The herald., 1898-07-12

mice, dogs, frogs, ROSTERS and donkeys.
It Is a modern Noah's ark, in which the
scientific tests now being carried on are
the most important that have been at
temple.
A regularly organized scientific search
Tor means of destroying the yellow fever
germs is now being carried on in the larg-
Est and best equipped, although not the
oldest, institution Of this kind in the world
Operates by Parke, Davis & Co., in De-
Iroit, Mich. The writer recently had the
privilege Of visiting it, and will describe
what he saw and learned.
In an immense brick building there are
lis horses, from which curative serum
was being drawn, or that were being i'm
munized" for that purpose, as we'll as
housed, fed and cared for. Horses at this
wonderful establishment were under i'm
munization for yellow fever. tuberculosis,
tetanus Qock-jaw), typhoid fever and
blood poisoning. There were animals of
all kinds and for many purposes; cows
for vaccine; pigs being treated for hog
rholera; pigeons with chicken cholera
ETC.. etc. Sheep rabbits, guinea pigs. cats.
white rats. white mice. dogs, frogs and
roosters-even donkeys-wsre in evidence.
The theory of immunization 10 that
something Is formed by the tissues Of the
infected animal body which enables the
body to Withstand the invasion Of disease
producing germs, or which destroys them
after they have gained an entrance; and
that the immunity Of one animal can be
taken and transferred to another. This
something" is found in the watery part
or serum of the blood. The experiments
.Axzvr vaf, nj ha hpr tori IA
vcribing are for the purpose of discover
Ing the yellow fever antidote that shall
make any of our soldiers inocculated
with It proof against being attacked by
the disease.
Roux of France and Behring of Ger
many share the honor of having stimuli
taneously discovered that the blood Sc
rum Of an immunized animal protected
or exerted an antidotal effect upon other
animals suffering from diphtheria. The
Idea harmonized with Pasteur's belief
that it would be possible, by process Of
vaccination, "for man to eradicate every
contagious disease from off the face Of
the earth
The process CT experimentation, as ex-
planned to me at the laboratory, is this:
In the production of the diphtheria
Berum-and this particular curative Sc
'um has the place of prominence above
Ill others-the experimenters first of all
require living dphtheria germs. The spe-
:ifc germ of diphtheria Is called Klebs-
Loeffler bacillus, from the two eminent
Psychologists who first studied it. Gull
lures of this bacillus are obtained from
the threats of diphtheritic patients. These
sultures, if pure that is free from other
,,In, ta1 in, Aoy ~ 1tn,
"a modified form of beef tea-whcb are
placed in an incunbator and allowed to
remain there at body temperature from
seven to fourteen days. The TASKS are
then taken out and the bouillon examined
microscopically to make sure that no for
ign germs are present. The bouillon Is
next filtered under strong pressure
through sterlized porcelain, which takes
out all the bacterias present and leaves
the clear, transparent fluid which now
consists Of the original bouillon, plus the
poison which the germ secreted during
Its growth. This latter substance is diph-
iberia toxin. The virulence of the bouillon
containing this toxin must now be de-
.ermined before 1t is used for immuniz-
ing. Its potency may be inferred from
the fact that one-fiftieth to tenth of
drop will suffice to kill half grown
guinea pig. A healthy 120-pound horse
has been known to die with typical symp-
toms Of diphtheritic paralysis when only
two drops of the fluid had been given as
IN initial injection.
un to this point. l. have been describing
he preparation of the diphtheria toxin.
The manufacture of the anti-diphtheritic
serum-Nature's antagonist to the diph-
;hsria poison-properly begins with the
animal selected for immunization. The
sorse has been found to be the most suit
able animal, for many reasons. Small
initial injections of the toxin aee made at
he laboratory, and careful record kept
" the reaction to the poison, as manifest
"A by the rise in the animals tempera-
:uye, effect ON respiration. etc. In short
lime, from gradually Increased doses. the
aofse. which may have almost died from