78 



Scientific Proceedings (36). 



We obtained the described reactions with the serum both be- 

 fore and after filtration, through a Berkefeld filter. The serum 

 which was employed the day after drawing gave the reaction, and 

 serum, after standing in the ice-box for ten days, also gave it. 

 The same serum after three weeks did not give the reaction 

 (protocol, Dec. 22, 1909). 



The anesthetic used consisted of iomgs. of morphine sulphate 

 followed in about thirty minutes by 1.5 gms. of chloretone and 

 a little ether. The animals used were dogs averaging thirty 

 pounds in weight. 



The results obtained are summarized as follows : 



1. Dogs injected intravenously with 3 c.c. of serum from a 

 rabbit infected with tuberculosis do not suffer a reduction in ar- 

 terial pressure. The serum was injected into the femoral vein and 

 pressure taken in the carotid (protocol of Nov. 17, 1909). 



2. Dogs that have been injected intravenously with 5 c.c. of 

 crude tuberculin and five minutes later with 3 c.c. of serum 

 (administered in the same way), which had been obtained from a 

 tubercular rabbit do not suffer a reduction in arterial pressure. 

 The same is true when the serum is administered first and then 

 the tuberculin five minutes later (protocol of Nov. 17, 1909). 



3. Dogs sensitized by a subcutaneous injection of 5 c.c. of 

 tuberculin, which is followed in from twelve to eighteen hours by 

 an intravenous injection of 1.5 to 3 c.c. of tubercular rabbit serum 

 do suffer a marked reduction in arterial pressure. 



4. This reaction is specific as far as we have been able to test 

 it (protocol of Dec. 4, 1909). The following sera have been 

 tested : glanders (horse), typhoid (human), antityphoid (horse), 

 antistreptococcus (horse) normal rabbit, normal horse and a two 

 per cent, solution of Witte's peptone. We have one record show- 

 ing that the 5 weeks' old tubercular rabbit serum which did not 

 cause the reaction in a sensitized dog, was reactivated by the addi- 

 tion of an equal amount of fresh rabbit serum. 



5. Based on this reaction an attempt was made to immunize 

 two rabbits against tuberculosis without success. The rabbits 

 were injected with one cubic centimeter of the crude tuberculin 

 and beginning upon the next day received 2 c.c. of the tuber- 

 culosis serum on alternate days during a period of ten days. 



