Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1875-06-09
Chemistry of Explosive Agents.

Modern chemistry has brought to no.
tlce several explosive compounds Of such
extraordinary character that they have
produced in the popular mind a great de-
gree of interest. 1t is true however, that
the number of new explosive compounds
which attract public notice is very small
compared with the number fabricated by
chemists or known to exist. The fright
ful nature of many of these agents renders
them extremely hazardous to handle. and
their fabrication is attended with great
peril. Such are chloride of nitrogen and
lodide of nitrogen. These bodies are so
sensitive that breath of air will explode
them with extreme violence. The fulmi-
mates of silver and mercury are less sem
sitive, but slight friction disturbs the
chemical equilibrium Of the particles, and
rends aSunder everything brought in con-
tact with them
In paper recently published by Walter
\. Hill. chemist, L. S. Torpedo Station,
Newport, r. l.. a large amount of inter
eStlng information is presented regarding
explosive agents, much of which is new.
Mr.. Hill has been Il frequent contributor
to the Journui, and we are indebted to him
for many interesting facts.
An explosive body must be composed of
constituents which will on cxplo>i' n from
large quantities of permanent gas, and
they must be so associated that the reac-
ton can be readily brought about. and
Will proceed with great energy and rapid
itv. Whenever II solid or a liquid body
by sudden decomposition passes into the
gaseous condition, great expansive force
Is developed and explosion results. Nearly
all explosive bodies are composed of car
bon. nitrogen, and oxygen. The carbon
uniteS with the oxygen to form carbonic
acid gas and the nitrogen is set free in
the gaseous condition. Carbon and oxygen
readily combine. and the combination is
attended with n great evolution of heat,
and this heat is an important agent in in
crea>ing the force of the explosion. If
gun is charged with an ounce of gun
powder. and flame is applied lccomposi-
tion at once occurs in the solid grains. the
elastic volume of the carbonic acid and
nitrogen gases liberated seeks liberty,
and. held in restraint 10y the iron tube they
push before them the shot or bullet with
great force, because in that direction there
is the least resistance. In addition to the
expansive force of the gases, the atmos-
pherlc Air entanglcd in the spaces between
the grains of powder is greatly heated and
expanded, and thus the force of the ex-
plosion is augmented by the mechanical
energy of the heated air 1t will be found
that the dull. negative element. nitrogen.
is almost an Indispensable agent in ex
plo>ive compounds, and in this fact we
have :, remarkable instance of the con-
trarictieS of character which some Of the
elements are capable of manifesting. All
the combinations of nitrogen are feeble
owing to the negative nature Of the cle
L., al. l.,,tt =
affinity i slight that it is readily dis>ev-
erred in the presence of cOrbon, and it as
>umes lis Naked elementary condition.
In "unpowdtr we have the nitrogen in
the saltpctrc used; in nitro-glycerine we
have it from the nitric acid employed in
the manufactures in iodide of ammonia. 4
most explosive agent, we have it from
the ammonia. Nitrogen in itself is a
harmless body. and although it is capable
of holding in is embrace clements which
hen set free are as terrible the thun-
dcrbut, it comes out of the most awful
conclusions simply rs nitrogen. Nitrogen
serves to closely associate together plrtl
cles of carbon and oxygen before direct
combination takes place and also it helps
in increasing the volume of heated gases
produced in explosions.
There are explosive mixtures and ex
plosive compounds. and distinction
should be made between them Gun
powder is an explosive mixture. but nitro
glvccrinc is not. In the former, the in
gredient> are mechanically mixed together
and can be separated by mechanical
means; in the latter, the elements are in
chemical combination. and cannot be sep
arated unless by chemical change The
ingredients of gunpowder are not cXplo-
Sivc when used separately; to obtain ex-
plo>ive force they must be mixed. There
arr. however. some mixtures which con-
tain substances in themselves explosive.
The salts of picric acid are of this nature.
A picrate has a certain quantity of oxygen
available in the explosive action. but not
enough. 50 it Is mixed. with a substance
supplying oxygen, such as saltpetre or
potassium chlorate. Nitrc-ylycerine. dyna
mite. giant powder. &c. are essentially
the same thing. and on explosion are re-
ed entirely into the gases, a bonic
anhvlride. water. nitrogen, and oxygen.
If the explosion is perfect, the nature Of
the decomposition is :,S above given; but
if it is imperfect. oxides of nitrogen are
formed and the force is diminished When
the explosion is perfect. no poisonous or
di>agrceabe gases are given off, but other
-
ative force of nitro -glycerine is not easily
estimated. MS the effect produced depends
greatly on the circumstances. Thus a
charge of the agent in wet sand, or other
soft material. will exercise but a slight ef-
feet. while the same charge in the hardest
rock will shitter many tons. Roughly
estimated. nitro -glycerine may be said to
he eight times rs powerful rs gunpowder.
weight for weight
In future numbers upon explosives we
shall consider the nature and uses of nitro
glycerinc. dynamite. and other explosive
agents which have come into practical en-
ployment in modern timeS.-BOstOn JOur-
nal Of Chemistry.
The winter of l14l WAS famous through
ont New England, rs being much colder
than any which had preceded it. Prob
ably no year since could furnish testimony
for cold either SO intense prOtracted.
The snow, which covered the whole coun-
try as early rs the 18th of November, was
still fouad. the next April covering the
fences. The Boston Post Boy for January
10 reports Il tent on the Charles river for
the entertainment of Travellers The Bos-
ton News Letter for March 6, tells us that
people ride every day from Stratford.
Conn, to Long Island, which is three
leagues" Even rs far east as New Lon
don. we are told that the ice extended
into the Sound as far rs could be seen
from the town. and that Fishers Island
was united to the main land by a solid
bed" On March %, the Boston News
Letter reports that people living on Thom
sons island had crossed over to Dorches-
ter to church on the ice for the - preced-
ing Sundays. AS late us the 9th of July
"a letter from New London, Ct. reports on
the east side of the Connecticut river Il
} body of ice is large as two carts can draw
], clear and solid, and artlessly thought it
4" might lay there a month longer We're it
not that so many resort out of curiosity to
drink punch made out of it." On the 18th