96 IMMUNE SERA 



phore group. The fact that heated complement 

 produces an anticomplementary serum is readily 

 explained by Bordet as due to the absorption of 

 complement by precipitates. An illustration will 

 bring out this point more clearly. 



Goat serum heated to 55 C., and therefore con- 

 taining no active complement, is injected into a 

 rabbit. According to Ehrlich it excites the pro- 

 duction of an " anticomplement " in response to 

 the " complementoid " which it contains. As we 

 shall see in the next chapter, the injection of this 

 heated goat serum in addition to whatever else it may 

 do does actually excite the production of a specific 

 precipitin in the serum of the rabbit, so that when 

 such a rabbit serum is mixed with goat serum, a pre- 

 cipitate will be "produced. Ehrlich 's demonstration 

 of the " anticomplement " is somewhat as follows: 

 Ox blood corpuscles, plus suitable amboceptor (serum 

 of a rabbit injected with ox blood corpuscles), plus 

 fresh, normal goat serum as complement, undergo 

 haemolysis. When, however, the fresh, normal 

 goat serum is mixed with the serum of a rabbit 

 previously injected with goat serum, and then the 

 above combination carried out, no haemolysis 

 occurs. The rabbit serum contains an " anti- 

 complement," says Ehrlich. On the other hand, 

 Bordet and Gay believe that the anticomplement- 

 ary action is due to the absorption of goat com- 

 plement by the precipitate produced by the mix- 



