260
XIV
RESIDUAL CHARGE
this corresponded to a portion of the residual charge which other-
wise would have developed upon the plates A and B. Now, it is
easily seen that if the residual charge is an after-effect of polari-
sation, the sign of this deflection must be opposite to what it
would be if it were due to electric absorption from the plates;
for the electrical double stria produced between plates 1 and 2
would have opposite signs in these two cases. The result of
the experiment indicated that the effect was due to polarisation.
It is not surprising that the results of such experiments are
somewhat irregular; for it is impossible to prevent friction
and irregular motions which disturb the polarised elements.
As a matter of fact, the magnitude of the deflection varied
very considerably, and now and again an experiment even gave
a result in the opposite direction. But the results of the large
majority of the experiments were such as to justify the state-
ment above made.