AN IMPROVED METHOD OF SUB- LIMATION AND EVAPORATION
Year: 1815

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MOULT, of Bedford Square, in the County of Middlesex, 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 Thirteenth day of
February, in the fifty-fifth year of His reign, give and grant unto me, the said
William Moult, my exors, adiñors, and assigns, His especial licence, full power,
sole privilege and authority, that I, the said William Moult, my exors, admors,
and assigns, 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, my Invention of "AN IMPROVED METHOD OF SUB-
LIMATION AND EVAPORATION;" in which said Letters Patent there is contained
a proviso that if I, the said William Moult, shall 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 six calendar months next and immediately after the date of the said
Letters Patent, that then the said Letters Patent, and all liberties and advan-
tages whatsoever thereby granted, shall utterly cease, determine, and become
void, as in and by the same (relation being thereunto had) will more fully and
at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Moult, do hereby declare that the nature of my said Invention,

page_text: and the manner in which the same is to be performed, are particularly
described and ascertained to the effect and in manner following, that is to say :-
For distillation or sublimation by my improved mode I employ the usual
apparatus of still and warm pipe, retort, and receiver, alembic, and head
mattrass, or any other apparatus which is usually employed to effect the same
purposes; but my improvement consists in the means of applying the heat of
fire to the still, retort, or alembic through such a medium that the heat shall
be regular and equable; also that the heat cannot by accident be increased
beyond such a point as is found to be the maximum which can be safely
admitted for the process to which my improvement is applied. The apparatus
consists of a boiler, pan, or other similar vessel of any required size or figure,
placed over a furnace, fire, or lamp, so as to receive heat therefrom. Within
this boiler or vessel I place a second or interior vessel, which shall be the still,
retort, or alembic, or other vessel to contain the articles to be operated upon
by distillation or sublimation, leaving all round a space between the two
vessels, which space I fill up with some fluid, such as oil, sulphuric acid, mer-
cury, or other similar fluid, which will boil or rise in vapour at that tempera-
ture which is the greatest that can be admitted for the process. The heat
will be so kept down or carried off by the evaporation or vapour that it can
never rise above the boiling point of the fluid, which must be chosen and
adapted to the process to which it is applied; and here be it observed that
the apparatus I have just described is the same thing known amongst cheymists
and philosophers by name of bath or balneum, but has heretofore chiefly con-
fined to the balneum or sand bath, the balneum aqua, or water bath, and the
balneum mariea or salt-water bath, and I do not claim the Invention of such
apparatus, unless conjointly with the addition with the following improve-
ment: I make a junction between the two vessels aforesaid, viz, the exterior
one, which is exposed to the fire, and the interior one, which is to contain the
matter acted upon. By this means the fluid contained in the interval between
the two vessels is closed or shut up on all sides, and when it boils the steam
or vapour cannot escape except by a pipe, which is provided to lead the vapour
into a cooling apparatus or refrigeratory, which may be constructed in the
manner of the worm pipe of a still and immersed in cold water, or it may be
a simple straight pipe passing through cold water, otherwise the vapour may
be introduced into a flat metalic vessel, which, being immersed in cold water,
and having a large surface or surfaces exposed to the action thereof, will cool
or condense the vapour very rapidly.
Another form for the cooling apparatus is that of two cylinders placed
one within the other, and leaving a small space all round between the two;

page_text: but this space is closed on all sides whilst the internal cylinder is open
at each end; the vapour being admitted into the space, when the whole is
immersed in cold water, will be inclosed on both sides with the vicinity of
the cold water, having only the intervention of the thickness of the sub-
stance of which the cylinders are composed. By the addition of this con-
densing apparatus the fluid of the bath is not wasted or diminished by the
process, for as fast as it rises in vapour it is condensed and may be preserved
in a separate vessel, so as to be returned to the bath when it is thought
requisite to fill it up again; or the apparatus may be constructed to return it
constantly as fast as it is condensed by means of a pipe leading from the
refrigeratory to the bath or space between the two vessels. When the fluid
which is employed, such as salt dissolved in water, oil of vitrol and water, or
mercury amalgamated with other metals, such as lead, tin, zinc, &c., the
addition of the refrigeratory, according to my Invention, will prevent the
escape of the more evaporate fluid, as the mercury in the instance above
mentioned, and therefore the compounded fluid does not become more con-
centrated or dense, as it would otherwise do, and render the heat transmitted
by the bath variable.
I claim the application of my said Invention to the following purposes:-
For the distillation of spirits; for such liquors as mint water, rose water, and
other similar preparations; as also for the boilers to raise steam for steam
engines, or other such purposes. I employ mercury for the bath or intervening
fluid thro' which the heat is to be transmitted. It may be applied either at the
lower part of the vessel, where the fire acts, or it may be applied to the whole
of the still or boiler, so as to surround it on all sides with the mercury, and
thus transmitting the heat to all parts at the same time, the refrigeratory
to be applied to prevent the loss of the mercury by evaporation. The same
method to be used for the boiling of evaporation of sugar and various liquids,
as well as distillation. I also employ a bath of linseed oil for such purposes
of distillation or sublimation as require a less heat than that at which linseed
oil boils, such as refining camphor, sulphur, and other similar substances, and
carrying off that portion of the oil which rises in vapour, it is condensed in
the refrigeratory. I thus obtain an oil which I do not return into the bath,
but continue to use the oil as a bath until it is sufficiently boiled to become
the boiled oil used by painters. By this means I gain a double object, the
equalization of the heat of the bath, and at the same time boil the oil, and
that in an improved manner, as I preserve the part which rises in the boiling,
and which is lost in the common mode of boiling. For the sublimation of
sulphur, in making it from various articles, I employ a bath of mercury;

page_text: otherwise a bath of tin or lead, where the substance from which the sulphur is
to be extracted requires a more considerable heat than the boiling point of
mercury. For the refining of camphor by sublimation, which is usually per-
formed in a sand bath, I employ a bath of linseed oil, oil of vitrol, or mercury.
For boiling tar to the consistency of pitch, I employ the aforesaid apparatus
with a bath of linseed oil or mercury.
In witness whereof, I, the said William Moult, have hereunto set my
hand and seal, this Twelfth day of August, in the year of our Lord
One thousand eight hundred and fifteen.
EDAANDER
AND BE IT REMEMBERED, that on the Twelfth day of August, in the
year of our Lord 1815, the aforesaid William Moult came before our said
Lord the King in His Chancery, and acknowleged the Specification aforesaid,
and all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stampt according to the tenor of
the Statute made for that purpose.
Inrolled the Twelfth day of August in the voor of our Lord On
Inrolled the Twelfth day of August, in the year of
thousand eight hundred and fifteen.
Lord One