CHAPTER V 



TOXIN AND ANTITOXIN 



THE EEACTION BETWEEN TOXIN AND ANTITOXIN 

 (EHBLICH'S ANALYSIS) 



THE TOXIN-ANTITOXIN REACTION 



WHEN Behring and his collaborators, Kitasato and Wernicke, 

 had definitely shown that the cell-free blood serum of animals im- 

 munized with tetanus and diphtheria toxins respectively possessed 

 the power to protect other animals of the same and different species 

 against the poisons, it became of the utmost importance to deter- 

 mine, if possible, the mechanism by which the "antitoxic" effect was 

 attained. The earlier opinion, expressed by Behring himself, held 

 that in all probability the toxin was directly injured or destroyed by 

 the action of the antitoxic serum.- That this assumption was incor- 

 rect was soon demonstrated by the experiments of Eoux and Vail- 

 lard 1 and by those of Buchner. 2 The worl: of the former investiga- 

 tors showed that the mixtures of tetanus toxin and antitoxin, meas- 

 ured in such proportions that they were harmless for normal guinea 

 pigs, could still be found toxic for animals weakened by preliminary 

 inoculation with other bacteria. Buchner claimed in analogous ex- 

 periments that similar mixtures, harmless for mice, could still show 

 toxicity for guinea pigs. He inferred from this that the nature of 

 the cell reactions of different animal species influenced the antitoxic 

 effect. Both investigations led the workers to conclude that the pro- 

 tective action of antitoxin was not due to a direct effect upon the 

 poison but was potent by acting upon the tissue cells of the animal by 

 protecting these from subsequent harm by the toxin. Their concep- 

 tion implied an indirect protective function on the part of the anti- 

 toxin, not due to any direct reaction between it and the poison. 



That this explanation, too, was faulty was made evident by a 

 number of investigations which took advantage of the peculiar dif- 

 ferences in resistance to temperature between certain toxins and 

 their specific antitoxins. 



1 Roux and Vaillard. Ann. de I'Inst. Past., 1894. 



2 Buchner. Munch, med. Woch., p. 427, 1893. 



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