IMPROVEMENTS IN THE PREPARATION OF CHARCOAL, AND ITS APPLICATION TO THE PURIFICATION OF WATER AND THE PRESERVATION OF ORGANIC MATTERS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Julius Dahlke at the Office of
the Commissioners of Patents, with his Petition, on the 22nd October
-1859.
I, JULIUS DAHLKE, of Providence Row, Finsbury, in the County of Mid-
dlesex, Analytical Chemist, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE PREPARATION OF CHARCOAL, AND ITS APPLICATION TO
THE PURIFICATION OF WATER AND THE PRESERVATION OF ORGANIC MATTERS, AND IN
APPARATUS CONNECTED THEREWITH," to be as follows:-
In carrying out my improvements in the preparation of charcoal, I take
about 50 parts by weight of animal charcoal, 25 parts of quartz, in coarse
powder, silver sand, for example, 17 parts of coal tar, & 8 parts of fire-clay,
& combine them as follows :-I first mix the fire-clay with the coal tar, so as
to thoroughly incorporate them; I then add the quartz & animal charcoal,
having previously reduced the same to coarse powder; the whole mass is to
be intimately mixed and reduced to a plastic state, when it is fit to be moulded
or fashioned into shapes or articles as required. The articles so made are
then exposed to a gradually increasing heat in closed vessels, in order to
carbonize the tar, and produce the necessary solidity. When gas is no longer
generated, and has been all evolved, the heat is increased till the vessels and
their contents become red hot, and remain so for about 3 hours. The plates
or other shapes or articles so made I employ for the purification of water, as
will be herein-after described. In preparing charcoal to be used for the
preservation of meat, vegetables, and other organic matters, I proceed as

page_text: before explained, but I use vegetable instead of animal charcoal. For
filtering and purifying water, it may be used in the form of plates, cylinders,
solid or hollow, or in other convenient form. One convenient form consists
simply of a china or other earthenware cylindrical vessel, having a ledge half
way down, on which I place and cement a plate of the prepared charcoal, thus
separating the vessel into two compartments, an upper one to recieve the
unfiltered water, which percolates through the charcoal plate, and so passes to
the lower compartment, to be drawn off by a suitable tap, as usual.
An improvement in filters consists in forming the filtering and purifying
medium in two parts, the one thick and permanent, while the other & upper
part is removable for the purpose of cleansing it. For this purpose I enclose
the purifying medium in a cylinder or casing of gutta percha, enclosed below
by a funnel bottom terminating in a pipe. The casing is flanged at top, and
recieves a rim or flange, which dips inside the vessel, forming an internal
flange, in which the upper plate of filtering material is fixed; on the top is
placed a funnel cover, terminating in a pipe; this cover is bolted down upon
the other flanges, so as to grip the three parts together. Thus, by removing
the cover the loose flange and upper plate of charcoal can be removed to be
cleansed by scrubbing or making it red hot, and when together the whole forms
an air-tight vessel. This filter may be placed in the supply pipe of house
cisterns, or used on board ship through which to pump water before using
it, as a filter to pass the water to drinking fountains, &c. The casing may be
of any other suitable material. When of metal, I coat it with a solution of
shelac in spirit to prevent any prejudicial action of the metal and charcoal.
For large purifiers, such as the filter beds of waterworks, I lay down plates of
prepared charcoal, cemented together, so that the water must pass through the
charcoal.
For the preservation of organic matters, I prepare the charcoal from
vegetable charcoal, as before mentioned, and form it into plates, of which
I construct or line meat safes or other chambers, so that the matters to be
preserved are entirely surrounded by the charcoal; water contained in vessels
lined with my prepared charcoal will also be preserved; chambers or vessels
may be moulded of this prepared charcoal.