[ 53 3 



acids 1 , but not in aqua regia; unalterable by 

 fire. 



a. It is often found native or pure, generally 

 of about fixteen carats ftandard. 



b. Minera argehti vitrea, or glafs filver ore, of 

 a dark color like lead ore, is ductile, and con- 

 tains fulphur. 



c. Minera argenti cornea, or horn ore, refem- 

 bling refin in color, and containing arfenic. 



d. Minera argenti rubra, red filver ore, a brit- 

 tle red-colored ore, containing arfenic and ful- 

 phur. 



e. Minera argenti alba, white filver ore com- 

 bined with arfenic, antimony, fulphur and cop- 

 per, containing more copper than filver, of a 

 light grey color, and of a dull fteel-grained 

 texture. 



Silver is found in all countries, but mod 

 plentifully in America, particularly in Peru and 

 Potofi. 



C. Copper, when pure, is near nine times 

 heavier than water, the moll fonorous of all 

 metals, dilTolves in all acids and alkaline folu- 

 tions, oils and water. The leaft quantity of 

 this metal in folution, turns blue by the ad- 

 dition of volatile alkali united with calamine it 

 forms brafs - 9 with tin, bell-metal. 



a. Native or virgin copper, malleable, fibrous •, 

 generally found adhering to other folHl fub- 

 ftances. 



Ziment copper, precipitated from the vitriolic 

 acid \ is granulated and friable. 



b. Mountain- blue, " Copper united with calca- 

 reous earth, diffolved and precipitated from an 

 alkaline menftruum." Lapis lazuli is reckoned 



E 3 an 



