IMPROVEMENTS: IN PROVISIONAL SPFIC
Year: 1855

page_text: LETTERS PATENT to George Chisholm, of St. John's Square, Clerkenwell,
in the County of Middlesex, for the Invention of "IMPROVEMENTS: IN
PROVISIONAL SPECIFICATION left by the said George Chisholm at the
Office of the Commissioners of Patents, with his Petition, on the 28th
December 1855.
I, GEORGE CHISHOLM, of St. John's Square, Clerkenwell, in the County of
Middlesex, do hereby declare the nature of the said Invention for IMPROVE-
MENTS IN THE MANUFACTURE OF ARTIFICIAL MANURE, to be as follows:-
To manufacture my improved artificial manure, I make use of leather, and
submit it to the action of hydrochloric acid in a gaseous form, and at an
elevated temperature; when saturated with the acid, I then pass through the
leather, carbonate of ammonia in a state of vapour, and in sufficient quantity
to neutralize the acid; the leather will now crumble into powder. In certain
descriptions of leather; I pass steam through it along with the hydrochloric
acid.
The carbonate of ammonia I obtain by submitting leather to distillation, and
forcing the vapour arising from it to pass through leather that has been acted
upon by acid. Chlorine and all the mineral acids will destroy the texture of
leather, but I prefer hydrochloric acid and sulphurous acid for the purpose.
The leather that has been acted upon by an acid may have such acid neutralized
by an alkaline-carbonate, such as potash, soda, &c. The leather may first be
acted upon by an alkaline carbonate and afterwards by an acid (mineral).
When leather is acted upon by a dilute solution of a mineral acid, heated to
or near to the boiling point, so as not to dissolve .but destroy its texture, and

page_text: then mixed with an alkaline carbonate, it may be easily reduced to powder.
I dissolve leather in boiling sulphuric acid, and with the solution, I cause it to
act upon bone or bone earth, or coprolite, so as to make a soluble phosphate
and an azotised compound.
The object is to render valuable the large quantity of refuse leather that is
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Chisholm in the Great Seal Patent Office on the
28th June 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
CHISHOLM, of St. John's Square, Clerkenwell, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of December, in the year of our
Lord One thousand eight hundred and fifty-five, in the nineteenth year of
Her reign, did, for Herself, Her heirs and successors, give. and grant unto
me, the said George Chisholm, Her special licence that I, the said George
Chisholm, my executors; administrators, and assigns, or such others as I,
the said George Chisholm, my 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 Man, an Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL MANURE," upon the condition
(amongst others) that I, the said George Chisholm, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and seals, 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 I, the said George Chisholm, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
To manufacture my improved artificial manure, I make use of leather, and
submit it to the action of hydrochloric acid in a gascous form, and at an

page_text: elevated temperature; when saturated with the acid, I then pass through the
leather, carbonate of ammonia, in a state of vapour, and in a sufficient quantity
to neutralize the acid; the leather will. now crumble into powder. In certain
descriptions of leather, I pass steam through it along with or before the
bydrochloric acid.
The carbonate of ammonia I obtain by submitting. leather to distillation,
and causing the vapour arising from it to pass through the chamber containing
the leather that has been acted upon.by.acid.
Chlorine and all the mineral acids will. destroy the texture of leather, but
I prefer hydrochloric acid for the purpose of the chamber process, herein-after
mentioned.
The leather that has been acted upon by an acid may have such acid
neutralized by an alkaline. carbonate, such as potash, or soda; or the leather
may first be acted upon by an alkaline carbonate, and afterwards. by
mineral acid..
Instead of preparing the manure from leather, as aforesaid,, the leather must
be acted upon by a dilute solution of a mineral acid, heated to or
or near. to the.
boiling point, so as not to dissolve but to destroy its texture; it is then mixed
with an alkaline. carbonate, & may be afterwards easily reduced to powder..
According to another method of manufacturing artificial. manure, I decom-
pose leather, in a dilute sulphuric acid, heated to the boiling point, and this
result I cause to act upon bone or bone earth, or coprolite,, so as to make a
soluble phosphate and an azotised compound.
The object of my Invention is to render valuable as a manure. refuse leather
that is otherwise comparatively useless.
"MODE OF MANUFACTURING ARTIFICIAL MANURE."
I construct a brick-built arched structure, which I denominate a gasing
chamber, of about twenty-three feet long, thirteen feet wide, and twelve feet
high, the walls to be thirty-two inches thick. The entrance to the chamber is
by a doorway formed at one of the ends, which are brick-built. of the same
thickness. The doorway is simply large enough to allow a. man to pass
through; this aperture is shut when required by a. wooden door lined in. the
inside with gutta percha. At the end of the chamber, opposite the door, two
stones are recessed into the wall about four feet from the ground, near the
middle of the wall, and twelve. inches apart; each stone has a circular boring,
four inches in diameter, to admit an earthenware. pipe. One the crown of
the arch, three stones are also introduced one about twelve inches from each
end of the arch, the third one in the centre. The stone at the end of the

