,o8 NATURAL SCIENCES. 



led up to medicine. During the prosperous reign of Al-Mansour, in the 

 eighth century, a large school was founded at Bagdad, which became a 

 refuge for the sciences when exiled from Athens and Alexandria. There 

 were translated into Syriac the works of Aristotle and Galen, the two 

 lights of Greece and of Rome, whom the Arabs in turn translated for the use 

 of their schools at Granada and Cordova. The legendary caliph, Ilaroun 

 Alraschid, followed the example of Al-Mansour, his predecessor, and showed 

 still more generosity towards the savants. His son, Al-Mamoun, obedient 

 to these traditions, carried the love of science so far as to declare war upon 

 the . Emperor of Constantinople, in order to compel him to send into Asia 

 Minor not only several Greek savants, but also some ancient manuscripts 

 relating to arts and sciences. 



.The Arabs had before this cultivated several branches of natural history, 

 and made some valuable botanical discoveries, thereby enlarging the domain 

 of materia medica. Thus, in place of the violent purgatives, such as 

 hellebore, which were previously resorted to, the Arab doctors recommended 

 the moderate use of cassia, senna, and tamarinds : a quantity of plants 

 useful for medicinal purposes were brought from India, Persia, and Syria by 

 Rhazes. -At the same time Serapion the younger commentated Dioscorides, 

 and added to that work a description of the newly discovered plants ; and 

 Avicenna scoured Bactriana and Sogdiana in search of medicines, and espe- 

 cially of vegetable preparations. Mesue wrote his treatise on Medicine (" De 

 Re Medica"), which, several times translated into Latin, was used as a manual 

 in all the schools up to the Renaissance. But, apart from the materia medica, 

 disorder and confusion prevailed in the works composed by the Arabs, who 

 were not acquainted with Aristotle's " History of Animals," or the " History 

 of Hants " by Theophrastus, and whose translations of, and commentaries 

 upon, Pliny and Dioscorides are a mass of nonsense, and for the most part 

 tmintelligible. 



Constantine of Africa first introduced into Europe certain Arab works 

 upon the materia medica, but in his own works, though they give proof of a 

 certain experience in practical medicine, it is easy to see that he was not well 

 informed in matters of detail, and this because there was a want of method in 

 his study of nature. Thus, in dividing medicines into four distinct classes, 

 he ranged them upon a sort of scale according to their degree of relative 

 activity. At about the same period the natural sciences were represented 



