570 COSMOS. 



The "opinion of some physicists" as to fiery meteors 

 (falling stars and aerolites), which Plutarch develops in detail 

 in the life of Lysander (cap. xii.), is precisely that of the 

 Cretan Diogenes. " Falling stars," it is said there, " are not 

 ejections and waste of the ethereal fire which, when they enter 

 our atmosphere, are extinguished after their ignition; they 

 are much rather the off-shoots of celestial bodies, of such a 

 nature that by a slackening of the revolution, they are shot 

 down."* We find nothing of this view of the structure of the 

 universe, this assumption of dark cosmical bodies which fall 



stone-Wee bodies (therefore porous stones), the occasion for 

 this term might have been the idea so generally diffused in 

 antiquity, that all celestial bodies were nourished by moist 

 exhalations. The Sun gives back again what is absorbed. 

 (Aristot. Meteorol. ed. Ideler, torn. i. p. 509 ; Seneca, Nat.. 

 Qucest. lib. iv. 2.) The pumice-stone-like cosmical bodies 

 have their peculiar exhalations. "These, which cannot be 

 seen so long as they wander round in the celestial space, 

 are stones; they ignite and are extinguished again when they 

 fall to the earth." (Plut. de Plac. PUlos. ii. 13.) Pliny 

 considers the fall of meteoric stones as frequent (Plinius,. 

 ii. 59) : " Decidere tamen crebro, non erit dubium." He also 

 knew that the fall in clear air produced a loud noise (ii. 43). 

 The apparently analogous passage in Seneca, in which he 

 mentions Anaximenes (Nat. Qufsst. lib. ii. 17), refers pro- 

 bably to the thunder in a storm-cloud. 



6 This remarkable passage (Plut. Lys. cap. xii.) literally 

 translated, runs thus : " But there is another and more probable 

 opinion which holds that falling stars are not emanations or 

 detached parts of the elementary fire, that go out the moment 

 they are kindled, nor yet a quantity of air bursting out from 

 some compression, and taking fire in the upper regions ; but 

 that they are really heavenly bodies which, from some relaxa- 

 tion of the rapidity of their motion, or by some irregular con- 

 cussion, are loosened and fall, not so much upon the habitable 

 part of the globe as into the ocean, which is the reason that 

 their substance is seldom seen." 



