SKETCH OF ROBERT KOCH. 261 



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 uncon- 

 ditional 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 path- 

 ogenic bacteria, this last work of his, on the etiology of tubercu- 

 losis, 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 identifi- 

 cation 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 Asso- 

 ciation for the Advancement of Medicine by Research, to the labo- 

 ratory 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 devel- 

 opment of tuberculosis. The examination of a large quantity 

 of tuberculous material showed the constant presence of tuber- 

 cle 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 ani- 

 mals 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 cir- 

 cumstances that seemed to identify them with the disease from 



