tuberculosis. Very naturally his thought on this subject was borne in
the direction of inoculation. That method had been used by Pasteur and
by himself in the case of other infectious diseases. Why should it not
be employed in consumption? If the "domestication," so-called, of the
virus of splenic fever and the use of the modified poison as an
antiseptic preventive of the disease was successful, as it had been
proved to be, why should this not be done with the attenuated virus of
consumption?

The last five years of the ninth decade were spent by Dr. Koch in
experimentation on this subject. He found that the tubercular poison
might be treated in the same manner as the poison of other infectious
diseases. He experimented with methods for domesticating the bacillus
of consumption, and reached successful results. On the fourteenth of
November, 1890, he published in a German medical magazine at Berlin a
communication on a possible remedy for tuberculosis. He had prepared a
sort of lymph suitable for hypodermic injection, and with this had
experimented on a form of _external_ tuberculosis called lupus. This
disease is a consumption of the skin and adjacent tissues. It is a
malady almost as dreadful as consumption of the lungs, but is by no
means frequent in its occurrence. It is found only at rare intervals
by the medical practitioner.

Dr. Koch had demonstrated that lupus is a true tuberculosis--that the
germ which produces it is the same bacillus which produces consumption
of the lungs. He accordingly directed his effort to cases of lupus,
treating the patients with hypodermic injections which he had prepared
from the modified form of the tubercular poison. He was successful in
the treatment, and was able to announce, to the joy of the world, that
he had discovered a cure for lupus; and the announcement went so far
as to express a belief in the salutary character of the remedy in the
treatment of consumption of the lungs.

Dr. Koch, however, with the usual caution of the true men of science,
did not announce his tuberculin, or lymph, as a cure for pulmonary
consumption. He did not even declare that it was positively a remedy
for the other forms of tuberculosis, but did announce his cure of
cases of lupus by the agent which he had prepared. The world, after
its manner, leaped at conclusions, and the newspapers of two
continents, in their usual office of disseminating ignorance,
trumpeted Koch's discovery as the end of