122 



kind is found between Bologna and Florence, on the side 

 of one of the Apennines. On a spot of ground three 

 or four miles diameter, there is a constant eruption of 

 lire. The flame rises very high ; yet without noise, 

 smoke, or smell. In great rains it sometimes intermits, 

 but afterwards burns with greater vigour. There are 

 three other such fires on the same mountain:}. Pro- 

 bably they rise from the veins of bitumen. 



20. A late ingenious writer ascribes all earthquakes to 

 the same cause, electricity. The impression, says he, 

 they make on land and water, to the greatest distance, 

 is instantaneous. This can only be affected by electrici- 

 ty. In the late earthquake the concussion was felt 

 through the space of a hundred Hies in length, and forty 

 in breadth, at the same instant. Now what could 

 throw a tract of land, of four thousand square miles in 

 surface, into such an agitation in a moment? No natu- 

 ral power is equal to this, but that of electricity which 

 alpine acknowledges no bounds, neither any sensible 

 transition of time. 



The little damage done by most earthquakes, is ano- 

 ther argument, for their being occasioned, by a simple 

 vibration of the earth, through an electric shock. This 

 vibration on the water, meeting with the solid bottoms 

 of ships, occasions that thump which, is felt by them. 

 That this shakes millions of ordinary houses, and yet 

 not one of them falls, is a farther proof, that it is not a 

 convulsion hi the bowels of the earth, but an uniform 

 vibration, like what we occasion in a glass, by rubbing 

 our finger on the edge ; which may be brought to such a 

 pitch, as to break the glass in pieces, by an electric re- 

 pulsion of its parts. 



There can be little doubt, but some earthquakes are 

 owing to electricity ; but many more are owing to other 

 causes: those ot Callao, Lima, Port-Royal, for in- 

 stance, uere unquestionably owing to water : those 

 in the neighbourhood of /Etna, and Vesuvius, with those 

 in the East-Indies, to lakes of five. The grand fault 

 4 



