PORTION OF THE COSMOS. AEROLITES. 423 



period intermediate between Anaxagoras and Deraocritus, 

 expresses himself still more clearly respecting the structure 

 of the Universe. According to him, as I have already re- 

 marked elsewhere, "together with the visible stars there 

 move other invisible ones, which are therefore without names. 

 These sometimes fall upon the Earth and are extinguished, 

 as took place with the star of stone which fell at JEgos 

 Potamoi" (Stob. Eclog. p. 508) ( 683 ). 



The "opinion of some natural philosophers" respecting 

 igneous meteors (falling stars and aerolites), developed in 

 detail by Plutarch in the Life of Lysander (cap. 12), is quite 

 that of the Cretan Diogenes. It is there said, "falling 

 stars are not emanations or rejected portions thrown off from 

 the ethereal fire, which, when they come into our atmosphere, 

 are extinguished after being kindled ; they are rather celes- 

 tial bodies, which, having once had an impetus of revolution, 

 fall, or are cast down, to the Earth by its intermission" ( 684 ). 

 "We find nothing of this view of the structure of the Uni- 

 verse, or of the assumption of dark bodies which fall on our 

 Earth from the celestial regions, in the teaching of the 

 ancient Ionic school, from Thales and Hippo to Empedo- 

 cles ( 685 ) . The impression of the great natural event above 

 alluded to, which took place in the 78th Olympiad, appears 

 to have had a powerful effect in calling forth ideas connected 

 with the fall of dark masses. In the late pseudo-Plutarch 

 writings (Plac. ii. 13), we merely read that the Milesian 

 Thales regarded "all the heavenly bodies as earthy and 

 igneous bodies (yewcfy KCU epirvpa) " The efforts and ten- 

 dencies of the early Ionic physiology were directed to seek- 

 ing out the primeval beginning of things ; the origin of sub- 

 stances by mixture, and their gradual alteration and transi- 



