fied by any
experiments or observations which he reported, and he did a great deal of
harm, which will be manifested for years to come, to those who endeavor to
guard the human race from the dangers of animal tuberculosis. The
researches which have been alluded to make these dangers more definite and
certain than they have appeared before, and sanitarians should therefore
most earnestly endeavor to counteract the erroneous and harmful impression
which was made by Koch's address at London and his subsequent address at
the International Conference on Tuberculosis at Berlin.

VACCINIA OR COWPOX.

Variola of cattle, more correctly vaccinia, is a contagious disease of
cattle which manifests its presence through an elevation of temperature, a
shrinkage in milk production, and by the appearance of characteristic,
pustular eruptions, especially upon the teats and udders of dairy cows.
Although this is a contagious disease, strictly speaking, it is so
universally harmless and benign in its course that it is robbed of the
terrors which usually accompany all spreading diseases, and is allowed to
enter a herd of cattle, run its course, and disappear without exciting any
particular notice.

The contagion of cowpox does not travel through the air from animal to
animal, but is transfused only by actual contact of the contagious
principle with the skin of some susceptible animal. It may be carried in
this manner, not alone from cattle to cattle, but horses, sheep, goats, and
man may readily contract the disease whenever suitable conditions attend
their inoculation.

An identical disease frequently appears upon horses, attacking their heels,
and thence extending upward along the leg, producing, as it progresses,
inflammation and swelling of the skin, followed later by pustules, which
soon rupture, discharging a sticky, disagreeable secretion. Other parts of
the body are frequently affected in like manner, especially in the region
of the head, where the eruptions may appear upon lips and nostrils, or upon
the mucous surfaces of the nasal cavities, mouth, or eyes.

Variola of the horse is readily transmitted to cattle, if both are cared
for by the same attendant, and, conversely, variola of cattle may be
carried from the cow to the horse on the hands of a person who has been
milking a cow affected with the disease.

The method of vaccination with material derived from the eruptions of
cowpox as a safeguard against the ravages of s