A NEW AND IMPROVED METHOD OR PROCESS OF
Year: 1821

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SADLER, of Penlington Place, in the Parish of Lambeth, in the County of
Surrey, Gentleman, send greeting.
WHEREAS His most Gracious Majesty King George the Fourth, by His
Letters Patent under the Great Seal of the United Kingdom of Great Britain
and Ireland, bearing date at Westminster, the Third day of January, in the
first year of His reign, did for Himself, His heirs and successors, give and
grant unto me, the said John Sadler, my executors, administrators, and assigns,
His especial licence, full power, sole privilege and authority, that I, the said
John Sadler, my executors, administrators, and assigns, and every of them,
by myself and themselves, or by my or their deputy or deputies, servants or
agents, or such others as I, the said John Sadler, my executors, administrators,
or assigns, should at any time agree with, from time to time and at all times
thereafter during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within that part of His United Kingdom
of Great Britain and Ireland called England, His Dominion of Wales, and
Town of Berwick-upon-Tweed, and in all His Colonies and Plantations
abroad, my Invention of "A NEW AND IMPROVED METHOD OR PROCESS OF

page_text: MANUFACTURING CARBONATE OF LEAD, FORMERLY DENOMINATED CERUSE, BUT NOW
COMMONLY CALLED WHITE LEAD;" in which said Letters Patent there is contained
a proviso obliging me, the said John Sadler, 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 enrolled in His Majesty's High Court of Chancery,
within six calendar months next and immediately after the date of the said
recited Letters Patent, as in and by the same Letters Patent, reference being
thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Sadler, do hereby declare that my said Invention consists in the pro-
duction of carbonate of lead by decomposing subacetate of lead by the
transmission into or upon it of carbonic acid. The carbonate of lead is the
substance formerly denominated ceruse, but now. commonly called white lead.
The subacetate of lead is the substance described in the Pharmacopoeia Londi-
nensis, page 58, edition 1815, as liquor plumbi subacetatis. The preceding
statement will sufficiently explain to every practical chymist the nature of my
discovery, and will enable every such person to repeat the process by which
I produce white lead.
For more general information, however, I add the following account of the
mode in which the process is usually conducted by myself:-I place a solution
of subacetate of lead (liquor plumbi subacetatis) in a cask or other vessel, either
closed or open (though I consider a closed vessel preferable); and I then
introduce into the same vessel carbonic acid, either in a state of gas or in
solution. I use frequent agitation of the ingredients to favor the combination
of the carbonic acid with the oxyde of lead, which is contained in the solution
of subacetate of lead. A precipitate is formed, consisting of carbonate of lead
(that is, of white lead or ceruse). I continue this operation as long as any
absorption of carbonic acid takes place, supplying such additions of carbonic
acid during the said process until precipitation ceases. The carbonate of lead
(ceruse or white lead) thus produced, I separate from the fluid by decantation
or filtration, and I wash and dry the product in the manner in which white
lead is commonly washed and dried.
In witness whereof, I, the said John Sadler, have hereunto set my hand
and seal, the Twenty-sixth day of June, in the year of our Lord One
thousand eight hundred and twenty-one.
JOHN SADLER. (L.S.)

page_text: AND BE IT REMEMBERED, that on the same Twenty-sixth day of
June, in the year above mentioned, the aforesaid John Sadler came before our
Lord the King in His Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained, in form above written. And also
the Specification aforesaid was stamped according to the tenor of the Statute
in that case made and provided.
Inrolled the same Twenty-sixth day of June, in the year above written.