86 



is so hot as to destroy respiration. Hence we learn that 

 there is another source of fire, or as it were another sun 

 in the bosom of the earth. 



Upon the application of fire to water, it boils : that 

 is, the particles of fire passing through the pores of the 

 vessel, strike on the lowest particles of the water, impel 

 them upwards, and render them lighter than before, 

 bolh by inflating them into little vesicles, and by break- 

 ing and separating their spherules. There will of conse- 

 quence be a constant flux of water, from the bottom of 

 the vessel to the top. And hence we see, why the 

 water is hot at the top, sooner than at the bottom. 



Farther, the air contained in the interstices of the wa- 

 ter being dilated, and its spring increased by the heat, 

 it ascends through the water into the air, carrying with 

 it the contiguous particles of water; and by this means 

 much of the water will be heaved up, and let fall alter- 

 nately, as the air has no power to carry away into the 

 atmosphere more than that small part that rises in the 

 steam. 



4. That this subtle matter is plentifully collected in 

 the bowels of the earth, appears from burning moun- 

 tains. It is observed, there is always in the neighbour- 

 hood of these, plenty of sulphur or bitumen, the stench 

 whereof spreads far and near, especially before any 

 great eruption. This feeds the fire, which may be 

 kindled by various means, so as to continue for nranj 

 centuries. jEtua and Vesuvius have burned for above 

 2000 years, and probably will till the end of time. 



5. Mount $ltna is divided into three distinct regions, 

 called La llegione Culta, the fertile region ; La Regione 

 Sylvosa, the woody region ; and La llegione Deserta, 

 tlie barren region. 



The three are as different, both iu climate and pro- 

 ductions, as the three zones of the earth : and perhaps 

 with equal propriety might have been stiled the torrid, 

 the temperate, and the frigid zone. The first region 

 surrounds the foot of the mountain, and constitutes the 



