1834.] A short notice of Earthquakes. 108 



responds witli 600 of liquid lava as proved by Sir James Hall. That 

 immense subterranean cavities exist there can be no reason to 

 doubt, there being apparent communications at great distances be- 

 tween different volcanoes. Ure mentions" that the limestone caverns 

 of Carniola contain many hundred thousand feet of cubic air, which 

 he says shews the extent to which subterranean cavities may exist 

 even in common rocks, and the deeper is the excavation, the denser 

 is the air, and the fitter for combustion." Lyail suggests that the 

 circulation of heat from the interior to the surface is probably regu- 

 lated like that of water, from the surface to the sea, in such a manner 

 that it is only, when some obstruction occurs that the usual repose 

 of nature is broken." In order next to prove the intimate affinity of 

 volcanoes and earthquakes, it will be found, that the former are dis- 

 tributed over vast tracts, and there is plentiful evidence that subter- 

 ranean fires are continually at work in the spaces between. Earth- 

 quakes being of frequent occurrence, hot springs being distributed 

 at intervals impregnated with the same mineral matters as are dis- 

 charged by volcanoes, and gaseous vapours being discharged plen- 

 tifully from the soil, several writers have of late years declared, that 

 the energy of subterranean fires has considerably abated, 

 several volcanoes having become dormant ; but it would be difficult 

 however to define a time in which a volcano may be said to be 

 extinct, as there are instances on record of a recurrence of eruption 

 after a dormant state of several centuries in the same volcano. In 

 continuance of the proof of the intimate relation of earthquakes, and 

 Volcanoes, the region of the Andes is said to be one of the best de- 

 I fined there being an uninterrupted line of volcanic vents, in almost 

 1 every degree of latitude from the 46 south to the 27 north ; in these 

 I different provinces hot springs are numerous and mineral waters of 

 various kinds, a year seldom passes without slight shocks of earth- 

 quakes, and once in a century convulsions occur by which continu- 

 ous tracts of land have been raised from one to twenty feet above 

 their former level, many extensive vallies in this chain of moun- 

 tains, have been filled up with volcanic products ; the volcano of 

 Jorullo, which is in about the centre of the range is 40 leagues dis- 

 tant from the sea which is considered important as it shews that 

 proximity to the sea, is not a necessary condition, though the ge- 

 neral characteristic of volcanoes ; besides the volcanic range of Andes, 

 there are others of even greater extent mentioned, of which a discripti- 

 on would occupy too great a space. The volcanic bands of the Mo* 

 lucca and Sunda Islands, are the nearest however to the continent of 



