41

The agglutinins were removed from this serum in the
following manner : —

10 c.c. of the serum was mixed with 10 c.c. of a thick
emulsion of H. S. bacilli and left 24 hours in the dark,
at room temperature.

The result was a thick sediment in the tube. The
supernatant fluid was tested for agglutinating powers, but
it had none, so all the agglutinins had been used up. The
supernatant fluid was drawn off and again saturated with
H. S. bacilli and left for 24 hours in the dark, at room
temperature.

The fluid was then centrifuged, pipetted off, shaken up
with chloroform and left 24 hours to kill the few remaining
bacilli.

Admixture with fresh chloroform was carried out twice
again, at 24 hours' interval, and the fluid, when pipetted
off, was tested for living bacilli by inoculating several bouillon
tubes. No growth occurred in 24 hours.

The serum was then tested on a hill bull for its protec-
tive powers, which were found to be quite equal to those
of ordinary protective serum from which the agglutinins
have not been removed.

                     IV. PATHOGENICITY.

Animals naturally attacked.—Buffaloes, oxen, horses
and elephants. It is principally a disease of buffaloes, and is
much less common in oxen. Horses are very rarely
affected.

Animals susceptible to experimental inoculation.—Buffa-
loes, oxen, horses, sheep, goats, pigs, camels, rabbits,
guinea-pigs, rats, mice, pigeons.

Camels, sheep, goats and house pigeons are very
resistant and only die when large doses of pure culture are
inoculated, though resistance varies with the individual.

Animals resistant to experimental inoculation.—Dogs,
fowls and man.

Symptoms in the buffalo from natural infection.—The
disease is most common in young animals, but old animals
are not immune.