370 



also contains recent shells, and which has been extensively perforated 

 by Lithodomi. Of similar age with this conglomerate, is a bone brec- 

 cia observed by the author in three different caves, one of which is a 

 hundred feet, and another three hundred feet above the sea. As the 

 bones belong to extinct species of the elephant, hippopotamus, &c, and 

 as they are intimately mixed up with i-ecent sea shells, he infers, that 

 these races of large quadrupeds, now extinct, prolonged their dura- 

 tion in Sicily, after the Mediterranean became inhabited by its pre- 

 sent species of marine animals ; and he proves, by the workings 

 of Lithodomi, that some of the breccia, as at St. Giro, was 

 long washed by the waves. The detritus of the island is divided 

 by this author into two periods, the older of which is marked by 

 large rolled blocks, and is supposed to be of the same age as the 

 bone breccia; while the smaller and younger occupies the bottoms 

 of valleys. 



The venerable Count Montlosier, — desirous of proving to us that 

 the fire of his youth, during which he gave to the world so clas- 

 sical and original a sketch of the old volcanoes of Auvergne, 

 still burns within him, — has sent us a lively account of the im- 

 pressions made upon him by a first visit to Vesuvius in 1813. It then 

 appeared evident to him, that the present mountain is a parasitic 

 cone, established on the flank of Somma, which he considered to have 

 been the true Vesuvius of the ancients ; and that its vast crater must 

 have been produced by one great explosion : a mode of formation to 

 which he assigns the existence of the lake-craters of the extinct vol- 

 canoes of the Eyfel and of Auvergne. 



Dr. Daubeny, having for some time paid much attention to ther- 

 mal springs, has lately published it as his opinion, that they all owe 

 their origin to volcanic agency, whether they issue from the neigh- 

 bourhood of active and extinct foci of eruption, or upon linear fis- 

 sures and dislocations of the ancient strata, produced by expansive 

 forces during former periods of elevation. The views of this able ex- 

 positor of igneous operations, are entitled to our deepest attention: and 

 in regard to the last-mentioned class of them, it is highly gratifying 

 to observe that the numerous facts adduced by him of the source of 

 thermal waters upon lines of elevation, and at points of fracture, are 

 remarkably supported by the observations of M. Stifft* in the Duchy 

 of Nassau. Dr. Daubeny supposes that the forces which give rise to 

 volcanoes, are at work throughout the globe; and that the evolution of 

 gases and increased temperature of springs may be looked upon 

 in the light of volcanic phenomena, with the same propriety as 

 eruptions of lava and shocks of earthquakes ; and having repeatedly 

 detected the presence of nitrogen gas in thermal waters, he concludes, 

 that the chemical theory of the origin of volcanoes is still to be 

 maintained, as being more philosophical and more consistent with 

 facts and experiments, than the hypothesis of a central ignited fluid, 

 which has been, from time to time, mechanically forced up to the 

 sqrface of the earth. 



* Ferussac, Bulletin des Sciences Naturettes, Juillcl 1833, p. 7-- 12. 



