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EXPERIMENTAL PHYSIOLOGY. 



LESSON XLIII. 



VELOCITY OF NERVE ENERGY IN A MOTOR 



NERVE DOUBLE CONDUCTION IN NERVE 



KUHNE'S GRACILIS EXPERIMENT. 



1. Velocity of Nerve Energy in a Motor Nerve. 



The rate of propagation of a nerve impulse may be estimated 

 by either the pendulum or spring myograph. With slight 

 modifications the two processes are identical, only in using the 

 spring myograph it is necessary to use such a coiled spring, as 

 will cause the glass plate to move with sufficient rapidity, to 

 give an interval long enough for the easy estimation of the latent 

 period. 



(a.) Use the spring myograph and arrange the experiment 

 according to the scheme (Fig. 93) i.e., an induction coil for 



n 



Fig. 93. Scheme for Estimating the Velocity of Nerve Energy. 



single shocks with the trigger-key of the myograph (1, 2) 

 arranged in the primary circuit; in the secondary circuit 

 (which should be short-circuited, not represented in the 

 diagram) place a Pohl's commutator ivithout cross-bars (C). 



