, 1875-02-27

heat and light which accompanies chemi
cal combination.
The human body may be compared tC
a furnace where combustion is all the
while in progress, and, to supply the
waste, food IS taken in sufficient quanti-
ties to keep up the necessary heat tC
enable the tissues TO perform mans al
lotted work.
The decay of all animal and vegetable
substances is nothing more than slow
oxidation, in which they lose their natu-
raj cohesion and unity of parts, and are
either wholly or partially discOmpOSed
by the natural operation of heat and air
Combustion is only another name foI
| rOtting, or disSOlving, and is either the
act of passing rapidly or gradually from
a sound and perfect state to one less
perfect.
Ordinary burning Is nothing but rapid
oxidation, or the union of the combusti-
BILE body with the oxygen Of the air,
while decay is only slow combustion
The log of wood which lies rottingin the
forest is destroyed by a process the
same in nature, and may be said 10 be as
truly burned up as if it were blazing in
the fireplace. The products in both
cases are the same-carbonic acid and
water.
The chemist Brande says that com
bustion cannot be regarded as dependent
on any peculiar principle or form of
water, but must be considered as a gen
eral result of intense chemical action
A very curious case of combustion, or
the development of heat, occurred in
England during the manufacture of a
submarine cable, and is related in the
Natural Philosophy" of Rolfe and
Gillet.
The copper wire of the cable was Gov
cred with gutta-Percha, tar, and hemp,
and the whole inclosed in a casing of
iron wire. The cable, as it was finished,
was coiled in tanks filed with water;
these tanks leaked and the water was
therefore drawn OFF, leaving about one
hundred and siXty-three nautical miles
Of cable COiled in mass thirty feet in
diameter with a space in the middle six
feet IN dlameter) and eight feet high. 1t
ruSted so rapidly that the temperature in
the center of the coil rose in four days
from siXty-siX 10 Seventy-nine degrees,
though the temperature of the air did
not rise above sixty-six degrees during
the period and was rs low as fifty nine
degrees part of the time. The mass
would have become even hotter had it
not been cooled by pouring on water"
This action is precisely what takes
place in spontaneous combustion, which
is simply a very rapid oxidation devel-
oped gradually from slow combustion;
the circumstances or conditions neCeS-
sary TO produce this being the result OF
carelesSnesS, or the design of an Incendi-
AIRY who is acquainted with the mysteries
OF chemical laws. Waste used for wiping
machinery, saw-dust, where oil has been
split. straw mixed with manure, tow, flax,
hemp, etc, in damp state are all liable
10 ferment or ignite, and as the heat in
creases oxidation is rapidly developed
until it destroys much valuable property.
On tbi9 narricular point the expert
mentS of John Galletly are very UUu-
vincing:
In one instance small quantity of
cotton waste soaked in olive oil was
loosely packed in paper box, exposed
to temperature of about l4O deg Fair
Active combustion took place in a little
more than five hours, and a second cN-
pertinent Welded the same result IN less
Than six hours Cotton soaked IN rape
oil and put in box subjected to tenn
peratuTe of about 40 deg. was found,
both box and cotton, in ashes within ten
hours. Cotfon-waste soaked IN seal oil,
with an applied temperature Of l3O deg,
e wi ibited ignition in 100 minutes. Some
were conducted with silk in
stead of cotton, and although neij her
flame nor incandescence took place, yet
the heat engendered was sufficient 10 ex-
plode gunpowder, and this temperature
was reduced more rapidly with silh than
with cotton. Hence Maj Majendic gives
the following conclusions as clearly es-
tabished:
FTrst-That oiled waste, whether silk
or cotton, should invariably be regarded
with suspicion as liable to spontaneous
ignition under moderately elevated tenn
peratures.
.Sec0nG-That silk waste is at least as
dangerous as cotton or even more so IN a
building containing gunpOwder or other
which is capable Of being lg-
nited or exploded without the actual ap-
plicatiOn of flame.
Perhaps the most singular of all the
numerous observations Of this kind IS
the fact that pulYerized charcoal, stored
in large heaps, but neither oily nor damp,
has been known to ignite and burn with
great rapidity until it was ali consumed
". y. Mercantile Journal.