RELATION OF TOXINES TO ANTITOXINES. 31 



This conception at once gives us two highly important points 

 of view regarding the reciprocal relationship of the toxine to the 

 antitoxine. 



Its acceptance immediately renders untenable two possible 

 modes by which the poison might be influenced by its specific 

 anti-body viz., by direct destruction of the poisonous substance 

 in its entirety, as it might, for instance, be destroyed by, say, a 

 strong acid ; and secondly, by the action of the antitoxine on the 

 specifically injurious toxophore group of the poison, just as, for 

 instance, the poisonous property of aniline is considerably reduced 

 by the introduction of acetic acid into its toxic amino-group. 

 Neither is reconcilable with the side-chain theory, for there can 

 only be any influence in the sense that the antitoxine saturates 

 the haptophore group of the toxine, and thus prevents the possi- 

 bility of its bringing its toxophore group into action by seizing 

 upon the cell, while in reality its toxic force remains unchanged. 



While we have deduced this fundamental point of view as a 

 consequence of the side-chain theory accepted by us as a heuristic 

 principle, the actual development of the theory has naturally 

 proceeded in a converse manner. Tedious experiments were 

 first made to establish the correctness of these facts in order to 

 use them as important supports of the theory. EHRLICH and 

 BEHRING were at first of opinion that the poisonous property of 

 the toxine was affected by the antitoxine, but subsequently came 

 to the conclusion that it was a question of simple combination. 



The facts that led to this now generally accepted conclusion 

 were of different kinds. 



At first it was the general view that the action of an anti- 

 toxine was only an indirect one, its function being to render the 

 organism "proof" against the toxine. 



This opinion was afterwards abandoned when it was found 

 that toxine and antitoxine combined in accordance with definite 

 arithmetical laws (law of multiples), with which we shall deal 

 more fully later on. Then results of the greatest importance 

 were obtained by a closer study of processes in which the inter- 

 vention of the living organism could be absolutely excluded, and 

 in which plainly visible reactions in the test tube were used as 

 indicators of the influence of the antitoxine upon the toxine. 



The earliest of these were EHRLicn's 1 celebrated experiments 

 upon the agglutinating action of ricine upon the red corpuscles 

 of the blood, the results of which showed that there were fixed 

 numerical relationships between ricine and antiricine, inasmuch 



1 Ehrlich, " Zur Kenntn. d. Antitoxin wirkg.," Fortschr. d. Med., 1897, 

 41. 



