DOMAIN XII. VOLCANIC. 303 



fluidity is required in stony substances, 

 that in their consolidation, after their dis- 

 solution by fire, they may assume the forms 

 to which they have a natural tendency. 

 It cannot be denied that many modern 

 lavas have all the fluidity of which they are 

 capable : what circumstance then has per- 

 mitted the ancient* lavas sometimes to as- 

 sume the form of prisms, which is entirely 

 denied to the modern ? 



" A lava which rises from the bottom of 

 the sea, must be consolidated in a shorter 

 or longer time by the cold contact of the 

 water. The lava being thus amassed 

 around the orifice, while the subterranean 

 ferment continues, or is even augmented, 

 the elastic vapours, acting from beneath, 

 must break the upper surface, and occa- 

 sion the lava to accumulate on itself. The 

 sides, however, remaining always consoli- 



* By this word he always understands, as he explains himself, 

 the primeval submarine volcanoes. 



He supposes, p. 28Q, that the rocks are rendered fluid by elastic 

 vapours, vapori elastici; and, from their resemblance to rivers, are, 

 like them, called lavine or lave. Does he refer to the Sicilian 

 dialect ? In pure Italian, lavare is to wash, or water. 



