CABLE NEWS. [BY ELECTRIC TELEGRAPH.— COPYRIGHT.]

Evening Post, Volume LXXIII, Issue 29, 4 February 1907, Page 7

CABLE NEWS. [BY ELECTRIC TELEGRAPH.— COPYRIGHT.]

A DISTINGUISHED CHEMIST. « DEATH OF DMITRI MENDELEJEFF.. [PUES3 ASSOCIATIOS.I (Received February 4, 9.3 a.m.) LONDON, 3rd February. The death is announced of Dmitri Men-deloj-3ff, a distinguished Russian chemist. Dmitri Ivanovitch Mondelcjeff. who woo in his 73rd year, was best known for his work on the Periodic Law. He wa3 not the first to take up this uubject, for beforo him vaiious chemists had traced numerical sequences among the atomic weights of gome of the elements find noted connections between them and the properties of the different 6ubst;unceii, but it was left to him to give a full expression to the generalisation, and to treat it not merely as a system of classifying the elements according tn ce-rtain observed facts, but tta a "law of nature" which could be Telied upon to predict new facts and to disclose errors in what were supposed to bo old facts. Thus in 1871 he was led bj certain gaps in his tables to awert the existence of three new elements so far unknown' to the chemist, and to assign them definite properties. These tlrreo he called ekaboron, ekaaluminium, and okasilkon ; and his prophecy was completely vindicated within fifteen years by the diffjovery of gallium by de Boisbaudran in 1871, scandium by Nilson in 1879, and germanium by Winkler in 1886. Again, in several cases ho ventured to question the correctness of the "accepted atomic weights," on. the ground that they did not correspond with the Periodic Law, and here also he was justified by eubsequ-ent investigation. Since his early work the periodic arrangement of the elements has engaged the attention of many chemical thinkers, and 1 numerous variations in it and in tho 1 modes of stating it have bean proposed. So far, however, no formulation has been suggestsd which commands universal acceptance aa final,' and the task still remains not only of finding a solution of certain anomalies, real or apparent, but of explaining the cause and inner meaning of the periodicities that have already been observed. In another department of physical chemistry Mendelejeff investigated tho expansion of liquids with heat, and devised a formula for its expression similar to Gay-Lus£>ac\3 law of the uniformity of the expansion of gases, while so far back as 1861 he anticipated Andrew's conception of the critical temperatuio of gases, by defining the absolute boiling-point of a substance as the tompeTature at which cohesion and heat of vaporation become equal to zero, and the liquid changes to vapour, irrespective of the pressuTO and volume.