page_text: chamber above the door, and the centre one, have a circular boring four inches
in diameter, but in the stone at the opposite end of the arch the boxing need
only be one inch in diameter; a lead pipe, having a main joint and stop-cock,
'is fixed in the two stones having the four-inch holes. In the one-inch hole a
lead pipe is also to be fixed and fitted with a stop-cock. In the inside of the
'chamber, immediately below the stones let into the end wall, I place two stone
ware receivers, holding about eighteen gallons each, to receive any condensed
fluid that may pass through the pipes; I adapt one below each hole, to each of
them a stone ware pipe, which should project about a foot through the wall on
the outside, and on the inside are turned down and dip into the receiver. The
bottom of the chamber I pave with flag stones; upon the floor of this chamber
I spread refuse leather shavings to about the depth of four inches, leaving a
passage for the workmen to pass to and fro. Upon perforated wooden trays or
common hurdles I spread leather lightly about three inches deep; I fill the
chamber with these trays; they should be supported so that when they are
built one above another, there shall be an inch space betwixt the leather on
the one tray, and the bottom of the next above. In filling the chamber, I
begin at the end where the acid receivers are placed, and filling the chamber
to the full height, recede backwards to the door. The chamber being thus
filled, the door is closed, and the joints well secured by luting or an india-rubber
joint packing. Opposite the two stone ware pipes projecting from the chamber,
and about six feet from them, I erect two iron pans or retorts, with a furnace
under each report. The size of the retorts in proportion to the chamber before
described should be about three feet in diameter, and about twenty-two inches
deep, and made of iron half an inch in thickness.
I place the furnace bars about 6 inches below the bottom of the retorts,
whence the flame rises and plays round the sides. One retort has a cast-iron
domed top or cover, which is luted to the body of the retort when in action; to
this top is attached an iron pipe slanting downwards from the retort to a con-
densor containing water, which is simply a covered cask or other vessel, into
which the pipe dips about six inches; an exit pipe for the passage of the gases
evolved in the retort is also fixed on the top of the condensor, communicating
with one of the stone ware pipes before mentioned, projecting from the end
wall of the arched chamber. The mouth of the other' retort is to be covered
with a slab of siliceous freestone perforated with two holes, one about two
inches in diameter, and the other four inches in diameter. Into the small
hole a leaden syphon-shaped pipe with a funnel is placed, and into the other
a stone ware elephant head is fitted; stone ware pipes are conducted from
'this, direct to the other and remaining stone ware pipe projecting from the

