I9I4-] 



MECHANISM OF THE HEART-BEAT. 



289 



especially fortunate, for fresh discoveries in anatomy and physi- 

 ology were almost simultaneously announced. In the interpretation 

 of the significance of these, the galvanometric method of registration 

 was especially valuable. 



The principles Einthoven employed were in use in Deprez- 

 D'Arsonval's instrument. From these he developed formulae which 

 formed the basis of the galvanometer he constructed. An instru- 



PROC. AMER. PHIL. SOC, LIII, 215, S, PRINTED DEC. II, I9I4- 



