The Sun.
London, England, 1846-11-04 00:00:00

GUN COTTON.
TO THE EDITOR OF THE TIMES.
Sir,—The great excitement created in the minds of the
scientific portion of the community by this discovery should
create regret for the injudicious publicity given to the
means of producing it; thus enabling every chemist's
shopboy to become an explosive compound manufacturer.
The effects will be accidents as " plentiful as blackber-
ries." One, unfortunately, has already occured to a gifted
young man which every one must regret; to prevent a
recurrence of this, and to lay bare this specious but very
doubtful benefit to science, I ail], with your leave,
endeavour to put the public in possession of the rationale
of this mechanical distribution of explosive matter ; for,
in reality, it is but a mechanical discovery after all. In
endeavouring to do this, I will use language of the
plainest description, and convey my explanation as
briefly as possible. The two agents in the production
of gunpowder of all qualities are nitre and charcoal.
Sulphur is an adjunct not absolutely necessary, save as
an agglomerating substance, to give an enduring
consieteney to the grains of gunpowder. Experi.
ments have shown gunpowder to be equally pro-
pellant without this agent as with it. Sir Iluinphry
D.evy discovered that gunpowder, formed mechanically
into the smallest state of grain or granulation possible,
gave a much more instantaneous explosion than when
in a larger grain. The principle is, that the smaller
grains present the greatest amount of surface, a
greats r nutribA- of interstices to be acted upon by the
11. one, and hence the whole c .averted into explosive
11 rid siintiltaneomly. Experience figs shown this dis-
covery to be perfectly worthless in practice, as cone ic-
ti m has grLdually returned to the fact that gunpowder,
to be beneficially employed in the expulsion of projec-
tiles, must be made of a grain proportionate to the size
of the gun used. In sporting gunpowder there are
three or four sizes of grain ; in artillery a very much
larger grain is necessary ;—why ? That the grain
may burn longer, to keep giving out fresh expulsive
matter, until the larger mass of projectile is put into
motion, and to continue this generation of force until
it has reached the highest state of velocity. This
slight introduction brings us to the fact that gunpowder,
to be beneficial, must be a propellant, moderated in its
explosive tendency by mechanical means. We possess a
knowledge of explosive materials vastly more powerful
than gunpowder, but, from this very tact, quite useless
as a projectile force. This has been sufficiently tested on
many occasions. The discovery of the gun cotton is the
extreme diffusion of nitre in immediate contact with char-
coal, or, more properly speaking, carbon, the ingredients
of which exist in the most minute portions that can be
conceived, the nitre in solution, the carbon in the
smallest particles, many thousand times more minute
than ever attempted (or possible) to be obtained by
any other means whatever. The action of the acid
upon the cotton, when immersed is it, is to remove the
small proportion of vegetable matter, and to impregnate
the remainder, which is nearly all carbon, with nitre;
thus forming by the simplest means the most perfect
incorporation of the explosive agents, and exposing
an amount of surface to the action of the flame
greater than obtainable by any other means yet
discovered. It will be perceived this is but the exten-
sion, to an enormous extent, ef Davy's scheme of
small granulation ; for it is but the simultaneous libe-
ration of, the gases of gunpowder by mechanical agency;
there is no new power obtained ; its action is thus
powerful by its instantaneous ignition. The low tem-
perature at which it is ignite I arises from the minute-
ness of the particles brought in contact with the beating
agent. The reason of its being exploded over granulated
gunpowder without igniting it is, that its explosion does
not endure sufficiently long to raise the particles of gun-
powder up to 600 degrees of heat ; but could the gun-
powder be reduced to the most impalbable state of pow-
der, similar to the cotton wool, it would explode with
the same degree of heat. Sporting powder explodes at
a less temperature than cannon powder, and so on, all
depending on the quantity of matter heated. Another
point, that 40 grains of the gun cotton effects more force
or gives more velocity (to small projectiles) than
50 grains of gunpowder, may be explained by two
facts—firre its instantaneous explosion, secondly, filling
a greater space, or being more bulky than the gun-
powder in grain, it gains the aid of the expansion of
the air contained within its interstices, and a corres-
ponding velocity acquired. But that the same weight
of the one will generate the same amount of perma-
nent gasses as the other is a chymical certainty; there-
fore, we are justified in asserting the discovery to be a
really mechanical means of diffusing and incorporating
the agents of explosion. The just estimation of these
facts must impress us with the conviction that, save for
very limited purposes, this discovery can never benefit
the human race, and is certain to cause many lamentable
accidents; no gum ever made will long withstand its
use, if quantity is employed, as the intensity of its velo-
city brings it on a perfect similarity with the fulminat-
ing compounds; these will project small projectiles
with great velocity a given distance, but to obtain an ex-
tended range is impossible, with safety; its application
to cannon will (if very great caution is not used) be the
means of destroying many valuable lives; for sufficiently
do I feel conversant with the subject to affirm, that there
is not a gun in her Majesty's service but would burst if
charged with anything like the same weight as is used
of gunpowder, and under no circumstances will an ex-
treme range be obtainable. Time will show this view to
be correct,. I am, &c.

Aston New-town, Birmingham, NovILLIov. 2GREENER..

PEDESTIIIANISIII.
JAMES BRIAN AND THE BRECKNOCK Nov:cE.--The
match, tre,iously announced, i❑ which the above-men-
tioned men were nweed as competitors for 201. a side,
and as much as their reepective friends might please to
bet at odds or evens, came off on Monday, the New Inn,
Bedforr, being the rendezvous. The distance to be
walked, fifteen miles, was very aptly chosen, between
the fifteenth, and sixteenth mile-stones on the Staines
and Windsor-road. The day grew old ; in plain
English, time was wasted till three minutes to three
before the pedestrians started, at which time both put
best leg foremost. For the first eight miles the longer
man (he of Brecknock innocence) kept the lead ; it was
thought, nevertheless, by the cognoscenti, that the tiny
one (Brian) showed most wire and lasting in his pace.
This was shortly afterwards proved ; for although bets
had been made that at nine miles the novice led by nine
yards at least, at the turn of coming down, Brian showed
the way. Shortly after the Novice was first, and so
kept, till half-way down the thirteenth mile, at which
point Brian again passed him, and came in a winner by
200 yards. The time was not great, namely, two hours
and thirty minutes, but the diminutive stride of the
winner must be taken into consideration. He is, we
should say, at a guess, 41t.
ROBINSON AND JohiEs.—Joseph Robinson, of Huck-
nall, and William Jones, of Marylebone, were some time
since announced as being matched. They also ran a
race, which was eventually disputed. They have now
agreed to run 120 yards, Robinson staking 30/. to Jones's
20/., on the 16th November (Monday se'nnight), on a
fair turnpike road. To meet at the Swan Inn, Mitcham.
THE Foun MILE HANDICAP FOOT-RACE.—For this
event, which we trust will put the best leg foremost with
the bipeds, now that the last meeting at Newmarket has
placed the quadrupeds in the straw, a brilliant muster of
the fleet footed ones will assemble. William Jackson
(the American deer), Sheppard (of Birmingham), Mosley
(of Derby), and another or two whose names dwell not
in our memory, are among the long-winded ones for this
entry. For the shorter distance (200 yards), Seward
(the Cockfield putter), Robinson (of Newton Moor), and
a numerous tail, are entered. The entries close to morrow
night.