page_text: arched chamber.
I fill the retort with the iron cover about two-thirds full of
the thickest refuse leather shavings or old shoes, or other old leather, and
secure all the joints by luting; into the other retort with the stone slab I.put
one hundred pounds of the chloride of sodium (common salt), and also secure
the joints by luting; I attach to the pipe in the stone immediately .over the
door of the chamber a gutta percha.tube, having a union joint, and conduct
it into the chimney. To the middle pipe let into the arch of the chamber, I
fix either a lead or gutta percha tube, also having a union joint, and bend or
arch it over so as to dip into an earthenware 'condenser, about half full of a
weak solution of sulphuric acid. Having charged the arched chamber, also
the several retorts and condensors, as described, preparatory to the manu-
facture, I open. the cock of the gutta percha tube communicating to the
chimney, and shut off the other two; I then light the fire under the retort
into which the leather has been put, and keep up a brisk fire for about
three hours. The gases evolved during the destructive distillation of the
leather will deposit tar, ammoniacal liquor, and other matters in the cask
condensor, and will pass into the chamber still considerably charged with
ammoniacal gas, which will be absorbed by the leather in the chamber in its
passage through amongst it. At the small pipe on the arch of the chamber, I
examine from time to time the state of the interior, by the emission of gas on
turmeric paper; when this test indicates the presence of ammonia, by turning
the colour of the turmeric paper brown, I turn off the communication with 'the
chimney, and open that from the centre of the arch connected with the earthen-
ware condenser, containing diluted sulphuric acid. The foul gases from this
condenser should be conducted by a tube under the furnace fire to be burned:
When the operation with this retort is over, which takes about three hours, I
disconnect the communication between the gasing chamber and retort, and
close up the orifice of the pipe into the chamber with a plug, and lute 'it with
clay. I now remove the sulphuric acid condenser connected with the centre
pipe from the arch of the chamber, and replace it with another condenser half
filled with water, and let the pipe dip into this about two inches. The fire
under the retort into which the salt has been put is now to be ignited, and
seventy-four pounds of concentrated sulphuric acid is to be gradually poured
into the retort,.through the syphon pipe and funnel. Hydrochloric acid gas
will now pass by the pipe from this retort into the gasing chamber; the heat
should be gentle at first, but increased during the second hour, and rather a
brisk fire kept up during the remainder of the operation, which altogether will
take about three hours. While this operation is going on, the other retort
should be recharged with leather, and a fire lighted under it, immediately the

page_text: .
At
hydrochloric acid gas has ceased to pass over; when this gas has ceased to
pass, over, the leather in the arched chamber is again a second time exposed
to the influence of the gases arising from the 'distillation of the leather in the
retort; when the gas from the leather ceases to pass over from the retort, the
operation is so far complete. The chamber is then to be left for 8 or ten
hours, having all its communications with the exterior atmosphere closed.
the end of this time, the chamber may be emptied of the contents, which are
spread upon a, dry floor and exposed to a current of air, and allowed to remain
so exposed for a week, when it may easily be reduced to fine powder. When
the leather in the gasing chamber is of a dry nature, it is desirable to turn on
a jet of steam into the chamber for about ten minutes or quarter of an hour, in
order to impart a general moisture to the leather, in which state it is more
favorable for the subsequent operations...
Nitrate of potash or nitrate of .soda may be decomposed by its equivalent of
sulphuric acid in the retort. instead of salt; and the nitrous gases passed into
the gasing chamber to act upon the leather; it is, however, considerably more
expensive and without, an equivalent advantage.<
.The succession of the processes in the gasing chamber may be reversed;
that is. to say, the hydrochloric acid gas may be applied first, and then the
ammonia process; but, from experience; I prefer the whole operation to be
conducted as herein-before described.
Another mode of manufacturing manure according to my Invention is as
follows: Put one hundred and twelve pounds weight of bone ash into a
strong tub, and work it into a thin pulp with twenty gallons of water, stirring
it well with a wooden bar, and while in motion keep pouring into it, in a small
stream, seventy-six pounds of concentrated sulphuric acid; after it has stood
about four hours, I pass steam into it for half an hour; stirring all the time;
then let it stand for twenty-four hours. The pulp is now to be removed into
a series of tall casks, and further diluted with water; when it has settled, the
supernatant liquor, consisting of the clear superphosphate of lime, may be run
off. by a syphon, from above the deposit of sulphate of lime. More water is
now.to.be, mixed with the precipitate in the casks, and after subsidence, the
supernatent liquor is to be drawn off. The last and weaker liquor from one
cask should be employed to wash the deposit in another cask. The collected
liquors are to be put into an enamelled iron pan, which has fitted to it a steam
jacket, and concentrated therein, until the liquor acquires the consistence of a.
syrup; add to this while hot five hundred pounds of leather that has been
acted upon in the gasing chamber, and stir it well with a wooden bar; when.
well mixed remove and spread the compound on a dry floor, and after allowing

