20 



BELL SYSTEM TECHNICAL JOURNAL 



I 



ISSH^^JWWW^^ 



Fig. 25 — Action current of a stimulated frog-nerve.' 



Fig. 26 — Make of current through direct contact and break through tuned circuit— 



Dufour." 



22 Gasser and Erlanger, Am. Jl. Physiol, 73, p. 613, 1925. 



