NEUTRALISATION OF SIMPLE POISONS 199 



the free poison is bound near the area of injection. The 

 remainder on entering the circulation is therefore relatively 

 harmless. The mixture behaves, however, in a wholly 

 different manner. If the greater part of its free poison 

 is bound near the area of injection, the diffusing mixture 

 on entering the circulation gives off free poison through 

 dissociation of the toxin-antitoxin compound and therefore 

 causes a much stronger paralysis than does the smaller 

 quantity of originally free poison. It must also be con- 

 ceded that if, as in the case of poison No. 471, in the one 

 case less than one lethal dose, and in the other case about 

 forty lethal doses, together with a large quantity of anti- 

 toxin, are injected, the animal will have much more diffi- 

 culty in freeing its body of the poison in the second than in 

 the first case. For in the first case it has only to neutral- 

 ise and eliminate less than one lethal dose ; while in the sec-, 

 ond case, after the neutralisation or elimination of one lethal 

 dose, new quantities of poison are set free to be eliminated 

 from the animal's body. In the meantime large enough 

 quantities of poison to cause a marked paralysis may diffuse 

 to the nervous organs and disturb their functions. From this 

 point of view the long period of incubation is also easily 

 understood. There is therefore no adequate ground to 

 assume the presence of a poison such as the toxon or epi- 

 toxin of Ehrlich, different from the lethal poison in the 

 diphtheria poison. In recent times a great number of in- 

 vestigations have been done to strengthen the probability 

 of the existence of "toxons." Morgenroth 1 has made a 

 very elaborate study of the action upon guinea-pigs of pure 

 diphtheria-toxin and of mixtures with antitoxin. He con- 



1 Morgenroth: Zeitschr.f. Hygiene, 48. 177 (1904). 



