The first German of whom we have any record as having studied in Italy was Peter Luder (c. 1415-74), who returned in 1456, and lectured on the new learning at the Universities of Heidelberg, Erfurt, and Leipzig, but awakened no response. In 1470 Johann Wessel (1420-89) and in 1476 Rodolph Agricola (1443-85), two noted Dutch scholars, studied in Italy. On returning, Agricola, [19] who has been called "the Petrarch of German lands," did much "to spread the great inheritance of antiquity and the new civilization to which it had given birth among his uncouth countrymen" (_barbari_, he calls them). He made Heidelberg, for a time, a center of humanistic appreciation. Johann Reuchlin (1455-1522), a German by birth, studied in Florence and elsewhere in Italy in 1481 to 1490, and there learned Hebrew. Returning, he became a professor at Heidelberg and the father of modern Hebrew studies. In 1506 he published the first Hebrew grammar. In 1493 the University of Erfurt established a professorship of Poetry and Eloquence, this being the first German university to countenance the new learning. In 1523 the first chair of Greek was established at Vienna. Thus slowly did the revival of learning spread to northern lands. THE REVIVAL AIDED BY THE INVENTION OF PAPER AND PRINTING. Very fortunately for the spread of the new learning an important process and a great invention now came in at a most opportune time. The process was the manufacture of paper; the invention that of printing. The manufacture of paper is probably a Chinese invention, early obtained by the Arabs. During the Mohammedan occupation of Spain paper mills were set up there, and a small supply of their paper found its way across the Pyrenees. The Christians who drove the Mohammedans out lost the process, and it now came back once more from the East. By about 1250 the Greeks had obtained the process from Mohammedan sources, and in 1276 the first paper mill was set up in Italy. In 1340 a paper factory was established at Padua, and soon thereafter other factories began to make paper at Florence, Bologna, Milan, and Venice. In 1320 a paper factory was established at Mainz, in Germany, and in 1390 another at Nuremberg. By 1450 paper was in common use and the way was now open for one of the world's greatest inventions.