I. Johaim Christoph, a German lexicographer, born at Spantekow, Pomerania, Aug. 8, 1732, died in Dresden, Sept, 10, 1806. He finished his studies at the university of Halle, and went to Leipsic, supporting himself by translations of valuable foreign works. His Glossarium manuale ad Scriptores medics et infimae Latinitatis (Halle, 1772-,84) is his most important achievement in this department. His great work, for which he took Johnson's English dictionary as a pattern, is his Grammatisch-kritisches Worterbuech der hochdeutschen Mundart (Leipsic, 1774-'80). He also produced Deutsche Sprachlehre fur Schulen (Berlin, 1781), and Umstandliches Lehrgebaude der deutschen Sprache (Berlin. 1782). In 1787 Adelung was Vailed to Dresden, and appointed head librarian to the electoral library in that city, where he conceived the plan of his Mithridates, a work which was to contain an account of all the known languages of the earth, with a translation of the Lord's prayer given as a specimen of each. He only lived to finish the first volume, which gave an account of the Asiatie languages. The work was afterward taken up by Johann Severin Vater, and his own nephew Friedrich Adelung, and finished in 4 vols.

It is said that he devoted 14 hours a day to study.

II. Friedrich von, nephew of the preceding, born in Stettin, Feb. 25, 1708, died in St. Petersburg, Jan. 80, 1843. He began his career as a private tutor, and spent several years in Rome, but subsequently went to St. Petersburg, where he was appointed by the emperor Alexander preceptor of his brothers Nicholas (afterward czar) and Michael. His principal works are: "The Relations between the Sanscrit and Russian Languages" (1815), an "Essay on the Sanscrit Literature and Language" (1830), and Bibliotheca Sanscrita (1837).