22 PA THOGENIC BACTERIA.

laboratory were organized bodies. If these were planted
in sterile infusions, abundant crops of micro-organisms
were obtainable. By the use of more refined methods
he repeated the experiments of Schwann and others, and
showed clearly that ccthe cause which communicated life*
to his infusions came from the air, but was not evenly dis-
tributed through it."

Three years later he showed that the organized cor-
puscles which he had found in the air were the spores or
seeds of minute plants, and that many of them possessed
the property of withstanding the temperature of boiling
water—a property which explained the peculiar results
of many previous experimenters, who failed to prevent
the development of life in boiled liquids enclosed in
hermetically-sealed flasks.

Chevreul and Pasteur (about 1836) proved that animal
solids did not putrefy or decompose if kept free from
the access of germs, and thus suggested to surgeons that
the putrefaction which occurred in wounds was due rather
to the entrance of something from without than to some
change within. The deadly nature of the discharges
from these wounds had been shown in a rough manner
by Gaspard as early as 1822 by injecting some of the
material into the veins of animals.

Examinations of the blood of diseased animals were
now begun, and Pollender (1849) and Davaine (1850)
succeeded in demonstrating the presence of the anthrax
bacillus in that disease. Several years later (1863) Da-
vaine, having made numerous inoculation-experiments,
demonstrated that this bacillus was the materies morbi
of the disease.

Tyndall enlarged upon the experiments of Pasteur,
and very conclusively proved that the micro-organismal
germs were in the dust suspended in the atmosphere, not
ubiquitous in their distribution. His experiments were
very ingenious and are of interest to medical men. First
preparing light wooden chambers, with one large glass
window in the front and one smaller window hi each