PROPERTIES OF ANTISENSITIZERS. 299 



The hypothesis of " complement deviation" (Komplementablen- 

 kung) formulated to explain the observations of Neisser and Wechs- 

 berg on the inhibiting influence of too large an amount of sensitizer 

 on bacteriolysis when the amount of alexin is relatively small, is 

 well known.* It has been claimed, without direct demonstration 

 that, since the bacteria in such an experiment cannot absorb the 

 large amount of sensitizer, the excess remaining in the fluid unites 

 with the alexin and monopolizes a larger or smaller part of it, so 

 that it does not attack the bacteria. It is rather strange that the 

 inhibiting effect of an excess of sensitizer has never been noted in 

 hemolytic experiments, and Morgenroth has attempted to fill this 

 rather important gap in the theory. He admits in the first place 

 that hemotoxic sensitizers must first be combined with the recep- 

 tors of the appropriate corpuscles in order to show any marked 

 affinity for the alexin. f Consequently, in a mixture of corpuscles, 

 alexin, and too large a dose of sensitizer, the excess of the latter 

 substance remaining free in the fluid cannot take up the alexin 

 because it needs corpuscle receptors in order to become avid of the 

 complement. The introduction of these receptors is necessary to 

 produce complement deviation. On the supposition that the 

 antisensitizer is identical with corpuscle receptors as far as affinities 

 are concerned (since they both possess the same haptophore group, 

 according to the lateral-chain theory), Morgenroth conceived the 

 idea that a mixture of sensitizer and antisensitizer should be able 

 to fix a certain amount of alexin. Such a mixture should act, in 

 other words, precisely as we have shown J that sensitizer and cor- 

 puscles do, that is, should absorb alexin energetically. It is evident 

 that if these two substances corpuscle receptors and antisen- 

 sitizer are considered as identical the addition of either one of 

 them to a mixture of sensitizer and alexin should bring about the 

 fixation of a certain amount of the active substance and conse- 



* Studies on Immunity, Ehrlich-Bolduan, John Wiley and Sons, p. 120. See 

 also in this connection this volume, p. 357. 



f It may well be questioned why antimicrobial sensitizers should not be subject 

 to the same necessity. It is certain that if the experiment had turned out the 

 other way, that is to say, if the phenomenon of complement deviation had been 

 found, not in bacteriolysis, but in hemolysis, that the same explanation would have 

 been forthcoming; it would simply have been necessary to apply it to the other 

 instance. 



$ See p. 191. 



