IMPROVEMENTS IN THE TREATMENT, MANUFACTURE, AND USE OF EXPLOSIVE COMPOUNDS.
Year: 1868

page_text: LETTERS PATENT to George Clark, of No. 9, Northumberland
Street, Strand, in the County of Middlesex, for the Invention of
*"IMPROVEMENTS IN THE TREATMENT, MANUFACTURE, AND USE OF EXPLOSIVE
COMPOUNDS.
Sealed the 7th May 1869, and dated the 10th November 1868.
PROVISIONAL SPECIFICATION left by the said George Clark at the
Office of the Commissioners of Patents, with his Petition, on the
10th November 1868.
1, GEORGE CLARK, of No. 9, Northumberland Street, Strand, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE TREATMENT, MANUFACTURE, AND USE OF EXPLOSIVE
COMPOUNDS," to be as follows:-
This Invention relates to improvements in the treatment, manufacture,.
and use of explosive compounds, which improvements I for convenience
of description divide into three parts, namely:-
1st. A new mode of treatment in manufacturing pyroxyline whether in
the form of gun cotton, gun cloth, wood powder, or any other explosive
[Price 8d.]

page_text: Compound produced by treating vegetable more with mixed nitric and
sulphuric acids.
2nd. The formation of explosive compounds produced by the process
herein-after described as well as of compounds produced by my Inven-
tion for which I obtained Letters Patent, numbered 1210, and dated the
11th April 1868, into pellets or compressed charges.
3rd. An improved mode of applying glycerine oil in combination with
other substances for explosive purposes.
1st Part. My new mode of treatment in manufacturing pyroxyline
has for its object,-
Firstly. To dispense with one of the well-known processes of its manu-
facture, which consists in washing such pyroxyline for the purpose of
separating from it the excess of acids mechanically adhering to the
compound after it has been withdrawn from the acid bath and drained
and pressed or otherwise partially dried.
Secondly. To utilize apart of the excess of acids above referred to for
the purpose of increasing the strength, specific gravity, and uniformity,
and reducing the cost of the explosive produced.
The washing process adopted in the manufacture of gun cotton and
other forms of pyroxyline which occupies much time and attention,
requiring a large and continuous supply of cold running water, and is
carried on for several days at considerable expense, is by my Invention
entirely obviated and rendered unnecessary, and a part of the excess of
acids above referred to as adhering to the pyroxyline after it is with-
drawn from tlie acid bath and partially dried instead of being wasted by
being washed away with the water in the washing process, as before men-
tioned, is turned to account to improve the properties of the pyroxyline
as an explosive compound. To effect these objects I first dilute the
excess of acids adhering to the pyroxyline (after it has been withdrawn
from the acid bath and drained) with sufficient water to prevent oxidisation
of the pyroxyline, and I allow part of such diluted acids to drain off in
a strainer, leaving the compound in a moist state. I then mix the com-
pound with carbonate or bi-carbonate or chlorate or chromate of potash,
that is, with one only or more than one of those substances, the quantity of
the one or the other or of any of them being proportioned to the quantity
of free nitric and sulphuric acid adhering to the pyroxyline in its
aforesaid moist state. The effect of this mixing is a chemical action

page_text: whereby the free acids in excess are neutralized and the continuous
washings of which the object is to separate such excess of acids from
the pyroxyline, are rendered unnecessary, and at the same time the
properties of the pyroxyline as before-mentioned are improved.
2nd Part. The object of this improvement is to regulate and fix the
charges (for small arms, ordnance, or blasting) of explosive compounds
produced by this my said Invention, or by the Invention for which I
obtained Letters Patent, numbered 1210, and dated the 11th April 1868,
and that object I attain in the following manner :-I form a box or case of
the proper form and size to fit into the cartridge case of a breech-loading
or the chamber of a muzzle-loading gun, or into the blasting hole
intended to receive the charge. Such box or case may be made of metal,
paper, or cloth, or other suitable material closed at one end and open at
the other. Inside this case I introduce a determined charge, and I form
it into a compressed pellet or charge of the explosive compound with
the required degree of compression, and I then close and hermetically
seal the open end, leaving at one end a small orifice to be placed over
the fulminating cap for ignition. Either the materials with which the
pellet cases are formed and closed are impervious to water, or I make
them so by covering the pellet cases when loaded with india-rubber
or other waterproof varnish or coating. The pellet thus protected in
its case is waterproof, and, consisting of the proper charge, is inserted
and rammed in the cartridge, gun, or blasting hole into which it is
made to fit. Thus there is no difficulty or danger in loading, and
uniformity of explosive effect is insured.
3rd Part. The improvement forming the third part of my Invention
refers to the use of glycerine oil in combination with other substances
for explosive purposes in a way not hitherto practised. It has been
proposed to combine nitro-glycerine with porous materials in a com-
minuted state, and also with gun cotton, but it is to be apprehended.
that the dangerous properties of that highly explosive compound (nitro-
glycerine) and its liability to decomposition will not be entirely remedied
by any admixture with other materials. The principle of my improve-
ment is to make use of glycerine oil as an adjunct to pyroxyline by
treating the former with nitric and sulphuric acids, not alone, but in
combination and mixed with vegetable fibre. The method by which I
propose to proceed is to mix glycerine oil with textile or other vegetable
fibre in a comminuted state in sufficient quantity to impregnate the

