IMMUNITY IN TUBERCULOSIS 229 



IMMUNITY IN TUBERCULOSIS 1 



BY SIMON FLEXNER, M. D. 

 ROCKEFELLER INSTITUTE FOR MEDICAL RESEARCH, NEW YORK CITY 



CAN not begin this address without delaying a moment to testify 

 -*- to my sense of the great honor which has been conferred upon 

 me by your invitation. Neither can I proceed with it until I have 

 expressed to you my conviction that there are persons present in this 

 audience whose scientific work on tuberculosis makes them far abler 

 than I to discuss the complex problem of immunity in tuberculosis. 

 My work in bacteriology in the past has not led me to an especial con- 

 sideration of the highly important problem of the prevention and cure 

 of tuberculosis, and I can therefore account in no other way for my 

 selection to address you this evening than that you desired this topic 

 presented to you from the point of view of one who has done some 

 work in the general field of bacteriology. 



The modern study of tuberculosis, as you know, begins with the 

 generation which immediately preceded the epoch-making discoveries 

 of Koch. It may, I think, be said with justice that this study was 

 inaugurated by the first purposeful transmission by inoculation of the 

 disease from animal to animal. For whatever may have been the specu- 

 lations upon the infectious and transmissible character of the disease 

 before this demonstration, yet the demonstration was necessary before 

 further steps in the elucidation of the cause and prevention of the 

 disease could be taken. Koch in his masterful monograph gives the 

 credit of successful inoculation to Klencke, who in the year 1843 suc- 

 ceeded in inducing an extensive tuberculosis of the lungs and liver 

 in rabbits by inoculation with portions of miliary and infiltrating 

 tubercles from man. Klencke, after accomplishing this result, did not 

 continue his investigations and they were consequently soon forgotten. 

 In the meantime Villemin's experimental investigations were begun 

 and pursued to a successful termination. He inoculated not only with 

 tubercular material from human beings, but also from cases of bovine 

 tuberculosis, and he seemed to have proved experimentally the identity 

 of the latter disease with human tuberculosis. Villemin's researches, 

 from the number of his experiments, the careful manner in which they 

 were carried out and the employment of suitable control experiments, 



1 Address delivered at the joint meeting of the Association of American 

 Physicians and the National Association for the Study and Prevention of 

 Tuberculosis, held at Washington. D. C, May 16, 1906. 



