XXXVII. THE CONSTITUENTS OF DIPHTHERIA 



TOXIN. 1 



By PAUL EHRLICH. 



THE Festschrift, published at the opening of the Serum Institute 

 in Copenhagen, contains a study by Arrhenius and Madsen 2 which 

 deals mainly with the neutralization phenomena of toxin and anti- 

 toxin. We must all rejoice that Madsen has succeeded in interest- 

 ing so excellent a physical chemist in this question, especially as I 

 had tried unsuccessfully for years to secure the interest of physical 

 chemists in Germany. In the present state of scientific knowledge 

 we shall for the present have to give up our attempts to isolate the 

 toxins in pure form. For the same reason also in the analysis of the 

 relations between toxin and antitoxin we cannot conform to the 

 ordinary methods of the chemist working with the balance. On the 

 other hand, the study of toxin and antitoxin is of too great practical 

 importance for us to wait idly for years or decades until chemistry 

 is so far advanced. We must, therefore, content ourselves with the 

 slight means at our disposal, applying these, however, in all direc- 

 tions in order to gain as great an insight into this complicated 

 subject as the present state of our knowledge permits. I had ap- 

 plied myself to this problem for years and come to the conclusion 

 that the only way to approach it was by an exact quantitative study 

 of the neutralization phenomena. Particularly in partial neutraliza- 

 tion I believed I had found a method by which we could gain an 

 insight into the most intricate constitution of the toxins. To my 

 regret high authorities pronounced this method as incorrect and of 

 no avail. I am all the more pleased, therefore, to see that so high 



1 Reprint from the Berl. klin. Wochenschr. 1903, Nos. 35-37. 



2 S. Arrhenius and Th. Madsen, Physical Chemistry applied to Toxins and 

 Antitoxins, Festkrift ved indvielsen af Statens Serum Institute, Kopenhagen, 

 1902. (This is to be had in English text, Kopenhagen, 1902.) 



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