An investigation has been made of the effect of temperature on the dielectric constants and densities of bromobenzene and iodobenzene in dilute solution with hexane and of hexane, and of m-p-o-xylenes as pure liquids.

The values of the electric moments and the validity of the Debye law: The values obtained for the electric moments are as follows; p-xylene, 0; m-xylene, 0.34×${10}^{-18\mathrm{}}$; o-xylene, 0.44×${10}^{-18\mathrm{}}$; bromobenzene, 1.35×${10}^{-18\mathrm{}}$; iodobenzene, 1.25×${10}^{-18\mathrm{}}$. In every case it was found that the Debye law, $P=P_0+\frac{a}{T}$, was valid.

Variation of the electric moment with variation of the atomic weight of a substituted atom; The results of this investigation give additional evidence of the rule that, as the atomic weight of a substituted atom is increased, the electric moment of the molecule decreases.

Change of induced polarization with the temperature. Evidence has been deduced which suggests that the induced polarization may be a function of the temperature and that this effect may neutralize or diminish the effect of a small dipole.

• Received 14 September 1931

DOI:https://doi.org/10.1103/PhysRev.39.666