73° Tuberculosis 



performance of necropsies upon tuberculous cattle. The tubercle 

 ■ bacilli were demonstrated in some of the excised cutaneous nodules. 



Theobald Smith,* in studying 3 cases of supposed food infection, 

 found what corresponded biologically with the human rather than 

 the bovine bacillus. 



In a later paper Kochf analyzed the cases usually selected from 

 the literature to prove the communicability of bovine tuberculosis 

 to man, and showed that not one of the cases really proves what is 

 claimed for it, and that the subject requires further careful investiga- 

 tion and demonstration before it will be possible to express any posi- 

 tive opinion in regard to it. 



During the years that have elapsed since 1901 and the present 

 time sentiment has been almost uniformly against Koch, and an 

 enormous literature has accumulated that in reality means very 

 little. The most important is that of the Royal Commission on 

 Tuberculosis of Great Britain.! The general tenor of this report 

 is contrary to Koch's views, and many believed it settled the ques- 

 tion. At the International Congress on Tuberculosis in Washington, 

 1908, Koch reviewed the subject and stated his continued belief 

 in, the principle he had enunciated seven years before. Practically 

 the same contentions were raised against him by much the same 

 group of men, but the controversy was more bitter than before. 

 Koch, § however, leaves us in no doubt upon the subject, summarizing 

 his views in these words : 



1. The tubercle bacilli of bovine tuberculosis are different from those of 



human tuberculosis. 



2. Human beings may be infected by bovine tubercle bacilli, but serious dis- 



eases from this cause occur very rarely. 



3. Preventive measures against tuberculosis should, therefore, be directed 



primarily against the propagation of human tubercle bacilli. 



He weighed the contrary evidence that had been collected dur- 

 ing seven years, showed how errors had crept into the investi- 

 gations, and laid down certain rules to be observed before the 

 experiments could be accepted. At the close of the congress the 

 matter remained unsettled, Koch appearing to have the best of the 

 argument. 



The opponents of Koch based their opinions upon the supposed 



modifiabihty of the tubercle bacillus in different environments. 



When it lived in man, it was by virtue of the contact with the 



human juices and their chemical pecuharities compelled to assume 



the human form; in the cow, by virtue of the different chemical 



conditions, the bovine form, etc. Proofs of this were, however, 



wanting, and have not yet been published. On the other hand, 



Moriya|| seems to have shown that such changes are either purely 



* "Amer. Jour. Med. Sciences," Aug., 1904, vol. cxxviii, No. 389, p. 216. 



t Eleventh International Congress for Tuberculosis, Berlin, 1902. 



t See the "British Medical Journal," 1907 and 1908. ' 



§ "Jour. Amer Med. Assoc," Oct. 10, 1908, 11, No. 15, p. 1256. 



II Centralbl. f. Bakt. y. Parasitenk.," 1909, i, Abt. Orig., li, 460. 



