AN IMPROVED METHOD OF OBTAINING COMPOUNDS OF NITROGEN
Year: 1860

page_text: LETTERS PATENT to John Chisholm and George Chisholm, both of Mark
Lane, in the City of London, Manufacturing Chymists, and Robert
Thomas Kent, of the same Place, Esquire, for the Invention of "AN
IMPROVED METHOD OF OBTAINING COMPOUNDS OF NITROGEN."
Sealed the 19th April 1861, and dated the 24th October 1860.
PROVISIONAL SPECIFICATION left by the said John Chisholm, George
Chisholm, and Robert Thomas Kent, at the Office of the Commissioners
of Patents, with their Petition, on the 24th October 1860.
We, JOHN CHISHOLM and GEORGE CHISHOLM, both of Mark Lane, in the
City of London, Manufacturing Chymists, and ROBERT THOMAS KENT, of the
same Place, Esquire, do hereby declare the nature of the said Invention for
"AN IMPROVED METHOD OF OBTAINING COMPOUNDS OF NITROGEN,' to be as
follows:-
'The object of our Invention is to obtain compounds of nitrogen. For this
purpose we take the products of combustion, that is to say, the atmospheric
air that has passed through a fire or furnace, with the matters which it carries
away with it, and subject them to the action of hydrogen obtained by the
decomposition of steam or from other source, or instead of first decomposing
steam in order to obtain the hydrogen, we sometimes bring steam in various
[Price 8d.1

page_text: forms or conditions into contact with the products of combustion, so that they
may be acted on by the hydrogen of the steam. And we sometimes also use
electric action in our process. In addition to the foregoing agency or agencies,
we sometimes use compounds of potassium, sodium, barium, or strontium, or
substances of that class, to effect the combinations and take up the products
according to the particular nitrogenous compound we desire to obtain.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Chisholm, George Chisholm, and Robert Thomas Kent,
in the Great Seal Patent Office on the 21th April 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
CHISHOLM and GEORGE CHISHOLM, both of Mark Lane, in the City of London,
Manufacturing Chymists, and ROBERT THOMAS KENT, of the same Place,
Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing dato the Twenty-fourth day of October, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said John Chisholm, George Chisholm, and Robert Thomas Kent, Her
special licence that we, the said John Chisholm, George Chisholm, and Robert
Thomas Kent, our executors, administrators, and assigns, or such others as
we, the said John Chisholm, George Chisholm, and Robert Thomas Kent,our
executors, administrators, and 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 Mau, an Invention for "AN IMPROVED METHOD OF OBTAINING COMPOUNDS OF
NITROGEN," upon the condition (amongst others) that we, the said John
Chisholm, George Chisholm, and Robert Thomas Kent, our executors or
administrators, by an instrument in writing under our or their hands and seals,
or under the hand and seal of one of us or them, 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
said Letters Patent.
NOW KNOW YE, that we, the said John Chisholm, George Chisholm,
and Robert Thomas Kent, do hereby declare the nature of the said Invention,

page_text: and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is to say:-
The object of our Invention is to obtain compounds of nitrogen. For this
purpose we take the products of combustion, that is to say, the atmospheric
air that has passed through a fire or furnace, with the matters which it carries
away with it, and we subject them to the action of hydrogen obtained by the
decomposition of steam, or from other source; or instead of first decomposing
steam in order to obtain hydrogen, we sometimes bring steam in various,
forms or conditions into contact with the products of combustion, so that they
be acted on by the hydrogen of the steam; and we sometimes, also, use
electric action in our process. We sometimes use, in addition to the foregoing
agency or agencies, compounds of potassium, sodium, barium, or strontium, or
substances of that class, to effect combinations and take up products, as
herein-after described, according to the particular nitrogenous compound
we desire to obtain.
may
We now proceed particularly to describe in what manner our Invention
may be carried into effect.
We provide a furnace with arrangements for intercepting its products of
combustion in their escape from the fire, and for conveying them into a
chamber, vessel, or receptacle, or into chambers, vessels, or receptacles called
herein the "operating receptacles," and placed at the side of the furnace or
otherwise conveniently in respect thereof, into which receptacle or receptacles
we admit hydrogen obtained beforehand from any convenient source; or we
adinit steam, and decompose it therein, so that it may set free its hydrogen;
the hydrogen so admitted or produced combines with the nitrogen of the
products of combustion, and forms ammonia, which is intercepted in its escape,
separated from the waste products and absorbed, taken up, or received by
water or other agent,selecting a particular medium so as to receive it according
to the compound or product we desire to obtain; the waste products are
allowed to escape into the chimney or elsewhere. It sometimes happens, even
when the operation is conducted with considerable care, that ammonia is only
partially formed or not formed at all; in these instances we assist or effect the
combination of the hydrogen and nitrogen by the agency of electricity. In
producing ammonia as above described, cyanogen will also be formed, and this
may be separated from the aminonia by passing the results of our processes,
that is, the products of combustion treated with hydrogen or steam, as afore-
said, with or without electric agency, over a caustic alkali.
To explain our methods more in detail, we premise that we are operating
on the products of a furnace furnished with a chimney. We cause our

