384 BACTERIA IN INFECTIOUS DISEASES. 



" The result of these recent experiments is such that I am not 

 only forced to deny the pathogenic nature of the micro-organisms 

 described in rny first communication, but also to add that I am 

 convinced their presence in the secretions was due to external 

 influences." 



Klebs claims to have produced syphilis in the 

 monkey, and Martineau and Hamoine to have 

 communicated the disease to young pigs (Morison). 

 But with these exceptions, so far as the writer is 

 aware, attempts to inoculate syphilis in the lower 

 animals have given negative results. 



TUBERCULOSIS. The experimental researches 

 of Villeman, Tappeiner, Colmheim, Toussaint, and 

 others, having apparently established the fact that 

 tuberculosis is an infectious disease, the medical 

 profession was not unprepared for the discovery, 

 first announced by Koch in the spring of 1882, of 

 a parasitic micro-organism in tuberculous material, 

 bearing a causal relation to the disease in question. 

 Coming from Koch this announcement had great 

 weight and at once received the most attentive 

 consideration in all parts of the civilized world ; for 

 he was already well known to be both a skilful 

 and a cautious investigator. 



The experimental proof offered in favor of the 

 view that the bacillus discovered in the sputum of 

 tuberculous patients, and in recent tubercles in the 

 lungs and elsewhere, was the veritable cause of 

 tuberculosis, seemed so convincing, that it might 

 have been received almost without question, but 

 for the fact that other experimenters had pre- 



