Writers on the medical and natural sciences we cannot well separate; since, in most cases, the same individuals distinguished themselves in the departments of medicine, astronomy, and mathematics. The following, along with many others, are named with distinction: Th. Hagek, body physician of the emperors Maximilian and Rudolph, and a celebrated astronomer; Zhelotyn, author of medical and mathematical works; Zaluzhansky, physician and naturalist, who anticipated Linnæus in his doctrine of the sexual distinction and impregnation of plants; P. Codicillus, historian, philosopher, theologian, and astronomer, who wrote on all these different subjects; Huber von Reisenbach, a physician and rector of the university of Prague; Shud, a celebrated astronomer; and many more.[35] The number of books printed during this period cannot well be ascertained; since by far the greater number were burned, or otherwise destroyed, in the dreadful catastrophe which signalized its close. Prague alone had eighteen printing offices; and fourteen more existed in other places in Bohemia and Moravia. Besides these, many Bohemian books were printed at Venice, Nürnberg, Wittenberg, and some in Holland and Poland. In 1617, the emperor Matthias succeeded in obtaining the crown of Bohemia for his nephew Ferdinand, archduke of Austria. This was the signal for the Romanists, in spite of the _Literæ Imperatoriæ_ of the emperor Rudolph, to make new attempts for the suppression of the Protestants. The Estates belonging to this denomination brought their complaint before the emperor, who gave them no redress; and thus the spark was kindled into flames, which for thirty years continued to rage throughout all Germany. At the death of Matthias in 1619, the Bohemians refused to receive Ferdinand II as their king; and elected the Protestant palatine Frederic V, a generous prince, but incapable of affording them support. The battle at the White Mountain, near Prague, in 1620, decided the destiny of Bohemia. Twenty-seven of the leaders of the insurrection were publicly executed; sixteen were exiled or condemned to prison for life; their property, as also the possessions of seven hundred and twenty-eight noblemen and knights, who had voluntarily acknowledged themselves to have taken part in the insurrection, and of twenty-nine others who had fled, was wholly confiscated; and thus the amount of fifty-three millions of rix dollars transferred from Protestant to Romish hands. The _Literce Imperatorice_ were annulled; the Protestant religion in Bohemia abolished; and that kingdom declared a purely catholic hereditary monarchy. All non-catholic preachers were banished; thirty thousand families, who preferred exile to a change of their religion, emigrated. Among them 185 were noble families; the others artists, mechanics, merchants, and labourers. Yet in the villages, among the woods and mountains, where neither soldier nor Jesuit had penetrated,