On the origin of the gases evolved by Mineral springs

Abstract

It has long been known that thermal springs, such as those at Bath, give off considerable quantities of gas, which bubbles up with the water, and consists, for the most part, of nitrogen. Of recent years interest in this subject has been revived by Lord Rayleigh’s observation that helium and argon are present along with nitrogen. Dewar has used the Bath gas as a practical source of helium, and has observed that it contains a trace of neon; more recently, Moureu has exhaustively studied the thermal springs of France, some forty in number, and has found that the same constituents are of quite general occurrence. It appears from his analyses that the Bath gas may fairly be regarded as typical of the gases of almost all other thermal springs, although a much larger percentage of helium is occasionally met with. It has been found that such gases, when fresh, are rich in radium emanation, and that the deposit thrown down by the water on standing contains a notable quantity of radium. It is natural to connect this observation with the discharge of helium by the springs. I was formerly inclined to think that the facts were most easily explained by supposing that the supplies of helium and radium were derived from the disintegration of uranium lodes at a great depth by the water; but this view scarcely seems compatible with the universal presence of helium and radium in mineral springs, which has since been brought to light; for uranium lodes are very rare near the earth’s surface, and there are fatal objections to supposing that metal to be generally more abundant at greater depths.