Show STUDENT LIFE died at Paris February 24 1907 as a result of an operation for ap- pendicitis France lost within a month the two men esteemed by Ostwald as her greatest men of genius Pierre Eugene Berthelot was horn in Paris October 25 He was therefore 1827 older than his colleagues Moissan and Curie but he did not come into At prominence as early in life electthe age of thirtv-tw- o he was ed professor of chemistry in the Paris School of Pharmacy He did an immense amount of work on the syntheses of dyes and determined the exact composition of several of the coal tar colors He also published reports of his investigations on isomerism in organic compounds and did considerable original work in thermodynamics Berthelot died in Paris last February For the discovery of one of the greatest of the fundamental laws of chemistry we are indebted to the Russian chemist Dimitri Ivan-ovitc- h Mendeleeff He was born in Tobolsk Siberia in 1834 He was educated in Saint Petersburg and held a professorship in chemistry in the University of Saint Petersburg from 1866 to the time of his death In 1869 Mendeleeff published i classification of the elements based on their atomic weights and clearly demonstrated that the properties 211 of the elements are periodic functions of their atomic weights This is known as the “Periodic Law” and it furnishes a basis for determining the chemical and physical properties of an element from its atomic weight and reference to its analogues in the periodic table he constructed Mendeleeff had such confidence in the law he had formulated that he predicted the discovery of some new elements that were required to complete the periodic table He described three elements then unknown which he believed would be discovered He announced the color atomic specific gravity atomic volume and valence weight of each and the solubility boiling point and density of many of their compounds Thirteen years later the German chemist Winkler discovered an element which he named for his country germanium It corresponds in every detail to one of the three whose discovery was predicted and properties described by the great Russian scientist Since then the other two have been isolated and are known as scandium and gallium The Engineering and Mining Journal says “Mendeleeff was one of the world’s most renowned chemists and one of the few scientists who have had the distinction of discovering a great natural law” He died at Saint Petersburg Feb 2 1907 CWP |