"Next his interest turned to the natural phenomena of high energy. He studied lightning in an open steel network laboratory, with few results save a succession of rheumatic attacks, and an improved electric interrupter, since adopted by one of the great telegraph companies. The former obliged him to stop these experiments, and the invention he considered trivial. Probably the great problem of getting at the secret of energy led him into his attempts to study the mysterious electrical waves radiated by lightning flashes; at any rate he was soon as deep into the subject of electrical science as his countryman, Hertz, had ever been. He used to tell me that he often wondered why he hadn't taken up this line before--the world of energy he now set out to explore, waves in that tremendous range between those we hear and those we see. It was natural that he should then come to the most prominent radio-active elements, uranium, thorium, and radium. But though his knowledge surpassed that of the much-exploited authorities, he was never satisfied with any of his results. "'Pitchblende; no!' he would exclaim. 'It has not the great power. The mines are not deep enough, yet!' "Then suddenly the great idea that was to bring him success, and cost him his life, came to him. The bowels of the earth must hold the secret! He took up volcanoes.... Does all this sound foolish? It was not if you knew the man. He was a mighty enthusiast, a born martyr. Not cold-blooded, like the rest of us. The fire was in his veins.... A light, please. Thank you. "We chased volcanoes. There was a theory under it all. He believed that volcanic emanations are caused by a mighty and uncomprehended energy, something that achieves results ascribable neither to explosions nor heat, some eternal, inner source.... Radium, if you choose, only he didn't call it that. Radium itself, as known to our modern scientists, he regarded as the harmless plaything of people with time hanging heavy on their hands. He wasn't after force in pin-point quantities: he wanted bulk results. Yet I believe that, after all, what he sought was a sort of higher power of radium. The phenomena were related. And he had some of that concentrated essence of pitchblende in the chest when we started. Oh, not much: say about twenty thousand dollars' worth. Maybe thirty. For use? No; rather for comparison, I judge.