358 Chapter XII 



similar evidence. The same mixture of tetanus toxin and specific 

 serum which is borne without the least difficulty by noniial guinea- 

 pigs, causes typical tetanus in other guinea-pigs of the same weight, 

 and apparently in the best of health, but which have been im- 

 [376] munised some time before against the Massowah vibrio. In another 

 series of experiments, Roux and Vaillard injected into guinea- 

 pigs a very large amount of antitetanus serum "capable of im- 

 munising them thousands of times,'' and, shortly afterwards, a lethal 

 dose of tetanus toxin. The normal guinea-pigs were thoroughly 

 resistant to this test, whilst several guinea-pigs into which were also 

 injected the products of other micro-organisms, acquired tetanus. 

 Analogous results were obtained with mixtures of diphtheria toxin 

 and antidiphtheria serum. Roux concludes from these facts "that 

 the antitoxins act on the cells." Against the theory of the destruc- 

 tion of toxins by antitoxins, he invokes the influence of heat on 

 mixtures of these two substances. Calmette^, under Roux's inspi- 

 ration and in his laboratory, carried out various experiments on anti- 

 venomous serum. A mixture of this with snake venom, in such 

 proportion that the poison became inactive, regained its toxicity 

 after being heated for five minutes at 68° C. A normal animal, in- 

 jected with this mixture, succumbed as if it had received pure 

 venom. On being heated at 68° C. the serum lost all its antitoxic 

 power over the venom, and the latter, which only becomes modified at 

 a much higher temperature, remained intact. Later, a similar result 

 was obtained by Wassermann^ in his experiments with pyocyanic 

 toxin. This poison is resistant at even higher temperatures than is 

 snake venom, whilst the antitoxin of the serum is destroyed under 

 the same conditions as are the other antitoxins. Taking advantage 

 of these peculiarities, Wassermann boiled the mixture of pyocyanic 

 toxin and antitoxin serum, being careful to dilute it with two volumes 

 of distilled water before doing so. This mixture which, before it was 

 heated, was quite innocuous for guinea-pigs, again became a fatal 

 poison after the destruction of the antitoxin. 



These experiments prove clearly that, in the action of the anti- 

 toxin on the toxin, there can no longer be any question of an actual 

 destruction of the latter, a view which has been accepted by both 

 von Behring and Ehrlich. But, as pointed out by Roux at the 



^ "Le venin des serpents," Paris, 1896, p. 58. 

 2 Ztschr.f. Hyg., Leipzig, 1896, Bd. xxii, S. 263. 