page_text: operating receptacle to communicate with the furnace by a pipe or flue
furnished with a damper, and so placed that the products of combustiou may
pass into it from the fire. We may here mention that in properly set
furnaces the gascous or aeriform products of combustion chiefly consist of
nitrogen, carbonic acid, and carbonic oxide, but the nitrogen is in the largest
proportion. The receptacles in which the products are treated with hydrogen
or steam lead into a chamber or vessel which contains the agent intended to
absorb or receive the ammonia, which chamber or vessel we call in this
Specification the "ammonia chamber." From this chamber the waste products
having parted with the ammonia, escape through a pipe or passage into the
chimney. The chimney has a damper or register at bottom, as usual, which
we close when we begin to work, and we open the communication between the
fire and the operating receptacles, and between the ammonia chamber and
the chimney, so that the products pass from the fire into and through the
operating receptacles; and when the natural draft is insufficient for that
purpose, we use a jet of steam injected into the chimney, or a fan, or a pump,
or other known means of driving or propelling aeriform matters. We
generally first allow the products to pass for a short time through the operating
receptacles into the chimney without being operated on to expel atmospheric
air from the receptacles; we then proceed to treat them according to our
Invention; for this purpose, according to one mode we place at the side of
the furnace a retort or a series of retorts, preferring about six, set in the same
manner as retorts used in the manufacture of coal gas, and having in like
manner a fire beneath them. We nearly fill our retorts with coal or charcoal,
and bring them to a high temperature, and lead through them the products of
combustion to be operated on. Superheated steam is then admitted in minute
jets into the retorts through conveniently placed pipes, and at such a tem-
perature as not to reduce that of the retorts. The steam in passing over the
coke or charcoal in the retorts becomes decomposed by its contact therewith,
carbonic acid and carbonic oxide being thus formed and the hydrogen set free,
which in a nascent state combines with the nitrogen of the products of
combustion, and so forms ammonia, which is intercepted in escaping from the
retorts by a liquid or other agent placed in a vessel or "ammonia chamber,"
communicating with the retorts by pipes or retort necks. The waste products
not so intercepted escape into the the chimney. Old or refuse iron, iron
filings, or iron chain, may be mixed with the coal or charcoal in the retorts to
accelerate the decomposition of the steam. When the operation is to be
assisted by electric agency, we introduce into the necks of the retorts or the
passages leading from the retorts into the ammonia chamber, a number of

page_text: streams or currents of electricity, for which we prefer to place therein the
contrivance known to electricians as an "interrupted circuit," or we use some
other known arrangement for producing a series of electric sparks. This
electric agency promotes or effects the combination of the hydrogen and
nitrogen. We prefer that the capacity of the passage in which such electrical
contrivance is placed should be one-fourth of that of the retort, or even less,
and should widen in area towards the ammonia chamber, to prevent back
draft. The products of combustion from the fire which heats the retorts may
be carried therefrom into the retorts, to be treated according to our
Invention.
According to another mode, in which instead of passing steam into the
products of combustion we admit hydrogen produced before hand, we fit in a
chamber a number of indepen lent metal nozzles or mouths, each intended for
the passage of a jet of hydrogen; opposite the aperture of each nozzle is
placed a metal knob or ball, at a distance of about a quarter of an inch there-
from, one knob for each nozzle or jet. Each knob is at the end of a metal
rod, connected by a wire to an electrical machine or other means of generating
electricity. The knobs are wholly disconnected from the nozzles, and are
introduced into the chamber in an insulated state. Into this chamber we
admit the products of combustion to be operated on, and as soon as they have
filled the chamber and begin to pass out of it, we introduce streams of
hydrogen into the nozzles. These streams emerge from the mouths or orifices
of the nozzles in jets, and we send continuous currents of electricity into the
knobs, thereby producing sparks between the knobs and the nozzles, which
cause the hydrogen to combine with the nitrogen of the products,and produce
ammonia. The products escape into an ammonia chamber, in which the
ammonia is taken up or absorbed, as in water, for example, the water being
admitted into the chamber through roses or perforated spreaders, falls in
showers into a channel or furrow at the bottom of the chamber, along which
it flows in a continuous stream (or if cot continuous the liquid should be
frequently changed), the water converts it into liquor ammonia. The orifice
through which the volatile products escape from this chamber is at the surface
of the water, or so placed with respect to the channel that the gases in
escaping may be forced to come in contact with the water and any ammonia
still left in the gases will be thereby intercepted by the water.
According to a third mode the products are passed into cold set retorts, in
which case we prefer that they should carry with them from the fire some
unburnt carbon or smoke. Into these retorts superheated steam is also
introduced, and the products and the steam mingle and pass together into a

