ABSTRACT
The amount of radium emanation to be obtained from 1 gr. of radium in equilibrium is a definite quantity, and is equal to q/λ where q is the rate of production of emanation per second, and λ is the radioactive constant of the emanation. There are two general methods of obtaining the emanation from preparations of radium, by heat or by solution. In the earlier experiments, the radium preparation was placed in a thin quartz tube which was enclosed in a larger quartz tube. The latter was heated to the desired temperature by means of an electric furnace. Preliminary experiments showed that the volume of the emanation was certainly much lower than that found by Ramsay and Cameron; the purity of the emanation was examined spectroscopically in the capillary itself without the use of electrodes. The emanation purified after the manner described was introduced in a spectrum-tube with platinum electrodes.
