A METHOD OF PREPARING OR REDUCING TO AN IMPALPABLE POWDER FOR MEDICINAL USE THE SUBSTANCE COMMONLY CALLED OR KNOWN BY THE NAME OF CALOMEL, WHEREBY THE PROCESS USUALLY EMPLOYED OF LEVIGATING THE SAME IS RENDERED UNNECESSARY
Year: 1807

page_text: JEWELL'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
JEWELL, of Stratford-le-Bow, in the County of Essex, Chymist, send greeting.
"WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Seventeenth day of
November last, reciting that whereas I, the said Joseph Jewell, had, by my
petition humbly presented unto His Majesty, that I had invented or discovered
"A METHOD OF PREPARING OR REDUCING TO AN IMPALPABLE POWDER FOR MEDICINAL
USE THE SUBSTANCE COMMONLY CALLED OR KNOWN BY THE NAME OF CALOMEL,
WHEREBY THE PROCESS USUALLY EMPLOYED OF LEVIGATING THE SAME IS RENDERED
UNNECESSARY,"
"His Majesty did, by His especial grace, certain knowledge, and
meer motion, for Himself, His heirs and successors, give and grant unto me,
the said Joseph Jewell, my executors, administrators, and assigns, His especial
licence, full power, sole privilege and authority, that I, the said Joseph Jewell
my executors, administrators, and assigns, by myself and themselves, or by
mine or their deputies, servants, or agents, or such others as I, the said Joseph
Jewell, my executors, administrators, or assigns; should at any time-agree with,
and no others, from time to time and at all times hereafter during the term of
years therein expressed, to make, use, exercise, and vend my said Invention
within that part of the Kingdom of Great Britain called England, the Dominion
of Wales, and Town of Berwick-upon-Tweed, in such manner as to me, the said
Joseph Jewell, my executors, admors, and assigns, or any of them, in my or
their descretion should seem meet; to have, hold, exercise, and enjoy the said
licence, powers, privileges, and advantages to me, the said Joseph Jewell, my

page_text: executors, adiiors, and assigns, for the term of fourteen years from the date of
the said recited Letters Patent; in which said Letters Patent is contained a
proviso that if I, the said Joseph Jewell, should not particularly describe
and ascertain the nature 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 His Majesty's High Court of Chancery within
one calendar month next and immediately after the date of the said Letters
Patent, that the said Letters Patent, and all liberties and privileges thereby
granted, should utterly cease, determine, and become void, as by the said
Letters Patent, relation being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that I, the said. Joseph Jewell, in pursuance of the said
proviso in the said Letters Patent contained, do hereby describe and ascertain
the nature of my said Invention, and in what manner the same is to be per-
formed, as follows:
"Calomel, or mercurius dulcis, as usually prepared is, at first, a hard crystal-
line substance, and requires to be pounded and triturated with water, either
in a morter or on a slab with a muller, or in a mill; after having been ground
or triturated for a considerable time, more water is added, and the whole well
stirred up. The finer particles, which remain suspended for a short time,
being poured off with the water into another vessel, and left to subside, the water
is then decanted, and the fine powder dried for use. The coarser particles are
again submitted to the operations of grinding and washing over, until the
whole be finished.
Now, the nature of my Invention is to produce the effect of the grinding or
trituration above described in a more perfect manner during the last sublima-
tion of the calomel, which I do as follows:-I tako calomel or mercurius
dulcis broken into small picces, and put into an earthern crucible of the form
of a long barrel, so as to fill about one half thereof; I place the crucible on its
side in a furnace provided with an opening, through which the mouth of the
crucible projects about an inch; I then join to the mouth of the crucible an
earthenware receiver. having an opening at its side to receive the open end of
the crucible; this receiver is about half filled with water. I lute the joint with
a mixture of sand and pipe clay. The receiver has a cover, which cover bas a
side continued upwards for containing water, with a chimney or tube in it to
allow the escape of steam from water below. I then apply a fire around the
crucible, suflicient to raise the calomel in vapour, and force it through the
mouth of the crucible into the receiver, where by the water while cold, or
assisted by the steam, when it becomes hot, it is instantly condensed into an

page_text: impalpable powder, possessing all the qualities of calomel in its most perfect
state, which, when thus prepared, is purer, whiter, and more attenuated than
that obtained by grinding. It is proper to wash the product over with water
before it is dried, to rid it of any coarser particles which may form about the
mouth of the crucible.
My Patent does not rest upon any particular shape or composition of the
apparatus, or any part thereof; but that which I claim as my discovery to be
secured to me is the rendering of calomel or mercurius dulcis fit for medicinal
use by a sublimation or distillation, so conducted as suddenly to condense the
vapours and prevent the concretion or cristallisation of the product, thus
rendering trituration, or what is commonly termed levigation, unnecessary.
In witness whereof, I, the said Joseph Jewell, have hereunto set my hand
and seal, the Fourteenth day of December, in the year of our Lord
One thousand eight hundred and seven.
JOSEPH JEWELL (L.S.)
AND BE IT REMEMBERED, that on the same Fourteenth day of
December, in the year of our Lord One thousand eight hundred and seven,
the aforesaid Joseph Jewell came before our Lord the King in His Chancery,
and acknowledged the Specification aforesaid, and all and every thing therein
contained and specified, in form above written. And also the Specification
aforesaid was stamped according to the tenor of the Statute made for that
purpose.
Inrolled the Fourteenth day of December, in the year of our Lord One
thousand eight hundred and seven.