applying himself to the demonstration of the fact that
the bacteridium was the sole cause of anthrax. Without
entering into the details or the chronology of his mem-
oirs on this subject, it will suffice here to point out the
status to which he had brought the question at the time
when Pasteur attacked it in so masterly a manner.

It can be said that Davaine had perfectly demon-
strated the coexistence of the bacteridium and of the
anthrax. This fact of coexistence which is not, how-
ever, necessarily to be considered a relation of cause
and effect, became known as the result of a long series
of observations made on cases of malignant pustule,
which is the most common form of anthrax in man, as
well as on animals killed by anthrax either naturally, or
as a result of artificial infection. This coexistence had
been disputed. After Brauell, Signol, Leplat and Jail-
lard, Bouley and Sanson had published observations
or experiments in which anthrax seemed to be present
and the bacteridium absent. But Davaine had replied
to this by showing that these scientists either had failed
to recognize the bacteridium or else had called something
anthrax which was not anthrax.

Leplat and Jaillard, for example, imparted a deadly
malady to rabbits by inoculating them with putrid
blood from an anthrax victim, or in default of that, with
bacteria of putrefaction, and did not find bacteridia
in the blood of the dead animals. "Nothing is less
astonishing," replied Davaine, "your malady, and also
that of Signol, is not anthrax. It differs from the latter
in its shorter incubation period, because it is accom-
panied neither by the agglutination of the blood-cor-
puscles nor the congestion of the spleen, the most con-
stant and characteristic symptoms of anthrax, and
because it kills birds, on which the bacteridium has no
effect. Do not be surprised, therefore, that in this new

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