ON A NATURAL SYSTEM 



J CLVI. T&e different Species of Met ah admit of 

 a/mo/l fiumberlefs Variations. 



WHOEVER, confidcrs, that we arc acquainted 

 already with fixteen metals, and that of theft 

 the greater number of the perfed can be in fe- 

 veral ways combined together, as well as thofe 

 mineralifed by fulphur and various acids, will 

 naturally exped that, by means of accurate ana- 

 lyfes, many more fpecies might be difcovered, 

 which have as yet probably efcaped the re- 

 fenrches of the laborious philofopher. Were we 

 to purfue the plan applied to the earths, (Scxliii.) 

 the number would be really aftonifhing ; but I 

 am almoft of Pliny's c pinion, who ibmewhcrc 

 confcflcs : " Mihi contucnti fcfe pcrluafit re- 

 " rum nutura nihil incrcdibilc exillimare de ca." 

 FormuLT, indeed, point out to us what may be 

 done; but whether, and where, they are employ, 

 ed, mu ft be learned from a faithful analyfis ; 

 which aflifls us, beiidcs, better to underftnnd 

 thofe of them that prcfcribe the true limits to 

 our invefligations. 



J CLVII. Spifcies fjf Fbhg \Jlic Sub/lances. 



THE fourth clafs is exceedingly poor both in 

 genera and fpecies. 



tCLVIJI. 



