ABSTRACT
The heating effect for freshly prepared radium compound was small at first, but gradually increased to a maximum after a month's interval, and remained constant over a further interval of two months. The present experiments were undertaken with the view of seeing how the heat emission of radium is connected with its radioactivity. A non-separable radiation consisting entirely of rays and constituting about 25 per cent of total radiation. The radiation from emanation occluded in the radium, also consisting entirely of rays. The excited radiation produced by the emanation in the mass of the radium, and consisting of, and rays. The excited activity produced on bodies has been shown to be due to a deposit of radioactive matter on their surface. The term excited activity refers only to the radiations from this active matter. On heating or dissolving a radium compound in an open vessel, the emanation is released and can be entirely removed by a current of air.
