IMPROVEMENTS IN PURIFYING WATER
Year: 1877

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company,
Patent Solicitors, of Frankfort-on-the-Maine, in the Empire of Germany, for the
Invention of " IMPROVEMENTS IN PURIFYING WATER." A communication
from Edward Bohlig, Chemist, of Eisenach, in the Empire of Germany.
Sealed the 7th May 1878, and dated the 1st December 1877.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office of
the Commissioners of Patents on the 1st December 1877.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort-on-the-Maine, in the Empire of Germany. "IMPROVEMENTS IN PURIFYING
WATER." A communication from Edward Bohlig, Chemist, of Eisenach, in the
Empire of Germany.
The Invention relates to an improvement in the method of purifying water, and
consists in the application of oxide of magnesia; that is, basic carbonic magnesia,
which like lime purifies water from the following impurities at ordinary temper-
ature; the impurities referred to are bicarbonate of magnesia, calcium, iron, silicious
and clayey earths, and such like.
On mixing with water any of the above they immediately turn very thick, but
soon precipitate, and after having stood for some time the water becomes perfectly
clear.
The improved method has a great advantage over the lime method, inasmuch as
magnesia not being easily decomposed in water, it can be placed in the water
holder a considerable time before the water is required, the super-abundance
precipitates enveloping the lime; this precipitation being repeated each time the
water holder is filled with fresh water, and taking less time as it gets thick, and
therefore falling more rapidly.
In the lime method great care has to be taken that too much is not introduced,
or else the water is only charged with more impurities. The magnesia acts first in

page_text: absorbing that portion of the carbonic acid contained in the water, which holds the
carbonate of lime and the magnesia also present in solution; these are thus pre-
cipitated as simple carbonic salts. The second and most important part now comes
into operation, as the newly formed simple carbonic magnesia overpowers the
gypsum, and through repeated precipitations, insoluble carbonate of lime and easily
soluble sulphate of magnesia are formed.
In the case of steam boilers the easily soluble sulphate of magnesia which is
contained in the water has not the least injurious effect on the iron, but on the
contrary is beneficial, as on the water being boiled away, the small quantity of
magnesia which would in the ordinary way become separated, is in the improved
method prevented from becoming separated by the sulphate of magnesia, a solution
of which possesses the property of dissolving inagnesia, and so remaining a liquid.
The non is thus kept clean and free from rust, moreover the sulphate of magnesia
produced by the combination of carbonate of magnesia and gypsum, has a beneficial
nction on iron, removing any old boiler crust at a pressure of about 3 atmospheres,
and a proportionato temperature in the boiler.
In performing the Invention the magnesia is to be put directly into the water to
be purified, and the mixture to be stirred.
For steam boilers the water may be pumped into a reservoir containing magnesia,
or the magnesia be thrown into the water reservoir.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 22nd May
1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Agency, at Frank-
fort-on-the-Maine, in the Empire of Germany. "IMPROVEMENTS IN PURIFYING
WATER" A communication from Edward Bohlig, Chemist, of Eisenach, in the
Empire of Germany.
The Invention relates to improvements in the method of purifying water, and
consists in the application of oxide of magnesia, which like lime purifies water from
the following impurities at an ordinary temperature; the impurities being bi-
carbonate of inagnesia, calcium, iron, silicious and clayey earths, and such like.
On mixing with water any of the above it immediately turns very thick, but the
matters soon precipitate, and after having stood for some time the water becomes
perfectly clear.
The improved method has a great advantage over the lime method, inasmuch as
magnesia not being easily decomposed in water, it can be placed in the water
reservoir or holder a considerable time before the water is required, the super-
abundant precipitate enveloping the lime, this precipitation being repeated each time
the water reservoir is filled with fresh water, and taking less time as it gets thick,
and therefore falling more rapidly.
In the lime method great care has to be taken that too much lime is not introduced,
or else the water is only charged with more impurities. The magnesia acts, first, in
absorbing that portion of the carbonic acid contained in the water which holds the
carbonate of lime, and the magnesia also present in solution; these are thus pre-
cipitated as simple carbonic salts. The second and most important part then comes
into operation, as the newly formed simple carbonic magnesia overpowers the gypsum
through repeated precipitations, insoluble carbonate of lime and easily soluble
sulphate of magnesia are formed.
In the case of steam boilers the easily soluble sulphate of magnesia which is con-
tained in the water has not the least injurious effect on the iron, but on the contrary
is beneficial, as on the water being boiled away the small quantity of magnesia which
would in the ordinary way become separated, is in the improved method prevented
from becoming so by the sulphate of magnesia, a solution of which possesses the
property of dissolving magnesia, and so remaining a liquid. The iron is thus kept
clean and free from rust; moreover the sulphate of magnesia produced by the com-
bination of carbonate of magnesia and gypsum has a beneficial action on iron,
removing any old boiler crust at a pressure of about three atmospheres, and a
proportionate temperature in the boiler.
In performing the Invention the magnesia in sufficient quantity is to be put
directly into the water to be purified, and the mixture to be stirred.
For steam boilers the water may be pumped into a reservoir containing magnesia,
or the magnesia be thrown into the water reservoir.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Eighteenth day of May, in the year of our Lord One thousand
eight hundred and seventy-eight