108 HISTORY OF 



but we have mentioned nothing of the benefits 

 they may possibly produce. They may be of 

 use in warming and cherishing the ground, in 

 promoting vegetation, and giving a more exqui- 

 site flavour to the productions of the earth. The 

 imagination of a person who has never been out 

 of our own mild region, can scarcely reach to 

 that luxuriant beauty with which all nature 

 appears clothed in those very countries that 

 we have just now described as desolated by 

 earthquakes, and undermined by subterranean 

 fires. It must be granted, therefore, that though 

 in those regions they have a greater share in the 

 dangers, they have also a larger proportion in the 

 benefits of nature. 



But there is another advantage arising from 

 subterranean fires, which, though hitherto disre- 

 garded by man, yet may one day become service- 

 able to him ; I mean, that while they are found 

 to swallow up cities and plains in one place, they 

 are also known to produce promontories and 

 islands in another. We have many instances of 

 islands being thus formed in the midst of the sea, 

 which though for a long time barren, have after- 

 wards become fruitful seats of happiness and in- 

 dustry. 



New islands are formed in two ways; either 

 suddenly, by the action of subterraneous fires ; 

 or more slowly, by the deposition of mud, carried 

 down by rivers, and stopped by some accident.* 

 With respect particularly to the first, ancient 



* Bufibn, vol. ii, p. 343. 



