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mcnts of what they denominate fchorl and felt-fpar ; whence 

 Sir John Strange, Monfieur de Dolomieu, and others, have called 

 it granitical, though unlike granite in many important points : 

 But the fuppofed compacfl lava of the Vicentine and Veronefe 

 is black, or dark blue, of a clofe and rather fine grain, even, 

 and almofl homogeneous, except that it fometimes contains a 

 few fragments of fchorl, and is wholly of the argillaceous 

 genus, and of the trapp or homblend fpecies ; and in fhort 

 almofl perfedlly refembles our bafaltic ftone of the county of 

 Antrim, and the N. W. of Scotland. The bafaltic columns of 

 San Giovanni Ilarione, defcribed by Sir John Strange, lie not 

 many miles from Bolca, on the fide of a valley that leads to 

 it, and the fummit of this hill itfelf was, many years ago, 

 difcovered by Abate Fortis to be crowned with a great mafs 

 of tolerably defined columnar bafalte. 



The whole of the hill, as far as I could obferve, feems to 

 be compofed of fimilar, or at leaft of argillaceous matter, ex- 

 cept the quarries in which the fiih are found, which are cal- 

 careous, and lie at about half a mile from the fummit. Befides 

 the diflimilarity of thefe to the other materials of the hill, it 

 is further important to remark that they do not form a con- 

 tinued ftratum, but lie in great and wholly detached and 

 dillindl mafl^es, as it w^ere accidentally imbedded in the fide of 

 the hill, fet in a loofe rubble of argillaceous, and the fame 

 kind of calcareous fragments, the whole more or lefs in a 

 itate of decompofition. 



The 



