ABSTRACT
The radium emanation has been found in the water from deep wells and springs, in surface and lake water, in escaping natural carbonic acid and in the oil from wells. The study of geology early showed that the surface of the earth had undergone profound changes in the past. The radiations from radium are able to produce such marked luminous, photographic and electrical effects, are qualitatively very similar to those emitted by the other radioactive bodies, already mentioned, but differ from them in intensity. Dr. Barnes and the writer showed that more than three-quarters of the heating effect of radium was due to the radioactive emanation stored in it. The emanation had been separated, on the other hand, spontaneously regained its heating effect in the course of one month. Sir William Ramsay and Mr. Soddy recently found that the volume of the radium emanation stored in one gram of radium is about one cubic millimetre at atmospheric pressure and temperature.
