JOHANN SEVERIN, an eminent linguist and theologian, born at Altenburg in 1771. He was educated at first at the gymnasium of Altenburg, and at the age of nineteen was sent to the University of Jena, and pursued there and at Halle, to which he went in 1794, the study of philosophy and theology. At the latter university, after completing his academical course, and graduating in 1796, he became a private tutor; and in 1798 he was appointed extraordinary professor of theology at Jena. His studies were especially directed to the Hebrew language, the grammatical knowledge of which he materially improved; but he also extended his researches to a number of other languages, with a view of ascertaining the great principles common to all. In 1800, Vater removed to Halle as professor of theology and oriental literature, to which position he returned, after having been from 1809 till 1820 at Königsberg as librarian and theological professor. His greatest linguistic labour was the completion of the Mithridates of Adelung, which had been left unfinished by the death of that scholar. Besides this, he wrote grammars of the German, Polish, Russian, Hebrew, and other languages, several works on universal grammar, and an index of grammars and lexicons of all languages. After his final settlement at Halle, without giving up his linguistic studies, Vater laboured more in biblical exegesis and church history, and published a commentary on the Pentateuch, a critical edition of the New Testament, and several works of church history. His last publications were The Preacher's Journal, Church History Archives, and Annual of Family Devotion, which he set on foot in 1819, and conducted with the aid of Bretschneider and others till his death in 1826. In his own department the learning of Vater was unequalled by any of his contemporaries; and his works contain an immense store of materials for the study of comparative grammar and philology.