IMPROVEMENTS IN THE MANUFACTURE OF GUNPOWDER
Year: 1871

page_text: LETTERS PATENT to John Thomas Smith, of Lee, in the County of
Kent, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
GUNPOWDER."
Sealed the 25th July 1871, and dated the 4th February 1871.
PROVISIONAL SPECIFICATION left by the said John Thomas Smith
at the Office of the Commissioners of Patents, with his Petition,
on the 4th February 1871.
I, JOHN THOMAS SMITH, of Lee, in the County of Kent, do hereby
5 declare the nature of the said Invention for "IMPROVEMENTS IN THE
Manufacture of GUNPOWDER," to be as follows:-
This Invention relates to improvements in the manufacture of gun-
powder of the character described in the Specification of a Patent
granted to Ernest Dronke, dated 11th April 1864, No. 900.

page_text: The gunpowder made in accordance with the description given in the
Specification above referred to, consists of grains of wood treated with
nitric acid and other chemicals to render the same explosive.
My improved method of manufacture differs from that described in
the said Specification in the following particulars :-
First. In regard to the removal of the acids as described under the
second head of the said Specification, I do not in all cases follow the
prescription there given, but can use caustic soda in a similar manner
but in smaller quantities instead of the carbonate of soda mentioned
therein.
Secondly. I do not invariably carry out the processes described in the
said Specification for the removal of proteine, albumin, and colouring
matter, but occasionally dispense with these second and third processes.
Thirdly. In regard to the use of nitric acid, as described, I do not
confine myself to the use of concentrated acids of the greatest strengths,
but sometimes employ acids weaker than those specified in the said
Specification, thereby making weaker powder, and in addition to this I
use for the manufacture of weaker powder the " spent” acids, that is
those acids which have been used before for the same purpose.
Fourthly. In regard to the saturation of the grains of wood with salts
containing oxygen and nitrogen, my Invention differs materially from
that described in the said Specification, inasmuch as, instead of one
uniform process or treatment of the nitrified grains, I treat them
according to the strength of the action of the acids upon them in the
last process, as discovered by experiment. For instance, when the
mixed acids used are of full strength they require from 60 to 70 pounds,
or thereabouts, of salts containing oxygen and nitrogen to every 100
pounds of nitrified wood grains, in order to produce a strong powder;
but when the wood grains have been nitrified by weak acids, or acids
that have been used before and thereby partially exhausted, then 40 to
60 pounds of the same salts to every 100 pounds of nitrified wood grains,
will produce a weaker powder. The powders thus produced of various
strengths being mixed together in order to obtain an uniform and safe
powder of the degree of strength required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Thomas Smith in the Great Seal Patent
Office on the 3rd August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
THOMAS SMITH, of Lee, in the County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of February, in the year
of our Lord One thousand eight hundred and seventy-one, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Thomas Smith,
Her special licence that I, the said John Thomas Smith, my executors,
administrators, and assigns, or such others as I, the said John Thomas
Smith, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 OF GUNPOWDER," upon the con-
dition (amongst others) that I, the said John Thomas Smith, my
exccutors 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 John Thomas Smith, 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 thereof, that is to say:
This Invention relates to improvements in the manufacture of gun-
powder of the character described in the Specification of a Patent,
granted to Ernest Dronke, dated 11 April 1864, No. 900, for "a new
mode of manufacturing gunpowder suitable for war, mining, and
general purposes.
The gunpowder made in accordance with the description given in the
Specification above referred to consists of grains of wood treated with

page_text: nitric acid and other chemicals to render such prepared grains of wood
explosive.
As the several processes for the manufacture of gunpowder from grains
of wood suitably prepared are fully described in the Specification of the
Letters Patent above referred to, it will not be necessary for me to repeat
the same here except so far as relates to my present improvements, as
any one acquainted with the processes described in the said Specification
will readily understand the nature of my improvements from the
following description thereof.
My improved method of manufacture differs from that described in
the said Specification in the following particulars :-
First. In regard to the removal of the acids, as described under the
1st. head of the chemical treatment of the woody fibre, (contained in
part II., page 3 of the printed copies of the Specification before referred
to,) I do not in all cases follow the prescription there given, but 1
according to this part of my improvements I use caustic soda instead of
the carbonate of soda mentioned therein in the following manner :-
I dissolve the caustic soda (which is to be used in the proportion
of about 8 lbs. of soda to 200 lbs. of wood grains) in 50 to 80 gallons
of water. The wood grains are boiled in this solution for about 5 hours
filling up the vessel with water from time to time to compensate
for evaporation. The grains are then washed four times successively in
boiling water, and finally in clean cold water.
Secondly. When manufacturing gunpowder according to my improved
method, I do not invariably carry out the chemical processes as described
under the 2nd and 3rd heads (contained in part II. of the Specification
before referred to) for the removal of the proteine, albumen, and colouring
matters, but in carrying on the manufacture of gunpowder according to
this part of my improvements I dispense with these 2nd and 3rd processes
as being unnecessary except through washing and drying, thus simplifying
and reducing the cost of manufacture.
Thirdly. In regard to the use of nitric acid as described under the
4th head (part II. of the Specification before referred to), I do not in
the manufacture of gunpowder according to my improved method
confine myself to the use of concentrated acids of the greatest strength,
but sometimes I employ weaker acids than those of the strength
referred to in the said Specification, thereby making a weaker powder,
and I also use the "spent acids" for the manufacture of weaker kinds

