The weekly Portage sentinel. [volume] (Ravenna, Ohio) 1854-1861, 1854-10-11
trrom the Westminster Review.I re
Why Epidemics RaRe af Nt~kt.

IL was in one night that four thousand Der
sons Perished of the plague in London. Il
was BY night that the army Of Sennseharit
was destroyed. Both in England and on the
continents large proportion Of cholera cases
in Its several forms, have been observed "a
have occurred between one and two O'Clock
IN the morning. The danger of exposure
10 the night air has been theme of physi
clans from time immemorial; but il is re.
markable that they have never yet called in
the aid OF chemistry to account for the fact.
It's at night that the stratum of air near.
est the ground must always be the mos,
charged with the particles of anamalized
matter given out from the skin, and de lete-
rious gases, such as carbonic acid gas, the
product OF respiration, and sulphurated hy-
drogen, the product of the sewers. In the
day, gases and various substances of all
kinds rise in the air by the rarefacton of the
heat. At night, when this rarefaction leaves,
they fall by an increase of gravity, if imper-
fectly mixed with the atmosphere, while the
gases evolved during the night, instead Of
ascending, remain at nearly the same level.
1t is known the carbonic acid gas, at low
temperature, partakes so nearly of the ma
ture of fluid, that it may be poured out OF
one vessel into another. 1t rises at the
temperature at which it is exhaled from the
lungs, but its tendency is towards the floor,
or the bed of the sleeper, in cold and un-
ventilated rooms. , .-...- ,....4 s.t s..
At Humburg,the alarm of cholera at night
in some parts Of the city, was 80 great that
many refused to 60 to bed, lest they should
be attacked unawares in their sleep. Sit
ting up, they probably kept their stoves or
open fires burning for the sake of warmth,
and that warmth giving the expansion to any
deleterious gases present, which would best
promote their escape, and promote their d.
luton in the atmosphere, the means OF safe.
ty were then unconsciously assured. At
Sierra Leone, the natives havea practice in
the sickly season of keeping fires constantly
burning in their huts at nights, assigning
that the fires keep away the evil spirits, to
which. in their ignorance, they attributed
fever and ague. LatterIy, Europeans have
begun to adopt the same practice, and those
who have tried it assert that they have now
entire immunity from the tropical fevers to
which they were formerly subjected. &c.
In the epidemics of the middle ages, fires
used to be lighted in the streets for the puri-
fication of the air, and in the plague of Lon
don, in 1865, fires in the streets were at one
time kept burning necessarily, till extin.
guished by violent storm ofrain. Latterly,
trains of gunpowder have been fred, and
cannon discharged for the same object, but
it is obvious that these measures, although
sound in principle, must necessarily, though !
out of doors, be on too small scale, as
measured against an ocean Of atmospheric
air, to produce any sensible effect. Within
doors, however, the case is different. 1t is
quite possible to heat a room sufficiently to
produce rarefaction and consequent dilu-
Eion of any malignant gases it may contain,
and it is, of course, the air of the room, and
hat alone, at night, which comes in contact
with the lungs of the person sleeping.