An investigation of the thermal conductivity of the electret

In 1936, G. Groetzinger reported apparent increases of as much as 71% in the thermal conductivity of beeswax electrets over that measured for unelectrified beeswax. In view of the technical advantages of such a property, we decided to repeat these experiments. Groetzinger´s experimental conditions were reproduced, but no difference between the thermal conductances of electret and normal wax, within an experimental error of ± 15%, could be detected; data on the two waxes were statistically indistinguishable. Furthermore, measurements by the more precise parallel plate method showed that any difference must be less than about 5%.