page_text: -10.co remain about a week, it is to be reduced to .nne powder by any suitablC
means. In manufacturing manure according to the process last herein
described, on a large scale, the same description of plant may be adopted' as
that made use of by the manufacturers of soda, in obtaining their clear solution
of soda.
.
According to another part of my Invention, I prépare the superphosphate of
lime liquor, as last herein-before described, but the concentration is not to be
carried so far, and add to the solution in, the iron pan with steam jacket, fifteen
pounds of concentrated sulphuric acid; then introduce gradually unprepared
leather shavings, stirring all the time with a wooden bar, until five hundred
pounds of leather has been reduced and formed into an homogeneous mass';
then add twenty-eight pounds of finely powdered bone ash, mix the whole well
by stirring, then turn off the steam which has been kept on during the whole
operation of mixing and, stirring with wooden bars. The mass is now to be
removed from the steam pan and thrown upon a paved floor; wooden bars or
other implements of wood should be used in handling the compound. In a
few days this mass will split in various directions, and may be ground to
powder by edge runners, or by any of the usual grinding apparatuses.
By another mode of proceeding, according to my. Invention, into a steam
pan, as before described, I put twenty gallons of water and fifty pounds of
concentrated sulphuric acid, and keeping the steam full on, gradually add five
hundred pounds of unprepared leather shavings, stirring it all the time with 'a
wooden bar. When the leather has been reduced to a smooth pulp, add one
hundred pounds of finely-ground bone ash, which I mix intimately, and
then remove the mass to a paved floor, as described; this mass should stand
a week before grinding. Instead of the twenty gallons of water before
mentioned, I sometimes use ten gallons of water, with ten gallons of the
solution of sulphate of ammonia from the condensed.
According to another part of my Invention, I dilute fifteen pounds of
sulphuric acid with one hundred pounds of water, moisten unprepared leather
shavings or other refuse leather with the solution, and put it in heaps con-
taining from five to twenty tons; in a few weeks a considerable portion of the
bulk will be reduced to powder; this is a rude operation causing a disagreeable
odour, and is not so economical as the other processes herein-before described.
The ammoniacal liquid found in the condensers should be filtered through
charcoal taken from the leather retort, and this solution of carbonate of
ammonia I saturate with sulphuric acid, so as to convert it into a sulphate
and I prefer using this solution of sulphate of ammonia, instead of water, in
the preparation described in the fourth part of my Invention. When the

page_text: compounds prepared according to the second and third parts of my Invention
are too stiff to work easily, I had a quantity of the filtered solution of sulphate
of ammonia.
Hydrochloric acid may also be used instead of sulphuric acid, in the pre-
parations according to the third, fourth, and fifth parts, but it does not dry so
well; it also absorbs moisture from the atmosphere, the manure becoming
lumpy, and commercially it is not so valuable as the sulphuric acid.
I have mentioned bone ash, that is, bones burnt and ground, but any earth
rich in phosphates may be used, such as coprolites; and I recommend the
clear solution of superphosphate of lime to be used in my improved manu-
facture of manure, as being a preparation upon which the former can
demand..
I have mentioned only one gasing chamber for acting upon the leather, but
a series of chambers could be economically worked, the waste gases from one
chamber passing through another, and they may be so arranged that one or
more chambers might be emptied and filled every day, and at the same time
allowing a longer period for the leather to remain under the influence of the
various gases.
I do not confine myself, to the quantity of acid used to set upon the leather
or bone ash, nor to the proportion of bone ash in the manure; it will be
'evident, that the operator can make the phosphate or the ammonia prepon-
derate at pleasure in the manure. For instance, the leather that has passed
through the gasing chamber process may be estimated to contain fifteen per
cent. of ammonia. If I desire to make a manure containing twenty-five per
.cent. of superphosphate of lime, and make this superphosphate of lime as it
is generally done for commercial purposes, I shall have nearly three hundred
pounds of sulphate of lime in a ton; but if I make the phosphate soluble in
the mode I have described in the second part of this my Invention, then I
can substitute three hundred pounds of leather that has been acted upon,
instead of the sulphate of lime, making, the manure so much richer in
ammonia.
In witness whereof, I, the said George Chisholm, have hereunto set my
hand and seal, this Twenty-eighth day of June, in the year of our
Lord One thousand eight hundred and fifty-six.
GEO. CHISHOLM. (L.S.).