PROPHYLAXIS AND ERADICATION OF TUBERCULOSIS 359 



6. The immunity acquired by two vaccinations with human 

 bacilli should be fortified by a subsequent injection of attenuated 

 bovine bacilli. 



7. Investigations should be made looking toward the selection, 

 by the injection of attenuated bovine bacilli, of races or breeds of 

 cattle which posses naturally a high degree of resistance to tuber- 

 culosis. The capacity of different breeds to acquire a high degree of 

 immunity should also be investigated. 



8. The survival of human and bovine bacilli in the lungs and 

 udders of calves vaccinated intravenously with them should be more 

 definitely determined. 



9. Vaccines may be easily and cheaply prepared in the form of 

 suspensions in fluids ready for injection. The length of time during 

 which suspensions maintain their highest efficiency remains to be 

 determined. 



Prophylaxis and Eradication of Tuberculosis among Domestic Animals. 

 The recognition of the fact that tuberculosis is an infectious disease, 

 due to a specific bacillus or to several varieties of a single species, 

 has led to effective measures to prevent the spread of the disease, 

 particularly after the extensive and excellent work of Cornet had 

 shown that the tubercle bacillus is not ubiquitous but only present 

 where it is disseminated by tubercular persons or animals. Human 

 tuberculosis has been reduced particularly by such measures as the 

 destruction of the tubercular sputum, the prevention of its broadcast 

 dissemination, the isolation to a certain extent of tubercular persons, 

 the avoidance of overcrowding of human residences, and the proper 

 use of direct and diffuse sunlight as a disinfectant against the tubercle 

 bacillus. Efforts have also been made on a large scale to prevent 

 tuberculosis and limit its spread among the meat and milk-producing 

 animals. These efforts are justified and demanded imperatively, not 

 merely because there is a certain amount of danger of the spread of 

 tuberculosis from domestic animals to man (though the principal 

 danger among mankind is the infected person), but also because 

 tuberculosis among domestic animals is a constant source of great 

 national loss, and its eradication would be a great purely economic 

 gain apart from all hygienic considerations. An elaborate plan for ' 

 finally stamping out tuberculosis among cattle has been devised 

 by Bang. The method consists in a careful clinical examination of 

 all cattle and subjection of the animals to the tuberculin test. Those 

 animals which already show well-marked clinical evidence of tuber- 

 culosis, particularly of the lungs, intestines, uterus, and udder, are 

 separated from the others and slaughtered as soon as possible. The 

 apparently healthy animals which do not react to the tuberculin test 

 are likewise placed by themselves in a separate class. If possible 

 they are kept in a separate barn, but if this is impracticable, they 

 are at least divided from the others by a partition wall in a space 