page_text: of powder, that is to say, I use for that object the contents of those.
acid baths which have been used before for the same purpose. By this
means according to this part of my improvements the whole of the
acids employed or nearly so are taken up by the wood grains so treated,
thus economizing the cost of manufacture, and the results are various
kinds of powder of various degrees of strength, which may be readily
ascertained by trials made in the ordinary way.
Fourthly. In regard to the saturation of the grains of wood with salts
containing oxygen and nitrogen, my Invention differs materially from
that described in the Specification before referred to inasmuch as
instead of employing one uniform process or treatment of the nitrified
grains I treat them according to the strength of the action of the acids
upon them in the last process as ascertained by experiment or examination
of the same. When the mixed acids used are of full strength they
require from 60 to 70 lbs. or thereabouts of salts containing oxygen and
nitrogen to every 100 lbs. of nitrified wood grains in order to produce a
strong powder. But when the wood grains have been nitrified by
weak acids, or acids that have been used before, and which have been
thereby partially exhausted, then 40 to 60 lbs. of the same salts to
every 100 lbs. of nitrified wood grains will produce a weaker kind of
powder. The various kinds of powders thus produced of various
strengths should be mixed together in order to obtain an uniform and.
safe powder of the degree of strength required. For instance, if the
wood grains have been nitrified with a mixture of nitric acid of 1.48
specific gravity and sulphuric acid of the specific gravity 1-85 in the pro-
portion of 5 parts of the former to 13 parts of the latter by weight, and
after thorough washing and drying the grains have been salted with the
salt known as nitrate of barytes or a mixture of equal parts of the salts of
nitrate of barytes and the nitrate of potash in the proportion by weight
of 70 of salt or salts to 100 lbs. of the nitrified dry grains the powder
will be strong enough for use, but it may be made stronger by using
less and less of the salts down to a proportion by weight of 40 of salts
to 100 lbs. of wood grains, as may be required, according to the strength
of the gunpowder it is desired to obtain.
The following proportion of the ingredients will answer for making
Schultze gunpowder of moderate strength in accordance with my im-
provements. Three pounds of the prepared wood grains after being
treated with caustic soda washed and dried as above described are to be

page_text: steeped for about 3 hours in a mixture of 5 parts of nitric acid of 1.47
specific gravity, and 13 parts of sulphuric acid of 1.85 specific gravity
keeping the mass perfectly cool. The wood grains are then to be taken
out and thoroughly washed in pure running water during 12 to 15 days,
in the course of which they may be steeped 24 hours in a weak solution
of carbonate of potash or soda and afterwards dried. The "nitrified "
grains are then to be salted by putting them into a watery solution
containing 60 lbs. of nitrate of barytes (or a mixture of 30 lbs. each of
nitrate of barytes and nitrate of potash) for every 100 lbs. of the wood
grains and evaporating the solution to dryness, after this the salted grains
are thoroughly dried, the dust separated, and the finished gunpowder put
up in hermetically sealed metallic cases.
I make a stronger powder, 1st, by using stronger nitric acid, all the
rest of the process being unaltered; 2nd, by reducing the proportion of
the weight of the grains to that of the mixed acids in which they are 1
steeped; 3rdly, by increasing the time of immersion, or by a second and
third immersion; 4thly, by reducing the weight of the salts used in the
salting process in proportion to that of the nitrified grains.
Weaker powder may be made in accordance with my improvements;
1st, by employing weaker nitric acid, that is of less specific gravity 2
than 1.47 in the same proportion, or mixed acids that have been used
before the other part of the process being unchanged; 2ndly, by in-
creasing the proportion of the grains to the mixed acids; 3rdly, by
increasing the proportion by weight of the salts (nitrate of barytes or
equal parts of nitrate of barytes and nitrate of potash) to the weight of 2
the nitrified grains.
The alterations in the process for the purpose of producing stronger or
weaker powder may be used either singly or in combination.
Lastly, having obtained by the improved methods above described
powders of different strengths which separately are stronger or weaker 3
than the strength suitable for use as measured and ascertained by trials
at a target, as is well understood, I manufacture gunpowder therefrom
for various uses of the exact strength and specific gravity required by
mixing those of greater and less strength and specific gravity together
in suitable proportions, by which means a perfectly safe and uniform 3
gunpowder is obtained of the strength required.
Having now described my Invention, and the manner in which it is
to be performed, I claim the further improvements upon the process of.

page_text: manufacturing gunpowder described in the Specification of the said
Ernest Dronke, when employed as and for the purposes herein-before
described.
Second, I claim the improved methods of manufacture used for the
production of various kinds of gunpowder of regulated degrees of strength
as herein-before described.
In witness whereof, I, the said John Thomas Smith, have herc-
unto set my hand and seal, this Second day of August, in
the year of our Lord One thousand eight hundred and seventy-
one.
Witness,
J. G. TONGUE,
Patent Agent,
34, Southampton Buildings,
Chancery Lane,
W.C.
J. T. SMITH. (L.S.)