UNSYSTEMATIC KNOWLEDGE. 301 



them ; for the Arabic Dioscorides was the source and 

 standard of their knowledge. The flourishing com- 

 merce of the Arabians, their numerous and distant 

 journeys, made them, no doubt, practically acquaint- 

 ed with the productions of lands unknown to the 

 Greeks and Romans. Their Nestorian teachers had 

 established Christianity even as far as China and 

 Malabar; and their travellers mention 17 the cam- 

 phor of Sumatra, the aloe-wood of Socotra near 

 Java, the tea of China. But they never learned the 

 art of converting their practical into speculative 

 knowledge. They treat of plants only in so far as 

 their use in medicine is concerned 18 , and follow Dios- 

 corides in the description, and even in the order of 

 the plants, except when they arrange them accord- 

 ing to the Arabic alphabet. With little clearness of 

 view, they often mistake what they read 19 : thus 

 when Dioscorides says that ligusticon grows on the 

 Apennine, a mountain not far from the Alps; 

 Avicenna, misled by a resemblance of the Arabic 

 letters, quotes him as saying that the plant grows 

 on Akabis, a mountain near Egypt. 



It is of little use to enumerate such writers. One 

 of the most noted of them was Mesue, physician of 

 the Calif of Kahirah. His work, which was trans- 

 lated into Latin at a later period, was entitled, On 

 Simple Medicines; a title which was common to 

 many medical treatises, from the time of Galen in 

 the second century. Indeed, of this opposition of 

 17 Sprengel, i. 206. ls Ib. i. 207. 19 Ib. i. 211. 



