IMPROVEMENTS IN THE MANU- PACTURE OF ALUM
Year: 1858

page_text: LETTERS PATENT to John Bethell, of No. 8, Parliament Street, West-
minster, Gentleman, for the Invention of "IMPROVEMENTS IN THE MANU-
PACTURE OF ALUM."
Sealed the 30th November 1858, and dated the 3rd June 1858.
PROVISIONAL SPECIFICATION left by the said John Bethell at the
Office of the Commissioners of Patents, with his Petition, on the
3rd June 1858.
I, JOHN BETHELL, of No. 8, Parliament Street, Westminster, Gentleman, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF ALUM," to be as follows:-
My improvements in the manufacture of alum consists in a mode of getting
ammonia from gas for the purpose of making alum.
I take weak sulphuric acid or sulphuric acid and water, and put it in a
closed tank, and cause the gas from coal, or any other gas containing ammonia,
to pass through this liquid until the sulphuric acid is saturated with ammonia,.
and I then take this liquid with the ammonia it has retained, and with it
I dissolve sulphate of alumina, and proceed to make alum by evaporation. and
crystallization in the usual way, adding of course as much of this liquid so.
obtained as will be sufficient to combine with the sulphate of alumina to mako
alum. The closed tank above named may be the usual purifier at the coal
gasworks.
The same effect may be produced by moistening small pieces of coke
or sawdust or other substances with the weak sulphuric acid, and putting them
in the closed tank or purifier, and causing the gas to pass between them until

page_text: the liquid becomes saturated with ammonia; I then take them out, and wash
out the ammoniacal liquid, and add that to the sulphate of alumina, and
proceed to make alum.
The above processes have been used before for purifying gas, and therefore
I disclaim them as a purifying process for gas; but I do claim the manu-
facture of alum by the process above described, and the getting the necessary
ammonia from gas for the purpose of making the alum in the manner above
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Bethell in the Great Seal Patent Office on the
2nd December 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOIN
BETHELL, of Number 8, Parliament Street, Westminster, Gentleman, send
grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of June, in the year of our Lord One
thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Bethell, Her special licence that I, the said John Bethell, my
executors, administrators, and assigns, or such others as I, the said John
Bethell, 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 ALUM," upon the condition (amongst others) that I, the
s.id John Bethell, 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 John Bethell, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement :-

page_text: My improvements in the manufacture of alum consist in a mode of getting
ammonia from gas for the purpose of making alum, and in useing the liquid
sulphate of ammonia obtained from gas, as hereafter described, for making
alum.
I take weak sulphuric acid or sulphuric acid and water, and put it in a
closed tank, and cause the gas from coal, or any other gas containing ammonia,
to pass through this liquid until the sulphuric acid is saturated with ammonia,
and the liquid becomes liquid sulphate of ammonia; and I then take this
liquid sulphate of ammonia and I add it to a solution of sulphate of alumina,
and proceed to make alum by evaporation and crystalization in the usual way,
adding of course as much of this liquid sulphate of ammonia so obtained as
will be sufficient to combine with the sulphate of alumina to make alum.
The closed tank above named may be the usual purifier at the coal gas-
works.
The same effect may be produced by moistening small pieces of coke or
sawdust or other substances with weak sulphuric acid, and putting them in the
closed tank or purifyer used at gas-works, and causing the gas to pass between
them until the liquid in the pores of the substances becomes saturated with
ammonia; then take out the pieces of coke, &c., and wash out the
ammonical liquid, and add that to the sulphate of alumina, and proceed to
make alum, as above described.
I am aware that the above processes have been used before for purifying gas,
and therefore I disclaim them as a purifying process for gas; but I do claim
the getting the necessary ammonia from gas for the purpose of making alum,
in the manner above described, and in useing the liquid sulphate of ammonia
so obtained from gas for making alum, as above described.
In witness whereof, I, the said John Bethell, have hereunto set my
hand and seal, the Second day of December, in the year of our Lord
One thousand eight hundred and fifty-eight.
Witness,
A. H. HOSKING,
Parliament St., Westminster.
JNO. BETHELL. (L.S.)