22 ROYAL SOCIETY OF CANADA 



such large amounts were being employed the injections were only given 

 once in from ten to fourteen days. After the animals' were considered 

 immune to the emulsion a period of three weeks was allowed to elapse, 

 until all excess • of the toxin should have been eliminated from the sys- 

 tem. One of the goats was then bled from the jugular with the same 

 precautions as before adopted and the serum used for the purposes of 

 the experiment. Tested by the Arloing-Courmont method as to its 

 powers of agglutinating a homogeneous culture of the tubercle bacillus 

 (kindly furnished me by Prof. Courmont), it gave a positive reaction in 

 a dilution of one to fifty. 



This power of agglutimation might, no doubt, have been greatly 

 increased, as has been shown by Ko'ch, but it was deemed sufficient for 

 the immediate purposes of the experiment. 



Experiment III. 



In carrying out the third experiment I have laboured under con- 

 siderable difficulties. Owing to the great disturbance caused by the 

 injection of the serum in guinea-pigs it was thought better to use rab- 

 bits exclusively. Ten rabbits were taken, their temperature was noted 

 daily for a week to establish a normal average, and their weight was 

 recorded. They were then grouped in pairs according to their weight. 

 Four were injected intravenously through the auricular vein; four 

 intraperitoneally ; and two in thei left leg, with one half c. cm. of an 

 emulsion of a mild tubercle bacillus in saline solution standardized as 

 before. One member of each pair then received one c. cm. of the for- 

 tified goat serum. Unfortunately, after the experiment was well start- 

 ed, rabbit septicaemia broke out in the hutches and about half of the 

 animals had to be replaced. At the end of a m'onth several of the 

 remaining animals were killed but it was found that the germ was not 

 virulent enough to produce characteristic lesions. The animals were 

 therefore reinoculated with the same quantity of an emulsion made 

 from a mild germ received from Dr. DeSchweinitz, of the Bureau .of 

 Animal Industry, Washington. In addition two other rabbits were 

 inoculated in the anterior chamber of the eye, affording a convenient 

 means of watching the progress of the tuberculous infection. At the 

 end of another month four rabbits were killed and again no lesions 

 were discovered, a condition of things that was a little surprising when 

 it was found that the disease progressed steadily although slowly in the 

 case of those inoculated in the eyes. The results of more than two 

 months' work was almost nil, although it served to indicate the effect 

 produced by the antitoxic serum on the healthy organism. The aver- 

 age temperature before inoculation of the rabbits which did not receive 

 serum was 103.9° and the average weight 1,865 grms. After the injec- 



