OBITUARY.

Press, Volume LXIII, Issue 12720, 5 February 1907, Page 7

OBITUARY.

A CELEBRATED RUSSIAN

CHEMIST.

United Press Association—By Electrio Telegraph—Copyright.

LONDON, February 3,

Dr. Dmitri Mendeleeff, the distinguished Rus-ian chemist and forniulator of tho Periodic Law, is dead.

Dmitri MendeJeeff was born at Tobolsk, Siberia, in 1&34. He was educated at St. Petersburg and at Heidelberg, and became Protessor of Chemistry in the University of St. Petersburg. His original work covered a wide range, from questions in applied chemistry, such as the origin of petroleum deposits and the application of nitro-oompounds to the manufacture of smokeless powders, to the most general problems of chemical and physical theory. When the elements are arranged in programme order of their atomic weights a certain regularity of succession of chemically analogous elements is observed. The regularity of the recurrence of the ■cycles or periods is bo striking that the appearance of gaps in the list led to the prediction not only of the existence of undiscovered elements, hut of their probable properties. Mendeleef waa not the first to draw attention to this, but he it was who developed the idea and formulated the Periodic Law, which states that the properties of an ele-* ment are a function of its atomic weight. In 1871 he was led by gar«s in his tables to assert the existence of three undiscovered elements, and to assign their properties. Within fifteen years his prophecies were completely vindicated by tne discovery of gallium, 6C.andium, and germanium. In several cases he ventured to question the correctness of accepted atomic weights on the ground that they did not correspond with the Periodic Law, and here also he was justified by subsequent investigation. He also gave much attention to solutions, holding the opinion they were merely instances of ordinary definite or atomic compounds. He wrote largely on chemical topics, and his "Principles of Chemistry" has gone through many editions in various languages.