Conduction of Electricity in Highly Insulating Liquids

Investigations have been made on the natural conductivity, and on the conductivity induced by gamma-rays in isooctane and liquid oxygen. The characteristics of the two types of conductivity are so very different that it may be concluded that the natural conductivity is not due to stray radiation or to cosmic rays. The curves for the natural conductivity are such that the current increases much faster than the field. Evidence is presented supporting Plumley's theory that the observed conductivity is due to dissociation of the liquids by the field, and against the view that it has a thermionic origin at the cathode, or the view that it is due to radiation. The prediction that the logarithm of the current should be a linear function of the square root of the field is verified. The much larger currents induced by gamma-rays rise at first rapidly and then more slowly in a manner indicating a slow approach toward saturation. The results fit Jaff\'e's formula satisfactorily.