Alpena weekly argus. [volume] (Alpena, Mich.) 1871-1893, 1882-05-17
The Power OF Gnn Cotton.

1
"If gunpowder,' says Professor Do
remus, "is placed in basket made Of
coiled platinum wire, and is then in
serted in a glass jar arranged so that it
can be exhausted of air by an air pump,
on applying a current of electric
ity to the coil, so as to render the
wire red hot, the gunpowder will Meth
er explode nor burn with q fash. 1t
will apparently boil, with purple
light, and will require from five to
twentS seconds for its complete COM
bustion, depending on the quantity of
powder and the amount of air removed.
"All know that gunpowder has its
own supply of oxygen it does not re-
quire any from the air, for we shut out
the air when we load a pistol, rifle,
or cannon. The nitrate of potash
furnishes the oxygen for the carbon
and sulphur Of the powder. The cause
of the tardy combustion of the exhaust
ed receiver is the diminished pressure.
'But wrap the powder in paper, and
we have the fire cracker enclose the
powder in an iron sphere, and we have
the bomb she'll AS the powder burns
under increased pressure produced by
its own gases, it explodes with increases
force. An ounce, or even pound of
powder, when burnt in the open air,
produces no explosive sound merely
puff.
"The Eliminates Of silver or mercury
which are used in percussion caps will
also burn slowly when placed in the
platinum coil referred to and heated
red hot after the air has been exhausted
from the glass jar. Yet in the open
air, when fired, they will explode with
sharp sound.
If lock Of gun cotton of the most
explosive kind, say foot in length, be
suspended in n glass jar, with said
platinum coil, and after removing the
pressure OF the air by pump, if the
coil is made red hot by an electric cur
rent, the gun cotton will not explode,
nor will a flame or spark be seen the
gun cotton will gradually disappear. i.
even under the pressure of the air,
or, in other words, in the open air,
small quantities of gun cotton of the
most explosive variety when lighted do
not explode; they merely burn with a
bright flash of light. When VIC pre-
pare gun cotton before a class in chem
istry, we frequently place lock of il
on students hand and fire it to show
how quickly it burns for he scarcely
feels it. This is one Of the trivial tests
of its good quality. Another is to
place tho gun cotton on gunpowder,
then apply light. If ii fails to ig-
mite the powder it is the explosive va.
riety; if it sets fire to the powder it is
inferior in character. Photographers
gun cotton, which is soluble in alcohol
and ether, and is used for making col.
lodion, will burn slower. If placed on
gunpowdcr it will ignite it.
Enclose the explosive variety of gun
cotton in stout receptacle. Now fire
it, and it will exhibit three times the
force of gunpowder.
"If person will fill teaspoon
with nitro-glycerine, and apply to it
lighted match, he will find that the
nitro-glyccrine will quitely and slowly
burn, with green colored fame, be-
cause it is only subjected to the pres
sure of the air.. But if he places this
amount Of nitro-glycerine in a closed
vessel and fires it, | would advise hin
to remain at a respectful distance from
it.
81 have placed fluid ounce of nitro
glycerine in metal cup, connected
with one pole of a galvanic battery
and on applying the opposite pole o
the battery to said liquid, | have showr
before a medical class that the nitro
glycerine burns tardily and withou
noise. With said battery had pre-
viously fused and volatilizcd platinum
iridium, and other refractory metals t.
demonstrate the intensity of the heat
Yet, If a single drop Of nitro-glyccrint
is placed on smooth surface and strucl
with q sudden blow, the explosion i
stunning to the car. The same law ap
plies to giant powder, dynamite, rene
ock, and other terrific explosives
They must have pressure to exhibi
atheir power"