IMPROVEMENTS IN THE MANUFACTURE OF SODA AND POTASH
Year: 1867

page_text: LETTERS PATENT to Joseph Townsend, of Glasgow, in the County of
Lanark, North Britain, Manufacturing Chemist, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF SODA AND POTASH."
Sealed the 19th May 1868, and dated the 21st November 1867.
PROVISIONAL SPECIFICATION left by the said Joseph Townsend at the
Office of the Commissioners of Patents, with his Petition, on the 21st
November 1867.
I, JOSEPH TOWNSEND, of Glasgow, in the County of Lanark, North Britain,
Manufacturing Chemist, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF SODA AND POTASH," to be as
follows, that is to say :-
This Invention has for its object the manufacture of soda and potash in
a more economical manner than that hitherto in use, and it consists in adding
to a solution of sulphate of soda or of potash carbonate of baryta or carbonate
of strontia and lime or magnesia.
The substances should be taken in about the following proportions, that is
to say-To seven parts (by weight) of sulphate of soda or nine parts of
sulphate of potash are to be added ten parts of carbonate of baryta, or seven
and a half parts of carbonate of strontia and three parts of lime, or two parts
of magnesia. The mixture is by preference boiled, and on the reaction being
completed the soda or potash in a caustic state is found in solution, whilst

page_text: the remaining substances are precipitated. The solution may be drawn off and
evaporated, or it may be at once converted into carbonate or bi-carbonate by
well-known means.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Townsend in the Great Seal Patent Office on the
20th May 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
TOWNSEND, of Glasgow, in the County of Lanark, North Britain, Manufac-
turing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of November, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
ne, the said Joseph Townsend, Her special licence that I, the said Joseph
Townsend, my executors, administrators, and assigns, or such others as I, the
said Joseph Townsend, 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 MANUFACTURE OF SODA AND POTASH," upon the con-
dition (amongst others) that I, the said Joseph Townsend, my executors or
administrators, by an instrument in writing under my, or their, or one of their
bands and seals, 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 Joseph Townsend, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement in writing, that is to say:-
My said Invention has for its object the manufacture of soda and potash
in a more economical manner than that hitherto in use, and it consists in
adding to a solution of sulphate of soda or of potash carbonate of baryta or
carbonate of strontia and lime or magnesia.

page_text: And in practically carrying out my said Invention I take the substances
in about the following proportions, that is to say:-To seven parts (by
weight) of sulphate of soda or nine parts of sulphate of potash in solution at
a strength of about twenty degrees Twaddell, I add ten parts of carbonate of
baryta or seven and a half parts of carbonate of strontia, and three to four
parts of caustic lime previously slacked, or two to three parts of magnesia.
The mixture is then by preference boiled, so as to be of a strength of from
fifteen to eighteen degrees Twaddell, and on the reaction being completed,
which may be ascertained by well-known tests, the soda or potash in a caustic
state is found in solution, whilst the remaining substances are precipitated.
The solution may be drawn off and evaporated, or it may be at once converted
into carbonate or bi-carbonate by well-known means.
Having thus particularly described my said Invention, and the manner in
which the same is to be performed, I have to state that I do not restrict
myself to the precise details herein described; but that what I believe to be
novel and original, and claim as the Invention secured to me by the herein-
before in part recited Letters Patent is, the obtaining of soda or potash from
its sulphate by adding carbonate of baryta or of strontia and lime or magnesia,
substantially as herein-before described.
In witness whereof, I, the said Joseph Townsend, have hereunto set my
hand and seal, this Nineteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-eight.
5
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JOSEPH TOWNSEND. (L.B.)