EPOCHS IN THE HISTOUY OF THE CONTEMPLATION 



were increased and multiplied. Great desire was felt to 

 become acquainted with articles so precious and so important 

 to medicine, industry, and the luxury of the temple and the 

 palace ; to distinguish them carefully from each other ; and 

 to find out their native place, which was often artfully con- 

 cealed from motives of covetousness. Numerous caravan 

 roads, departing from the commercial mart, Gerrha, 

 on the Persian Gulf, and from the incense district of 

 Yemen, traversed the whole interior of Arabia to Phoenicia 

 and Syria ; and thus the names of these much -desired pro- 

 ductions, and the interest felt in them, became generally 

 diffused. 



The science of materia medica, the foundation of which was 

 laid in the Alexandrian school by Dioscorides, is, in its scien- 

 tific form, a creation of the Arabians, who, however, had 

 previously access to a rich source of instruction, the 

 most ancient of all, that of the Indian physicians. ( 328 ) 

 The apothecary's art was indeed formed by the Arabians, 

 and the first official authoritative rules for the prepara- 

 tion of medicines were taken from them, and were diffused 

 through southern Europe by the school of Salerno. Pharmacy 

 and the materia medica, the first requirements of the healing 

 art, conducted to the studies of botany and chemistry. 

 Erom the confined sphere of utility and of single application, 

 the study of plants gradually expanded into a wider and freer 

 field: it examined the structure of organic tissues; the 

 connection of this structure with the laws of their develop- 

 ment; and the laws according to which vegetable forms are 

 distributed geographically over the earth's surface, according 

 to differences of climate and of elevation. 



After the Asiatic conquests, for the maintenance of which 



