A New PROCESS FOR OBTAINING SODA FROM COMMON SALT
Year: 1866

page_text: LETTERS PATENT to Walter Weldon, of Park Villa, West Hill, High-
gate, in the County of Middlesex, for the Invention of "A New
PROCESS FOR OBTAINING SODA FROM COMMON SALT."
Sealed the 28th August 1866, and dated the 1st March 1866.
PROVISIONAL SPECIFICATION left by the said Walter Weldon at the
Office of the Commissioners of Patents, with his Petition, on the
1st March 1866.
I, WALTER WELDON, of Park Villa, West Hill, Highgate, in the County
of Middlesex, du hereby declare the nature of the said Invention, "A NEW
PROCESS FOR OBTAINING SODA FROM COMMON SALT," to be as follows:-
This Invention consists in the decomposing chloride of sodium. in
solution, in cold water by means of the bicarbonate of any metal whose
chloride in aqueous solution is not decomposed in the cold by bicarbonate
of sodium. The bicarbonate which I prefer is that of magnesium, and I
produce this bicarbonate and cause it to react upon the chloride of sodium
by placing either oxide, hydrate, or carbonate of magnesium, preferably in
fine powder, together with chloride of sodium, and cold water in a suitable
vessel capable of resisting considerable internal pressure, and then forcing
carbonic acid gas into this vessel as long as the gas is absorbed. The
carbonic acid gas converts the oxide; hydrate, or carbonate of magnesium
into soluble bicarbonate, which as fast as it is formed decomposes an
equivalent of chloride of sodium, forming chloride of magnesium, which is

page_text: an extremely soluble compound, and so remains in solution, and bicarbonate
of sodium, which is much less soluble, and therefore for the most part
precipitates. By evaporating the solution of chloride of magnesium to
dryness, and igniting the residue, the whole of the chlorine in the mag-
nesium chloride is driven off in combination with hydrogen as hydrochloric
acid, which may be condensed in the usual way, and the magnesia is
recovered for use over again.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Walter Weldon in the Great Seal Patent Office on
the 31st August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
WELDON, of Park Villa, West Hill, Highgate, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of March, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of
Her reign, did, for Iferself, Her heirs and successors, give and grant unto
me, the said Walter Weldon, Her special licence that I, the said Walter
Weldon, my executors, administrators, and assigns, or such others as I, the
said Walter Weldon, 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 "A NEW METHOD OF OBTAINING SODA FROM COMMON SALT," upon the con-
dition (amongst others) that I, the said Walter Weldon, my executors
or administrators, by an instrument in writing under my, or their, or one
of their hands 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 Walter Weldon, do hereby declare
the nature of said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement.:

page_text: This Invention relates to a new method of obtaining soda from chloride
of sodium or cominon salt. This new method consists in decomposing
chloride of sodium, in solution, in cold water by means of the bicarbonate
of any metal whose chloride in aqueous solution is not decomposed in
the cold by bicarbonate of sodium. The bicarbonate which I prefer is
that of magnesium, and I produce this bicarbonate and cause it to react
upon the chloride of sodium, by placing either oxide, hydrate, or carbonate
of magnesium, preferably in fine powder, together with chloride of sodium
and cold water, in a suitable closed vessel capable of withstanding a con-
siderable amount of internal pressure, and furnished or not, as may be
preferred. with any convenient appliances for mechanically agitating its
contents, and then forcing carbonic acid gas into this vessel as long as the
gas is absorbed. The carbonic acid gas converts the oxide, hydrate, or
carbonate of magnesium into soluble bicarbonate, which as fast as it is
formed decomposes an equivalent of chloride of sodium, forming chloride
of magnesium, which is an extremely soluble compound, and so remains in
solution, and bicarbonate of sodium, which is much less soluble, and there-
fore for the most part precipitates. It is preferable, but not essential, to
agitate the contents of the vessel while the process is going on. By
evaporating the solution of chloride of magnesium to dryness and heating
the residue the whole of the chlorine in the chloride of magnesium is
driven off in combination with hydrogen as hydrochloric acid, which may
be condensed in the usual way, and the magnesia is recovered for use over
again.
Having now described the nature of my said Invention, and the manner
in which the same is to be performed, I claim as my Invention, and desire
to be secured to me by the herein in part recited Letters Patent, the new
method or process of transforming salt into soda, which consists in decom-
posing the salt by a metallic bicarbonate produced and caused to react
upon the salt substantially as is above described.
In witness whereof, I, the said Walter Weldon, have hereunto set my
hand and seal, this Thirty-first day of August, in the year of our
Lord One thousand eight hundred and sixty-six.
WALTER WELDON. (L.S.)