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ON ELECTROMOTIVE WAVE ACCOMPANYING MECHANICAL DISTURBANCE IN METALS IN CONTACT WITH ELECTROLYTE
Take a rod of metal, and connect the two points A and B with a galvanometer by means of non-polarisable electrodes. (Fig. 71a.) If the point O is struck, a wave of molecular disturbance will reach A and B. It will be shown that this is attended by a wave of electric variation. The mechanical and the attendant electrical disturbance will reach a maximum and then gradually subside. The resultant effect on the galvanometer will be due to EA − EB where EA and EB are
Fig. 71. In (a) mechanical disturbance at O produces similar electrical variations at A and B; there is no resultant effect. In (b) owing to a clamp, molecular disturbance initiated at A cannot reach B. A tap or vibration imparted to the end A produces responsive current which flows in the wire from the unexcited B to the excited end A. Disturbance at B gives rise to a current in the opposite direction. (c) gives the record of the response to equal stimuli applied to A and B. The ascending part of the curve shows the effect of stimulus, the falling part shows recovery. (d) Simultaneous stimulation of A and B gives no resultant response. (In the records dotted lines represent recovery.)
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