Although answers to many questions about the life, writings, travels, places of residence – even the birth date – of Albertus Magnus are uncertain, his preeminence in medieval Latin European culture is beyond dispute. In the words of Lynn Thorndike, Albertus was “the most prolific of its writers, the most influential of its teachers, the dean of its scholars, the one learned man of the twelfth and thirteenth centuries to be called ‘the Great’” (HMES 2:521). Born in Swabia in Germany, Albertus achieved distinction as a member of the Dominican order and holder of high ecclesiastical offices, such as the bishopric of Ratisbon, 1260-62. His greatest fame, however, resulted from studies in most of the known fields of learning, which, following the plan of his master Aristotle, included physics, psychology, celestial phenomena, geography, botany, zoology, minerals, medicine, and optics, as well as theology. Only in the last of these was he exceeded by his pupil, Thomas Aquinas.

Albertus's writings on the “occult” arts of alchemy, astrology, and magic are often regarded as spurious, and it is difficult to separate the genuine from the false. The Libellus de Alchimia, from which the following selections are taken, is as likely to be authentic as any of the alchemical attributions and provides an excellent overview of the art in the early medieval period. It is also remarkable for its avoidance of the obscure rhetoric that plagues so much medieval and early modern alchemical writing. For these reasons, the brief tract enjoyed wide circulation in manuscript.