IMPROVEMENTS IN THE MANUFACTURE OF MANURES AND DISINFECTANTS
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Fredrich Gerbartz at the Office
of the Commissioners of Patents, with his Petition, on the 24th October
1867.
I, FREDRICH GERHARTZ, of Cologne, Rhenish Prussia, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
MANURES AND DISINFECTANTS," to be as follows:-
My Invention relates to the preparation and use of charcoal obtained in the
following manner in the manufacture of sugar from beetroot.
The molasses of beetroot is fermented and the alcohol formed by fermen-
tation being separated by distillation the residue in the still is evaporated to
dryness and calcined; it is then exhausted by water to separate soluble
potash and soda salts, when a black carbonaceous mass is left behind. This
black carbonaceous mass contains besides traces of soluble potash and soda
salts about 25 per cent., highly divided nitrogenous carbon, from 20-78 to 16
per cent. phosphoric acid, as tribasic phosphate of lime, from 8 to 10 per cent.
carbonate of lime up to 8 per cent. insoluble silicate of potash, and sulphate
of lime and silicate of lime in variable proportions. The phosphates and

page_text: silicates and also the sulphate of lime give to this charcoal a high value as a
manure. But in addition to these compounds the necessary. nourishment for
the plants is the carbon, which acts beneficially on the vegetation, loosening
and warming the soil and assisting in fixing the ammonia from the atmosphere.
But to increase the value of this charcoal as a manure I subject it to the
following manipulation, which I call "the drying and concentration of the
charcoal." The charcoal obtained as described above contains a large amount
of water, which must be separated, and as its per-centage of phosphates varies
it is necessary to prepare the charcoal to obtain a manure of uniform compo-
sition. Both these processes, the drying and the concentration of the charcoal,
are carried out in the following one operation:-The material is so rich in
carbon that once ignited it continues to burn without the addition of fuel,
leaving from 30 to 33 per cent. of ashes very rich in phosphates. This
incineration is carried out in a reverberatory furnace with rising bed and without
fire-bars. The moist material enters the reverberatory furnace at the highest
point of the bed, where it is dried by the gases of combustion produced by the
burning off of another portion of charcoal further down the furnace; it gradually
passes to the front part of the furnace and ignites, and it is ultimately drawn
in the form of ashes. The roof of the furnace is formed by iron plates which
become heated by the gases of combustion passing along them underneath;
these iron plates thus form a drying floor for the charcoal spread over them
from 4 to 5 inches thick. The drying may be assisted by turning the charcoal
from tin:e to time, the ashes being from 30 to 33 per cent. of the original
material the manurial value is of course concentrated at least three times. The
ashes are then treated with dilute sulphuric acid to convert the insoluble
phosphates and silicates into soluble salts. Dried charcoal is then mixed with
30, 40, or 50 per cent. of the ashes treated with sulphuric acid, yielding a
mixture containing 6, 8, 10 or more per cent. of soluble phosphoric acid, and
from 2 to 5 per cent. of potash, besides soluble silica.
I now proceed to describe the application of my charcoal as a disinfectant
in the form of a compound which I call "universal disinfecting powder.. It is
well known the more highly divided charcoal is the more valuable it becomes
as a disinfectant, because of its enlarged surface and consequent increased
power of attraction for gases. My charcoal contains about 25 per cent. of
pure carbon in a state of such high division as is impossible to effect by
mechanical means. Its disinfecting property is therefore developed to the
highest degree, and its disinfecting power is very remarkable.
But in order still further to increase its value in this respect and to adapt it

page_text: for all cases of disinfection, in fact in order to produce a universal disinfecting
powder, I make the following mixture:-I take for 100 cwts.,
34 cwts. of my dried charcoal.
33
"
of bleaching powder.
25
4'
33
"
3
"
1
"
of hydrate of lime.
of binoxide of manganese.
of oxide of iron (caput mortuum).
of bichromate of potash.
But I do not bind myself to these exact proportions, which under certain
circumstances I may vary.
I have already fully explained the valuable disinfecting property of my
dried charcoal; that of bleaching powder and hydrate of lime is sufficiently
known.