ON PROTAGON: ITS CHEMICAL COMPOSITION AND PHYSICAL 

 CONSTANTS, ITS BEHAVIOUR TOWARDS ALCOHOL, AND 

 ITS INDIVIDUALITY. By R. A. Wilson and W. Cramer. (From 

 the Physiological Laboratory, University of Edinburgh.) 



Protagon is a Product of a Definite Composition. 



Within recent years the existence of protagon as a definite compound 

 has been categorically denied by Gies and his collaborators, whose views 

 have been endorsed by Rosenheim and Tebb, and positive assertions have 

 been made concerning the part played by protagon in the history of 

 neurochemistry, assertions which it is difiicult to test by the exact methods 

 of experimental investigation. Whether these authors are right or not. 

 wliether protagon is a mixture or not, there is one outstanding fact that 

 must be clearly recognised : namely, that from brain a substance of a 

 constant chemical composition can be extracted which has received the 

 name protagon. 



Gam gee, in his investigations on this substance, prepared a number of 

 samples, which on analysis gave figures agreeing inter se, and which re- 

 tained this composition after recrystallisation. From his analyses he gives 

 the following figures for the composition of protagon : 



C. 

 16-39 



H. 



10-69 



N. 

 2-39 



1-06 per cent. 



Gam gee's results were confirmed by a number of observers, who by 

 identical and by different methods extracted from nervous tissues substances 

 having the same composition as protagon, as will be seen from the following 

 table : 



We have not here considered observations in which substances were 

 prepared from brain, but only partially analysed, as was done, for instance, 



VOL. I. — JAN. 



