454 



STUDIES IN IMMUNITY. 



trifugalized, the supernatant fluid decanted, and G c.c. of normal 

 salt solution added. 



II. Fresh horse serum deprived of both sensitizer and alexin. 

 6 c.c. of salt solution plus 2 c.c. of washed guinea-pig blood is added 

 to 2 c.c. of the serum. After contact for an hour and a half the 

 mixture is centrifugalized and the supernatant fluid decanted. 



III. Bovine serum (56 degrees) deprived of its sensitizer. 2 c.c. 

 of salt solution plus 2 c.c. of washed guinea-pig blood is added to 

 2 c.c. of the serum. Contact for 1 hour, centrifugalization and 

 decantation of the supernatant fluid. 



IV. Intact bovine serum, 56 degrees. 2 c.c. of serum plus 4 

 c.c. of salt solution. 



V. Intact horse serum. 2 c.c. of serum plus 8 c.c. of salt solu- 

 tion. 



Mixtures are prepared as indicated in the following table from 

 these fluids, and 0.05 of a cubic centimeter of normal guinea-pig 

 corpuscles, or of corpuscles that have previously been treated with 

 0.3 of a cubic centimeter of heated bovine serum and subse- 

 quently carefully washed three times with a large volume of salt 

 solution, is then added. 



Mixtures in which the characteristic intense agglutination and 

 hemolysis occurred are designated by the letters AH. In the 

 other mixtures the corpuscles have shown no such modifications 

 even after a considerable period of time. 



TABLE I. 



