COMPLEMENTS 329 



stances that are so labile, yet the doctrine of the multiplicity of comple- 

 ments is quite generally accepted. 



(a) By digesting 20 c.c. of fresh goat serum that was found to activate 

 different hemolytic amboceptors with 3 c.c. of a 10 per cent, solution of 

 papain in the incubator for from thirty to forty-five minutes, it was 

 found that the complement for one amboceptor was destroyed, whereas 

 those remaining were left intact or but slightly impaired. 



(6) By treating 10 c.c. of this goat serum with 1 c.c. of a 7 per cent, 

 solution of soda for an hour it was found that some complements were 

 destroyed and others were weakened. 



(c) By sensitizing different blood-cells with homologous amboceptors 

 and adding these to a fresh serum for short and varying periods of time, 

 some complements could be destroyed, whereas others would be left 

 behind with undiminished or but slightly decreased activity. Pro- 

 longed exposure would remove all complements. 



(d) As was previously stated, anticomplements may be produced by 

 immunizing an animal with the complement of an animal of a different 

 species. The anticomplements appear to be specific for the comple- 

 ments responsible for their production, and by means of these anticom- 

 plements different complements may be demonstrated in one serum. 

 Since the formation of anticomplements w6dld depend upon whether or 

 not the body-cells of the immunized animal possess suitable receptors for 

 the various complements, in a series of animals it may be found that one 

 does not produce anticomplements for all the complements injected, 

 a finding that would tend to support the theory of the multiplicity of 

 complements. In addition, Marshall and Morgenroth actually found 

 in ascitic fluid an anticomplement for at least one of two complements 

 present in guinea-pig serum. 



These experiments go to show that complements differ in this respect 

 at least : that not all have identical haptophores. Whatever differences 

 between complements exist must be slight; probably the cytophilic 

 group of all are alike. At present the subject has more theoretic than 

 practical importance. In the various diagnostic reactions guinea-pig 

 serum ordinarily furnishes the complement for hemolysin, bacteriolysin, 

 or other cytolysins, and in the therapeutic administration of bacterioly- 

 tic serums we are compelled in any case to depend for activation of the 

 amboceptor upon the natural complement in the patient's serum. 



The Nature and Action of Complement. The true nature of the 

 complements is unknown. In many respects they bear a resemblance 

 to ferments, and certainly the part they play in the processes of cytolysis 



