RICINE. 197 



the slow filtration. 1 But even JACOBY'S own experiments, made 

 with unfiltered blood rendered non-coagulable, gave the same 

 results. The mixture had the same degree of toxic power. He 

 himself, however, raises the very important objection that 

 although the poison in this way reaches the cells of the tissues 

 in a combined form, these cells may very well possess the power 

 of decomposing this combination and of attracting the poison to 

 themselves to their own injury. For the receptors of the tissues, 

 like the free receptors, may possess greater affinity for the toxine 

 than do the erythrocytes, although, again, it must be less than 

 that of the free receptors ; otherwise no immunity against the 

 toxic action could be produced. 



This view is also supported by an argument which, to my surprise, was 

 overlooked by JACOBY. If we assume that the tissue receptors combine 

 more readily with the haptophore group of the ricine than does the latter 

 with the receptors of the blood-corpuscles, we have an explanation why in 

 cases of the poisoning of living animals with ricine the symptoms produced 

 in the blood are so slight in comparison with the general symptoms, a fact 

 for which it is otherwise difficult to account. 



These experiments, too, do not decide the question whether or 

 no ricine consists of two separate substances. 



JACOBY, in a further research, 2 made use of Ehrlich's method 

 of separating haemolysines, by subjecting mixtures of ricine with 

 blood-corpuscles to centrifugal force. The agglutinating power 

 was invariably found to have disappeared from the liquid, 

 whereas the amount of toxine varied from 25 to 90 per cent, of 

 the original amount. The poison had never combined quanti- 

 tatively with the receptors. Its action was also qualitatively 

 unchanged. 



JACOBY next rendered animals immune by means of this 

 poison freed from the agglutinine. The immune serum thus 

 obtained showed not only antitoxic, but also anti-agglutinating 

 power, although the plasma poison freed from agglutinine 

 required less antitoxine than ordinary ricine. 



Exactly similar results were obtained with ricine that had 

 been previously treated with pepsin-hydrochloric acid. This 

 agglutinine-free poison also produced an antitoxine which had an 

 influence upon both functions of the ricine. The action of 

 pepsin-hydrochloric acid upon ricine had already been studied by 

 JACOBY in his earlier investigation, and he had been able to 

 confirm MULLER'S assertion that the agglutinating power was 

 considerably reduced, even to -^ of its original amount. 



1 Loc. cit., p. 68. That is, if I have correctly understood the drift of 

 the argument, which is somewhat too briefly expressed. 



2 Jacoby, "Ueber Ricinimmunitat," Hofm. Beitr., ii., 535, 1902. 



