256 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



vein of the animal to be protected. The methods of bovo-vaccination 

 of Pearson and Von Behring were both tested, with what results will 

 follow later. 



In addition to studying these methods, attempts were made to 

 cause immunity by subcutaneous injections of tubercle bacilli of dif- 

 ferent degrees of virulence as well as by the transfusion of blood from 

 artificially immunized to susceptible animals. 



Finally, a test was made of what is known as Heymanns's cap- 

 sule method of protective treatment, for the efficiency of which the 

 discoverer, after applying it to a large number of animals in his own 

 country, makes very strong claims. 



TEST ACCORDING TO VON BEHRING'S METHOD. 



On June 2, 1906, the first nine calves and on June 12 the tenth 

 calf in the following list were given each an intrajugular injection of 

 3 cubic centimeters of a suspension of tubercle bacilli of the human 

 type. The tubercle bacilli used to make the suspension were from 

 what was known as Case 30 and each cubic centimeter, of the sus- 

 pension was equal to 0.0013 gram of tubercle bacilli : 



Bull calf No. 427, about 2 to 2% months old; bull calf No. 429, 

 about 2 to 2 1 /2 months old; bull calf No. 431, about 2 to 2 1/2 months 

 old; heifer calf No. 432, about 2^ to 3 months old; heifer calf No. 

 435, about 2 to 2% months old; heifer calf No. 436, about 2 to 2% 

 months old; bull calf No. 438, about 2 to 2^ months old; bull calf 

 No. 439, about 2V 2 to 3 months old; bull calf No. 441, about 2 to 2V 2 

 months old; bull calf No. 444, about 3 to 3% months old. 



The ages of the calves as above given refer to the date on which 

 the injections were made. With the exception of a subsequent brief 

 elevation of temperature and the development of a small tumor in the 

 skin over the jugular at the point of injection in several of the calves, 

 the injections were followed by no marked adverse conditions. 



On September 7, 1906, each of the 10 calves was given a second 

 intrajugular injection of tubercle bacilli prepared from culture Case 

 30. The suspension used for the second injection, of which the dose 

 was 3 c. c., represented 0.02 gram of tubercle bacilli per cubic 

 centimeter. 



The second injection was followed by a more marked elevation 

 of temperature than the first, which may, in part at least, be attrib- 

 uted to the mechanically irritant action of the injected tubercle 

 bacilli in the fine pulmonary capillaries. 



Of the 10 calves, 1 (No. 444) was killed and examined post- 

 mortem without being exposed to tuberculosis to determine what 

 changes had been caused by the injections of tubercle bacilli it had 

 received. The remaining 9 were exposed to a tuberculous environ- 

 ment, as follows: 



Nos. 427 and 432, October 30, 1906 ; Nos. 429 and 435, February 

 27, 1907; Nos. 431 and 436, April 25, 1907; Nos. 438 and 441, July 

 25, 1907 ; No. 439, November 8, 1907. 



Control animals were added at the time of each exposure, but as 

 a matter of convenience the controls will be treated separately, as 



