KLAPROTH, MARTIN HENRY, a distinguished analytical che mist, was born atIVernegerode in Upper Saxony on the 1st of December 1743. It was his intention to study theology ; but the severe treat ment which he met with at school disinclining him to study, he preferred the profession of an apothecary, and ho accordingly spent seven years in the public laboratory at Quedlinburg, where ho learnt little else than how to manipulate in pharmaceutical operations. After spending two years in the public laboratory at Hanover, he went to Berlin, and in 1770 went to Danzig, in both which places he was an assistant in a laboratory; he afterwards returned to Berlin as an assistant to Valentine Rose, one of the most distinguished chemists of the day, and on his death in 1771 he succeeded him, having, at the request of Rose, undertaken the superintendence of his office and the education of his two sone. In 1780 ho underwent tho necessary forms and examinations for the profession of an apothecary with great applause. Ilis thesis 'On Phosphorus and Distilled Waters' was printed In the 'Berlin Memoirs' for 1782.
Klaproth's various analyses and contributions to chemical science were diffused through periodical publications till 1706, when he began to collect and publish them. This work, under the title of Contri butions to the Chemical Knowledge of Mineral Bodies,' was published in German; the last and sixth volume appeared in 1815, about it year before the death of the author. Besides this work, which contained 207 treatises, he pnblished a 'Chemical Dictionary' jointly with Professor Wolff, and ha superintended a new edition of Gren's 'Manual of Chemistry.' To enumerate the various minerals which he analysed by processes perfectly new and peculiar, and with greater accurecy than had ever before been practised, would be tedious ; we may however mention, as the results of these labours, the discovery of the peculiar metal uranium in pechblende, and the earth zirconia in the hyacinth; he also more perfectly detailed the properties of titanium, which had previ ously been discovered by Gregor in Cornwall, and of tellurium, which had been noticed by Muller as a peculiar metal. There were many
minerals which, when Klaproth began their analysis, ho found it extremely difficult to render soluble iu acids, and without this it was in many cases impossible to arrive at a correct result; among those bodies was the corundum, or adamantine spar. This substance, though consisting almost entirely of clay or alumina, so long resisted all pre viously known moans of analysis, that Klaproth at first regarded It as a peculiar and distinct earth. He found however that by treatment with mottle potash, instead of the carbonate, In a silver crucible, this refractory utioeral was at length rendered soluble in acida, and was in fact alumina. Numerous other improvements were introduced by this laborious and accurate analyst, into the processes of the chemist ; the above is not the least important, and has therefore been referred to as a specimen of the value of his contributions to science. The above process was of Itself sufficient to alter the face of mineralogy, and indeed it Is hardly asserting too much when we state that of all analyses previously performed scarcely half a dozen were correct The great services thus rendered to chemistry and mineralogy were duly appre ciated; about 1787 he was elected a member of the Royal Academy of Arts; and the year following he was chosen a member of the Royal Berlin Academy of Sciences. In 1782, he was made aseossor in the Supreme College of Medicine and Health, and he was professor of chemistry in the Royal Mining Institute; he had also other honourable appointments; and in 1811 the King of Prussia added the Order of the Red Eagle of the third class. He died at Berlin on the 1st of January 1817.