ITALY." LETTER XXIII. 305 



voy, and Rubilantc found many reafons to prefer 

 retirement; which, proving agreeable and happy 

 to a philofophic mind, deprived the ftate of 

 an ufeful member, and the Sciences of an 

 active friend. Happily he had formed by his in- 

 ftructions a man of great merit, who is his fuccef- 

 for. This is Mr. Grafton, an artillery-officer. By 

 his commifiion he is obliged to go often into Sa- 

 voy, and might give many curious obfervations 

 on the nature of the mines and mountains of that 

 country. The collection of minerals under his 

 infpection contains many remarkable pieces from 

 the German and Saxonian mines, together witk 

 fome minerals and petrifactions from Piedmont, 

 Sardinia, and Savoy. Unhappily the number of 

 thefe laft is the lefs confiderable ; as but few- 

 mines are ftill working. I mail take notice of 

 fome. 



i. Native gold in quartz, from Valle d'Aajla 

 neile vaile di Cbialland, in Piedmont. There are 

 in thefe parts feveral considerable quartz-veins, 

 with plenty of native gold, of fine-grained lead- 

 glance, containing fome filver, of pyrites, and 

 fallow copper, and filver-ore. The quartz is fome- 

 times cryftallized, which appeared by feveral 

 cryftallizations penetrated and tinged by copper- 

 azure. The brooks, which from the mountains 

 run over thefe quartz^veins, commonly warn down 

 X large 



