. STUDIES ON ILEMOLYSINS. 1 



FIFTH COMMUNICATION. 

 By Professor Dr. P. EHRLICH and Dr. J. MORGENROTH. 



IN the few years since its formulation the side-chain theory has 

 exercised a marked influence on the direction of the investigations 

 in immunity. The subject of toxins and antitoxins has to a certain 

 extent been concluded, at least for the present. Several objections 

 raised by Roux and Borrel 2 in connection with their splendid 

 work on cerebral tetanus, as well as those made by Metchni- 

 koff 2 and Marie, 2 rested on a misconception of the theory, and the 

 facts on which these are based serve rather as a complete confirma- 

 tion of the theory. 3 The attempt of Pohl 4 to place the doctrine 

 of antitoxins purely on the basis of inorganic chemistry has been 

 completely controverted by Bashford. 5 



Thus the facts proved themselves thoroughly in harmony with 

 the theory, and the latter furthermore proved its inventive value 

 in many directions. It was but natural that the side-chain theory 

 originally formulated for the antitoxins, if it had any general 

 biological significance at all, should also include the complicated 

 phenomena of immunity which result from the introduction of 

 bacteria or tissue-cells. Hence we began two years ago to investigate 

 experimentally the applicability of the doctrines resulting from this 

 theory to the specific hffimotysins obtained by immunization, which 

 had been discovered by Bordet a short time previously. These studies 



1 Reprint from the Berliner klin. Wochenschrift, 1901, No. 10. 



2 Annales de 1'Institut Pasteur, 1898. 



3 See Weigert, Lubarsch's Ergebnisse der Pathologie, 1897; also Levaditf 

 Press medicale, 1900, Xo. 95. 



4 Arch, internat. de Pharmacodyn., 1900. 



5 Arch, internat. de Pharmacodyn. et Therapie, Vol. VIII, fasc. I and II, 

 1901. 



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