THE LYSINS. 126 



four c.c. of the five per cent, dilution of sheep's blood were treated 

 with from one to one and three-tenths c.c. each of the serum of the 

 goat rendered inactive by heat. The mixture was allowed to remain 

 for fifteen minutes at 40° and then centrifnged. The supernatant 

 clear fluid was removed and treated with 0.2 c.c. of normal sheep's 

 blood g,nd then 0.8 c.c. of the serum from a normal goat added. 

 This mixture was allowed to stand for two hours at 37°, when it 

 was found that no hemolysis had occurred. Next, the sediment 

 which had formed in the centrifuge was placed in four c.c. of physio- 

 logical salt solution and 0.8 c.c. of the blood of a normal goat added. 

 When this mixture was allowed to stand at 37° for two hours, it was 

 found that all the blood corpuscles were dissolved. This experiment 

 can be explained only by supposing that the immune body in the 

 heated serum combined with the corpuscles and subsided with them 

 in the centrifuge, leaving the supernatant fluid without the immune 

 body, and therefore the addition of the addiment to the supernatant 

 fluid did not induce hemolysis. On the other hand, the presence of 

 the immune body in the sediment was shown when hemolysis oc- 

 curred after distributing the sediment in saline solution and adding 

 a small quantity of normal blood serum. 



It was shown that the combination between the corpuscles and the 

 immune body may take place at low as well as at higher temperatures, 

 while the addiment does not enter into the compound at low temper- 

 ature. When five c.c. of the five per cent, sheep's blood dilution was 

 treated with from 1 to 1.3 c.c. of inactive serum and 0.5 c.c. of the 

 serum of a normal goat added, and this mixture kept at 37°, com- 

 plete hemolysis occurred within two hours. On the other hand, when 

 the same mixture was kept at from 0° to 3° there was no hemolysis, 

 but at this temperature it was shown by a repetition of the experi- 

 ment already detailed that the immune body was combined in the 

 sediment with the corpuscles, while the addiment remained in the 

 supernatant fluid. 



It was also shown that at high temperatures the combination be- 

 tween the corpuscles and the immune body occurs before the addi- 

 ment enters into the compound. Tubes containing blood corpuscles, 

 inactive serum, and fresh goat serum, were placed in a water-bath at 

 40° and the time before visible solution of the corpuscles took place 

 was noted. It was found that no evident hemolysis occurred within 

 ten minutes ; therefore the tubes which had been kept at 40° for ten 

 minutes were centrifuged. When the sediment in the centrifuge 

 was distributed through physiological salt solution slight hemolysis 

 occurred, but complete hemolysis resulted only after the addition of 

 normal serum to this mixture. This experiment demonstrated that 

 all of the immune body had combined with the corpuscles and had 

 subsided with them, while the greater part of the addiment remained 

 in the supernatant fluid. The affinity of the immune body for the 



