1901.] on the Response of Inorganic Matter to Stimulus. 



627 



It will be seen from these arrangements : 



(1) That the cell depicted in d, Fig. 9, is essentially the same as 

 that in Fig. 8. 



(2) That as the wires in the cell are immersed to a definite depth 

 in the electrolyte there is always a perfect and invariable contact 

 between the wire and the electrolyte. The difficulty as regards 

 variation of contact is thus eliminated. 



(3) That as the wires A and B are clamped below, we may im- 

 part a sudden molecular disturbance to either A or B by giving a 



(b) 



(o) 



Fig. 9. — Modifications of experimental arrangement to show electric 

 response in metals. 



quick torsional vibration round the vertical wire, as axis, by means 

 of the handle. As the wire A is separate from B, disturbance of one 

 will not affect the other. Vibration of A produces a current in one 

 direction, vibration of B in the opposite direction. Thus we have 

 means of verifying every experiment by obtaining corroborative and 

 reversal effects. When the two wires have been brought to exactly 

 the same molecular condition by the processes of annealing or 

 stretching, the effects obtained on subjecting A or B to any given 

 stimulus are always equal. 



2 t 2 



