5IO Veterinary Medicine. 



The Relation of the Bacillus Tuberculosis of Man to that of Cat- 

 tle. On the discovery of the bacillus tuberculosis it was largely 

 assumed that it was the same in all tuberculous animals, in all 

 organs and in all circumstances. But it was soon found that the 

 bacillus of chicken tuberculosis differed materially from that of 

 the mammalian, that it could be inoculated only with difiSculty on 

 cattle or Guinea pig, as could that of the latter on the bird. The 

 bacillus of the chicken found a most receptive home in the rabbit 

 and horse, and was more easily started in artificial culture in 

 glycerine bouillon, than was that of man or ox. But presently it 

 appeared that the affinities and disparities did not end here. The 

 bacillus from man or ox led to much more pronounced lesions in 

 Guinea pigs than in rabbits, and the abdominal bacillus of the 

 horse was inoculable on the chicken. Both horse and parrot 

 proved receptive to the bacillus from man. Swine, like Guinea 

 pigs showed a receptiveness to the bacillus of man or ox. The 

 bacilli from the sputum, open tuberculous sore, or bones of man 

 showed less virulence for Guinea pigs and rabbits than did those 

 from tubercles in the human lungs and liver. The bacillus from 

 the ox showed a greater virulence toward rodents and other small 

 animals than did the bacillus from man. The bacillus of human 

 sputum inoculated on the ox did not habitually cause generalized 

 tuberculosis, but often a local tubercle or group of tubercles, 

 and sometimes the inoculation wound healed without permanent 

 lesions. These last points were seized upon to sustain a doctrine 

 of probable duality for the microbe of tuberculosis, but if duality 

 it was quite evident it could not end there, but must be extended 

 to multiplicity, each small group of genera having a tubercle 

 bacillus peculiar to itself. Those who thought their interest lay 

 in arresting all sanitary control of tuberculous cattle and their 

 products, became urgent in opposition to active government meas- 

 ures, demanding mathematical proof of the infection of man from 

 cattle, under conditions that would exclude the remotest possi- 

 bility of the introduction of infection from another source. The 

 clearest and most abundant circumstantial evidence would not 

 suffice, they must have direct experimental inoculation under con- 

 ditions of precaution against outside germs, which were practi- 

 cally impossible in any community, conveniently ignoring that 

 such inoculation, if successful, would have amounted to man- 



