Despite the enormous amount of energy given off by radium it seems not to change in itself, there is no appreciable loss in weight nor apparently any microscopic or chemical change in the original body. Professor Becquerel has stated that if a square centimeter of surface was covered by chemically pure radium it would lose but one thousandth of a milligram in weight in a million years' time. Radium is a body which gives out energy continuously and spontaneously. This liberation of energy is manifested in the different effects of its radiation and emanation, and especially in the development of heat. Now, according to the most fundamental principles of modern science, the universe contains a certain definite provision of energy which can appear under various forms, but which cannot be increased. According to Sir Oliver Lodge every cubic millimeter of ether contains as much energy as would be developed by a million horse power station working continuously far forty thousand years. This assertion is probably based on the fact that every corpuscle in the ether vibrates with the speed of light or about 186,000 miles a second. It was formerly believed that the atom was the smallest sub-division in nature. Scientists held to the atomic theory for a long time, but at last it has been exploded, and instead of the atom being primary and indivisible we find it a very complex affair, a kind of miniature solar system, the centre of a varied attraction of molecules, corpuscles and electrons. Had we held to the atomic theory and denied smaller sub-divisions of matter there would be no accounting for the emissions of radium, for as science now believes these emissions are merely the expulsion of millions of electrons. Radium gives off three distinct types of rays named after the first three letters of the Greek alphabet--Alpha, Beta, Gamma--besides a gas emanation as does thorium which is a powerfully radio-active substance. The Alpha rays constitute ninety-nine per cent, of all the rays and consist of positively electrified particles. Under the influence of magnetism they can be deflected. They have little penetrative power and are readily absorbed in passing through a sheet of paper or through a few inches of air. The Beta rays consist of negatively charged particles or corpuscles approximately one thousandth the size of those constituting the Alpha rays. They resemble cathode rays produced by an electrical discharge inside of a highly exhausted vacuum tube but work at a much higher velocity; they can be readily deflected by a magnet, they discharge electrified bodies, affect photographic plates, stimulate strongly phosphorescent bodies and are of high penetrative power. The radiations are a million times more powerful than those of uranium. They have many curious properties.