Page:On Electromotive Wave accompanying Mechanical Disturbance in Metals in Contact with Electrolyte.djvu/12

284 was then allowed to cool to its old temperature, when a second series of responses were taken, the stimulus intensity being the same as before. It will be seen how the responses are enhanced by annealing.

Effect of Previous Vibration—The increased sensitiveness conferred by previous vibration has already been referred to before. I give below a record (fig. 7) obtained with platinum (I have obtained similar

records with other metals), which clearly shows how the response is enhanced after preliminary vibration.

Sometimes the wire gets into a very sluggish condition, when the response almost disappears; in other words, owing to some molecular modification, responsiveness is reduced from the normal positive value (by positive is meant that the acted wire becomes zinc-like or is zincoid) to zero. In these cases annealing or preliminary vibration are usually effective in transforming the sensitiveness from zero to a positive value.