RICINE. 193 



agglutination never occurred at all in the living blood. He 

 also discovered that pepsin-hydrochloric acid checked this action 

 upon the blood without affecting the toxic power a result 

 which, it is true, was denied by LAU, but was conclusively 

 confirmed by JACOBY (vide infra). 



This question is particularly important because it should 

 furnish an argument for deciding whether ricine is an individual 

 substance, or whether its action upon the blood ought to be 

 regarded as quite distinct from its toxic power, in the sense that 

 there are two separate constituents of the castor seed, exerting 

 their activity in a different way a point of view put forward, 

 e.g., by CUSHNY and MULLER. 



It is, however, extremely probable that the question in this 

 form is not sufficiently precise. It is quite in accord with 

 Ehrlich's theory that ricine should be a receptor of the second 

 class of a somewhat complex constitution, possessing only one 

 haptophore group but two ergophore groups viz., a toxophore 

 group which causes the poisoning, and another group producing 

 the agglutination, and for which the term " agglutinophore " 

 group has been suggested. 



This theory can be readily supplemented by the further 

 hypothesis that these two ergophore groups differ in their degree 

 of stability, a difference of susceptibility to digestion with 

 pepsin-hydrochloric acid being in fact capable of detection, so 

 that even to explain this phenomenon it is unnecessary to 

 assume the existence of two substances. 



On the other hand, however, it is not as yet possible to demonstrate 

 more fully the manifold nature of ricine poisons. As FRANKEL has shown, 

 the antitoxine of normal barbel serum is absolutely devoid of protective 

 power against the action of ricine upon cats' blood on the one hand, and, 

 on the other hand, also against its toxic action upon rabbits and even upon 

 the barbel itself, so that here there is evidence in support of the view that 

 there is a distinct fish blood agglutinine and fish poison. 



We cannot discuss this question more fully until we are able 

 to consider the action of ricine in the light of the side-chain 

 theory. As in the case of all true toxines there are four points 

 that justify a poison being included among the hap tines. 



We have already touched upon the small lethal dose, the 

 incubation period, and the variable toxicological behaviour. 

 But the most important point of all is the formation of anti- 

 toxine in the organism, the production of active and passive 

 acquired immunity. 



In this respect, also, the behaviour of ricine exactly corresponds 

 with that of the bacterial toxines. It was, in fact, experiments 



13 



