NA TL *RA L SCIENCES. 



since the twelfth century, and which, with engravings that often explain 

 and complete the text, are buried in the great libraries without having ever 

 obtained the honours of print. Most of these works contain singular revela- 

 tions as to the nature of plants and of stones, as to the usage and pro- 

 perties of simples, as to the hygienic qualities of various foods, &c. Several 

 special and less voluminous treatises, written by certain doctors of the twelfth 

 century, were alone printed at the close of the fifteenth century. Amongst 

 these latter may be mentioned a moral poem entitled, " Auti-Claudianus, sive 

 de Officio viri boni et perfecti," which was composed at the close of the 

 twelfth century by the celebrated Alain de 1'Isle, or de Lille, called the 



Fig. 83. Monks engaged in Agriculture. Capital Latter in the " Livre do Jurisprudence." 

 Manuscript of the Thirteenth Century. In M. Ambroise Firmin-Didot's Library, Paris. 



Universal Doctor, and which contains, with a general table of arts and 

 sciences, a number of very sensible remarks on natural history. 



The savants and philosophers of this epoch who had a taste for natural 

 sciences were but commentators and compilers, but the thirteenth century 

 produced observers, the first of whom were those whom the Crusades and a 

 passion for Eastern travel took into distant and hitherto unexplored lands, 

 where everything they saw was strange and unknown. Observations, imper- 

 fect as they no doubt were, resulted from these voyages, in which the curiosity 

 was continually being stimulated by the sight of novel objects ; and the 

 natural sciences profited largely by the expeditions, whether political, com- 



