Another eminent botanist of this period was Peter de Crescenzi, a man of good birth and fortune, who was born at Bologna in 1330, and who greatly interested himself in botany and horticulture. His great work, which was translated into several languages, was called _Opus Rubarium Commodorum_. Contemporary with Peter were three names we must not omit, _viz._, Vincent de Beauvais, Albertus Magnus, and Arnaud de Villeneuve, who professed a knowledge of alchemy, astrology, and physic. Vincent de Beauvais was a Dominican monk, and his great work, the _Speculum Naturale_, is saturated with the superstition of the time. In this book he states, “the mandragora is of the same shape as the human body; the winged dragon is capable of carrying off an ox, and devouring the same whilst flying”. He also describes the scythion lamb, a sort of animal plant which had roots and grew in the ground, and other fearsome creatures, and declared that “in Scotland the fruits of certain trees, when they fall into the water, produce the birds called black divers”. Villeneuve wrote many treatises on plants and animals, and eventually became teacher of medicine and botany at the University of Paris. He was undoubtedly a man in advance of his time, and boldly declared “that the most solemn mysteries of the Catholic faith could be explained by the teachings of natural history and experimental physics”. He was therefore accused by the magistrates of sorcery and magic, but escaped through the special protection of Charles of Anjou into Italy, where he settled for a long time. The fourteenth century saw little advance in the medical art, but it was enriched by one or two great works. One of these, written in Latin by Bartholomew Glanvil, an English monk, was a kind of encyclopædia of immense size, and was called _Liber de Proprietatibus Rerum_, and had a great reputation for centuries afterwards. The advent of printing about the middle of the fifteenth century rapidly spread the knowledge of more recent discoveries throughout Europe, and many large works on botany and herbalism, illustrated with woodcuts, were published at Mayence and Louvain. At Venice many of the works of the old Arab physicians, Avicenna, Mesué, and others, were printed and eagerly purchased. The discovery of America in 1492 heralded the introduction of numerous fresh additions to _materia medica_, which were brought to this country by explorers and naturalists.