564 BOARD OF AGRICULTURE. [Pub. Doc. 



Appendix B. 



PRELIMINARY REPORT UPON A COMPARATIVE STUDY 

 OF TUBERCLE BACILLI FROM MAN (SPUTUM) AND 

 FROM CATTLE. 



BY THEOBALD SMITH, M.D. 



For a number of years past the writer has been impressed with 

 certain differences in the lesions produced in the guinea-pig by 

 the tubercular products of cattle, on the one hand, and by sputum 

 from human beings containing many tubei'cle bacilli, on the 

 other. These differences are not great, nor are they easily de- 

 scribed ; but they were of sufficient moment to induce the writer 

 to attempt some experiments, to find out to what extent they 

 depended on differences in the bacilli of human and of bovine 

 tuberculosis, and whether such differences were of sufficient in- 

 tensity to be brought out by the bacteriological and pathological 

 methods in use. 



A beginning was made in 1895 with a fresh culture of bovine 

 tubercle bacilli and a fresh culture of bacilli from an animal 

 {Nasua narica) which had lived with a tuberculous master. It 

 was assumed then, and all evidence is in favor of the assumption, 

 that this animal had been infected from its master, and that the 

 tubercle bacilli obtained from it could be classed as human. The 

 careful study of other sputum bacilli subsequently also supports 

 this assumption. The experiments made with these cultures have 

 been fully reported elsewhere,* but I shall include them in the 

 summary of the work done more recently, as the methods pursued 

 are the same, and the results therefore comparable. No oppor- 

 tunity was given to continue this work until this year (1897), 

 when the Board of Cattle Commissioners offered to furnish me 

 cattle and to provide the food for their maintenance during the 

 period of the experiments. At the same time, the State Board of 

 Health, fully cognizant of the important bearing of this work 



* Transactions Association American Pliysicians for 1896, pp. 75-93; twelfth 

 and thirteenth annual reports of the Bureau of Animal Industry, United States 

 Department of Agriculture, p. 149. 



