108 ANNUAL REPORT OF THE Off. DOC. 



A similar dilTerence in pathogenic pow^r was found iu feeding 

 experiments, on pigs, where one lot of six received human tubercular 

 sputum, and a second lot of six were given pure cultures of the bovine 

 tubercle bacillus; and also in experiments on asses, sheep, and 

 goats, where the inoculations were made with pure cultures of human 

 and bovine bacilli into the circulation. 



Results similar to these iu the main have been obtained by Smith, 

 Frothingham, Dinwiddle, and at the laboratory of the State Live 

 Stock Sanitary Board of Pennsylvania, and we may admit that, as 

 a rule, cattle show a high degree of resistance to the human tubercle 

 bacillus, and tliat for all exi)erimental animals the bovine bacillus 

 has a pathogenic power equal to the human bacillus, while for the 

 great majority it is vastly more pathogenic; but this does not by any 

 means show that man is not susceptible to infection by the bovine 

 organism, and we have abundant proof tlhat it is quite possible to 

 infect cattle with the tubercle bacillus from human sources. 



The identity of tuberculosis as seen in man and cattle was held 

 by Villemin, who believed he had proved the correctness of this view 

 in his inoculation experiments, by which he showed conclusively that 

 small animals like rabbits become tuberculous following the injec- 

 tion of material from man as well as cattle. Chauveau^ was, ihow- 

 ever, the first to make the attempt to infect cattle with tubercular 

 material from man, and his success is shown in the following abstract 

 of his experiments: 



First iii^ies.— Infection by the Digestive Tract. — Three animals 

 were used, and as controls there were three other similar animals 

 which were infected with bovine material, and also three which 

 were not infected at all, these last remaining free from tuberculosis. 

 Those to which bovine material had been fed as well as those which 

 received human material became tuberculous. At the autopsy it 

 was impossible to distinguish one set from the other. In all of them 

 the lesions provoked showed the same character. The individual 

 histories of tihe three animals infected with human material are as 

 follows: 



1. A heifer, six months old, which received material from the lung 

 of a young man dead of acute miliary tuberculosis. Two doses of 

 an emulsion of this material were given morning and evening of the 

 same day. It was killed on the fifty-seventh day, having lost flesh 

 to a slight degree. The lesions were found almost exclusively in the 

 abdominal cavity. In the small intestine there were more than two 

 hundired tubercles varying from tIhe size of a pea to that of the head 

 of a pin. The liver contained upward of a dozen small tubercular 

 masses on its surface. The peritoneum showed a marked eruption 

 of tubercles. 



