infections, septicæmia, and anthrax, or splenic fever, with, great success; and was appointed in 1880 a member in ordinary of the Imperial Health Office. In 1885 he was appointed a professor, and the director of the Hygienic Institute in Berlin.
The first public report of Dr. Koch's to attract general attention was that in reference to the bacterium which had been found associated with anthrax, or splenic disease, and was made about 1878. His investigations went to show that the potency of this organism lay in the spores rather than in the developed bacterium. He found that, when no spores were visible in the dried diseased blood with which mice were inoculated, the power of conveying infection lasted only for a few weeks; while blood in which the spores had separated continued virulent for at least four years.
He next turned his attention to those infectious disorders which originate in the introduction of poisonous matter through wounds. Living organisms had already been observed in these diseases, but their connection with the development of the infection had not been determined. Dr. Koch's experiments with small animals showed that different forms of disease were produced by the injection of putrid blood, one of which was not accompanied by the development of bacteria, but seemed due to a special poison which he named septin or sepsin, while another form was evidently bacterial; and that the effects varied with different animals.
In 1882 Dr. Koch published the results of experiments which went to confirm the opinion already held by physicians who had observed the progress of the discovery of the fungoid origin of various infections, that tubercular disease was also caused by microphytic germs. He claimed not only that he had ascertained the bacterial origin of the disease, but to have detected the specific microbe, having found a characteristic and previously unknown bacillus in all tubercularly altered organs. He had observed it in pulmonary tuberculosis, cheesy bronchitis and pneumonia, tubercles of the brain, intestinal tubercles, scrofulous glands, and fungous inflammation of the joints; in all cases which he had examined of spontaneous consumption in animals—in cattle, hogs, poultry, monkeys, porpoises, and rabbits. In monkeys dead of consumption he had found the organisms in quanities pervading the lungs, spleen, liver, diaphragm, and lymphatic glands. He supposed that, escaping into the air from the expectorations of phthisical patients, they were inhaled into the lungs, where they developed. Whenever the tubercular process was in its early and active stage, they were present in great numbers. When the climax of the tubercular eruption was passed, they decreased and might totally disappear.
Dr. Koch's report of this investigation was published in one of
