a metal which possesses the property of emitting rays of light, heat and chemical action. It was discovered by Professor Curie and his wife, Madame Curie, at the Industrial School of Physics and Chemistry in Paris. In 1896 it was found that uranium and all its compounds continually emit radiations and have a penetrating power similar to that of the X-rays. Professor and Madame Curie followed this discovery with a series of experiments on the ore of uranium, commonly known as pitchblend, and they obtained a pure radium chloride in 1902. Radium emits light and heat without apparent loss of weight or strength, and it maintains a constant temperature of at least 2 deg. above that of the surrounding atmosphere. Its rays are likely to produce sores, which are difficult to heal, but in a mild form these rays have a curative effect upon lupus. The properties of radium are not well understood. It is obtained separately only in small quantities, but it is now believed that radium, or at least similar radio-active matter, exists in almost all substances, though in exceedingly small quantities. A variety of theories has been offered to explain its peculiar properties. Some learned investigators have even declared that radium is a source of much, or at least a part of the earth's heat, and that it is probably of the same substance as the sun, since it is known to emit certain gases of the same nature as those given off by the sun. Much of the speculation concerning radium, its properties and usefulness, have been found to be unwarranted by actual demonstration, but that it will prove of considerable value to man is conceded by all scientists.