a,
in Austria, belonging to the prince imperial. For ten years the silk
harvest there had not paid the cost of the eggs.

Although he was just recovering from an attack of paralysis brought
on by overwork, Pasteur travelled to Austria, introduced his methods
and the sale of the cocoons gave the villa a net profit of
26,000,000 francs. No wonder it was said of him that his discoveries
alone exceeded in money value to the French people the war indemnity
paid by them to the Germans.

Splenic fever, called _charbon_ in France, had for years decimated
the flocks in France, Italy, Russia, Egypt, Hungary, and Brazil. It
attacked the horse and cow as well as the sheep, and human beings
died of it when they developed malignant pustule. Many scientific
men had studied it, but Dr. Davaine, in 1850, was the first to find
in the blood of a sheep that had died of the disease, "little
thread-like bodies about twice the length of a blood-corpuscle.
These little bodies exhibit no spontaneous motion."

Pasteur began the examination of splenic fever by securing some of
the blood from an animal dying from it. In the work before him he
associated with himself M. Joubert, one of his former pupils. A drop
of the blood sown in the water of yeast--the medium used for
cultures by Pasteur at that time--produced myriads of the rods, the
bacilli or microbes. A drop of this taken at the end of twenty-four
hours, and placed in a fresh flask of the medium, again produced
thousands of the bacilli. Pasteur found that guinea-pigs inoculated
from the first flask developed the fever, and the same result
followed when the inoculation was from the twentieth. He had proved,
then, that splenic fever was produced by the bacilli, by living
organisms only to be seen with a powerful microscope.

While working on the bacilli of splenic fever, Pasteur had isolated
the bacillus of chicken cholera, had cultivated it and had
inoculated chickens with it, developing the disease. He found that
so long as the cultures were made from flask to flask within
twenty-four hours, the virus of the disease, that is, the power of
the bacilli to produce cholera in the fowls inoculated, remained the
same and the fowl died. But he discovered that if a flask containing
the bacilli were left exposed to the air for two weeks, and the
fowls were then inoculated with bacilli from this flask, they became
sick, but did not die. Following this up, he inoculated a hen that
had recovered f