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

GUN COTTON

TO TUE EDITOR OF TUE TIRES.
Sir,—The great excitement created in the minds of the
scientific portion of thecornmunity by this discovery should
create regret fcr 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 will, with your leave,
endeavour to put the public in possession of the rationale
of this mechanical distribution of exp!osive matter ; for,
in reality, it is but a mechanical discovery after al'. 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 aro nitre and charcoal.
Sulphur is an adjunct not absolutely necessary, save as
an agglomerating substance, to give an enduring
consistency to the grains of gunpowder. Expen •
ments have shown gunpowder to be equally pro-
pellant without this agent as with it. Sir Humphry
Davy 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. Thit principle is, that the smaller
grains present the greatest amount of surface, a
greater number of interstices to be acted upon by the
flame, and hence the whole converted into explosive
fluid simultaneously. Experience Las shown this dis-
covery• to be perfectly worthless in practice, as convic-
tion has gradually returned to the fact that gunpowder,
to be benefivially 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. 'l'hiu
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 ts. sted 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 selution, 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 in 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, of 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 ignited arises from the minute-
ness of the particles brought in contact with the heating
agent. The reason of its Leing expbded over granulated
gunpowder without igniting it is, that its explosion (Ines
not endure sufficiently long to raise the pat ticks 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—first, its instantaneous explosion, secondly, tilling
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 cor.res-
to be
a
perma-
nent gasses as the
poofntdhiengonveelocwiillgai:,entgitureli
risd.tabeel3hs'llatinmtilelaatiamdtehoreutansitadmtoyef; wtielii,greh.t
exhtosiu,,. The just estimation of these,
the discoveryud,i
incorporating
,actsicnl :aeons of Jill'usin},►
trfloe'earelit
i'wnegunleitsacirielijipress us with the conviction that, save for
very limited purposes, this discovery can never benefit
the human race, and is certain to cause many lainentabie
accidents; no gum ever made will long withstand its
use, if quantity is employed, as the intensity f its velo-
city brings it on a perfect sinilarity with the fulminat-
ing compounds; these will project rniad projectiles
with great velocity a given distance, but to obtain an ex-
tended range is impossible, ait h safety; its'applieatit,o
to cannon will (if very gusrytetyitivi,tesd
icssutuetat tribj.itt.lifieoccen
is nut used) he the
mlives; Per sutlici oily
disoenalontrs o to afsrm, chat the r
eaell destroying
g.culvinerslac.rn t
jttteh
but would burst if
charged with anything like the same weight as is used
of gunpowder, and under no eireumstane- s vvi:l an ex -
tri me range be obtainable. Time will show this view to
be correct. I am, &e.

W ILLIAM GREENER
Aston New-town, Birmingham, Nov. 2.

By his will, the late Robert Campbell, Esq., left
5001. towards forming a fund for the maintainance of tho
widows of clergymen, and 3001. to the Church Missionary
Society.— Sydney !Winning Herald, June 2.
THE TEMPLE CHURCH.--Yesterday, the 3d inst.,
a notice was taxed at the Temple Church, intimating.
that daily morning service, at nine o'clock, is again ro-
sumed until further notice.