Abstract
In the course of his experiments with the electret the author, upon with-drawing the electric field from the electret after it lead solidified, found charges Q on the electrode that had been generated by tht electret. The charges were bserved by the rising of the potential of the metal electrode which is placed in contact with the electret in order to produce an electric field, and which upon solidification of the electret mixture, adhered firmly toit. The electret was prepared in the usual way, as has been descrilred already by other investigators. The sign of the charges was the same as that of the electrode when the field was applied. Studies were made of the effects on the charge accumulation of various intensities of the applied electric field and also of various durations of applications. The relations between the rate of the accumulation of charges dQ/dt and time t and temperature T were also studied. The relation dQ/dt=A (T0-T) was found to hold good when the temperature of the electret was decreasing with time, where A and are constants independent of the temperature. T0 is the initial temperature, and T is the cooled temperature. Evidently an important factor influencing the amount dQ/dt is the extent to which the solidification of the electret mixture hasproceeded before the electric field is withdawn. The rate of change accumulation was most pronounced when the field was with Irawn before the mixture had turned very hard. When the electret mixture was in the liquid state, the charges generated on the electrode upon withdrawal of the field
