"You've said it, my boy: radium. Phenomena of radioactivity occur more or less everywhere; and we may say that they are manifested throughout nature, as in the healing action of thermal springs. But plainly radioactive bodies like radium possess more definite properties. For instance, there is no doubt that the rays and the emanation of radium exercise a power over the life of plants, a power similar to that caused by the passage of an electric current. In both cases, the stimulation of the nutritive centres makes the elements required by the plant more easy to assimilate and promotes its growth. In the same way, there is no doubt that the radium rays are capable of exercising a physiological action on living tissues, by producing more or less profound modifications, destroying certain cells and contributing to develop other cells and even to control their evolution. Radiotherapy claims to have healed or improved numerous cases of rheumatism of the joints, nervous troubles, ulceration, eczema, tumours and adhesive cicatrices. In short radium is a really effective therapeutic agent."
"So," said Stéphane, "you regard the God-Stone . . ."
"I regard the God-Stone as a block of radiferous pitchblende originating from the Joachimsthal lodes. I have long known the Bohemian legend which speaks of a miraculous stone that was once removed from the side of a hill; and, when I was travelling in Bohemia, I saw the hole left by the stone. It corresponds pretty accurately with the dimensions of the God-Stone."
"But," Stéphane objected, "radium is contained in rocks only in the form of infinitesimal particles. Remember that, after a mass of fourteen hundred tons of rock have been duly mined and washed and treated, there remains at the end of it all only a filtrate of some fifteen grains of radium. And you attribute a miraculous power to the God-Stone, which weighs two tons at most!"
"But it evidently contains radium in appreciable quantities. Nature has not pledged herself to be always niggardly and invariably to dilute the radium. She was pleased to accumulate in the God-Stone a generous supply which enabled it to produce the apparently extraordinary phenomena which we know of . . . not forgetting that we have to allow for popular exaggeration."