98 RESPONSE IN THE LIVING AND NON-LIVING 
mental modification, fig. 55, 6, where the wire was 
shown to give response when kept completely immersed 
in water, variation of surface being thus entirely 
eliminated. 
Both these questions may, however, be subjected to 
a definite and final test. When the wire to be acted on 
is clamped below, and vibration is imparted to it, a 
strong molecular disturbance is produced. If now it be 
carefully released from the clamp, and the wire rotated 
backwards and forwards, there could be little molecular 
disturbance, but the liquid friction and surface variation, 
if any, would remain. The effect of any shght disturb- 
ance outstanding owing to shaking of the wire would 
be relatively very small. 
We can thus determine the effect of liquid friction 
and surface action by repeating an experiment with and 
without clamping. In a tin wire cell, with interposed 
external resistance equal to one million ohms, the wire 
A was subjected to a series of vibrations through 180°, 
and a deflection of 210 divisions was obtained. A 
corresponding negative deflection resulted on vibrating 
the wire 8B. Now A was released from the clamp, 
so that it could be rotated backwards and forwards in 
the water by means of the handle. On vibrating the 
wire A no measurable deflection was produced, thus 
showing that neither water friction nor surface variation 
had anything to do with the electric action. The 
vibration of the still clamped B gave rise to the normal 
strong deflection. 
As all the rest of the circuit was kept absolutely the 
same in the two different sets of experiments, these 
