Among his works are the following: _Bereicherung des hochdeutschen Sprachschatzes_ (Leipzig, 1806), _Deutsches Volksthum_ (Lübeck, 1810), _Runenblätter_ (Frankfort, 1814), _Neue Runenblätter_ (Naumburg, 1828), _Merke zum deutschen Volksthum_ (Hildburghausen, 1833), and _Selbstvertheidigung_ (Vindication) (Leipzig, 1863). A complete edition of his works appeared at Hof in 1884-1887. See the biography by Schultheiss (Berlin, 1894), and _Jahn als Erzieher_, by Friedrich (Munich, 1895). JAHN, JOHANN (1750-1816), German Orientalist, was born at Tasswitz, Moravia, on the 18th of June 1750. He studied philosophy at Olmütz, and in 1772 began his theological studies at the Premonstratensian convent of Bruck, near Znaim. Having been ordained in 1775, he for a short time held a cure at Mislitz, but was soon recalled to Bruck as professor of Oriental languages and Biblical hermeneutics. On the suppression of the convent by Joseph II. in 1784, Jahn took up similar work at Olmütz, and in 1789 he was transferred to Vienna as professor of Oriental languages, biblical archaeology and dogmatics. In 1792 he published his _Einleitung ins Alte Testament_ (2 vols.), which soon brought him into trouble; the cardinal-archbishop of Vienna laid a complaint against him for having departed from the traditional teaching of the Church, e.g. by asserting Job, Jonah, Tobit and Judith to be didactic poems, and the cases of demoniacal possession in the New Testament to be cases of dangerous disease. An ecclesiastical commission reported that the views themselves were not necessarily heretical, but that Jahn had erred in showing too little consideration for the views of German Catholic theologians in coming into conflict with his bishop, and in raising difficult problems by which the unlearned might be led astray. He was accordingly advised to modify his expressions in future. Although he appears honestly to have accepted this judgment, the hostility of his opponents did not cease until at last (1806) he was compelled to accept a canonry at St Stephen's, Vienna, which involved the resignation of his chair. This step had been preceded by the condemnation of his _Introductio in libros sacros veteris foederis in compendium redacta_, published in 1804, and also of his _Archaeologia biblica in compendium redacta_ (1805). The only work of importance, outside the region of mere philology, afterwards published by him, was the _Enchiridion Hermeneuticae_ (1812). He died on the 16th of August 1816.