IMPROVEMENTS IN THE MANUFACTURE OF POTASH AND SODA
Year: 1854

page_text: LETTERS PATENT to Charles Cowper, of 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF POTASH AND SODA."
PROVISIONAL SPECIFICATION left by the said Charles Cowper at the
Office of the Commissioners of Patents, with his Petition, on the 24th
February 1854.
I, CHARLES COWPER, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF POTASH AND SODA" to be as follows:-
I manufacture potash and soda from natural or artificial silicates containing
those alkalies, by placing such silicates (either before or after calcination and
quenching in water, or alkaline or other solutions,) in heaps with straw, saw-
dust, or other fermentable materials, which are moistened with solutions of
organic matter or otherwise caused to ferment. The fermentation is allowed
to proceed for some time, and a thick cream of lime is then mixed with the

page_text: silicates, and the resulting paste or mixture is dried and calcined in a furnace.
It is then thrown into water and reduced to powder, which is lixiviated with
water, and the solution thus obtained is treated with quick lime or filtered
through it, and again filtered to obtain a clear solution, which contains the
potash or soda in a caustic state. The solution of caustic alkali may be
employed in that state, or it may be evaporated to dryness or converted into
carbonate of potash or soda in any of the ordinary manners. The silicious
residue of the process forms an excellent substitute for puzzolana.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Cowper in the Great Seal Patent Office on the 22nd
August 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWPER, of 20, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of February, in the year of our
Lord One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Cowper, Her special licence that I, the said Charles Cowper, my
executors, administrators, and assigns, or such others as I, the said Charles
Cowper, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANUFAC-
TURE OF POTASH AND SODA," communicated to me by Léonard Laureau, of
Paris, in France, upon the condition (amongst others) that I, the said
Charles Cowper, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Cowper, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,

page_text: to be particularly described and ascertained in and by the following state-
ment thereof (that is to say):-
The Invention relates to the extraction of potash and soda from natural or
artificial silicates containing those alkalies. Felspar is one of such silicates,
and there are many others, as is well known.
the operations are simple, and large quantities of material can be operated
upon at once.
"
In carrying out the Invention
The silicates may be employed in a pulverulent or earthy state when so
procurable, but if in the state of hard masses or rock, they are to be reduced
to pieces of about half a pound weight. For this purpose they are heated to
a red heat and thrown into water, which may be slightly acidulated by an
organic acid or rendered slightly alkaline. After this operation the lumps are
easily crushed or pulverized by the ordinary mechanical means.
The pulveru-
lent or earthy silicates do not require this operation, but they generally yield a
smaller proportion of alkali.
.
The crushed or pulverulent silicates are placed in alternate layers or beds
with straw or sawdust, and watered with a solution containing a small quantity
of urine or other animal matter, so as to produce fermentation. Equal weights
of silicates and straw or sawdust may be employed. Two or more of these
beds are constructed of considerable extent, so that each bed may be exposed
for six months to this fermenting process before proceeding to extract the
alkali from it. After this preparation, the whole is drenched with a thick
cream of lime (or mixture of lime and water), containing a quantity of lime
equal to double the weight of the alkali in the silicate. The paste or mixture
thus produced is left for a week, and is then calcined in a reverberatory furnace
or made into balls or lumps, which are dried and calcined in a continuously
acting furnace. The vitrification of the substance is to be avoided by pre-
venting the temperature from rising too high. The calcined substance may
be quenched in water, and is then ground. The powder is lixiviated with the
water employed to quench the calcined substance or with other water, and a
solution of the alkali is thus obtained. This solution is filtered through quick
lime and afterwards through linen, and is a solution of the alkali in a caustic
state and of remarkable purity. This solution may be employed at once in
the manufacture of soap and for other purposes, or it may be evaporated to
dryness or carbonated by any of the known processes. The insoluble residue
which remains after the lixiviation may be used in making mortar, and forms
an excellent puzzolana.
Having now described the nature of the said Invention, and in what manner

page_text: the same is to be performed, I wish it to be understood that what I claim is,
the manufacture of potash and soda from natural or artificial silicates con-
taining those alkalies, in manner herein-before described.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Twenty-second day of August, in the year of our
Lord One thousand eight hundred and fifty-four.
Witness,
THOB. TAYLOR, JNB,
7, Wellington Row,
Bethnal Green.
CHARLES COWPER. (L.S.)