The morning news. [volume] (Savannah, Ga.) 1887-1900, 1899-08-20

ing Experiments 10 fEONe Ihut In
sects carry Disease.
From the Baltimore Sun.
tn prove that mosquitoes convey ma
,s-a is the delicate and painstaking task
,,-.-6 number of Investigators have set
themselves in the Johns Hopkins Hospi-
tai laboratories.
THE scientific investigator avoids expert
rentation upon human beings for vari-
.,s reasons One of these reasons as
svar-ssed by a doctor, is that such ex-
osrInents are avoided, just as the practice
of cooking with dynamite for fear of i'm
psrfeet control of the heat and energy.
However, it has been found that birds
achuT' without emotion and are subject
to a type of maliarl fever closely resem-
bling that in human beings, except that
the germ is slightly different. Conse-
auenuy birds are used as the objects of
the mosquitoes incubation with germs
OF shakes"
Frenchman in Algiers discovered the
germ Of malaria in the sos. To this chill
producing microscopic object was given
The name of plasmodium malariae. SUB
sequent study has been along the lines of
the life history and characteristics of the
germ.
Manson and Ross. English investigators
I'm India, and Grassi an Italian, advanced
the theory of incubation of the disease
by insects, usually mosquitoes as being
the most abundant and widely spread
pest Ii is the work of these experiment.
ers which is being followed up and con-
frmed in Baltimore by Drs. John b. Mac
C4llum and Eugene L. Opie, at the Johns
Hopkins Hospital.
Catch Your Mosquito"
First catch your mosquito" is the pre-
cept of these Investigators. This is ac-
comphshed by the doctors themselves.
Armed with lot of small glass test tubes
and raw cotton for shoppers, they 90 down
10 the marshes of some river. Their only
bait is human hide, each one exposing a
portion of his body which is easiest to see
and reach with his right hand. When a
mosquito gets his bill well settled into this
tempting bait, a test tube is clapped over
IT and the surprised insect springs to the
top Of its crystal cage. The sportsman
quickly places bit Of raw cotton in the
open end of the tube, which holds the mos
quito in its prison. Then the hunter is
ready for another insect victim. Hundreds
of The insects must be caught for a single
experiment.
The other live part of the experimenters'
outfit is number of crows, which in this
region have been found the most suitable
birds for experimental purposes.
The mosquitoes viii survive for several
days in their glass cages, but the doctors
do not taTy long before beginning their
experiments. In the first place the mos
quitoes must be inoculated with the ma
larial germs. These are supplied from the
laboratory stock, for the mosqufto toes are
not generally furnished with the germs
when caught By feeding the germs are
introduced into each mosquitoes stomach
Then commences the delicate part of the
experiment.
Work of the Germs
Every two hours, or thereabouts, mos
quito must be killed and its body prepared
for microscopic examination. This search
under the magnifying lenses discloses that
the malarial germs are broken up in the
mosquitoes stomach. Each part becomes
impregnated in a little sac or tumor in the
stomach wall. Within this sac minute
bodies, lenticular or diamond-shape, are
formed, and finally the sac bursts without
the stomach, thus allowing the little bodies
which have the power of movement, to get
into the circulation of the mosquito. Once
In this condition they quickly find their
way 10 the salivary glands of the mosqui-
to. where they congregate. By this time
the mosquito is ready for business" and
those of the insects which have not already
given up their lives to the inquisitiVe eye
of science may be used to inocuate the
malarial germ into birds or animals.
During this intermediate process in the
body of the mosquito, the doctors have
learned that the malaria germ is one of
three varieties, producing one OF three dis
hnct types of the disease. One form of
germ, which splits up into from eighteen
10 thirty of the diamond-shaped bodies
natures every forty-eight hours and
causes the every-other-day chill, or tertian
variety, when introduced into the human
circulation. Another form, splitting into
fewer bodies, produces the chill one day
ana respite for two, or the quartan varie-
~ OF malaria. A third form develops ir-
regularly and produces a corresponding ir-
IeSularity in the time of chills recurring.
strangely enough, each variety Of germ
u ored by distinct variety of mosquito.
The tertion, or every -other-day chill, germ,
10 found only in the mosquito known as the
anopheles claviger or key bearer"
InOcuIating Crows.
With his mosquitoes thus loaded" as it
were, with germs, the doctor is ready 10
pegln his incubation of the crows. When
me mosquito uses its proboscis to suck
me blood of its victim it injects from its
saliVary glands portion of the fluid
"Alch is impregnated with malarial
germs. OF course, the germs get directly
INTO the blood vessels, travelling from
SHa4l capillaries to veins and arteries The
Hrst object of attack of the little diamond
SNAPPED bodies, bred in the mosquito is
tne red blood corpuscles. some of the
Siny bodies force their way into the
cofpuscles, although, of course, many of
me corpuscles successfully resist the at
TACK. Many of the little bodies perish in
the struggle for existence"
Inose of the little bodies which secure a
resting place within the corpuscles quickly
20 about their subdivision methods of pro-
pasation, and a the gwen time the in
creased number of acknowledged bodies
are ready to burst forth from the corpus
cies' This, occurring al stated intervals
according TO The time of maturing of the
particular variety of germ, causes a chill
az the thousands of infected corpuscles
ourst at nearly the same minute. In this
way a microscopic examination of the
oIood OF an infected person determines ex-
ec'y the variety of germ and the predic-
non can be accurately made as to the
llthe oil the next chill after a study of the
nf Il.