KLAPROTH, MARTIN HENRY

KLAPROTH, MARTIN HENRY, a celebrated Prussian chemist, professor of chemistry, member of the Academy of Sciences at Berlin, foreign associate of the Institute of France, and of several other academies and learned societies, was born at Berlin, on the 1st of December 1743. He had received from nature an observing, serious, reflecting mind, and a capacity of patient application which nothing could tire out or exhaust. After having terminated his classical studies, he applied himself wholly to that of mineralogy, for which he had a decided predilection; but he felt that he could not make rapid progress therein without calling in the aid of chemistry, wherefore he devoted himself to these two branches of physical science. The analysis of minerals appeared to him of extreme importance with re-

ference to the proper classification of these unorganic substances; and multiplied experiments soon afforded him the means of varying the chemical processes, and of recognizing new elements in the minerals which had already been subjected to analysis. It was thus that he discovered zircon in the jargon of Ceylon; that he demonstrated the presence of potash in volcanic productions; that he made known the sulphate of strontian; that he found potash in the leucite or white garnet; that he discovered in red schorl a new metal, which he named titanium, another in peckblende which he called uranium, and a third in the ore of white gold, to which he gave the name of telurium. He also made known the molybdate of lead, and proved that the ore of red silver was a sulphuret of silver and antimony. Such are the most important of M. Klaproth's labours, those, in fact, which entitle him to rank amongst the most distinguished chemists of his age; but he published, besides, a considerable number of analyses of fossil substances, which may be found in the Journal de Physique, the Annales de Chimie, the Journal des Mines, and other collections of this sort. He also prepared a mineralogical system, which is mainly founded upon the constituent principles of minerals. His memoirs of chemistry have been collected and translated into French by Tassaert, Paris, 1807, in two vols. 8vo. Lastly, he composed, in conjunction with Wolf, a Dictionary of Chemistry, in four vols. 8vo; a work which was translated into French by Bouillon-Lagrange and Vagel. Klaproth greatly contributed to advance the science of mineralogy, and his researches have thrown much light on the system of Werner, as well as on the classification of Häuy. His discoveries, and, above all, his particular means of analysis, have served to guide several French chemists, who are indebted to him for part, at least, of the fortunate results which have rewarded their researches. This distinguished mineralogist died at Berlin, on the 1st of January 1817. (A.)