22 THE ADVANCE OF SCIENCE 



by in- debt to science, it lias largely repaid the 

 improve- loan by the important aid which it has, in 

 its turn, rendered to the advancement of 

 science. In considering the causes which 

 hindered the progress of physical knowl- 

 edge in the schools of Athens and of Alex- 

 andria, it has often struck me * that where 

 the Greeks did wonders was in just those 

 branches of science, such as geometry, 

 astronomy, and anatomy, which are sus- 

 ceptible of very considerable development 

 without any, or any but the simplest, ap- 

 pliances. It is a curious speculation to 

 think what would have become of modern 

 physical science if glass and alcohol had 

 not been easily obtainable ; and if the 

 gradual perfection of mechanical skill for 

 industrial ends had not enabled investi- 

 gators to obtain, at comparatively little 



* There are excellent remarks to the same effect in 

 Zeller's Philosophie der Gi'iecJien, Theil II. Abth. ii. 

 p. 407, and in Eucken's Die Methode der Aristotelisclien, 

 Forsclmng, pp. 138 et seq. 



