72 IMMUNE SERA 



dition of destroying these also. When fresh serum was 

 first brought into contact with sensitized bacteria, simi- 

 lar results were obtained. The blood corpuscles sub- 

 sequently added did not then undergo haemolysis. 

 // such an action on one of the sensitive substrata has 

 once taken place, the active sera, as a rule, are deprived 

 of all their complement functions, from which Bordet 

 concludes that the destruction of the most varied 

 elements by one and the same serum must be due to a 

 single complement. 



It may be said in passing that Ehrlich admits the 

 correctness of the above experimental results, but 

 brings forward arguments to show that Bordet 's inter- 

 pretation as to the existence of only a single complement 

 cannot be accepted. 



This experiment of Bordet is usually spoken of as 

 the " Bordet-Gengou phenomenon " and is now used 

 largely in determining whether or not a given serum 

 possesses certain amboceptors. The serum to be 

 tested is first heated and then mixed with a small 

 quantity of fresh normal serum (complement) and 

 with an emulsion of the bacterium whose amboceptors 

 it is desired to discover. After standing for six hours 

 at room temperature, red blood cells previously treated 

 with heated haemolytic serum are added. If there is 

 no hsemolysis it is held to mean that the complement 

 in the fresh serum which was suitable for lysis of 

 properly prepared blood corpuscles, has been absorbed 

 by the bacteria by reason of the presence of specific 

 amboceptors in the serum tested. 



Wassermann 1 has attempted to apply this method 

 in measuring the amboceptor content of specific menin- 



* Wassermann, Neisser and Brack, Deutsche med. Wochen- 

 schr., 1906; Wassermann and Plaut, Ibid. 



