XXXVIII. TOXIN AND ANTITOXIN :* 



A REPLY TO THE LATEST ATTACK OF GRUBER. 

 By PAUL EHRLICH. 



IN a domain that is open to experimental investigation it is 

 neither easy nor without danger for one to express criticism merely 

 as a result of literary studies. 



This is especially true in that most difficult field in the entire 

 study of immunity, namely, the subject of toxins. Only one who 

 has devoted years of unprejudiced study at the laboratory table 

 to this subject and gathered a host of observations and experiences 

 will be in a position to orientate himself in the confused mass of 

 true and false statements contained in the literature. The outsider 

 will find it very difficult to correctly analyze all this material. 

 Hence it is all the more remarkable that Gruber 2 should choose 

 the subject of toxins for the main portion of his attack upon me, 

 for according to his own admissions that is the field which he knows 

 merely from literary studies. Against such critics I am in the unpleas- 

 ant position of a man who is compelled to discuss colors with the 

 blind. Nevertheless I cannot well escape the thankless task of 

 replying, at least to the main points in Gruber's polemic, for it is 

 indisputable that this attack, addressed chiefly to those without 

 special training in this field, is capable of causing wide-spread con- 

 fusion, owing to its positive tone and its severity. 



Gruber's first important error lies in the assumption that a con- 

 tro version of the plurality of poisons, to which I hold, signifies the 

 downfall of the side-chain theory without further ado. The side- 

 chain theory, however, proceeds from the assumption that the toxin- 



1 Reprinted from the Munch, med. Wochensch. 1903, Nos. 33 and 34. 



2 M. Gruber and Cl. v. Pirquet, Toxin und Antitoxin, Munch, med. Wochensch. 



1903, Nos. 28 and 29. 



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