Page:On the Similarities between Radiation and Mechanical Strains.djvu/9

182 In (c), fig. 14, is shown the interesting curve for a given piece of Ag. The effect is very much feebler, and curiously enough it gave an opposite response, the vibrated wire becoming cuproid. It was said that silver occupied a peculiar position as regards response to electric radiation,

sometimes responding in one, and again in an opposite manner, probably owing to its readiness to pass from one molecular condition to another, under slightly different external conditions. With mechanical vibration, too, I find silver exhibiting opposite electric variation, the acted wire becoming on different occasions either Z or C.

8. Reversal Effects.

Reversed Effect due to Sub-normal Stimulus.—Just like the negative effect (i.e., opposite to the normal) often exhibited under electric radiation