AN IMPROVED METHOD OF MANUFACTURING CALOMEL AND CORROSIVE SUBLIMATE
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANTHONY
TODD THOMSON, of Hinde Street, Manchester Square, in the County of Middle-.
sex, Doctor of Medicine, 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 Eighth day of March, in the fourth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Anthony
Todd Thomson, Her especial licence, full power, sole privilege and authority,
that I, the said Anthony Todd Thomson, my executors, administrators, and
assigns, and such others as I, the said Anthony Todd Thomson, my executors,
administrators, or assigns, should at any time agree with, and no 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 also in all Her Majesty's Colonies and
Plantations abroad, my Invention of "AN IMPROVED METHOD OF MANUFACTURING
CALOMEL AND CORROSIVE SUBLIMATE;" in which said Letters Patent is contained
a proviso, obliging me, the said Anthony Todd Thomson, 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 there-
unto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in. compliance with the said proviso, I, the said
Anthony Todd Thomson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof, reference being had
to the Drawing hereunto annexed, and to the letters and figures marked thereon,
that is to say:-
My Invention of an improved method of manufacturing calomel and corrosive
sublimate consists in combining chlorine in the state of gas with the vapour of
mercury, or as it is commonly called, quicksilver. This combination is effected
in such a manner and in such proportions as shall form corrosive sublimate or
bichloride of mercury and calomel. Having thus stated, in general terms, the
object of my Invention, I will proceed to describe the method I employ for
carrying the same into effect; and in order to explain my Invention more fully,
I will refer to the Drawing hereunto annexed, which represents a longitudinal
section of the apparatus for combining the two gases. A glass, earthenware,
or other suitable vessel A, provided with openings at both ends, is mounted in
brickwork, or in any other convenient manner, and exposed to the action of an
open fire B beneath; a certain quantity of mercury or quicksilver is placed in
the vessel A, and the temperature thereof is raised to between 350° and 660°
of Fahrenheit by means of the fire beneath. One end of the glass or earthen-
ware vessel A communicates with an alembic C, such as is generally used for
generating chlorine gas, and the other end is connected with a large chamber
D, which is made perfectly air-tight in order to prevent the escape of any of
the gases; and in order to produce the chlorine gas the alembic is charged
with a mixture of common salt, binoxide of manganese, and sulphuric acid, or
of binoxide of manganese and muriatic acid. The chlorine gas, as it is gene-
rated, passes from the alembic through the bent tube into the glass or earthen-
ware vessel which contains the mercury or quicksilver, where it combines with
the vapour of the mercury that is generated by raising its temperature to 350°
of Fahrenheit and above. This combination of the two gases forms either
corrosive sublimate or calomel, according to the quantity of chlorine gas which
is employed. The product is found at the bottom of the air-tight vessel D,
from whence it may be taken by means of the door E, after the operation is
completed.
Having now described the nature of my Invention, and manner in which the
saine is to be carried into effect, I wish it to be understood, that I do not
intend to confine myself to any particular description of apparatus to be
employed. in the manufacture of corrosive sublimate and calomel, nor do I
intend to claim the particular apparatus herein shewii, nor the method of

page_text: generating chlorine gas from a mixture of common salt, oxide of manganese,
and sulphuric acid, as above described, or any other mixture; but what I
do claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the direct combination of the gas called chlorine, with the
metal called mercury or quicksilver, either in a state of vapour or otherwise,
so as to form the compounds called corrosive sublimate and calomel, according
to the proportions in which the said vapours or materials are combined.
In witness whereof, I, the said Anthony Todd Thomson, have hereunto
set my-hand and seal, this Eighth day of September, in the year of our
Lord One thousand eight hundred and forty-one.
ANTHONY TODD (L.S.) THOMSON.
AND BE IT REMEMBERED, that on the same Eighth day of September,
in the year above mentioned, the aforesaid Anthony Todd Thomson came
before our Lady the Queen in Her Chancery, and acknowledged the Specifi-
cation 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 Eighth day of September, in the year above written.