1903.] Action^/ Choline, Neurine, Muscari-ne, and Betaine. 343 



FIG. 14. Muscarine-Atropine. 

 Muse 



_^oJwwiAu^^ 



Frog's heart ; suspension method. Four successive applications of muscarine 

 hydrochloride (1 per cent, solution in normal saline) and of atropine sulphate 

 (1 per cent.) at the points marked M 1? A], M 2 , A 2 on the four successive lines. 

 The record exhibits an antagonism of muscarine by atropine and vice versa 

 i.e., contrary to the usual statement, a bilateral antagonism is sometimes 

 demonstrable between these two drugs. 



FIG. 15. Neurine-Atropine. 



Frog's heart. Effect of neurine applied at the point N. 1 per cent, solution 

 neutralised by H 2 SO 4 . Subsequent application of atropine sulphate, 1 per 

 cent, solution, at A. 



