IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF THE FERRO-CYANIDE AND CYANIDE OF POTASSIUM.
Year: 1859

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn - Fields,
in. the County of Middlesex, and of 166, Buchanan Street, in the City of
Glasgow, North Britain, Gentleman, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OR PRODUCTION OF THE FERRO-CYANIDE AND CYANIDE
OF POTASSIUM. A communication from abroad by Jean Victor Lucas, of
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 9th April 1859.
!
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF THE FERRO-CYANIDE.
AND CYANIDE OF POTASSIUM," a communication from abroad by Jean Victor
Lucas, of Paris, in the French Empire, Chemist, to be as follows:-
This Invention relates to a peculiar process for obtaining the ferro-cyanide of
potassium or yellow prussiate of potash of commerce, and the cyanide of
potassium. In carrying out this Invention for the manufacture of prussiate
of potash, it is proposed to melt the carbonate of potash in a cast-iron vessel.
with water, and then to add thereto a sufficient quantity of wood, charcoal,. or
[Price 8d.1

page_text: coke, to completely imbibe the solution of carbonate of potash. The whole is
then heated until the charcoal or coke becomes thoroughly dry. The carbonate
of potash will then be found distributed in the permeable and spongey mass.
This mass, with an addition of iron filings is introduced into two retorts placed
vertically within a suitable furnace, the two retorts communicating with each
other by a pipe, which connects the upper part of one retort with the lower
portion of the other. The retorts are now heated for the purpose of expelling
all humidity or moisture from the charcoal mass, and of reducing the carbonate
of potash to the state of peroxide of potassium, whereupon, by the introduction
into the retorts of a current of ammoniacal gas whilst the retorts are at a
white heat, the yellow prussiate of potash will be obtained. Although the
ammoniacal gas may be obtained in various ways, it is preferred to produce it
from the admixture of equal parts by weight of sulphate of ammonia and
quicklime, which is poured into a vertical retort or vessel in the furnace before
referred to, or in a separate furnace: when placed in the same furnace as the
retorts above alluded to, separate fires are used, and a division wall must be
built to enable such retort or vessel to be raised to only a suflicient temperature
to cause the emission of the gas whilst the other retorts are maintained at a
white heat. The gas enters the bottom of the first retort containing the
charcoal, and acting on the potash converts it into prussiate, of potash. On
leaving the first retort the gas enters the bottom of the second retort, and
finally escapes by a pipe or chimney for that purpose. The conducting pipes
may be fitted with valves, for the purpose of intercepting at pleasure the
passage of the gas. The manufacture of the cyanide of potassium is accom-
plished in a precisely similar manner to that above described, with this
exception, that the addition of the iron filings is dispensed with.
SPECIFICATION, in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 4th October 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, Joux
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentle-
man, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent. hearing date the Ninth day of April, in the year of our Lord
One thousand eight hundred and fifty-nine, in the iwenty-second year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson. my executors, administrators, or 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 OR PRODUCTION OF THE FERBO-CYANIDE.
AND CYANIDE OF POTASSIUM,' a communication from abroad by Jean Victor
Lucas, of Paris, in the French Empire. Chemist, upon the condition
(amongst others) that I, the said John Henry Johnson, by an instrument
in writing under my hand and seal, 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 suid
Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson. do hereby
declare the nature of the said Invention. and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:-
The said Invention relates to a peculiar process for obtaining the 'ferro-
cyanide of potassium or yellow prussiate of potash of commerce. and the
cyanide of potassium. In carrying out this Invention for the manufacture of
prussiate of potash, it is proposed to melt the carbonate of potash in a cast-
iron vessel with water. and then to add thereto à sufficient quantity of wood.
charcoal, or coke, to completely imbibe the solution of carbonate of potash.
The proportions which have found to give the best result are:-Sixty-five
parts in weight of carbonate of potash. one hundred and fifteen parts in weight
of wood, charcoal, or coke, and sixty-five parts in weight of ordinary water.
The whole is now heated until the charcoal or coke becomes thoroughly dry.
The carbonate of potash will then be found distributed in the porous and
spongey mass. This mass, with an addition of five parts in weight of 'iron
filings is introduced into two retorts placed vertically within a suitable furnace,
the two retorts communicating with each other by a pipe. which connects the
upper part of one retort with the lower portion of the other. The retorts are
now heated for the purpose of expelling all humidity or moisture from the
'charcoal mass, and of reducing the corbonate of potash to the state of "per-

