THE CONSTITUENTS OF DIPHTHERIA TOXIN. 509 



So far as the behavior of partially neutralized mixtures is con- 

 cerned, the observations of these authors show that mixtures which 

 exert only toxon effects on guinea-pigs produce death in rabbits 

 with symptoms of diphtheria poisoning. I believe that all these 

 phenomena are best explained by the assumption that there are at 

 least three different varieties of poisons, and that these possess differ- 

 ent affinities and different actions. These poisons are: 



1. Toxin, possessing the highest affinity, kills rabbits and guinea- 

 pigs acutely, but is more toxic for the former. 



2. Toxon, killing rabbits acutely and guinea-pigs with symptoms 

 of paralysis. 



3. Toxonoid, producing paralyses in rabbits, non-toxic for guinea- 

 pigs. 



The fact that all three poisons act more strongly on rabbits than 

 on guinea-pigs is explained by the absolute higher susceptibility of 



the former. 



Dreyer and Madsen have recently described a diphtheria poison 

 in which toxoid effects could be demonstrated even on the injection 

 of sublethal doses of the pure poison . This behavior is at once under- 

 stood if we study the constants of this poison as they were determined 

 by these authors, for whereas in the other poisons examined there 

 were 33 toxon equivalents to 167 toxin equivalents (toxon: toxin = 

 1:5), in this poison the proportion was just the reverse, there being 

 three times as much toxon as toxin. No wonder therefore that with 

 the toxon fifteen times more concentrated even sublethal doses of 

 the pure poison should suffice to make toxon effects evident. 



In view of the high theoretical significance which attaches to the 

 poison described by Dreyer and Madsen, I cannot refrain from giving 

 briefly my conception of its constitution. The authors have repre- 

 sented the poison in the form of a curve, one which at first sight seemed 

 rather strange to me. As soon ; however, as I transformed their 

 graphic representation into a spectrum by the aid of their figures, 

 the constitution of the poison was found to agree very well with 

 other well-known diphtheria poisons. The only difference is the very 



is due to an incomplete neutralization, such as Arrhenius and Madsen, for exam- 

 ple, have demonstrated in the case of boric acid and ammonia, and in the union 

 of tetanolysin with its antitoxin. If that were the case one would expect to 

 see the phenomenon in all diphtheria poisons in equal degree, and this is not 

 the case. 



