INORGANIC RESPONSE 



95 



leading to the galvanometer and kept moderately and 

 uniformly stretched by spiral springs. The handle, by 

 which a torsional vibration is imparted to the wire, 

 may be slipped over either electrode. The amplitude 

 of vibration is measured by means of a graduated 

 circle. 



It will be seen from these arrangements : 



(1) That the cell depicted in (e) is essentially the 

 same as that in (a). 



(2) That the wires in the cell being 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 separately 

 below, we may impart a sudden molecular disturbance 

 to either A or B by giving 



a quick to-and-fro (tor- 

 sional) 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. Vibra- 

 tion of A produces a current 

 in one direction, vibration 

 of B in the opposite direc- 

 tion. Thus we have means 

 of verifying every experiment by obtaining corroborative 

 and reversed effects. When the two wires have been 

 brought to exactly the same molecular condition by the 



FIG. 56. EQUAL AND OPPOSITE KE- 

 SPONSES EXHIBITED BY A AND B 



