AN IMPROVED METHOD OF MANUFACTURING WHITE LEAD
Year: 1806

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES KEIR,
of West Bromwich, in the County of Stafford, Esquire, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, on or about the Third day of April, in the forty-sixth year of His
reign, did give and grant unto me, the said James Keir, my executors,
administrators, and assigns, His especial licence, full power, sole privilege
and authority, that I, the said James Keir, my executors, administrators,
and assigns, during the term of fourteen years therein expressed, should and
lawfully might make, use, exercise, and vend my Invention therein mentioned,
to wit, "AN IMPROVED METHOD OF MANUFACTURING WHITE LEAD," within that
part of the United Kingdom of Great Britain and Ireland called England,
the Dominion of Wales, and Town of Berwick-upon-Tweed, in such manner
as to me, the said James Keir, my executors, administrators, and assigns, or
any of them, should seem meet, to have, hold, exercise, and enjoy the said
licence, powers, privileges, and advantages therein granted unto me, the said
James Keir, my executors, administrators, and assigns, for and during and
unto the full end and term of fourteen years from the date of the said Letters
Patent next and immediately ensuing, and fully to be complete and ended,
according to the Statute in such case made and provided; in which said
Letters Patent there is (amongst other things) contained a proviso that if I,
the said James Keir, should not particularly describe and ascertain the nature

page_text: of my said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, and cause the same to be
inrolled in the High Court of Chancery within one calendar month next
and immediately after the date of the said Letters Patent, that then tho
said Letters Patent, and all liberties and advantages whatsoever thereby
granted, should utterly cease, determine, and become void, as in and by the
said recited Letters Patent, reference being thereunto had, will more fully
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Keir, do hereby describe and ascertain the nature of my said Inven-
tion, and the manner in which the same is to be performed, as follows (that is
to say):-
:-
The substance commonly called white lead, which is used for paint, and for
glazing earthenware, and for various other purposes, is generally mado by
combining the metal called lead with vinegar or some other vegetable acid.
Now I do declare that my Invention consists in making a white lead without
the help of vinegar or other vegetable acid, which white lead is fit for paint,
glazing earthenware, and all the other purposes for which the common white
lead made with vinegar has been used, and that my method for preparing my
said white lead is by altering and decomposing the preparation of lead known
to chymists by the name of muriato of lead or of muriated oxide of lead, in
the manner following (that is to say):-With any quantity of the said muriato
or muriated oxide of lead I mix such quantities and such proportions of alkali,
or of some substance containing alkali, and of carbonic acid, or of some
substance containing carbonic acid, as are sufficient for the intended alteration
and decomposition, together with as much water, or some substance containing
water, as shall be sufficient to give such a degree of liquidity to the said
muriate or muriated oxide and to the said alkali and carbonic acid as shall
facilitate their admixture, which admixture I further promote by repeated
stirring and agitation until the said intended alteration and decomposition are
offected. The alkali thus mixed with the inuriate or muriated oxide of lead
may be of any of the kinds distinguished by the names vegetable, mineral,
or volatile, pot ash, pearl ash, wood ash, barilla, salt of soda, natron, kelp,
ammonia, spirit or salt of hartshorn, or other name or names by which the
various alkalis and alkaline substances are or hereafter may be distinguished.
Farther, the alkali thus mixed may be the same alkali which is produced in tho
process for making the muriate or muriated oxide of lead by mixing litharge,
lead ashes, or other oxide of lead, with muriate of soda or common salt,
muriate of potash, muriate of ammonia, or some other substance containing

page_text: any of these saline muriates, and the carbonic acid, which is to be applied.and
mixed as aforesaid (which acid has been known by various names, such as
fixed air, mephitic gas, calcareous gas, choke damp, &c.), may be either (first)
in the state of a permanently elastic fluid or gas as when it is expelled from
calcareous, alkaline, and metallic substances by means of heat or of acids, or
when it is produced by the fermentation, or by the putrefaction, or by the
combustion of animal, vegetable, or mineral substances. Or (secondly) the
said carbonic acid may be in the state of combination with the above-
mentioned alkalis or alkaline substances in the form of what are called
carbonated or mild alkalis, or it may be combined with water, air, or other
substances.
And in order that this Invention may be better understood and practised,
for the public benefit after the expiration of my Patent, I add to the above
description of my method an explanation of the chymical principle on which
this ulteration and decomposition of the muriate of lead or muriated .oxide
of lead depends. I say that the process depends on the principle known by
chymists under the name of double affinity, that is, two affinities acting jointly,
which, in this case, are (1st) the affinity of the alkali to the muriatic acid of
the muriate or muriated oxide of lead, and (2d) the affinity of the carbonic
acid to the lead or oxide of the lead, in consequence of which two.affinities
operating jointly in the mixture above directed, the muriatic acid quits the
lead in order to unite with the alkali, by which union a neutral salt is formed,
while the carbonic acid unites with the lead or oxide of lead, forming by their
union a carbonate or carbonated oxide of lead, which when separated from
saline admixtures in the peculiar white lead or substance, the method of
making which, as above described, is that improved method which I claim
as my Invention. This white lead or substance prepared by the said improved
method may be sold either in a moist or dry state, or made into cakes or
other forms with gum water or other gummy, mucilaginous, or gluey substance,
according to the purposes to which it is to be applied. The popular and best
known name of the substance produced as above mentioned is white lead, but,
as whiteness is not essential to its use in glazing earthenware and in some
other purposes, the said substance may be disguised and altered in its colour by
mixing with it various coloured or colouring matters, or by heat or otherwise;
but whatever substance is prepared from muriate or muriated oxide of lead in
the manner and according to the principles above specified, and which is fit
for the above-mentioned purposes, however it may be disguised, altered, or
mixed with other matters, will be the substance which I mean by the term
white lead, and the manufacturing whereof during the said term of fourteen

page_text: years granted to me by the said Letters Patent, I claim as my sole and
absolute privilege by virtue of the said Letters Patent.
In witness whereof, I, the said James Keir, have hereunto set my hand
and seal, the Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and six.
Sigued, sealed, and delivered by the
within-named James Keir, being first
JAMES (L.S.) KEIR.
Extrary in Chancery.
RICHARD BLAIR,
Of the Parish of West Bromwich,
Staffordshire.
AND BE IT REMEMBERED, that on the same Twenty-eighth day of
April, in the year above mentioned, the aforesaid James Keir came before our
Lord the King in His Chancery, and acknowledged the Specification afore-
said, 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 Twenty-ninth day of April, in the year above written.