page_text: chamber, which we call the "electric chamber" (about one-fourth of the size
of a retort), having fitted within it a screen of platina wire, kept incandescent
by an electric or voltaic current, conducted to it by wires from an electrical
machine or other source of electricity. The mingled steam and products of
combustion pass through the interstices of the incandescent platina, by the
heat of which they are decomposed; the oxygen and carbon combining form
carbonic acid and carbonic oxide, while the nascent hydrogen combining with
the nitrogen produces ammonia, a combination which may be assisted by
passing currents of electricity through the aeriform matters, as before
described. The products pass off into an ammonia chamber, where the
aminouia is taken up and the waste matters escape into the chimney.
The various preceding arrangements may of course be readily applied to
furnaces without chimneys, the slight obvious modifications necessitated
requiring no special description.
The ammonia produced in our process may, as before stated, be intercepted
by or received in water to form liquor ammonia, or in an acid solution, or in
other intercepting,absorbing, or receiving medium, according to the particular
product required. For example, if received in sulphuric acid, sulphate of
ammonia will be produced; if in hydrochloric acid, chloride of ammonium
will be produced, and so forth. The absorbing agent may be in some cases
placed in trays fitted in an "ammonia chamber," consisting of a vessel or
chamber similar to that used in purifying coal gas, through which chamber
the escaping gases are caused to pass, and the ammonia is absorbed thereby :
for example, the trays may carry biphosphate of lime, in passing through
which the ammonia forms therewith a mixture of phosphate and sulphate of
ammonia, which is a valuable manure. We sometimes find it advisable to
cool the gases by a refrigerator just before they enter the ammonia chamber
or before they are acted on by electricity.
We
The cyarogen which we produce in obtaining ammonia according to our
Invention may, as before stated, be separated from it by passing theresults of
our processes over a caustic alkali, such as compounds of potassium, sodium,
barium, strontium, or substances of that class, by which the cyanogen will be
taken up and combinations effected forming compounds of cyanogen.
place the caustic alkali for this purpose in a passage or chamber, through
which the products are caused to pass immediately before they enter the
ammonia chamber. The products of combustion may, when desired,be freed
from carbonic acid previous to their entering the retorts by passing them direct
from the fire over a hydrate of lime, in the same manner as is done with coal
gas for a similar purpose.

page_text: We do not restrict ourselves to any particular arrangementofapparatus for
carrying our Invention into effect, and the steam, hydrogen, and electricity
which we use may be obtained by any known means.
Although we haveherein particularly described certain modes of performing
the Invention, we do not restrict ourselves to them, as the same may be varied
so only that the distinctive character of the Invention as herein described be
retained.
Throughout this Specification what we understand by the expression
"products of combustion" is the atmosphericair that has passed through the
fire or furnace with the matters which it carries away with it.
Having now described the nature of our said Invention, and the mode in
which the same may be carried into effect, we declare that what we claim as
new in our improved method of obtaining compounds of nitrogen is taking
products of combustion and subjecting them to the action of hydrogen obtained
in any desirable manner, or to the action of steam, decomposing the steam so
that its hydrogen may act on the said products, using, in addition, electric
action or not, as desirable.
In witness whereof, we, the said John Chisholm, George Chisholm, and
Robert Thomas Kent, have hereunto set our hands and scals, this
Twenty-fourth day of April, in the year of our Lord One thousand
eight hundred and sixty-one.
25 Witness,
M. HENRY, Patent Agent,
84, Fleet Street,
London.
JNO. CHISHOLM. (L.S.)
GEO. CHISHOLM. (L.S.)
ROBERT T. KENT. (L.S.)