AN IMPROVED METHOD OF MANUFACTURING SOLUBLE SILICATE OF POTASH
Year: 1860

page_text: LETTERS PATENT to William Charlton Forster, of Gibson Street, Lambeth,
in the County of Surrey, Gentleman, for the Invention of "AN IMPROVED
METHOD OF MANUFACTURING SOLUBLE SILICATE OF POTASH."
Sealed the 19th April 1861, and dated the 10th November 1860.
PROVISIONAL SPECIFICATION left by the said William Charlton Forster
at the Office of the Commissioners of Patents, with his Petition, on the
10th November 1860.
I, WILLIAM CHARLTON FORSTER, of Gibson Street, Lambeth, in the County
of Surrey, Gentleman, do hereby declare the nature of the said Invention for
"AN IMPROVED METHOD OF MANUFACTURING SOLUBLE SILICATE OF POTASH," to be
as follows:-
This Invention relates to a new and economical mode of preparing soluble
silicate of potash to be used as a manure, either alone or in combination with
other manures in common use.
It is found that with a deficiency of silicates that nitrogenous manures
produce a weak rank growth, and a tendency to lodge, but with a sufficient
quantity of soluble silica and ammonia the greatest perfection of weight and
strength is obtainable. The great difficulty has been to obtain silicate of
potash at a reasonable cost; the great expense has hitherto entirely precluded
its important recognized use as a manure.

page_text: In carrying out this Invention, to produce an economical solution of silicate
of potash, and surmount the expensive difficulty, I take about 8 tons of refuse
tan of tanners, and reduce it by burning to about 12 cwt. I sift the potash
from the charcoal through a fine sieve; I mix this potash with 2 cwt. of newly
slaked quicklime, 1 cwt. of chloride of soda, and 3 cwt. of fine sand, and
incorporate the whole thoroughly together with water to the consistency of
mortar, and allow it to remain in that state for from two to three months,
when the soluble silica will be produced. At the expiration of that time
I powder the charcoal that was sifted from the potash, and mix about 2 to
3 cwt. of superphosphate of lime with it, and mix and incorporate the soluble
silicate of potash with the charcoal and phosphate of lime thoroughly, when a
most perfect manure will be produced to suit all crops.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Charlton Forster in the Great Seal Patent Office
ou the 9th May 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CHARLTON FORSTER, of Gibson Street, Lambeth, in the County of Surrey,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of November, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Charlton Forster, Her special licence that I, the said William Charlton
Forster, my executors, administrators, and assigns, or such others as I, the said
William Charlton Forster, 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 "AN IMPROVED
METHOD OF MANUFACTURING SOLUBLE SILICATE OF POTASH," upon the condition
(amongst others) that I, the said William Charlton Forster, 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.

page_text: NOW KNOW YE, that I, the said William Charlton Forster, do bereby
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 (that is to say) :-
This Invention relates to a new and economical mode of preparing soluble
silicate of potash to be used as a manure, either alone or in combination with
other manures in common use.
It is found that with a deficiency of silicates nitrogenous manures produce a
weak rank growth, with a tendency to lodge, but with a sufficient quantity of
soluble silica and ammonia the greatest perfection of weight and strength is
obtainable. The great difficulty hitherto has been to obtain silicate of
potash at a reasonable cost; the great expense has hitherto entirely precluded
its important recognised use as a manure.
In carrying out this Invention, to produce an economical solution of silicate
of potash, and surmount the difficulty of expense before pointed out, I take
about eight tons of refuse tan of tanners, and reduce it by burning to about
twelve hundredweight in an oven or kiln; I then sift the potash from the
charcoal through a fine sieve; I next mix this potash with two hundred weight
of newly slaked lime, one hundredweight and a half of chloride of soda, and
about three hundredweight of fine sand or of powdered flint or powdered
felspar, or of any powdered clay, but I prefer the fine sand; I then incorporate
the whole thoroughly together with water to the consistency of mortar, and
allow it to remain in that state for three months, or a little more, when the
soluble silica will be produced; I then powder the charcoal that was sifted
from the potash, and mix about two or three hundredweight of superphosphate
of lime with it, and mix and incorporate the soluble silicate of potash produced
as above with the charcoal and superphosphate of lime thoroughly, when a
most perfect manure will be produced, suitable for all crops.
I claim as my Invention the mixing the potash produced from burnt
refuse tan with sand, or powdered flint, or felspar, or clay, for the purpose of
producing soluble silicate of potash, as described above.
In witness whereof, I, the said William Charlton Forster, have hereunto
set my band and seal, this Ninth day of May, in the year of our
Lord One thousand eight hundred and sixty-one.
W. C. FORSTER. (L.S.)