ANTITOXIN. 101 



For the explanation of the origin and action of an- 

 titoxin in the human body, Ehrlich first expressed the 

 idea that the antitoxins are exactly identical with those 

 constituent parts of the poison-susceptible cells which are 

 injured by the poison. The antitoxins are the " toxo- 

 pnoric side chains" or, more simply, according to Blumen- 

 tluil, the " toxin=binding group" of the toxin-susceptible 

 albumin molecule. 



The recent experiences of Wassermann, Behring, Blu- 

 menthal, Metschnikoff and Maria, and especially of Knorr 

 (Munch, med. Wochenschr., 1898, Nos. 11 and 12), accord 

 very well with this explanation. Thus, what occurs in the 

 case of tetanus may be presented somewhat as follows : 



If one introduces tetanus poison into an animal suscept- 

 ible to tetanus (guinea-pig), after a time the poison disap- 

 pears from the blood and becomes insolubly fixed by the 

 chemical constituents of the ganglia of the spinal cord, 

 and is therefore no more obtainable from the spinal cord. 

 The binding of the poison by the spinal cord leaves it dis- 

 eased ; the poison-binding cells become functionally inca- 

 pacitated. Wassermann could directly demonstrate that 

 the spinal cord (and brain) can bind tetanus poison, since 

 he showed that mixtures of tetanus toxin and emulsion 

 of spinal cord are non-toxic. It is further interesting that 

 the cord of animals susceptible to tetanus alone possesses 

 this property, the cord of hens, which are immune to teta- 

 nus, not at all. The side chains are absent here, and the 

 hen is insusceptible to tetanus for the same reason that its 

 cord is without effect upon the toxins. On the contrary, the 

 cords of animals dying from tetanus contain sufficient anti- 

 toxin to protect other animals from the disease. This is no 

 objection, if the first animal died when a certain part of 

 its spinal cells were poisoned through the union with toxin 

 and long before all the poison-binding affinities of its 

 spinal cord were satisfied. 



Knorr has shown the identity of the antitoxin and the 

 poison-fixing substance of the spinal cord by demonstrat- 

 ing that both possess the same susceptibility to injurious 

 influences. 



Where, by careful repeated poisoning of an animal until 

 the surplus supply of antitoxin is dissolved in the serum, 



