Evening journal., 1900-02-27

dropped on this spot and rubbed in.
When the hypOdermic injection is made
the part chosen is usually near the root
OF the tail or between the shoulders.
This is done to prevent the animal
from sucking the points of inocuauon.
The injection is OFTEN made right into
the circulation by incubation into
vein. The vein most commonly used is
an ear vein, because of its great
prominence.
After The inoculations are made the
animals are kept in comfortable cages,
which are kept thoroughly disinfected.
Galvanized iron wire cages are usually
used for this purpose and
all have the doors opening into the
top. This is to prevent the animal from
scratching infeclive material out of the
cage.
The animal is now observed closely,
pulse rate, breathing and temperature
are measured frequently. All of its
symptoms are recorded just as in the
case of a human being If the animal
dies from the disease a post-mortem eX-
animation is made of all its organs and
bacterial cultures are made from il to
find out and verify the bacillus which
has caused the disease.
FINDING PLAGUE GERM.
The bacillus of oriental, or bubonic.
plague, which is now causing so much
concern, was discovered by Kitassato
and Yersin, two Japanese physicians,
at Hongkong in 1894. It was known
that in preceding plague epidemics a
high mortality occurred among rats
and mice The bacillus was isolated
from these animals, as it was
from the glands OF human beings.
Rats, mice, guinea pigs and rabbits,
when inoculated with the plague ba-
cillus by means of the hypOdermic
needle. all have the characteristic
lsymptoms Of the disease. If suspect
ed case appears the physician inocu-
Hates one of these animals and observes
the result If it proves to be plague
the glands in the fore and hind legs
and neck will be seen to swell, and in
ilve to eight days the animal Will die Of
a general plague infection.
Monkeys are also susceptible to
plague and epidemics often occur
among wild ones.
The cholera organism, which was dis
covered by Koch in Egypt seventeen
! years ago, has never been found in ami
mails naturally. Even where cholera is
epidemic none of the lower animals
suffer from the disease. The organism
which causes cholera is usually fed to
the guinea pig or rabbit, together with
some opium-the opium prevents the
animal from getting rid of the microbe.
The animal then shows symptoms Of
prostration, the abdomen swells, the
respiration and hearts action become
slow and weak and the temperature
falls. Death occurs in a few hours. If
the dose is small the animal lives
longer. the bacteria increase in the di-
gestive tract and symptoms occur
which resemble those suffered by man.
TO PREVENT HYDRoPHOBIA.
Hydrophobia is an infectious disease
natural to the dog and the wolf. The
| Infection Is carried by the bite Of a
rabid animal or by a wound or scratch
being licked by the animal. Cattle,
sheep, horses, and deer. have been
4 known to suffer epidemics Of this
dreaded disease. The animal which
suffers becomes restless, snaps al
\ Everything and tears up and swallows
any object. 10 foams at the mouth, but
does not fear water, as is generally
supposed.
After a bite from one of these ami
mails the disease does not develop in
man within fifteen days, but it may
take longer. usually within forty days
Pains in the wound and along the
NERVES Of the limb in which the wound
has been received are observed when
/, the symptoms Of rabies are about tc
( appear.
Until Pasteur published his discover.
les IN 1885 the only means adopted tC
prevent hydrophobia was to cauteriz'
the wound. Pasteur's work revolution
lized the whole treatment Whede for
merly there were 16 per cent Of deaths
Of persons bitten by mad dogs, there il
at present less than one-half per cent
e from the same cause. The Pasteul
e. method consists in the incubation o.
b an animal, usually a rabbit with thu
e virus taken from a rabid animal. Ex
r alted virus. as Il Is called, Is, OBJ
}, tained. and it can be attenuated o
d weakened so as no longer TO pro
Cace rabies in dogs by drying tn
r spinal cords Of the diseased animals u
b an over caustic potash, which absorb
G the moisture The decrease in th
d strength Of the virus is in proportion
y 70 the length OF time the cords nav
,, been drying. A small piece of the spi
:, nal cord, fourteen days old, is rubbel
p up in sterilized bouillOn and injecte
e beneath the skin with a hypodermi
IS syringe. The next day a thirteen-day
old cord is used then, perhaps, ten
= day cord; then a O. 8. z, 6, down to
e fresh cord only one day old. In thi
y way the person Is made immun
A against hydrophobia. or. If bitten by
: supposed rabid animal, inOculatio
takes effect before the natural cours
Of the rabies from the bite.
HUNDREDS OF ANIMALS USED.
In the various medical colleges
Baltimore there are ten or fifteen hun
dred animals used for experiments
purposes, including the City Bacteria
logical Laboratory and the Pasteur In
sutute. Dogs are more used than an
other animal. with cats and rabbits
close second. Frogs. mice and rats al
used to the extent of one or two huI
dred while one school uses aboy
seventy-five turtles a year. Pigeon
chickens and guinea pigs are utilize
To-