ITALY. LETTER V. 55 



It is a very fingular phenomenon, that the 

 Vfcentine and Veronefe lavas and volcanic aihes 

 contain inclofed feveral forts of fire-ftriking and 

 flint-horn-itones, of a red, black, white, green, 

 and variegated colour, fuch as jafpers and agates; 

 that hyacinths, cryfolites, and petre olfidiane^ de- 

 fcribed by Mr- Arduini in the Giornak d'Italia> 

 ^re found at Leonedo\ a.nd, moreover, that chal- 

 cedony, or opal pebbles, and noduli, with inclofed 

 water-drops (chalcedony opali enhydri) are dug out 

 of the volcanic cinericious hills near Vicenza. One 

 might confider thefe flints as being torn and 

 dragged from the fcaglia, and thence to have been 

 by floods heaped together with afhes and lavas ; 

 becaufe it is a fact, that innumerable quantities of 

 flints, jafpers, and agates, are found in the above? 

 mentioned china and potters clay-hills near S. Ul- 

 derico nel Tretto (exactly as fimilar flints are found 

 in the Saxonian and other china clays). But how 

 did they come into thofe volcanic hills, which, 

 like thefe at S. Rocco, near S. Ulderico, never con- 

 tain any clay whatever? Suppofing their having 

 been by fubterraneous fire feparated from veins 

 pre-exifting in or near the very bottom of the 

 ancient volcanos ; this explains pretty well how 

 they came into their lava and the china-clay, 

 when in an aqueous difTolution or mixture it was 

 vomited, fmce fragments of quartz- cry ftallifations, 

 E 4 marble^ 



