26 



its perpetual verdure furnishes a proof that its 

 eruptions have never been very violent. 



Sect. IX. Earthquakes. The quantity of 

 inflammable substances with which the soil of 

 Chili abounds, rendered active by the electric 

 fluid, may be considered as one of the principal 

 causes of the earthquake, the only scourge that 

 afflicts this favoured country. Another, however, 

 not less capable, in my opinion, of producing- 

 this terrible phenomenon, is the elasticity of the 

 air contained in the bowels of the earth, in con- 

 sequence of the water which, insinuating itself 

 by subterranean passages from the sea, becomes 

 changed into vapour. This hypothesis will ex- 

 plain why the countries to the east of the Andes, 

 at a distance from the sea, are so little incom- 

 moded by earthquakes. Two provinces however, 

 Copiapo and Coquimbo, although near the sea, 

 and as rich in minerals as the others, have never 

 sulFcred from earthquakes ; and while the other 

 parts of the country have been violently shaken, 

 these have not experienced the least sliock, or 

 been but slightly agitated. It is a general opi- 

 nion that the earth in these provinces is inter- 

 sected by large caverns. The noises heard in 

 many places, and which appear to indicate the 

 passage of waters or subterraneous winds, seem 

 to confirm this opinion, and it is highly probable 

 that by affording a free vent to the inflamed sub- 



