1823.] M, Hiimholdt on Volcanoes, 123 



other, appear in the form of veins, or are elevated by elastic 

 powers. 



We need not be surprised, that, notwithstanding the great 

 assistance which our geological information derives from inqui- 

 ries, having whole countries for their object, an extensive class 

 of phajnomena (with which I venture to entertain this assembly), 

 has been treated, during so long a period, in a confined manner; 

 the points of comparison being more difficult, and, I might say, 

 more troublesome to find. Whatever we beheved we knew, 

 until the end of the last century, respecting the form of volca- 

 noes, and the action of their subterraneous forces, had been 

 derived from two mountains of the south of Italy, — from iEtna, 

 and from Vesuvius. The first being more accessible, and hav- 

 ing, hke all low volcanoes, more frequent eruptions, has served 

 for a type, according to which a whole distant world, — the 

 powerful volcanoes of Mexico, South America, and the Asiatic 

 Islands, has been considered. Such a method recalls to our 

 remembrance the shepherd of Virgil, who expected his narrow 

 cottage to contain the ideal of the eternal city, imperial Rome. 



A careful examination of the whole Mediterranean, and princi- 

 pally of its easterly islands and shores, where mankind first 

 awakened to mental culture, and to noble feelings, might cer- 

 tainly have dispelled such a narrow idea of nature. Out of the 

 deep bed of the sea, among the Sporades, rocks of trachyte have 

 arisen, like the Azoric island, which has thrice reappeared dur- 

 ing three centuries, the intervening periods being almost equal. 

 Between Epidaurus and Troezene, near Methone, the Pelopon- 

 nesus has a Monte Nuovo which has been described by Strabo, 

 and seen by Dodwell, higher than the Monte Nuovo of the 

 Campi Phlegrsei, near Baia ; perhaps higher than the new vol- 

 cano of Xorullo in the plains of Mexico, which I have found 

 among a thousand basaltic cones, raised out of the earth, and 

 still smoking. In the bason of the Mediterranean Sea also, the 

 volcanic fire bursts forth, and not only from permanent craters, 

 from isolated mountains which preserve a lasting communication 

 with the interior of the earth, like Stromboli, Vesuvius, and ^^tna ; 

 — on Ischia, near the Epomaeus, and also, as it would appear from 

 the reports of the ancients, near Chalcis in theLelantic plains, has 

 lava flowed out of fissures which have suddenly opened. Besides 

 these phsenomena, which have taken place in the period of history 

 within the narrow limits of certain traditions, and which Ritter 

 will collect and explain in his masterly Geography, the shores of 

 the Mediterranean contain abundant remains of more ancient 

 igneous effects. The south of France shows, in Auvergne, a 

 range of hills, in which hells of trachyte occur alternately with 

 cones of eruption, from which currents of lava have descended. 

 The Lombardic plain, which forms the innermost bay of the 

 Adriatic Sea, surrounds the trachyte of the Euganean Hills, 

 where domes of granular trachyte, of obsidian, and of pearlstone, 

 rise, which; passing into each other, break through the Jura 



