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EXPERIMENTAL PHARMACOLOGY 



the muscle lever has recorded a line half an inch long (be 

 Sure the lever is properly weighted and adjusted) stimulate 

 the muscle with one single shock. The muscle should con- 

 tract quickly but the relaxation is much prolonged and 

 usually shows certain peculiarities. Let the drum run and 



Fig. 345. Arrangement of apparatus for spinning the drum a single round at a time 

 and stimulating a muscle or nerve with a single shock during the revolution of the drum. 

 (See Jour. Amer. Med. Assoc., 1911, 56, 1705.) 



record the full relaxation but as soon as the lever again 

 reaches the base line stimulate the muscle again with one 

 single shock. Record this contraction and when the lever 

 again conies down to the base line repeat the stimulation. 

 A series of contractions will thus be secured. The charac- 