page_text: substances so used uniformly with the oil without excess, and then to
treat the mixture with nitric and sulphuric acids in the way usually
employed for the manufacture of gun cotton. By this process instead of
combining nitro-glycerine with pyroxyline, as already proposed, I produce
glycero-pyroxyline which is a different compound from that obtained
by mixing nitro-glycerine with gun cotton or any other form of
pyroxyline.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Clark in the Great Seal Patent Office on
the 10th May 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
CLARK, of No. 9, Northumberland Street, Strand, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of November, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Clark, Her special licence that I,
the said George Clark, my executors, administrators, and assigns, or such
others as I, the said George Clark, 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 terin 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 TREATMENT, MANU-
AND USE OF EXPLOSIVE COMPOUNDS," upon the condition (amongst
others) that I, the said George Clark, my executors or administrators,
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 Clark, do hereby declare
the nature of my said Invention, and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the
following statement :-
This Invention relates to improvements in the treatment, manufacture,
and use of explosive compounds, which improvements I for convenience
of description divide into the following parts, namely,-
1st. A new mode of treatment in manufacturing pyroxyline whether
in the form of gun cotton, gun cloth, wood powder, or any other
explosive compound produced by treating vegetable fibre with mixed
nitric and sulphuric acids.
2nd. The formation of explosive compounds produced by the process
herein-after described as well as of compounds produced by my Inven-
tion for which I obtained Letters Patent numbered 1210, dated the
11th April 1868, into pellets or compressed charges.
3rd. An improved mode of applying glycerine oil in combination
with other substances for the production of an explosive compound.
1st Part. My new mode of treatment in manufacturing pyroxyline,
the resulting product whereof for the sake of distinction I term pyro-
pulver, has for its object,-
Firstly. To dispense with one of the well-known processes of its
manufacture, which consists in washing such pyroxyline in water for
the purpose of separating from it the excess of acids mechanically
adhering to the compound after it has been withdrawn from the acid
bath submitted to the drench bath, drained, and pressed or otherwise
partially dried.
Secondly. To utilize a part of the excess of acids above referred to for
the purpose of increasing the strength, specific gravity, and uniformity,
and reducing the cost of the explosive produced.
The washing process adopted in the manufacture of gun cotton and
other forms of pyroxyline which occupies much time and attention,
requiring a large and continuous supply of cold running water, and
which is carried on for several days at considerable expense is by my
Invention entirely obviated and rendered unnecessary, and a part of the
excess of acids above referred to as adhering to pyroxyline after it is
withdrawn from the acid and drench baths instead of being wasted *by
being carried away with the water as before mentioned in the washing
process is turned to account to improve the properties of the pyroxyline
as an explosive compound. To effect these objects after the pyroxyline

page_text: has been withdrawn from the acid bath and drenched with sufficient
water to prevent its oxidisation I allow part of the diluted acids to
drain off in a strainer, leaving the compound in a moist state. I then
add to and mix with the compound by frequent stirring and agitation
carbonate or bi-carbonate or chlorate or chromate of potash, that is one
only or more than one of those substances, the quantity of one or the
other or any of them so added and mixed being proportioned to the
quantity of diluted acids adhering to the pyroxyline in its aforesaid
moist state. The rule to regulate the said proportions is the chemical
equivalent of the potash contained in the carbonate, bi-carbonate,
chlorate, or chromate of potash mixed in the pyroxyline as aforesaid to
the nitric acid adhering thereunto in excess, so as to produce by
chemical conversion resulting from affinity nitrate of potash intimately
combined with the pyroxyline without any or with little excess
of any of the compounds of potash mentioned. The effect of this
chemical action is to neutralize the acids in excess and render washing
in water (of which the object is to separate such excess of acids from
the pyroxyline) unnecessary. At the same time this process improves
the properties of the pyroxyline so treated as an explosive compound by
rendering it less sensitive to atmospheric influence and more uniform in
strength throughout the mass.
2nd Part. The object of this improvement is to regulate and fix the
charges in the shape of condensed pellets (for small arms, ordnance, or
blasting) of explosive compounds produced by this my said Invention
or by the Invention for which I obtained Letters Patent, numbered
1210, dated the 11th April 1868, and that object I attain in the
following manner :-I form a box or case of the proper size and form to
contain the charge and fit into the cartridge case of a breech-loading or
the chamber of a muzzle-loading gun, or into the blasting hole intended
to receive the charge; such box or case may be made of metal, paper,
or cloth, or other suitable material. Inside this box or case I introduce
and form into a pellet a determined charge of the explosive compound
with the required degree of compression, and I then close and her-
métically seal the case, leaving at one end a small orifice to be placed
over or under a fulminating cap or patch for ignition. Either the
materials with which the pellet cases are formed and closed are
impervious to water, or I make them so by covering the pellet case
when loaded with india-rubber or other waterproof varnish or coating.
The pellet in its case is inserted and rammed in the cartridge, gun, or

