CHAPTER XIII 



TOXINS AND ANTITOXINS 



The Toxin- Antitoxin Reaction. — Apart from the therapeutic possi- 

 bilities disclosed by the discovery of antitoxins, new light of inestimable 

 value was thrown by these observations upon the biological processes 

 involved in immunization. The most vital problem, of course, which 

 immediately thrust itself upon all workers in this field was the question 

 as to the nature of the reaction in which toxin was rendered innocuous 

 by antitoxin. 



The simplest conception of this process would be an actual destruction 

 of the toxin by its specific antitoxin, and it is not unnatural, therefore, 

 that this was the view which, for a short time, found favor with some 

 observers. Roux, and more particularly Buchner,' however, under the 

 sway of cellular pathology, advanced the opinion that the antitoxins 

 in some way influenced the tissue cells, rendering them more resistant 

 against the toxins. Antitoxin, according to this theory, did not act 

 directly upon toxin, but affected it indirectly through the mediation 

 of tissue cells. Ehrlich,^ on the other hand, conceived that the reac- 

 tion of toxin and antitoxin was a direct union, analogous to the chem- 

 ical neutralization of an acid by a base — an opinion in which Behring 

 soon joined him. 



The conception of toxin destruction received unanswerable refuta- 

 tion by the experiments of Calmette.' This observer, working with snake 

 poison, found that the poison itself (unlike most other toxins) possessed 

 the property of resisting heat even to 100° C, while its specific anti- 

 toxin, Hke other antitoxins, was delicately thermolabile. He noted, 

 furthermore, that non-toxic mixtures of the two substances, when sub- 

 jected to heat, regained their toxic properties. The natural inference 

 from these observations could only be that the toxin in the original mix- 

 ture had not been destroyed, but had been merely inactivated by the 



^Buchner, " Schutzimpfung,"etc., in Penzoldt u. Stinzing, "Handbuch d. spez. 

 Therap. d. Infektkrank.," 1894. 



'Ehrlich, Deut. med. Woch., 1891. 'Calmette, Ann. de I'inst. Past., 1895. 



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