300 DOMAIN XII. VOLCANIC. 



not seem to have borrowed from the French 

 mineralogists, but to have adopted from 

 his own observation. For this inference, 

 which to some may seem arbitrary, and 

 even visionary, is founded on an indubita- 

 ble fact that currents of lava, perfectly 

 identic with that of the historical and later 

 ages, are found covered, and often even 

 alternating, with products universally al- 

 lowed to have been deposited by the pri- 

 meval waters, such as thick beds of chalk 

 and limestone, sometimes compact, some- 

 times conchitic. 



C oTsicS tion ~^y ki g account, and the mineralogical 

 map which accompanies his work, the 

 whole of Sicily appears to be calcareous, 

 except the mountains of Peloro, in the 

 north-east corner, which consist of grey 

 granite, often covered with a bed of lime- 

 stone. In that quarter, near a hundred 

 mines were formerly wrought, producing 

 abundance of silver, copper, and lead. 

 The limestone of Sicily is often in the form 

 of what he calls creta, by which he does 

 not seem precisely to understand chalk; 



