Middletown transcript., 1899-08-19

| s2SSd1NZ selves in tn
S@5@& Johns Hopkin
Hospital labt
ratories.
The scientific Investigator avoids ex
perimentation upon human beings TO
various reasons. One of these reasons
as expressed by doctor, is that sucl
experiments are avoided, just as th
practice Of cooking with dynamite, TO
fear Of imperfs ct control Of the hea
and energy.
However, it has been found tha
birds "chill" without emotion and arr
subject to q type Of malarial fevel
closely resembling that in human
bsings, except that the germ is slightly
different. Consequently birds are
used as the objects of the mosquitoes
incubation with germs of ''shakes."
A Frenchman in Algiers discovered
the germ of malaria in the eos. Tt
this chill-producing microscope object
was given the name of plasmodium
malaria. Subsequent study has been
alone the lines of the life history and
characteristics of the germ.
Manson and Ross, English investi.
gators in India, and Grassi, an Italian,
advanced the theory of inoculation
of the disease by insects, usually mos
quitoes. as beirg the most abundant
and widely spread pest. 1t is the work
of these experimenters which is being
followed up and confirmed in Balti-
more by Drs. John B. MacCallum and
Eugene L. Opie, at the Johns Hopkins
Hospital.
"cATcH YOUR MOSQUITO"
"First catch your mosquito" is the
precept of these investigators. This is
accomplished by the doctors them
selves. Armed with lot of small test
tubes and raw cotton for shoppers, they
90 down to the marshes of some river.
Their only bait is human hide, each
one exposing portion of his body
which is easiest to see AID reach with
his right hand. When a mosquito
gets his bill well settled into this
tempting bait, test tube is clapped
over it and the surprised insect springs
to the top Of its crystal cage. The
sportsman quickly places a bit of raw
cotton in the open end of the tube,
which holds the mosquito in its prison.
Then the hunter is ready for another
insect victim. Hundreds Of the in
sects must be caught for a single ex'
pertinent.
The other live part of the expert
menters' outfit is number of crows,
which in this region have been found
the most suitable birds for experiment
tai purposes.
The mosquitoes will survive for
several days in their glass cages, but
the doctors do not tarry long before
beginning their experiments. In the
first place the mosquitoes must be
inoculated with the malarial germs.
These are supplied from the laboratory
stock, for the mosquitoes are not gener'
ally furnished with the germs when
caught. By feeding the germs are in
troduced into each mosquitoes stomach.
Then commences the delicate part of
the experiment.
WORK OF THE GERMS
Every two hours, or thereabouts, q
mosquito must be killed and its body
be prepared for microscopic examina-
tion. This search uEder the magnifying
lenses discloses that the malarial germs
are broken up in the mosquitoes stom-
ach. Each part becomes impregnated
in little sac or tumor in the stomach
wall. Within this sac minute bodies,
lenticular or diamond.shape. are form
ed, and finally the sac bursts without
the stomach, thus allowing the little
bodies, which have the power Of move
ment, to get into the circulation OF the
mosquito. Once in this condition they
quickly find their way to the saliyary
glands of the mosquito, where they
congregate. By this time the mosquito
is ready for s'business,n and those of
the insects which have not already
given up their lives to the inquisitive
eye of science may be used to inoculate
the malarial germ into birds or ami
mails.
During this intermediate process in
the body of the mosquito, the doctors
have learDed that the malaria germ is
one of three varieties, producing one
Of three distinct types of the disease.
One form of germ. which splits up into
from Is to 80 Of the diamond-shaped
bodies, natures every AZ hours and
causes the every-other-day chill, CT
tsrtian variety, when introduced into
the human circulation. Another form,
splitting into fewer bodies, produces
the chill one day and respite for two,
or the quartan variety of malaria. A
third form develops irregularly and
produces corresponding irregularity
in the time OF chills recurring.
Strangely enough, each variety OF
germ Is bred by distinct variety Of
mosquito. The tertian, or every-other-
day chill, germ, is found only in the
mosquito known as the anopheles ciavi-
ger, or .'key. bearer
REGULATING CROWS