The Kenosha telegraph. [volume] (Kenosha, Wis.) 1860-1888, 1872-06-13

vegetable matter. Accordingly in these
regions, the air over marshes will most
frequently receive almost the full amount
OF organic vapors which its high tempera-
ture enables it to sustain. But the rest
less condition Of the air often prevents it
from remaining over these localities Ionor
enough to be largely impregnated or pos-
oned by their exhalations; and the trade
WINDS contribute much to avert the insal-
u0rity which heat and moisture are ever
ready to produce IN tropical climates.
In marshes,surrounded by high grounds.
t1e air Is considerably impeded in its
movements and is thus caused to imbibe
larger quantity Of their volatile yapors.
10 The calmness from which such evils
arise, the presence of water in q valley
contributes in an indirect manner. From
the absorption Of heat, in the formation
OF aqueous Vapor, the lowest air in such
Localities would have a specific gravity
hlRner than its position would call for
and 1t would be accordingly less sensitive
to those forces which occasion crantla
WINDS. Numerous trees also tend much tn
the qoleScent condition of the air in the
valleys ana marshes; and it is chiefly on
CEls account that the destruction Of for
ests has contributed so much to check the
career OF intermittent fever in tbe Now
world Ii is partly in consequence of the
storms with which they are accompanied.
nat excessive rains arrest for time the
Effects OF malaria but the mitigation af
the evil also deepens on the excessive di-
Luton OF the volatile oils with water. and
heir diminished liability to escape into
the air.
In dry valleys, in marshes which have
Deen drained, and In lakes having an ONT.
let, INC excessive accumulation of the va.
por o! malaria is in a great measure pre-.
vented but the evils which it is caDable
or lnhIctlng are generally transferred to
otoer places Though volatile oils oxidize
ana become Inert In the air, they are slow
70 change t1eir characters IN water; and.
accordingly, liver which drains lands
teemlng with verdug and bearino p my
urlant vegetation, must lie imprepnated
with the volatile organic matter which
tney supply, and which is ready to eScaDe
into the air when favorsd by Tia, inf1uen.
cGs or neat and evaporation. It ia on this
account that the rivers of italy contribute
much to the insalubrity Of the lands
through which they pass;and many marsh
es along their banks exhibit the effects of
malaria importe from distant localities,
and surrendered to the air by the water
winch IS imprisoned and evaporated in
Stagnant pools. Rivers also find the con-
dltlons for 0ifusing their volatile organic
matter when they pass through lakes, or
when They spread their waters over the
deitas which are so generally formed at
their mouths III tideIess seas.
AS Volatile oils slowly escape from the
water or change their characters by oxi,
dat'on, there must be INIT to the dis.
ta2ce to which their poisonous characters
can be transmitted by rivers. An in.
STAGE OF the effects which THESE causes
produce, may be found Ia tho case of the
Nile, which, IN the latter part Of its course.
runs over thousand miles without re.
ce!9lng single tributary Whatever
volatile posons may have contaminated
Its waters IN Equatorial Africa, must have
been either expelled by heat, or rendered
inert by oxidation during its long Journey
to the Mediterranean Accordingly its
hoods do not prevent Egypt from cnioy
ing paratively healthy climate. This
boon may be partly ascribed to the dry
ness OF the air and the unfrequency of
rains in Egypt; but BuSsorah, IN a region
equally dry and free from rains. is rem
dered extremely pesti,entjal by the mum
dalton OF the Euphrates aud the streams
which descend along the verdant wales of
the southern side ofthe Elburz mountains.
give 10 the city Of Teheran degree of
which cannot be ascribed to
the luXurlance or t. the decay Of yeceta-
ton In its immediate vicinity.
1t ls probable that the various volatile
oils under consideration diff r much IN
their effects on human health; but this
question can only be settled by obserya-
ton and experiment These valuable
means of Inquiry however have been
rendered unproductive. as they have been
guided by the option that all lnalarious
carnations are produced by the plants
growing in the moist localities where
their evils are manifested. Yet we must
consider that, to impregnate the air which
changes SO frequently over them marshes
must have very abundant source OF these
and it seems impossible that
80 large all amount Of poisonous matter
could exist in their plants without being
tiscovelable by the resources of chemical
analysis. But the difficulty may be re-
moved, by suppOsing that the poison con-
'ists OF volatile vegetable oils, collected
rom wide areas 70 the low seats of msis-
ure, or occasionally transported away bv
lvers, and thus enabled to make inroads
N the human health i'll distant regions.
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