ANTITOXINS AND SERUM THERAPY. 



57 



It was in this direction that the experiments of Behring and 

 Kitasato, in 1890, proved to be of profound importance. It was 

 shown that the blood serum of a rabbit rendered immune against 

 tetanus or diphtheria had no destructive or retarding effect on the 

 growth of the bacilli, but it possessed the power of neutralising the 

 poison developed by the agency of the bacilli. In short, the serum 

 was shown to possess an antitoxic instead of a bactericidal power. 



Hankin conceived the idea that this property is due to substances 

 of the nature of defensive proteids, and the blood serum of the 

 naturally immune rat was found to contain a proteid body with well- 

 marked alkaline reaction, possessing the power of destroying anthrax 

 bacilli. Injection of this proteid into mice, together with fully 

 virulent anthrax spores, prevented the development of the disease. 

 Young rats are susceptible to anthrax, and, according to Hankin, 

 they can be protected from anthrax by injection of the blood serum 

 of the parent. Tizzoni and Cattani expressed the opinion that the 

 antitoxic substance in the blood serum of animals rendered immune 

 against tetanus is a globulin to which they gave the name tetanus 

 antitoxin. Buchner proposed the term alexins (dAe^w, I defend), 

 to signify these substances. Hankin subdivided them into sozins 

 and phylaxins. Sozins are defensive proteids occurring in normal 

 animals ; phylaxins are only found in animals artificially immune ; 

 and each of these are sub-classed by Hankin according to their power 

 of attacking the bacteria themselves or the products they generate. 



Defensive proteids 



(Hankin) 

 Alexins (Buchner) 



Sozins : 

 Defensive 



proteids 



present in the nor- 

 mal animal. 



Phylaxins : 

 Defensive 

 present 



proteids 

 in the 



animal after it has 

 artificially been 

 made immune. 



fMyco-sozins : 



Alkaline globulins from rat 

 (Hankin), destroying an- 

 thrax bacillus. 



Toxo-sozins : 



Of rabbit, destroying poison 

 of Vibrio Metchnikovi 

 (Gamaleia). 



Myco-phylaxins : 



Of rabbit, destroying pig 

 typhoid bacillus (Em- 

 merich). 



Toxo-phylaxins : 



Of rabbit, etc., destroying 

 diphtheria and tetanus 

 poisons (Behring and 

 Kitasato, anti-toxin of 

 Tizzoni and Cattani). 



Tizzoni and Cattani immunised dogs and other animals against 

 tetanus, and employed the antitoxin as a therapeutic agent. Its 



