262 



COLLECTED STUDIES IN IMMUNITY. 



Now if one injects any serum containing two different comple- 

 ments, the production of partial anticomplements will to a great 

 extent depend on the relative amount of the two complements. For 

 example, if in one case there is considerable complement A and but 

 little B, while in another case there is considerable B and little A, 

 the anticomplement will be directed for the greater part against A 

 in the one case, and against B in the other. It is therefore readily 

 understood that with isogenic sera the yield of anticomplements can 

 correspond fairly well to the mixture of complements present in the 

 injected material, for the average composition of this mixture is 

 quite constant. A serum thus results which to a certain extent is 

 fitted to the complements of the serum injected. 



Since, however, a serum contains, not two complements as we 

 have assumed for the sake of simplicity, but a large number of com- 

 plements, it can, of course, happen even with isogenic anticomple- 

 ments that a disharmony will occur so far as certain fractions of 

 complements are concerned. The following case shows that even 

 with an isogenic anticomplement the relative proportion between 

 complement and anticomplement with different amounts of ambo- 

 ceptor is not maintained. (See Table VIII.) 



TABLE VIII. 



HUMAN BLOOD + AMBOCEPTOR OF A HUMAN-BLOOD RABBIT + RABBIT SERUM + 

 ANTICOMPLEMENT FROM THE GOAT TREATED WITH RABBIT SERUM. 



Amount of Amboceptor. 



Amount of Complement Necessary for 

 Complete Solution. 



0.2 

 0.2 



0.05 



0.05 

 0.05 

 0.075 



In this case 1.0 cc. anticomplement neutralizes 4.0 cc. complement when 

 0.5 cc. amboceptors are present, 1.42 cc. when 0.1 cc. amboceptor is present, 

 and only 0.67 cc. complement with 0.2 cc. amboceptor. 



