Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1878-05-04

structlve hres had before that dat. Lapnensh
IN different parts of Germany. but tho appal.
Ing magnitude of the disaster that overlook
'ne i1aneston Mills in July, 1879, at ono
oAclteo general discussion and attracted the
noe1ce OF scientists. The insurance companies
AZ nfst refused to pay the insurance on the
property, out afterwards paid the full amount.
- II was known that the causes leading to the
explosion were not within the control of thu
owners OF the mill similar explosion oe-
CURED at the City Mills at Fort Dunda.. Scot.
land, ON September 10, 1874, attended with lea.
disastrous results; but it served to keen fre,h
in the minds of the British people the noss;b;1-
ity of explosions taking place even in .ncb
peaceful establishments as -four mills. The
n1ss OPINION as to the cause of these phonom-
ena which we shall notice is that of DR.. W.
Smith, OF Manchester, England, who gave con.
siderable attention to the subject. He relates
how an explosion was produced in the Ofen-
Pesth steam mill at Budapest, Hungary, which
blew off the roof of the building and caused
other damage, by workmen mixing some fine
varieties of -four. The door of the mixing
room was left open, and a thick cloud of dust
became lgnited from light. similar e1plo-
sion took place at Predict, Germany.
DIR. Smith states his opinion as follows: ut
mas been demonstrated that -four and bran in.
umately mixed, and in fine state of division.
gives OFT gas at $50 deg. Fab, which, when
mixed with nine Volumes of air, forms an ex-
ploslVe mixture, liable at any time to be fred
by a spark or fame" He recommends that tho
use of exposed portable lights in mills should
be prohibited.
Wiebe, German chemist, has advanced the
theory that grain in the form of impalpabla
-four undergoes rapid combustion when ieuit-
ed, and that during the process of combustion
highly explosive hydrocarbon gas is general
ed, which, when mixed with air, becomes high
ly explosive. We shall notice this opinion fur
Their on.
Perhaps the most generally received opinion
Is that advanced by Professor Stevenson Maca-
dam. When the Tradeston Mill explosion took
place. Professors Macadam and RANKING were
requested to take an active part in Investigate
ing the causes that led to the explosion Pro
fe'sor Macadam published in Iron an English
periodical from which we extract the follow
ing:
The chemistry of grain and -four m ay assist
us IN arriving at an understanding regarding
these fire explosions. The chemical compo-
nents are principally starch and gluten, with
small proportions of gum, sugar, oil, woody
fiber, and ash. The starch and woody fiber are
composed of carbon, hydrogen and oxygen
(C6HlGO5l; so are also the gum, sugar, and oil;
and the gluten contains these elements accom-.
panied by nitrogen sulphur and phosphorus
All these proximate constituents are combusti.
BILE when burned in the ordinary way, and are
consumed with greater rapidity when diffused
as a cloud through the air.
when the flour is showered from sieve
placed some distance above gas fame, rapid
combustion takes place; indeed the Gour burns
with explosive rapidity, and the fame ticks up
the flour shower somewhat in the same way
that 1T flashes through mixture of gas and
AR, or that 1t travels along train of gunpow-
der. Similarlarly, the -four, blown into cloud
by pair of bellows, at once takes fire and
burns with a sudden and vivid fash. The smut
taken from the grain during cleansing, and the
shorts separated from the -four, burn with
equal readiness.
Probably tho best way of showing the e1-
plosive combustibility of -four particles is to
place some flour in a box lying inverted on its
LID, introduce light, and blow the -four into
cloud by bellows, when instantly the box is
lifted from its lid and much fame PUSHES out
The fine division of the -four has necessarily
much to do with the rapid combustion: and
indeed, coarse gnnpowder can be passed
through flame without burning, while iron
filings can not fall through the same fams
When bruised. the -four resolves itself into
gases. The carbon, by uniting with the oxy-
gen of the air, becomes carbonic oxide (CO) or
carbonic acid (CO2), and the hydrogen and o1y-
gen become water, vapor steam (H2O).
The volume of these gases is mach increased
by their high temperatures at the moment of
combustion.
THE conditions required to bring about q
flour explosion are somewhat similar to those
| which cause gas explosion. Coal gas is conf
bustible and not explosive when unmixed with
air, and it only becomes explosive when it is
| mixed with sufficient air to burn it. This pro-
| portion is obtained in the most powerful de-
gree when one volume of gas is mingled in ten
| parts of air. lesser or larger proportion of
air lessons the power of the explosion by caus-
ing the gas to burn less quickly, and conse-
quently with less explosive force, and thus
| tending more to ordinary combustion.
| I'm order to bring about the explosion it is
necessary also that the four-ar mixture be
| confined within given space; hence, if the
| -four be incased in a box with the lid fastened
! down, and the bellows be brought into play to
| produce cloud while light is introduced, the
| box will be forced open with loud explosive
noise, and the side be split up, while weights
placed on the box are thrown off,
| Such is the theory of Professor Macadnm,
whose eminence scientist entities it to the
highest consideration. 1t is certainly very
plausible and has many facts in support of it.