(• 266 ) 



only be excluded from the clafs of volcanic 

 glalTes, but even from that of enamels. 



When, in the year 5789, I made an ex- 

 curfion over the mountains of Padua, in 

 fearch of volcanic objedls, accompanied by 

 the Marchefe Orologio, we, at Praglia, were 

 received and moft hofpitably entertained in 

 the ancient and magnificent monaftery of 

 the Benedidines- by the excellent Father 

 Terzi, who, after dinner, took us into his 

 private cabinet of volcanic-marine products, 

 collected on the Euganean mountains. He 

 prefented us likewife with fome fpecimens, 

 informing us at the fame time where they 

 had been found, which I think deferving of 

 a particular defcription. 



The firfl:, which, according to the ac- 

 count he gave us, was brought from Schi- 

 vanoja, is a mixture of amorphous, white, 

 and friable feltfpar, and black, prifmatic, and 

 extremely brilliant (hoerls, m.uch refembllng 

 fome fpecies of tourmalins. From this mix- 

 ture is obtained, in the furnace, an extreme- 



