xxii On Comparative Anatomy, and the 



successors of Aristotle, viz. Erasistratiis his grandson, and 

 Herophilus, who having been protected and employed by the 

 Ptolemies, sustained the character of the school of Alexan- 

 dria so well, that, during their lives, and for a long time 

 after, it continued the chief place of resort for students, 

 from all nations. 



About the year 160 of the Christian account, Galen, a 

 name familiar to the whole world, settled at Rome, and con- 

 tributed very largely to the advancement of medical science 

 generally, and particularly of anatomy, by his talents, in- 

 dustry in experiments and dissections, and by collecting to- 

 gether all that had been previously written on the subject by 

 the Greek teachers.^ After his days we have no account of 

 any addition having been made to the previous knowledge, 

 in either human or comparative anatomy, for a very long 

 time. To this suspension of the labours of science, the de- 

 cay and division of the Roman empire, in the close of the 

 second century, greatly contributed ; but the finishing stroke 

 to all liberal studies or mental improvement, in the western 

 parts of Europe, was given by the irruption of the Barbarian 

 tribes of Germany and Scythia, first into Rome, in 410, un- 

 der Alaric, and finally over the whole of Italy, Gaul, and 

 Spain, at different times afterwards, until the year 4^76, when 

 the Roman empire was finally extinguished in the West. 



A long interval of midnight darkness in science of every 

 kind, succeeded in the western parts of Europe. The Sara- 

 cens were at length, in their turn, destined to be the rulers of 

 the former seat of learning and of the liberal arts in the East,, 

 and for a long time they did little except destroy. The burn- 

 ing of the library of Alexandria will forever remain a splen- 

 did monument of their fanatic barbarity .^ Tlieir successors 

 were fortunately better disposed, and encouraged the arts,4 

 and after the subversion of the Visigoths in Spain, Arabian 

 learning was introduced by them into that country, (anno 

 710,) where it maintained its ground, and spread through 



