408 



Mr. H. E. Eoaf. 



The Acidity of 



Fig. 1. — Simple muscle twitch. 



Fig. 2. — Record of same muscle after treatment with veratrin (1 : 10 5 ). Records read 

 from right to left. Top line, time in 1/5". Second line, signal for single break-shock 

 given to muscle. Bottom line, downward movement shows increased tension by 

 muscle. Shadow shows movement of mercury in capillary. Movement upwards 

 corresponds to increased acidity at manganese dioxide electrode. 



