PLURALITY OF COMPLEMENTS OF THE SERUM. 



203 



20 cc. goat blood are treated with the stromata from 53 cc. guinea- 

 pig blood. After absorption has occurred the mixture is centrifuged 

 and the complement action of the fluid compared with that of nor- 

 mal goat serum. (See Table V.) 



TABLE V. 

 ABSORPTION OP THE GOAT SERUM BY GUINEA-PIG BLOOD STROMATA. 



Hence after the absorption, the complements of the normal hsemo- 

 lysins had almost completely disappeared, while complements III 

 and V were entirely preserved. Complement IV occupies a place 

 between these, for in this case also a partial absorption could not 

 be avoided. Its behavior very prettily confirms the demonstra- 

 tional ready made by us of this complement's peculiar isolated 

 position. 



Entirely analogous results are obtained when, instead of using 

 guinea-pig blood stromata, a series of experiments is made with 

 red blood-cells, using the red fluid obtained when the red blood-cells 

 have dissolved directly as complement for another combination. 

 In such experiments we could show that the blood solution thus 

 obtained had lost complements I and II and contained only the 

 complements for cases III, IV and V. This method of procedure 



blood hsemolysin (amboceptor+ complement) of normal goat-blood serum, 

 it is necessary to absorb with a large excess of guinea-pig blood stromata. It 

 then readily happens that some complements other than those belonging to 

 the two normal hsemolysins suffer injury to a greater or less extent. This 

 was observed especially in several cases in which, in order to render easier the 

 complete binding of the complements for the normal hsemolysins, the guinea- 

 pig blood stromata had been sensitized with a large amount of inactivated 

 normal goat serum. In that case, evidently, several partial amboceptors present 

 in the goat serum in relatively small amounts and possessing affinities also 

 for the other complements come into play. 



