AMBOCEPTOR, COMPLEMENT, AND ANTICOMPLEMENT. 259 



complement required, but with varying additions of amboceptor (see 

 columns a and b of Table V), different amounts of anticomplement 

 (corresponding to the amount of amboceptor present) are required 

 to neutralize the complement, more being required with larger amounts 

 of amboceptor. In these cases, therefore, the amount of anticomplement 

 required is far from being a simple function of the amount of comple- 

 ment, but is dependent on the amount of amboceptor present. 



TABLE V. 

 A. 



Amount of the Amboceptor. 



0.3 

 0.05 

 0.01 

 0.005 



Amount of the Complement Sufficient for 

 Complete Solution. 



0.005 

 0.005 

 0.01 

 0.035 



B. 



In several other combinations, which we analyzed in a similar 

 manner, we met w r ith the same behavior to a greater or less extent. 

 In Table VI such an experiment is reproduced; it deals with the 

 solution of ox blood by an amboceptor derived from rabbits and 

 complemented by guinea-pig serum. As in the previous case, inactive 

 serum of a goat treated with rabbit serum served as anticomplement. 



In this case when small amounts of amboceptor are present 1.0 

 cc. of the anticomplement serum neturalizes 1.0 cc. guinea-pig serum; 

 with larger amounts of amboceptor it neutralizes only 0.067 cc.; 

 i.e., about fifteen times less. 



