XIV
ON THE BEHAVIOUR OF BENZENE WITH RESPECT
TO INSULATION AND RESIDUAL CHARGE
(Wiedemann's Annalen, 20, pp. 279-284, 1883.)
ROWLAND and Nichols have shown' that in certain insulating
crystals dielectric polarisation is not accompanied by any
electric after-effect or formation of a residual charge. They
interpret this result as supporting the view that the forma-
tion of a residual charge is simply a necessary consequence
of imperfect homogeneity in an insulator.
Some years ago
I
wanted to find whether the formation of a residual charge
could be detected in a conductor undoubtedly homogeneous;
and with this object I tested various liquids. The conductivity
of most of these proved to be too high for such experiments;
but commercial pure benzene exhibited a sufficiently high
resistance, and also a distinct residual charge. A closer
investigation disclosed certain peculiarities in the behaviour
of benzene which are described below, and these can be inter-
preted in the same way as the behaviour of crystals. I had
not kept the numerical results of my experiments; but Herr
E. Heins has been good enough to repeat the experiments, and
to allow me to make use of his results. The numerical data
given below are taken from Herr Heins' experiments.
2
1. The method adopted is copied from that of Herr W.
Giese. The benzene is contained in a zinc canister (B, Fig. 34).
In this, and entirely surrounded by it, a zinc plate about 12
cm. long and 8 cm. broad was hung by two wires. This plate
1 Phil. Mag. (Series 5) 11, p. 414, 1881.
Wied. Ann. 9, p. 160, 1880.