I T A I, Y. L E T T E R V. ' %f 



I. Of the inferior Slate, de Montibus primariis. 



This date is of a clayifh (argillaceous) fub- 

 ftance, commonly containing much micaceous par- 

 ticles, now and then filver-coloured ; crofled by 

 Quartz veins ; lamellated or fhivery ; often ap- 

 pearing in wave-like bent ftrata. It is the deepeft 

 rock in the Vicentine and Veronefe countries, and 

 has never been dug through ; whence it is uncer- 

 tain whether there be any granite under ground as 

 in other mountainous countries ; though this be 

 very probable, fince the granite rocks appear from 

 under ground in the higher Alps of Tyrol ; and 

 the grey granite or granitello is to be found near 

 fozzino and Primiero, at the fpring of the river 

 Cifmonoe y which falls into the Brenta. Near Sckio in 

 the Vicentine territories there are facts to fupport 

 the fame opinion ; I mean, mountains of porphyry, 

 which are like wife very common in Brefciano and 

 Eergamafco ; but Mr. Arduini allures me, this laft is 

 fuperincumbent on the ilate and a volcanic produc- 

 tion, which I hope to examine myfelf. This flate 

 is here, as in other countries, that fort of rock 

 which commonly contains the metallic veins ; but 

 they are here, for the moft part, under the fame 

 law, which you, my deareft friend, have fo very- 

 well obferved in the Bannat , that is to fay, the veins 

 D 3 are 



