ASCENT OF VESUVIUS, 1834 



upon the volcano, its nature, its depth, and extent, and 

 to inquire whether it is not connected with Stromboli 

 and Etna, and whether this grand bed of fire does not 

 extend throughout Italy, which everywhere bears evi- 

 dences of former volcanoes and present subterranean fires? 

 However this may be, it appears that it may be said with 

 considerable confidence that at least fifteen or twenty 

 miles on each side will not more than include this burn- 

 ing furnace. Twelve miles from Vesuvius, beyond 

 Naples, are the vapor baths of San Germano. An old 

 stone building covers a spot of earth whence issues this 

 heated vapor. There is but a slight smell of sulphur, but 

 the heat throws one immediately into a profuse perspira- 

 tion. The walls inside are covered with an incrustation 

 of alum of from one-half to two inches thick. Here, 

 then, is sufficient evidence of subterranean fires. A short 

 distance from these baths is the Grotto del Cane, a small, 

 partly artificial cave, but twelve or fifteen feet deep, and 

 six high, in the side of a hill of tufa. It is noted for the 

 carbonic acid it contains. The smoke of a taper settling 

 upon it ran out of the entrance like a liquid, thus showing 

 that there is an incessant fountain of the gas. I stepped 

 in, and besides an increase of pressure, perceived an in- 

 crease of heat. This heat and the continual reproduction 

 of gas seem sufficient to prove its igneous origin. This 

 cave and the baths are situated on the borders of a small 

 lake (Lago d'Agnano), which, from its circular form, 

 great depth (five hundred feet), and the volcanic nature 

 of the surrounding country, is supposed to be an ancient 

 crater. A mile from the lake is the famous Solfatara, 

 not long since an active volcano, now abounding in sul- 

 phur, alum, and other volcanic productions. Near by is 

 a rivulet of boiling water. Not far distant is the crater 

 of another extinct volcano (Astroni), four miles in cir- 

 cumference; and just north of the bay of Baia there is 

 another hot spring. Nine miles west of Naples is the 

 island of Procida, with a volcanic soil; and fifteen miles 

 distant is Ischia, whose extinct volcano, currents of lava, 

 once the destruction of its town, and hot springs, are 

 sufficient to prove its volcanic origin. South of these, 

 the plain of Sorrento bears evidences of a former volcano. 

 Thus Vesuvius is nearly surrounded with volcanoes now 

 apparently extinct ; but whose fires, as is proved by the 



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