568 BOARD OF AGRICULTURE. [Pub. Doc. 



Experimental Inoculation of Calves with the Human 

 Tubercle Bacillus. 



The opinion has often been advanced that cattle are much less 

 susceptible to the human tubercle bacillus than man is to the 

 bovine.* As far as I have at present examined the literature, I 

 have been unable to find any reference to works which might 

 throw light upon this subject, with the exception of a short re- 

 port by Smith ;t hence it was that the following experiments 

 were begun, with the hope that some data might be obtained which 

 would tend to uphold, or reject, the above theory. 



In the following experiments young calves were employed, 

 which were the offsprings of healthy cows. In most instances 

 the mother had been injected with tuberculin, to prove the pres- 

 ence or absence of tuberculosis. In cases where the mother was 

 not subjected to this test, she was, as far as clinical symptoms are 

 evidence of the non-existence of this disease, apparently free from 

 tuberculosis. In the first experiments the calves were also tested 

 with tuberculin. The experiment animals were kept in a building 

 which had never before been used for housing animals, and the 

 milk which these calves were fed upon came from tested cows. 



Autopsies were made with the greatest care, that no tuberculous 

 lesion should escape detection ; and many suspicious bits of or- 

 gans were reserved for later microscopic examination, though, 

 as a rule, with negative results. 



Experiment No. 1. — Inoculation of Calves with Pure Cultures of 

 the Human Tubercle Bacillus. 



This bacillus was obtained directly from the liver of a child, 

 about one year previous to these experiments. The culture used 

 was one mouth old upon blood serum, and, as near as I was able 

 to ascertain, about the twentieth generation. A suspension of 

 this culture was made in boiled distilled water, and 1 cubic centi- 

 meter of this suspension was injected into the calves. 



Calf I. (three months old ; from tested mother ; calf tested 

 with tuberculin one week previous to inoculation). — The inocu- 

 lation was made by injecting one cubic centimeter of the above 

 suspension of tubercle bacilli into the abdominal cavity. After 

 five weeks this calf was injected with tuberculin, and showed the 

 following reaction : — 



* The terms human and bovine tubercle bacillus are used in this article for the 

 sake of convenience, not because the two organisms are to be considered as abso- 

 hitely different bacteria, though the}^ are, in all probability, varieties, according to 

 virulence of the same bacillus. 



t Theo. Smith, " Transactions of Association of American Physicians," 1896. 



