Artificial immunity against toxins 371 



by toxins, must be much more complicated than is usually sup- 

 posed. If the fresh injections of these poisons bring about a 

 specific hypersensitiveness on the one hand, and on the other a great 

 fall in antitoxic power, followed by its still more notable augmentation, 

 it is evident that the introduction of toxins must give rise to a great 

 perturbation in the cell functions. The general analogy between 

 acquired immunity against micro-organisms and against toxins pro- 

 bably rests on similar bases. Kretz 1 has already advanced the 

 hypothesis that, in antitoxic action, two factors, comparable to the 

 cytases and fixatives in the antimicrobial action, co-operate. In the 

 absence of one of these elements we can understand that the one 

 which remains may be incapable of bringing about the neutralisation 

 of the toxin. For this reason the antitoxic serum may act very 

 differently in the organism of the animal which produces it and in 

 that of a normal animal which receives it. An explanation which is 

 adequate for the antitoxic action of the blood of the crayfish injected 

 into mice serves equally well in the case of the antitoxic influence [390] 

 of the serums of animals which themselves succumb to intoxication. 



Wassermaim's 2 experiments on the anticytase serums might 

 appear to supply an argument against the hypothesis we are de- 

 fending. Having shown that animals injected with antityphoid serum 

 die of intoxication when serum which prevents the action of the 

 cytases is introduced simultaneously, Wassennann put the question : 

 May not the action of the antitoxins be prevented by this same anti- 

 cytase serum? To solve this point he injected into guinea-pigs a 

 mixture of antidiphtheria serum with toxin in excess and a fairly 

 strong dose (3 c.c.) of anticytase serum, upon which we have already 

 spoken (see Chapter VII). The animals, so treated, behaved exactly 

 as did the animals used for control which received the same 

 quantities of antitoxin and toxin but without the addition of anti- 

 cytase serum. Wassermann concludes from these experiments that 

 the exclusion of the cytase, contrary to what takes place with anti- 

 microbial serums, in no way impedes the action of the antitoxins. 

 This conclusion, which appears at first sight to be justified, cannot, 

 however, be accepted, as the two examples chosen by Wassermann, 

 typhoid infection and diphtheria intoxication, differ very profoundly 

 from each other. In the former, we have an experimental typhoid 

 peritonitis which kills the control animals in less than 24 hours, 



1 Ztschr.f. Heilh, Berlin, 1901, Bd. xxn, S. 1. 



2 Ztschr.f . Hyg., Leipzig, 1901, Bd. xxxvii, S. 194. 



242 



