Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1875-07-22
Spontaneous Combustion.

/ ~ IN k&f% y tG4F Fly N@fts79"Ns*~s%s
Which by LIelig has bern called Eyrnsac-
aasss. Thus. for example. piece u
esSsa which. wlaen burned. would produce
\ rise a femnesasure 90 deg far say
one minute. will, when slowly decAyi ing
during say 600 days efoive the same
(ssa deg. e,f heat but being diffused over
ihe length Of time az !. 90 days win only
evolve 0r,e deg. 10 twenty -four hours, or
/ -.sush ~ degree per minute, qnan.
tjty ~ hesa utterly inappfe1isbie, ~ II II
constantly Isysf in the surrounding atgn0s.
r,here. Every housekeeper knows that
deeaytd wossa IL near u worthless for fuel,
and The reason Il simply that the heat OBJ
;aiu.sl when sound wood combines rapid
Nv with oxygen MAS lost during the slow
combustion or decay.
n /. the came with coal when exposed
10 the aee.as Of the air Under a shed IL
loSes. according 30 the experiments Of
yaYrensifH-s, - per cent. Of gas by oxida.
ton and 10 per cent. of the heat giving
.ypwer, while when exposed without the
protection If amy slied, 80 much Of The
gaseous constituents are oxidized rs 10
cali.e The coal 10 lose oDe.third 81 Iis orig.
inai weight and more than half Of It's
heating power.
OF course during such oxidation heat il
developed. bit ii the oxidation goes on
slowly The heat IL carried on as soon las II
generates, and IL Is only when this carry.
ing off of heat or cooling IL prevented
thai tie temperature may ffse. The rise
Of temperature increases the tendency To
oxidation as nothing promotes more The
ACTIVITY Of The oxygen In combining with
eombustible substances than heat, This in
creased oxidation again develops more
heat, and thus, tie action and reaction con.
tinuing. at Last tie flame bursts oni; and
this IL what constitutes spontaneous CON
bustion,
There are some substances very subject
to such combustion, for instance, yegeia.
bic and animal oils, especially drying oils.
Thus linsecd oil fhc drying Of which - n
real oxidation) when poured upon heap
of sawdust or rags, placed 80 the air has
access 10 The interior will in u few hours
break out in flames If the air j. excluded
this will not take placc--ircc access Of air
or ventilation il necessary. When, how.
ever, tie sawdust or rags are not placed In
a single heap, but are diflnsed over The
ground, 80 that the heat developed can
dilFusc itself by radiation, spontaneous
combustion will be pfeycntedt notwifh.
standing the continued oxidation promoted
by the free access OF air, the moss viii DC
kept cool by the constant radiation Of heat
from The large surface exposed.
This Is All important hint In regard 10
the treatment 81 substances subject 10
spontaneous combustion; IL II IL impossi.
bic 10 spread them out 80 as 10 expose a
large surface, and they have 10 be confined
TO small space, as IL the case IN loading
ships with such materials, ventilation
must be prevented, as II Is not practical to
make II so active that the heat will be car.
ried off more rapidly ~ II Il developed Ny
oxidation In blast furnace the heat in
creases in proportion 10 the force oi ven
siiation, and what takes place there At q
high temperature takes place at lower
temperature Ia the ineipientstage OF spon.
tancous combustion.
The cases of spontaneous combustion OF
bituminous coal are - manifold and well
authenticated that II IL really sign OF
utter ignorance of the facts Taught by ex-
perience 10 deny H. We have had Il In
Goa. Yards rs we'll a. ON board of ships !;
and where IL took place a large mass OF
coal, say several thousand tons, was
placed, not on the ground, but on a wood.
en- floor, where air had access from below
and steady upward aircurreut took
place through the intcrs,ices oi the coal.
| Of course the coal lost Its gaseous con
sttuents by oxidation, an proved by the
observation Of Varrensirass, referred Ia
above This oxidation, by necessity, dc.
yeioped heat, and, rs the heat could not csr
cape from the interior OF the large mass,
| the temperature was constantly raised
until, nj last, combustion, u, the usual
higl, temperature, was established.
| Coal In mines, before shafts have been
sunk, never ignites 10y spontaneous com.
busiion; II Is only when, by the sinking
| OF shafts, ventilation has been established,
that we hear of fires In coal mines; and
| II we can lock up the coal In vessel as
| tightly a. II Ia In mine before the shafts
| have beer sunk tho coal will be perfectly
safe, and this none Of our antagonists dare
| deny.
| Ii Il significant fact that no fires have
occurred on board Of eoal.yessels trans.
porting coal across the Atlantic, or on any
voyage requiring no more time, but have
often taken place on. board OF vessels go
ing to the East Indies, California, and IN
general distances requiring more than
forty days. OF course where the action 81
atmospheric oxygen ON coal In large bulk
can only raise the temperature 81 the in
terror ten degrees Fair per day Il
. will In forty days, when starting nj eighty
degrees. be only 4s0 degrees; but evident
~ then the great danger commences, ant
II il clear how great an element time mus
be In this physical operation. --Naaa
faeturer and Builder.
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