ANIMAL ELECTRICITY. — LECTURE I. 



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Fig. 6 (2462). — Simultaneous record of the mechanical and electrical responses 

 of a gastrocnemius muscle (frog), excited by tetanising currents for 7| seconds (60 

 to 70 interruptions per sec.) at intervals of I minute. 



The upper line (white on black) gives the series of lifts of a weight of 10 grms. 



The lower line (black on white) gives the corresponding series of electrical 

 effects ; the large deflections at beginning and end of the series are standard 

 deflections made by ^^ volt. Dead-beat galvanometer (shunted). 



In the first and second pairs of responses the strengths of stimulation were 4 

 and 5 units ; in the third and subsequent pairs the stimulation was at 10 units. 