page_text: blasting hole into which it is made to fit, and thus there is no difficulty..
or danger in loading, and uniformity of charge and explosive effect is
insured, but the pellet case I prefer under this improvement is made of
copper, brass, or steel, or other metal; being hermetically sealed it is
water-tight, and by closely confining the explosive material adds to its
propulsive force.
3rd Part. The improvement forming the third part of my Invention
refers to the use of glycerine oil in combination with other substances
for explosive purposes in a way not hitherto practised. It has been
proposed to combine nitro-glycerine with porous materials in a commi-
nuted state, and also with gun cotton and gun wood, but it is to be
apprehended that the dangerous properties of that highly explosive
compound (nitro-glycerine) and its liability to decomposition, which is
a source of danger, will not be entirely remedied by any admixture with
other materials. The principle of my improvement is to make use of
glycerine oil as an adjunct to pyroxyline in manufacturing the latter by
treating the former with nitric and sulphuric acids, not alone, but in
combination and mixed with vegetable fibre. The method by which I
propose to proceed is to mix glycerine oil with textile or other vegetable
fibre in a fibrous or comminuted state (that is, in small grains or
particles) in sufficient quantity to impregnate the said substances so
used uniformly with the oil to the extent they will absorb the oil
without excess, and then to treat the mixture with nitric and sulphuric
acids in the way usually employed for the manufacture of
By this process instead of combining nitro-glycerine with! pyroxyline as
already practised or proposed, I produce glycero-pyroxyline which is a
different compound from that obtained by mixing nitro-glycerine with
gun cotton or any other form of pyroxyline.
gun cotton.
Having described the nature of my said Invention and the manner
in which the same is to be carried into effect, I wish it to be understood
that what I claim and desire to have secured to me by the herein-before
in part recited Letters Patent is,-
Firstly. Mixing carbonate, bi-carbonate, chlorate or chromate of
potash with pyroxyline after the pyroxyline has been withdrawn from
the acid and drench baths, in the manner described in the first part of
the above-mentioned improvements.
Secondly. The formation into pellets of any explosive compound made
by the process herein-before described as the first part of the aforesaid

page_text: improvements, or made under Letters Patent granted to me the 11th
April 1868, numbered 1210, by confining such explosive compound in a
case of paper, cloth, or metal, as described in the second part of the
above-mentioned improvements.
Thirdly. The mode of applying glycerine oil in combination with
vegetable fibre, and treating the two substances so combined with nitric
and sulphuric acids by the method usually employed in the manufacture
gun cotton, and thereby producing what I term glycero-pyroxyline
in the manner described in the third part of the above-mentioned
improvements.
of
I have further to explain that in making experimental trials of the
manufacture and use of the explosive compound which forms the object
of this Invention and which I term pyro-pulver, for the purpose of
perfecting the manufacturing processes thereof I have ascertained in
using sawdust as the form of vegetable fibre to be treated in the manner
herein-before described and referred to, that for the production of a
heavy granulated explosive by means of my said Invention it is
advantageous by sifting to separate from sawdust as it comes from
the mill the larger grains or particles of wood, and to submit the grains
or particles so separated to the processes of my said Invention, whereby
I obtain granulated pyro-pulver sufliciently heavy to run freely from
a flask like black gunpowder, and I further claim as part of my said
Invention,
Fourthly. The production of the compound I call pyro-pulver in
grains of sufficient weight to run freely from a flask by separating
from sawdust the heavier particles of wood and treating the same
by the process herein-before described as the first part of my said
Invention.
In witness whereof, I, the said George Clark, have hereunto set
my hand and seal, this Tenth day of May, in the year of our
GEO. CLARK, (L.S.)