ON A NATURAL SYSTEM 



Metals occur generally either complete, mi- 

 neralized, or deprived of their phlogifton. 



i c x L v i . Na five Metals. 



WHATEVER pofleflesa complete metallic form, 

 js denominated native. 



Into this (late no heterogeneous Jubilances are 

 admitted, unlefs they are perfectly metallic. 

 Hence arife various fpecies; the metal native 

 andfimple; combined with fome other; or 

 with feveral together. Native fimple metals 

 are very rare, and, as far as I know, have 

 never yet been difcovered perfectly pure. 



Mod metals are occafionally found native, as 

 gold, platinum, filver, quick-filver, copper, 

 bifmuth, niccolum, arfenic, cobalt,, and anti- 

 mony ; but fearce anyone of them occurs quite 

 pure. Cold is mixed with filver or copper; (il- 

 ver with gold or copper; platinum with iron; 

 niccolum and cobalt with arienic as well as iron; 

 antimony with iron or zinc; and further expe- 

 riments will without doubt difcover other com- 

 binations. 



The exigence of native lead, iron tin, and 

 7/i nc has been always much qucflionrd by ma- 

 ny. 



Magncfium and fiderite have never yet been 

 found in a native Hate. 



