IMPROVE- MENTS IN THE MANUFACTURE OF ALUM;
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WIESMANN, of George Yard, Lombard Street, in the City of London.
Merchant, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Ter
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Sixteenth day of November, in the third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said William Wiesmann, Her especial licence, full power, sole privilege and
authority, that I, the said William Wiesmann, my exors, adññiors. and
assigns, or such others as I, the said William Wiesmann, my exors, adñiors,
or assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF ALUM;" in which said Letters Patent is
contained a proviso, that I, the said William Wiesmann, shall cause
a particular of the nature of my Invention, and in what manner the same
is to be performed, 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
William Wiesmann, do hereby declare the nature of my said Invention,
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 relates to a mode of manufacturing alum, by which the samo
may be produced free of iron and alkali (or nearly so). In order to give the
best information in my power, I will proceed to describe the process pursued by
me take potters' clay, as free from iron as possible, and calcine the samo
to a moderate red heat, in order as much as possible to drive off all humidity.
The clay so calcined is next to be ground to a powder and to be placed in
leaden pans heated by a moderate fire or by steam, and sulphuric acid (about
sixty-six degrees by Beaumé) is to be applied in sufficient quantities that the
acid may dissolve nearly the whole of the clay; I prefer that the whole should
not be dissolved, as a saving of acid is thereby obtained. The mass in the
pans is to be stirred until it is dry, when boiling water is to be applied to
dissolve the salt formed, and water is to be so applied till the whole of the salt
is separated; the liquors thus obtained are mixed and placed in vats and left
therein till perfectly clear. A measured quantity of the liquor is to be tested
with prussiate of potash, or other suitable material, to ascertain the quantity of
iron contained in such measured quantity of the liquor; then the whole quan-
tity of liquor being known, the quantity of iron therein may be obtained by
calculation; and whatever be the weight of iron, the liquor to be operated on
is found to contain an equal weight of prussiate of potash dissolved in water
is to be stirred into the liquor when the prussic acid will take to the iron and
they together will be precipitated; by this means the liquor drawn off, clear or
filtered, will be composed of sulphuric acid, alumina, and water, and in this
condition may be used for the purposes of the arts, but when required to bo
crystallized I reduce the liquor by quickly evaporating it in large leaden
vessels, until a skin of salt forms on the surface, when the liquor is drawn into
shapes where it cools and crystallizes.
I would here remark that I am aware that the clay treated with sulphuric
acid has been employed in the process of making alum, but the processes
have been conducted in a different manner, requiring much time, and produc-
ing alum not so pure and concentrated. I do not, therefore, claim the same
generally, when practised according to the means heretofore known; and
although I prefer the employment of prussiate of potash for precipitating the
iron, I do not confine myself thereto, as other materials may be used, such as
the lixivium of blood or sulphate of lime; but what I claim is, the mode of

page_text: making alum from clay as herein described, whereby the alum will contain
nuch more alumine, and is free or nearly free from iron.
In witness whereof, I, the said William Wiesmann, have hereunto set
my hand and seal, this Seventeenth day of March, in the year
of our Lord One thousand eight hundred and forty.
Inrolled the Sixteenth day of May, in the year of our Lord One
thousand eight hundred and forty.