The discovery of radium is within the memory of all. Many exaggerated statements went abroad at the outset, but the real facts are full of interest, and they have shed much new light on many subjects. Three different kinds of radiation were found to be emitted by radium. At first man could not tell what these were, so he named them after the first three letters of the Greek alphabet--Alpha, Beta, and Gamma, rays. The electron tells the interesting story of these rays, and relates the experiences of some fellow-electrons who escaped from within a radium atom. CHAPTER XIX HOW WE MADE THE WORLD TALK We electrons were amused at the stir which we unconsciously caused throughout the civilised world. We had done nothing different from what we had been doing for ages, but a few men had been taking note of what we were about, and when the phenomena to which I refer became known to the world, many wild rumours were circulated. One of these rumours was to the effect that steam-engines and their expensive furnaces were to disappear very quickly. If the two last words had been omitted--I should not say that the prophecy is untrue, but man has a long way to travel yet before reaching that goal. My fellows within the atoms have sufficient energy to supply all mankind with power if he could but unlock even a small fraction of it. Another statement was that this newly discovered substance, _radium_, could cure some diseases which man had believed to be incurable. All I shall say about this is that the statement was an exaggerated one. Then it was said that radium disproved much of man's scientific knowledge, but instead of that being so, we electrons have greatly extended man's knowledge by our radio-active actions. If any man believed the atoms of matter to be eternal, we certainly disproved that. Here, in radium, man could see atoms going to pieces. I have questioned a fellow-electron who escaped from a radium atom as to what upset their equilibrium, but I find that he does not know, or he pretends not to know. All he has told me is that he was flung off suddenly from within the atom with great energy, for he had been revolving at a tremendous speed. In his sudden flight he passed some newly formed _helium_ atoms, which contained many of those electrons who had been his co-partners in the former radium atom. Being an electron, he was travelling at a far greater speed than these flying atoms of matter, but he assures me that these helium atoms were going faster than atoms can travel under any other circumstances.