This discovery has not been disproved but it appears that the amonat of polonium obtainable is exceeding small, and difficult to separate from bismuth. Subsequently Mme. Curie discovered another element of the barium group, possessing enormous powers of discharge, and to this element, which occur in relatively greater amount, she gave the radium."
It is an undoubted element in the sense in which that term is generally used salis resemble closely those of barium, its spectrum has been observed by M. Demareay, by Professor Runge, and by Sir William Crookes. Its utomi weight has been determined by Mme. Curie as 225 the atomic weight of uranium is the highest known—240; and' there is some evidence from its spectrum that radium may have even a higher atomic weight—over 250—and that the sample analysed by Mme. Saom, of which the atomic weight is only Curie may not have been quite free from
137.
"While these researches were in progress M. Curie and Dr. Schmidt discovered simultaneously that another element. thorium, of which the atomic weight is 232, also possesses the power of discharging an electroscope; and, moreover, that if air be led over salts of thorium, the air acquires and retains for a short time discharging power.
Text read from the printed page and cleaned; old type leaves the occasional error.