Pathogenic Bacteria

ANTHRAX. 363

which extend throughout its meshworks in long threads.
Most beautiful bundles of these bacillary threads can, at
times, be found in the glomeruli of the kidney and in
the minute capillaries of the intestinal villi. In the
larger vessels, where the blood-stream is rapid, the bac-
teria are relatively few, so that the burden of bacillary
obstruction is borne by the minute vessels. The con-
dition is thus one of pure septicemia, and bacilli can be
secured in pure cultures from the blood and tissues.

The susceptibility of the anthrax bacillus to the influ-
ence of heat, cold, antiseptics, etc. not only permitted
Buchner, Behring, and others to produce biological curi-
osities in the form of bacilli unable to bear spores and
robbed of their pathogenic powers, but also suggested
to Pasteur the important practical measure of protective
vaccination. Pasteur found that the inoculation of non-
virulent bacilli into cows and sheep, and their reinocula-
tion writh slightly virulent bacilli, gave them the ability
to withstand the action of highly virulent organisms.
Loffler, Koch, and Gaffky, however, found that these
immunized animals were not absolutely protected from
intestinal anthrax.

The methods of diminishing the virulence of the
anthrax bacilli are numerous. Toussaint, who was cer-
tainly the first to produce immunity in animals by inject-
ing them with sterile cultures of the bacillus, found that
the addition of i per cent, of carbolic acid to blood of
animals dead of anthrax destroyed the virulence of the
bacilli; Chamberland and Roux found it removed when
0.1-0.2 per cent, of bichromate of potassium was added to
the culture-medium ; Chauveau used atmospheric pressure
to the extent of six to eight atmospheres and found the
virulence diminished; Arloing found that direct sunlight
operated similarly; Lubarsch found that the inoculation
of the bacilli into immune animals, such as the frog, and
their subsequent recovery from its blood, diminishes the
virulence markedly.

Protection can be afforded in still other ways. The