Among the men who, during the thirteenth century, exerted more or less influence upon the growth of medical knowledge there are three who deserve to receive some consideration at our hands. They were not physicians, but yet some of their writings deal with topics which are closely related to the science of medicine. They are: Albert von Bollstädt, a German who is generally known as Albertus Magnus, one of the greatest scholastic philosophers of the Middle Ages; Vincent of Beauvais (Vincentius Bellovacensis), a French Dominican monk, who was reader to Louis IX., and who compiled a general encyclopaedia which brought him great fame at that period; and Roger Bacon, an Englishman who, by reason of the extraordinary extent of his knowledge and his remarkable powers of observation, was given the name of “Doctor mirabilis.” _Albertus Magnus._--Albertus Magnus was born at Lauingen, Swabia, in 1193 A. D., obtained his education in Italy (at the University of Padua, during the latter part of his stay), joined the Order of the Dominicans on arriving at the age of thirty, and afterwards, throughout his long life, devoted himself largely to teaching, particularly at Paris and Cologne. He was a prolific writer and his works, particularly those which treat of topics belonging to the domain of natural history, were greatly appreciated. The effect, however, which they produced upon a certain class of readers was to persuade them that he was a great magician. The chief distinction of his writings lies in the fact that they contain a large number of original observations which he made during the course of his journeys afoot through Germany in the character of Provincial of the Dominican Order. This habit of exercising entire independence in the use of his reasoning powers was something quite rare in those days. His observations were directed chiefly to matters belonging to the domains of zoölogy, botany, climatology, mineralogy, chemistry and physics. The following significant advice, says Neuburger, is attributed to him: “As regards the doctrines which relate to questions of belief and of morality, it is the part of wisdom to attach greater authority to Saint Augustine than to the philosophers; in matters belonging to the domain of medicine put your chief trust in Galen and in Hippocrates; in natural history, however, your best guide is Aristotle.” Neuburger adds that, throughout the writings of Albertus Magnus, there appear interesting statements relating to anatomy, physiology, psychology, and the plants and minerals which may be used for remedial purposes. An edition of the writings of Albertus Magnus (21 folio volumes) was published in Lyons by Petrus Jamy in 1651. The work was republished in Paris in 1892 and following years.