A CERTAIN PROCESS OR CERTAIN PROCESSES FOR OBTAINING CARBONATE OF SODA AND CARBONATE OF POTASH
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, J, FREDE-
RICK ALBERT GATTY, of Accrington, in the County of Lancaster, Manufac-
facturing Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Eleventh day of
June (One thousand eight hundred and fifty), in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Frederick Albert Gatty, my exors, adññors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Frederick
Albert Gatty, my exors, adñors, and assigns, or such others as I, the said
Frederick Albert Gatty, my exors, admors, 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 expressed, should and lawfully might make, use, exer--.
cise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "A CERTAIN PROCESS OR CERTAIN PROCESSES FOR
OBTAINING CARBONATE OF SODA AND CARBONATE OF POTASH;" in which said
Letters Patent is contained a proviso that I, the said Frederick. Albert
Gatty, shall cause a particular description of 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, to be inrolled in Her said 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 thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Frederick Albert Gatty, do hereby declare that the nature of my said In-
vention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, that is
to say :-
My Invention consists in obtaining carbonate of soda and carbonate of
potash by decomposing solutions of the neutral tartrate of soda and the neutral
tartrate of potash with carbonic acid gas and lime or carbonate of lime in the
following manner :-I employ a wooden vessel, of a cylindrical form, capable
of containing four hundred gallons, which is furnished with an air-tight lid.
Into this vessel I pour, through an opening which is subsequently closed, three
hundred gallons of the neutral tartrate of potash, at five degrees on Twaddel's
hydrometer, and add thereto thirty-four gallons of lime milk, each gallon con-
taining one pound of lime. Instead of lime, carbonate of lime may be used,
or a mixture of lime and carbonate of lime, but I prefer the use of lime alone.
An agitator is placed within the liquid in tho vessel attached to a shaft or axis,
passing through an air and water tight stuffing box, having a handle fixed to
it by which it can be turned. A stream of carbonic acid gas is then passed
into the liquid, and mingled with it by the agitator. The supply of carbonic
acid gas is continued until the liquid is saturated with it. The operation
being thus completed, the contents of the vessel consist of a solution of
bicarbonate of potash and insoluble tartrate of lime, which is run off into
another vessel, and allowed to subside. The liquid containing the bicarbonato
of potash is then drawn'. ; but as some of the bicarbonate of potash remains
among the tartrate of lime, I wash it out by adding about fifty gallons of water
to what remains. After the whole has been stirred up, I allow it again to
subside, and then draw off the clear liquid. The operation of washing is
repeated a second and a third time, the clear liquid from the second and third
washings being advantageously used instead of water for the first washing in
the succeeding process. The bicarbonate of potash, which is drawn off in the
first instance after the tartrate of lime has subsided, and the liquid which is
drawn off after the first washing, are evaporated to dryness in an iron pan.
By this operation the bicarbonate of potash is changed into subcarbonate of
potash, which is then calcined in a reverberatory furnace in the manner well
understood by manufacturing chemists. In this state the carbonate of potash
is sufficiently pure for most manufacturing purposes; but if it is necessary to
purify it still more, I re-dissolve it in water, and evaporate the clear liquor
again to dryness. The tartrate of lime which is obtained in the above process
may be used as is now customary in the inanufacture of tartaric acid.

page_text: In the production of the carbonate of soda from the neutral tartrate of soda
I make use of the process above described. I produce the carbonic acid gas
in any one of the well-known methods, and pass it through a pipe into the
solution beneath the surface of the liquid.
Having now described the nature of my Invention, and the manner in
which the same is to be performed, I would have it understood that I do not
confine myself to the precise details above set forth, nor to the exact pro-
portions herein described, and that I do not claim as of my Invention mixing
lime or carbonate of lime with tartrate of soda or tartrate of potash. But
what I claim as my Invention is, obtaining carbonate of soda and carbonate
of potash by decomposing solutions of either the neutral tartrate of soda or of
the neutral tartrate of potash with carbonic acid gas and lime, or with car-
bonic acid gas and carbonate of lime, or with carbonic acid gas and a mixture
of lime and carbonate of lime, as above described.
In witness whercof, I, the said Frederick Albert Gatty, have hereunto
set my hand and seal, this Thirtieth day of November, in the year of
our Lord One thousand eight hundred and fifty.
FREDERICK ALBERT (L.s.) GATTY.
AND BE IT REMEMBERED, that on the Thirtieth day of November, in
the year of our Lord 1850, the aforesaid Frederick Albert Gatty came
before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and speci-
fied, in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Enrolled the Eleventh day of December, in the year of our Lord One
thousand eight hundred and fifty.