Evening star. [volume] (Washington, D.C.) 1854-1972, 1900-05-18
MALARIA AND MOSQUITOES.
Theory That the Insect Causes the
Disease Practically Established.

DSeaSc AEActlcHAly EStaDAIBncus
From the Medical Record.
Malaria in Its several forms constitutes
perhaps the greatest obstacle to a success
full colonization Of the tropics. The mala-
rial fevers are by far the most deadly of
the tropical maladies In both white man
and native. Large parts of India are
devastated and rendered valueless by this
scourge. and immense tracts of land IN
Africa and South America cannot be In
hab.ted by the white race without almost
inevitably fatal results. The problem OF
the causation of malaria, which has been
the despair of scientists for generations.
would appear to be daily drawing nearer
and nearer to its final solution. The large
majority of scientific men throughout the
world have virtually accepted as decisive
the theory that it is mainly, IL not wholly,
by the agency of the genus Anopheles, or
the mosquito family. that malarial fevers
originate and are spread. In fact, by many
this is no longer looked upon as theory.
but as a doctrine.
A number of investigators have had q
share in the discovery that the mosquito
plays an important part in causing and dis
seminating malaria, but to Manson and
Ross Is generally conceded the honor Of
bringing the matter to its present advanced
stage. Although Americans have not spe-
cially distinguished themselves in these in
NeStiSdtioIlS II SHOULD not De IOrSOtten, as
was pointed out in the London Lancet. Feb
ruary IL. 1888. that A. F. A. King. at the
meeting of the Philosophical Society Of
Washington. d. c.. held on February 10.
ton Of Malarial Fevers." In which he sug-
gested the likelihood of marsh fevers being
produced by the bites Of proboscidian in
sects. notably in this and some other coun-
tries by mosquito bites. This. we believe
was the first occasion upon which the
theory was publicly mooted.
Great activity Is now being displayed in
Europe with the object of deciding the
Italian investigators have been perform
ing splendid service in the endeavor to
probe the malaria mystery. and probably
their researches have done more toward its
calculation SO far than has the work Of
any other school. Since the establishment
OF the two schools OF tropical medicine in
Great Britain vivid and practical interest
mas been taken IN that country In the dis
eases of the tropics in general and of mala-
ria in particular. The British government
in conjunction with the Royal Society, first
dispatched a scientific commission to the
west coast of Africa for the purpose Of at
tempting to find the Misunderstanding mos
quito and to locate its breeding places.
Shortly after this the Liverpool School of
Tropical Medicine equipped and sent out at
its own expense an expedition under the
leadership Of Major Ross to the east coast
with similar end in view. Major Ross
and his coadjutors succeeded in discover
ing the mosquito Anopheles claviger. and in
few Instances in determining the situa-
ton of its breeding places. The London
School of Tropical Medicine, authorized by
the British colonial office has lust sent
Lowe. to the Roman Campagna there to
conduct certain experiments, which, If ter
minating favorably. should convince the
most skeptical that the mosquito Is the
dominating factor in the causation of ma
laria- 1t may be said that experiments of
like nature have already been prosecuted
by the Italians Cell and Grassi with most
satisfactory results.
If. then. it be taken as proved that ma
laria is caused by mosQuitoes-and the evil
dence in support of this contention is SO
strong as to appear almost unassailable-
and when it is further considered that the
malady is conveyed by but one species Of
mosquito. 1t follows a natural sequence
that by wholesale destruction of the sim
ming insect the ravages OF malaria Will be
curtahed and perhaps in time altogether
ended.
The Liverpool School Of Tropical Medi-
cine has recently published a book entitled
instructions for the Prevention OF Mala-
rial Fever. for the Use of Residents in
Malarious Places which concludes as fol-
lows:
IAN speculations about air. about SOIL
about malaria belts and the like have been
rendered obsolete. There Is no reason to
believe that the parasite Of malaria finds
access to the human body through any
other channel than by means of the
Anopheles mosquito. or that .gnats' or mos
quitoes' which infest regions free from ma
iaria are examples of Anopheles. If this
particular insect could be extirpated there
Is every justification for the hope that ma
larious fevers would disappear from the
earth; and fortunately the extirpation does
not seem likely to present any insurmount-
able difficulty. The eggs are laid in water,
and the larvae when Matched live in water
for about week before they assume the
mosquito form. As larvae. like those Of
the common gnat they rise to the surface
to breathe, and film of Oil on the surface
is speedily fatal to them by blocking up
their air spiracles. Much may be done by
drying up pools in the vicinity OF houses
or by treating them once a week with q
film of kerosene oil. Much may be done
also oy killing the mature insect when rest
ing upon wall after its meal, and 1t is to
be noted that the true Anopheles rests with
its body almost at right angles to the sur
face of the wall. while the absolutely or
comparatively harmless gnat rests with its
body parallel to the wall or even some
what inclining to it."