DOMAIN XII. VOLCANIC. 309 



in opposition to his friend Spallanzani, that 

 the modern lavas on the east of Etna as- 

 sume the prismatic form when they reach 

 the sea ; and regards this opinion as a mere 

 illusion arising from the fissures common in 

 amorphous lavas, and Avhich may be equal- 

 ly observed in those that are inland. " I 

 must therefore repeat/' says he, " that the 

 prismatic lavas around Etna, do not be- 

 long to the modern eruptions of that vol- 

 cano, but to the ancient volcanoes under 

 the ocean ; and that modern lavas, whether 

 on the land or in the sea, and under what- 

 ever circumstances, never pass into regular 

 forms ; but only appear in shapeless masses, 

 or in such accidental shapes as arise from 

 their site or refrigeration. Two or three 

 prisms which I have found of modern lava 

 near Mount Finocchio, on the upland 

 skirts of Etna, and some small ones in the 

 clefts beneath, must, from their singularity, 

 be ascribed to an accident, which can never 

 establish a general system : and I am of 

 opinion that to the same accident may be 

 ascribed the two or four prisms, which 



