Page:Popular Science Monthly Volume 36.djvu/273

Rh the Berlin medical journals, in a memoir on "The Etiology of Tuberculosis," of which Dr. Klein, a distinguished pathologist, said that any one who carefully reviewed it would "come to the conclusion that Dr. Koch's results are to be accepted with unconditional faith, and I have no manner of doubt will be considered by all pathologists as of the very highest importance. To those who are familiar with Dr. Koch's previous work, especially that on the etiology of splenic fever, or anthrax, and his observations on pathogenic bacteria, this last work of his, on the etiology of tuberculosis, will be an additional and brilliant testimony to his ingenious and successful method of research." This testimony is the more significant because Dr. Klein afterward disputed Koch's identification of the "comma bacillus" with the cause of cholera. In the next year a report was published by Mr. Watson Cheyne of a visit which he had made as a commissioner of the British Association for the Advancement of Medicine by Research, to the laboratory of Dr. Koch, and also to that of M. Toussaint, who was engaged in a similar investigation. It represented that such results of Toussaint as disagreed with those obtained by Dr. Koch were not borne out. But the result of inoculation with cultivations obtained from Dr. Koch was in all cases rapid development of tuberculosis. The examination of a large quantity of tuberculous material showed the constant presence of tubercle bacilli, but of no other micro-organisms. The rapidity and certainty of action of this matter, when inoculated into animals, was in direct ratio to the number of bacilli introduced, and the most certain and rapid means of inducing tuberculosis seemed to be the inoculation of the tubercle bacillus cultivated on solid blood-serum. These facts led Mr. Cheyne to the conclusion that these bacilli are the virus of the acute tuberculosis caused in animals by inoculation.

When the cholera broke out in Egypt in 1883, the German Government appointed Dr. Koch chief of a commission to go to that country, and also to India, for the purpose of watching the course of the epidemic and investigating the nature and cause of the disease. The report of the work of this commission in Egypt, published in the early autumn of 1883, while it did not make known any certain results of the investigation, and dealt "in a very guarded manner" with the question of the discovery of a definite cholera bacillus, pointed out the line on which future studies were to be pursued. In experiments carried on in both living and dead subjects, while no distinct organism could be traced in the blood and the organs which are most frequently the seat of micro-parasites, bacteria having distinct characteristics were found in the intestines and their mucous linings, under circumstances that seemed to identify them with the disease from