Atomic Disintegration and the Distribution of the Elements

Abstract

WITH reference to the association of uranium and radium, would you permit me to put on record a point that must have occurred to many, though possibly not to some, of those who are speculating so brilliantly about uranium and its disintegration products. I refer to the extraordinary conjunction in nature between silver and lead. This conjunction is so frequent that it can hardly be casual. A lead mine is a silver mine and a silver mine a lead mine all the world over, and yet the chemical attraction between silver and lead is slight, and the two metals are not sufficiently common to concur by chance. It is to be noted also that the concurrence, if the word may be used in this sense, is usually of the order of ounces for silver and tons for lead, and that the atomic weight of lead is 207 and of silver 108. Hence there appears to be some ground for the suspicion that silver is a disintegration product of lead. Lead also happens to present special facilities for experiment to test this surmise. It is cheap, and it is a comparatively inexpensive matter to free ten tons of lead from all traces of silver by the usual crystallising process, and then put it aside for ten years and test again for silver by the same process.