hould be submitted to a decisive
public test. He proposed to furnish a drove of fifty sheep half of which
were to be inoculated with the attenuated virus of Pasteur. Subsequently
all the sheep were to be inoculated with virulent virus, all being kept
together in one pen under precisely the same conditions. The "protected"
sheep were to remain healthy; the unprotected ones to die of anthrax;
so read the terms of the proposition. Pasteur accepted the challenge;
he even permitted a change in the programme by which two goats were
substituted for two of the sheep, and ten cattle added, stipulating,
however, that since his experiments had not yet been extended to cattle
these should not be regarded as falling rigidly within the terms of the
test.

It was a test to try the soul of any man, for all the world looked on
askance, prepared to deride the maker of so preposterous a claim as soon
as his claim should be proved baseless. Not even the fame of Pasteur
could make the public at large, lay or scientific, believe in the
possibility of what he proposed to accomplish. There was time for all
the world to be informed of the procedure, for the first "preventive"
inoculation--or vaccination, as Pasteur termed it--was made on May 5th,
the second on May 17th, and another interval of two weeks must elapse
before the final inoculations with the unattenuated virus. Twenty-four
sheep, one goat, and five cattle were submitted to the preliminary
vaccinations. Then, on May 31 st, all sixty of the animals were
inoculated, a protected and unprotected one alternately, with an
extremely virulent culture of anthrax microbes that had been in
Pasteur's laboratory since 1877. This accomplished, the animals were
left together in one enclosure to await the issue.

Two days later, June 2d, at the appointed hour of rendezvous, a vast
crowd, composed of veterinary surgeons, newspaper correspondents, and
farmers from far and near, gathered to witness the closing scenes of
this scientific tourney. What they saw was one of the most dramatic
scenes in the history of peaceful science--a scene which, as Pasteur
declared afterwards, "amazed the assembly." Scattered about the
enclosure, dead, dying, or manifestly sick unto death, lay the
unprotected animals, one and all, while each and every "protected"
animal stalked unconcernedly about with every appearance of perfect
health. Twenty of the sheep and the one goat were already dead; two
other sheep expired un