TOXIN AND ANTITOXIN. 531 



emanating from the Institute with all of which Gruber seems quite 

 unfamiliar. I shall content myself therefore with a brief discussion 

 of Gruber's conclusions. Gruber states: 



1. " There is no warrant for assuming that the bacterial toxic 

 solutions contain a number of poisons possessing qualitatively simi- 

 lar actions but differing in intensity and in their affinity to the anti- 

 toxin." 



In the preceding pages I have conclusively shown that his view 

 cannot be harmonized with the actual facts. But even a priori 

 there is no reason to assume that bacterial cells always produce 

 only a single poisonous metabolic product. Thus, to mention only 

 a few examples, we know that cinchona bark contains about twenty 

 different alkaloids, opium about the same number; Flexner and 

 Noguchi's researches show that snake venom contains at least four 

 different poisons (hsemotoxin, leucotoxin, neurotoxin, endothelio- 

 toxin), and the yeast cell, we know, contains a number of different 

 ferments. Furthermore, 1 may again call attention to the fact that 

 the secretion of tetanus bacilli contains four distinct poisons, namely, 

 two varieties of tetanospasmin, my tetanolysin, and the poison 

 which, according to Tizzoni, causes the cachexia. So far as diphtheria 

 poison is concerned the reader is referred to my previous statements. 

 My assumption of the existence of at least two poisons, toxins, and 

 toxons, is borne out by the clincal observation that in certain epi- 

 demics there is a large percentage of paralyses. 1 



2. " There is no reason for assuming that the mode of action of 

 the toxins is absolutely unlike that of other organic poisons." 



Nevertheless, the fact remains that the principal characteristic 

 of the toxins, namely, the production of antibodies, does differentiate 

 them from all other poisons, Gruber to the contrary notwithstand- 

 ing. Two years ago Gruber could have found an ally in Pohl, who 



1 In animal experiments as a rule, the toxons do not manifest themselves 

 until the toxins (which possess a greater affinity) have been neutralized by 

 the antitoxin. Dreyer and Madsen, however, have described a diphtheria 

 poison (Festskrift, Kopenhagen, 1902), in which the toxons could be demon- 

 strated even by the injection of sublethal doses, the injections being followed 

 by paralytic phenomena. In view of the constants of this poison, as they were 

 determined by Dreyer and Madsen, this behavior is not at all surprising, for 

 while old diphtheria bouillons ordinarily contain about 33 toxon equivalents 

 to 167 toxin equivalents, this poison contained about 500 toxon equivalents 

 for that amount of toxin. 



