opinions respecting Volcanic Phenomena. 137 



land, and in generalj what has been said on this subject has been 

 exaggerated. Besides, were it true that this communication of the 

 waters of the sea with volcanoes was one of the causes of their erup- 

 tions, how should the present state of rest of certain of ihem, 

 although always placed in the same circumstances, be accounted 

 for? The islands of Ischia, of Procida, and the Pumice Isles, 

 are always surrounded by the sea ; the bases of the craters of 

 Averne, Gauro, Astroni, &e. are still bathed by it ; and yet 

 none of these places at present exhibit any signs of action. Will 

 it be said, that the subterranean canals by which the waters in- 

 troduced themselves into the volcanic abysses are now closed, or 

 that the masses of alkaline and earthy metals which existed in 

 these different localities arc exhausted ? It would be difficult, 

 indeed, to conceive such reasons. Besides, a great number of 

 volcanoes are situated in the interior of continents: we may 

 mention, for example, those of the Andes of Quito, Sanguay, 

 Pichincha, Cotopaxi, &c. What means of communication can 

 be supposed to exist over a space of more than 40 leagues ? It 

 is true, that the waters of the sea are supplied by great subter- 

 ranean lakes, whose existence is attested by immense mud erup- 

 tions, great inundations, and especially by the fishes (pimeJodes 

 cyclopum) sometimes ejected in prodigious quantity ; but many 

 circumstances prove that these lakes have no communication with 

 the volcanic focus itself. Many of these fishes are found ahve 

 at the moment of their ejection, and almost all of them are in so 

 entire a state, notwithstanding the great softness of their flesh, 

 that it is impossible to admit their having been exposed to the 

 action of heat. The water ejected along with them is commonly 

 cold. It is easy to account for these extraordinary facts, the first 

 knowledge of which we owe to M. de Humboldt, by the forma- 

 tion of subterranean lakes which are peopled by fishes ejected 

 during eruptions, the latter, besides, only taking place at long 

 intervals. 



It therefore remains highly probable, that the alleged commu- 

 nication of the sea or of subterranean lakes with the foci of vol- 

 canoes, is altogether imaginary. And besides, were it admitted, 

 it would remain as difficult to explain certain facts, to the dis- 

 cussion of which we now proceed. One of the most important 

 consequences of the action of water upon the alkaline and earthy 



