of Great Britain, bearing date, at
Westminster, the First day of August, in the second year of Her reign, and.
in the year of our Lord One thousand eight hundred and thirty-eight did, for
Herself, Her heirs and successors, give and grant unto me, the said Edward
Heard, my executors, administrators, and assigns, Her especial license, full
power, sole privilege and authority, that I, the said Edward Heard, my execu-.
tors, administrators, and assigns, or such others as I, the said Edward Heard,.
my executors, administrators, or assigns, should at any time agree with, and
others, from time to time and at all times during the term of years therein
mentioned, should and lawfully might make; use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, and in all Her.
Majesty's Colonies and: Plantations abroad,, my Invention of "CERTAIN.
IMPROVEMENTS IN OXIDIZING LEAD AND CONVERTING, THE SAME. INTO PIGMENTS OR
WHITE AND RED LEAD, AND MANUFACTURING PART OF THE PRODUCTS ARISING
FROM THESE PROCESSES INTO SODA;" in which said Letters Patent is contained
no

page_text: a proviso obliging me, the said Edward Heard, by an instrument in writing
under my hand and seal, particularly to describe and ascertain the nature of
my said Invention, and in what manner the same is to be performed, and
to cause the same to be inrolled in Her 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, I, the said
Edward Heard, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained as follows (that is to say):-
I take any known weight of lead and melt it in a reverberatory furnace; to
the melted lead I add about half its weight of a salt called nitrate of soda,
throwing in small quantities at a time and stirring it well, in order to mix it
with the fused metal. When the whole of the salt is thus put into the furnace
it is kept continually stirred, until the lead entirely loses its lustre and metallic
appearance, which takes place by exposure to a low red heat in the course of
a few hours, and becomes converted into a protoxide of lead, resembling in
colo litharge; when it has attained this state the charge is withdrawn from
the fur ice and cast in moulds to consolidate, or spread on a clean stone floor
to get cold. It is next ground to a very fine powder, and if intended for the
manufacture of white lead it is put into a large vat, close covered, and mixed
with water to about the consistence of thick cream. Into this mass a current of
carbonic acid gas is directed, and agitation kept up until the protoxide of lead
is converted into carbonate of lead. This should be well washed, and the
saline solutions mixed together and evaporated to dryness. The salts thus
obtained, consisting of a mixture of subcarbonate and nitrate of soda, may be
used again two or three times successively, when thus recovered with fresh
portions of lead, taking care that the metal employed is about double the
weight of the saline matter in each charge. When the whole of the nitrate
of soda is decomposed by these successive operations, it is lastly conveyed into
an alkaline furnace and there finished with carbonaceous matter, the alkaline
salt is then lixiviated, and the solutions mixed and evaporated to dryness, or
brought to such a specific gravity as will, under proper circumstances, cause it
to form crystals of carbonate of soda, according to the views of the operator.
Thus, white lead and carbonate of sods are produced. When the object is to
manufacture "red lead," the protoxide of lead above mentioned as being pro-
duced by the first process of oxidation, when taken out of the furnace and cold,

page_text: is ground fine and put into a vat, where it is repeatedly washed until all saline
matter is separated; this latter being reserved for future operations. The
protoxide of lead thus purified is then removed into a red lead furnace, such
as are in common use, and there finished in the usual manner.
is ground fine and put into a vat, where it is repeatedly washed, until all saline
matter is separated; this latter being reserved for future operations. The
protoxide of lead thus purified is then removed into a red lead furnace, such
as are in common use, and there finished in the usual manner.
In witness whereof, I, the said Edward Heard, have hereunto set my
hand and seal, this Twenty-ninth day of January, in the year of our
AND BE IT REMEMBERED, that on the Thirtieth day of January, in
> the second year of the reign of Her Majesty Queen Victoria, the said Edward
Heard came before our said Lady the Queen in Her Chancery, and acknow-
ledged the instrument aforesaid, and all and every thing therein contained
and specified, in form above written. And also the instrument aforesaid was
stamped according to the tenor of the Statute made in the fifty-fifth year of
the reign of His late Majesty King George the Third.
Inrolled the First day of February, One thousand eight hundred and
thirty-nine.