TOXINS AND ANTITOXINS. 35 



are found in the blood of vaccinated animals, from 

 which may be obtained antitoxic serums with a 

 specific but transient immunity ; and they are also 

 found in the plasmas of the lymph and exudates, 

 in aqueous tumors, and in the milk. They are 

 seldom found in the cells. 



Mode of Action. — Frequent attention has been 

 paid to the mode of action of the antitoxins upon 

 the toxins, a phenomenon of great importance in 

 relation to the phenomenon of immunity acquired 

 against the toxins. At the beginning of our 

 knowledge on this subject, the idea of a destruction 

 of the toxin immediately suggested itself, and was 

 advanced by von Behring.* According to this 

 scientist the antibody inhibits the morbigenic action 

 of the toxin by neutralizing the toxin, combining 

 with the latter to form a compound of a chemical 

 nature which is devoid of toxicity and without 

 action on the organism. According to this theory, 

 the influence of the antitoxin on the toxin is direct, 

 and does not require the intervention of the living 

 cellular protoplasm. Such was also the belief of 

 Prof. Ehrlich.f 



Buchner, a little later, believed that the anti- 

 toxin, instead of acting directly on the toxin, 

 exercised a direct influence on the living elements 



* Von Behring and Kitasato: Deutsch. med. Wochenschr.f 

 1890, p. 1113. 

 t Ehrlich: Klin. Jahrb. 1897, vi, p. 292. 



