ABSTRACT
Prof. J. J. Thomson suggest that the radio-activity of radium may possibly depend upon its degree of concentration, and that a given quantity of radium, diffused throughout a mass of pitchblende, may be less than when concentrated in a small mass. The test point, measurements of the radio-activity of radium bromide were made when in the solid state and when diffused throughout the mass of a solution more than a thousand times the volume occupied by the radium compound. Measurements of the radio-activity of the radium were made by means of an electroscope. The tubes, fixed on a stand, were placed in a definite position near an electroscope and the rate of discharge observed. The experiment shows that, over the range investigated, the radio-activity of radium is not influenced by its own intense radiations. Experiments are in progress to test whether still further dilution of the radium solution produces any alteration in its radio-activity.
