

GEOLOGY. 685 



this strange hypothesis. It says, " These eggs and these 

 seeds are tangible things ; one can generally feel and see 

 them ; whoever speaks of them is bound to show them. 

 Then show them ! " But this is what no one has yet done. 



I have vainly sought for these atmospheric germs, in- 

 vented to support certain hypotheses, and have never been 

 able to find them. Two observers, equally illustrious for 

 their learning and the splendor of their diction, P. Mante- 

 gazza, of the University of Pavia, and N. Joly, of the faculty 

 of Toulouse, have not been more fortunate than myself. 



But although the atmosphere is not surcharged or satu- 

 rated with these indiscoverable eggs, it must yet be admit- 

 ted that, notwithstanding its transparence and penetrabil- 

 ity, there are an immense number of invisible corpuscules 

 floating in it. Is there any one who has not recognized 

 this in entering a dark place traversed by a ray of light ? 

 The beholder is quite surprised to see the infinite variety 

 of all the objects whirling about in it, rising and falling, so 

 as to form iridescent and sparkling waves. 



These light corpuscules represent the remains, the detri- 

 tus, of all bodies on the surface of the earth, which have 

 been borne away by the agitation of the atmosphere. 



In the open sea and in calm weather, scarcely any motes 

 are seen in a ray of light ; a few specks of dust detached 

 from the ship alone float in it. 



On the summit of a lofty mountain we notice the same 

 paucity of corpuscules. Near the crater of Etna the breeze 

 only brought to us particles of ashes and sulphur thrown 

 out by the volcano. 



But so soon as we abandon the solitudes of the sea or the 



