GENERAL PHYSIOLOGY OF MUSCLE 



81 



experiment on the heart, on the contrary, there is a negative 

 oscillation in the first phase, which expresses the negativity of 

 the base to the apex at the commencement of systole, and a 

 positive oscillation in the second phase, which expresses the 

 positivity of base to apex at the close of systole and commence- 

 ment of diastole. 



Hermann succeeded in demonstrating the diphasic variation in 



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Fie;. 58. Distribution of electrical potential to different parts of the human body at the moment 

 at which the diphasic action current of the heart arises. (A. D. Waller.) A, apex ; B, base of 

 ventricles ; 0, equatorial line or plane in which the electrical potential is nil ; a, a, a and 

 6, ft, b are the equipotential curves of A and L. 



the muscles of the fore-arm of a man by stimulating the brachial 

 plexus in the axilla. The current was led off by special electrodes, 

 applied one between the middle and upper third of the fore-arm, 

 the other to the wrist or elbow (Fig. 57). 



In the first case there is a descending-ascending, in the second 

 case an ascending-descending diphasic current, as shown by 

 arrows 1, 2 of the diagram. This diphasic action current is the 

 only electrical phenomenon which can be positively demonstrated 

 for skeletal muscle on living man. 



The ascending current in the arm after a voluntary contraction 

 of the muscles (du Bois-Eeymond) is not a muscular action 



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