page_text: oxide of potassium, whereupon by the introduction into the retorts of a
current of ammoniacal gas whilst the retorts are at a white heat, the yellow
prussiate of potash will be obtained. Although the ammoniacal gas may be
obtained in various ways, it is preferred to produce it from the admixture of
equal parts by weight of sulphate of ammonia and quicklime, which is poured
into a vertical retort or vessel in the furnace before referred to, or in a separate
furnace; when placed in the same furnace as the retorts above alluded to,
separate fires are used, and a division wall must be built to enable such
retort or vessel to be heated only to a sufficient temperature to cause the
emission of the gas, whilst the other retorts are maintained at a white heat.
The gas enters the bottom of the first retort containing the charcoal, and
acting on the potash converts it into prussiate of potash. On leaving the
first retort the gas enters the bottom of the second retort, and finally escapes
by a pipe or chimney for that purpose. The conducting pipes may be fitted
with valves, for the purpose of intercepting at pleasure the passage of the gas.
The manufacture of the. cyanide of potassium is accomplished in a precisely
similar manner to that above described, with this exception, that the addition
of the iron filings is dispensed with.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same and for that purpose 1 shall
refer to the Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts in both Figures.
Figure 1 of the annexed Sheet of Drawings represents a vertical section of
the furnace I prefer to employ in carrying out my Invention, taken along the
linc 1-2, in Figure 2, and Figure 2 is a sectional plan of the same. taken
along the broken line 3, 4, 5, 6, 7, and 8, in Figure 1.
A, B, are the two retorts, into which the spongy mass of charcoal and potash
with the iron filings is introduced; these retorts are of cast iron or other
suitable material and of a cylindrical or other convenient form; they are
placed vertically side by side in the furnace X, or in any other suitably con-
structed furnace. These two retorts A, B, communicate the one with the
other by the pipe C, which extends from the upper part of the retort A to the
lower portion of the retort. B. The retorts A, B, are heated to a white heat
to entirely expel any remaining moisture or humidity which may be contained
in the charcoal or coke, and also to reduce the carbonate of patash to the state
of peroxyde of potassium. Having effected the transformation, it is simply
requisite in order to obtain the prussiate of potash to maintain the two retorts
at a white heat, and to cause a stream of ammoniacal gas, obtained in any
convenient manner, to pass through the interior of the retorts in contact with

page_text: the charcoal or coke and iron filings contained therein. The mode I prefer to
adopt in producing the ammoniacal gas consists in mixing together equal parts
in weight of sulphate of ammonia and quicklime, which is then poured into
the cast iron or other retort D, placed vertically in the same furnace X, or'in
a suitable reverberatory furnace. Care must however be taken that the
retort D be not subjected to a greater temperature than is requisite 'to
disengage the ammoniacal gas. For this purpose I construct in the furnace X
a partition wall Y, which allows the retorts A, B, to be heated to a white heat
by the fire-place E, whilst the fire-place G supplies the amount of heat
required for the retort D. One common chimney serves for the two fire-places
E and G, and for the final escape of the ammoniacal gas after it has first
passed by the pipe L to the bottom of the first retort A, and permeated the
mass contained therein, and thence passed by the pipe C to the base of the
second retort B, through which it also passes when it finally escapes at the
top by the pipe M leading to the chimney H. The whole of these connecting
pipse may be furnished with stop valves, for the purpose of regulating or
intercepting at pleasure the passage of the gas. On the completion of the
process the retort D is emptied into the waggon P, which serves to remove
the residuum. The contents of the retorts A, B, is emptied into an
"etouffoir" or charcoal box placed in the waggon Q; the two waggons P
and Qrunning along the rails R laid beneath the arches S and T, which
receive the bottoms of the retorts A. B, and D. After the contents of the
retorts A and B has been cooled down, the ordinary lixiviation and chrystal-
lization of the yellow prussiate of potash contained in the mass is proceeded
with. So soon as the retorts are empty, they are again charged with a fresh
supply of the ingredients, and the process is repeated. The gratings a, b, in
the retorts A, B, should be so disposed as to admit of casy removal and
replacement at pleasure. The cyanide of potassium is obtained in precisely
the same manner as the prussiate, by simply omitting the iron filings.
Having now described and particularly ascertained the nature of the said
Invention. and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is,-
First, the general construction and arrangement of apparatus for, and the
peculiar method or mode of producing the yellow prussiate of potash and
cyanide of potassium, as herein-before described and illustrated by the
Drawings hereunto annexed.
Second, the application and use of wood. charcoal, coke, or other similar

page_text: porous material, for the purpose of inaintaining the carbonate of potash in as
divided a state as possible when submitted to the action of heat and
ammoniacal gas, as herein-before described.
Third, the peculiar arrangement of furnace, provided with two fire-places
and suitable retorts for the manufacture of prussiate of potash and cyanide of
potassium, as herein-before described.
Fourth, the peculiar process for producing ammoniacal gas, and its com-
bination with the means described for making prussiate of potash and cyanide
of potassium, as herein-before described.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Twenty-second day of September, One thousand
eight hundred and fifty-nine.
J. HENRY JOHNSON. (L.s.)