ABSTRACT
The difficulty felt by Prof. Schuster apparently arose from the fact that includes in the heating effect of the emanation not only that due to the emanation itself, but also that due to the secondary products to which the emanation gives rise. It was an oversight on the part to have omitted in the sentence more than two-thirds of the heating effect is not due to the radium at all, but to the radio-active emanation which it produces from itself, the words together with the secondary products to which the emanation gives rise. The fully aware that the heating effect was in part due to the excited activity produced by the emanation. The rapid rise of the excited activity in a tube containing the radium emanation, the separation of the heating effect of the emanation from the complicated secondary changes which result from it is a difficult experimental problem.
