Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1901-12-05
INSECTS AND DISEASE.
Interesting and Instructive Lecture b
Prof Chester.

Interesting and Instructive Lecture by
Prof Chester.
Prof. Frederick d. Chester OF Della
ware College made an interesting and
Instructive address on THE Relation
Of Insects to the Spread OF Infectious
Diseases" before the Natural History
Society, at Friends School Monday
night. A good audience was.present.and
the lecture was highly appreciated.
Prof. Chester is an authority on such
matters. Following is synopsis Of his
address
The closing years Of the Nineteenth
Century were marked by bril1iant dis.
ooyeries In the domain of infectious
diseases, and a numbar OF old ideas
have been completely changed. Layerhn
in 1880 demonst ated that mslar n is a
disease caused hy definite oragnism
to be found in the blood of ma arial
patients. Five years later Golgi showed
TINT tie malarial parns to pres nts u
regular life cycle within the blood
corresponding in turn TO the different
phases Of the diseasr. That these cycles
follow one another in fixed and reRu-
lar orde-, Civ ng thu disease It's usual
intermittent character. 10, 1885 Ross
in india and in 1898 Bastianne i,
Bignani and Grass in Italy showed
that the mosquito was the intermediate
host OF the maarial parasite The latter
en- ering its body and undergoing a
regul n cycle Of development its final
elements the blasts ente ing the sslivary
or poison gland Of the mosquito, whence
they are injected into healthy human
he ng by its bite.
CRASH showed that only certain mos
quitoes. i. .. those belonging 10 the
genus anoEhelos, were carriers OF
malaria. Thus he was able TO infect
hea thy anophe,es by permitting them
to prey on infected men, and In turn tc
infect healthy men by allowing The
latter to bite them.
THAI malaria is not directly due tC
bad air or the miasma of swampy
regions is shown by recent SKI erimenta.
The experiments consisted in the resi-
dence OF several men in the most
malar Gus parts Of the Roman Cam.
ragnn, drinking the water and exposed
to the night air, taking no ouinine and
protected only from the hiles of the
malaria mosquito, by remaining In
screened houses after nightfall. Al
remained in perfect health notwith
standing their apparently unwholesomt
sur oundlngs.
The closing months OF the last cen
fury have also demonstrated that yellow
fever is carried by mosquitoes, and tht
experiments conducted at Camp Lszeal
near Quemados, Cuba, are among the
most no eworthy and interesting IN tn,
history OF experimental pathology. 81,
volun eered to allow themselves to b,
bitten by mosquitoes which had pre-
u fLn - r.
patients. OF these five became infected
and developed In three or four dayt
typical cases OF the fever.
In the infected mosquito house were
two rooms divided only by screen; OF
one side were placed infected mos
guitoes Persons admitted to til room
were repeatedly bitten, and in TURF
contracted the disease. Those on The
other side, and protected by the screen,
remained unaffected. In the infected
clothing house screened to protect
against the invasion OF mosquitoes
quantities of bedding used and cloth
ing worn by yellow fever patients were
| unpacked by five volunteers and for q
days they were brought in the most
intimate contact with these artic es
sleeping between infected bedding. auc
wearing injected clothing. All re-
manned however in perfect health. thu,
showing that the disease cannot b,
conveyed by contact with infected
articles, audith 10 contract the disease
one must be bitten by mosquito
which at least IL days before has bitter
yellow fever patient. There is gouc
reason to believe, as shown by Howard
that the alarming spread Of typhoic
fever 10 the army oamps at the close
of The recent Spanish American Wal
was due largely to the agency of flies
which carried the germs from the sicl
TO articles of food consumed by the
well. AS a preventive against thil
source Of infection articles OF fooc
should be aasIdiously protected against
the invasion OF flies.
Anthrax is undoubtedly conveyed Il
cattle and ho:ses through the aEenc,
of flies and other biting insects. Texal
fever or cattle malaria is oony eyed b,
the bitee of the cattle-tic Buboni,
plague is also III part propagated b,
flies and fersin has isolated the plagu
nacil Illus from the bodies of dead file
found in his own laboratory. In fac
insects will pr badly prove TO be create
and greater actors in the spread o
disease, and t BIAS been recently show
that number of pathogenic bacteri
will grow readily in the bodies O
insects.