RICINE. 195 



and that antiricine consists of broken-off normal receptors. He 

 has observed a very interesting deviation from the bacterial 

 toxines. If an active immune serum be brought into contact 

 with solutions of ricine a distinct precipitate is formed, which is 

 also the case when solutions of antiricine are used (vide infra). 

 On the other hand, there is no precipitate produced when active 

 ricine is treated with normal serum or with destroyed antiricine, 

 or when ricine rendered inactive by boiling is brought into con- 

 tact with antiricine. 



DANYSZ (loc. cit.) simultaneously investigated this precipitate, and found 

 that there was invariably an optimum of admixture at which the strongest 

 precipitation occurred. We shall return presently to the conclusions that 

 he drew from this result. 



This combination of ricine with antiricine is, as JACOBY rightly 

 concludes, a primary one. The resulting neutral compound is, 

 however, in this case only sparingly soluble, and thus forms a 

 precipitate which also carries down, as usual, other proteids 

 of the serum ; for this is the only way of explaining the amount 

 of the precipitate. But there can be no question of any precipita- 

 tion of proteid by some preeipitine that has been formed, and of 

 this precipitate then carrying down with it the mixture of ricine 

 and antiricine ; for even ricine that is free from albumin produces 

 in the organism a serum that gives the albumin reactions. More- 

 over, the strictly quantitative combination that is formed is 

 opposed to the view that there might be any removal of the 

 toxic power of the ricine by adsorption during a simultaneous 

 precipitation of proteids for the proteid precipitates containing 

 ricine that have been formed in another manner e.g., by nucleic 

 acid (vide supra) are poisonous, whereas this precipitate is not. 

 But as soon as there is any excess of ricine present, the filtrate 

 remains poisonous in exactly the degree corresponding to that 

 excess. A removal of toxic power so quantitatively regulated 

 cannot be accounted for by adsorption. 



An apparently paradoxical phenomenon can be simply ex- 

 plained by the theory. The washed erythrocytes of highly- 

 immunised animals are at least as susceptible, and apparently 

 still more susceptible than the normal erythrocytes. It is 

 theoretically conceivable that the power of forming receptors 

 may become temporarily spent, so that the erythrocytes may 

 contain few or none at all, with the result that their suscepti- 

 bility may be very insignificant, or nil ; this appears to happen 

 frequently in the case of eels' blood (q.v.). 



Conversely, the theory can also assume the possibility of the 

 erythrocytes being endowed with the power of a very vigorous 



