RADIUM

a metal discovered by ind, rie Gergana husband, w nves r eR rays of fate and for which the Davy medal for the most im t discovery in preys om tho year was awarded to by the a some! of England in December, 1903. nel i ty ae ea tain very a as a whitish or groyiah powder, from pitchz Pre Ne tains fa found in the rzgebirge Aloun ’ at Redruth in Cornwall. As a result of two years’ labour 2 and Madame Curie, eight tons of mineral Senet eed tt about a gram of radium and it has been calculated that in the whole world scarcely more than one-fifth of an ounce is available. On December 3lst the price quae wan Soa ning ine milligramme, an a a grain have been recently sold at £10 each. Traces of the substances have also been detected in the deposits from the waters of the malnere) epics cS Eee and, lecturing in May, 1904, Profesor Rutherford, who has been one of the principal investigators in England of the properties of the new element, expre ed the opinion that radium is an ubiquitous constituent of the earth’s crust, which tends to become more abundant as we descend deeper. Radium is found to be a perpetual source of light and heat. The chloride and bromide emit a light that resembles that of the glow-worm. A diamond placed close to a small quently se ee box in a dark room scintillates as if a lighted candle were brought nesr it. It ~« y ~ out sufficient heat to melt its own ‘ [s. 253]