I'e ANALYSIS OF A MINERAL, &C. 



from muriatic acid by water, is to metallic antimony as 130 i» 

 • 100; therefore, the 63 grains of the oxide muft be eftimated 

 at 4-8.46, grains of the metal. 



Again, fulphate of lead is to metallic lead as 141 to 100; 

 therefore, 120 20 grains of the former are zz 85.24 grains of 

 the latter. And, laftly, black oxide of copper contains 20 

 per cent, of oxygen ; confequently , 32 grains of the black oxide 

 are = 25.60 grains of metallic copper. 

 Component The proportions for 200 grains of the ore, will therefore be, 



^^^^- Sulphur ... - 34, 



Antimony - - . - 48.46 



Lead 85.24 



Iron 2.40 



Copper . - - - 25.60 



195.70 

 Lofs - 4.30 



Ofj per ant. 



Sulphur . - - - 17. 



Antimony - - - - 24.23 



Lead ----- 42.62 

 Iron - - - - - 1.20 



Copper , - - - 12.80 



97.85 

 Lofs - 2.15 



Thefe proportions, I have reafon to believe, are tolerably 

 exad; for I did not obferve any elTential variation in the refults 

 of two other analyfes, which I made of this fubftance, with 

 every poffible precaution. 



The lofs may be principally afcribed to the oxide of anti- 

 mony and fulphate of lead ; but efpecially to the former, 

 which has a great tendency to adhere to filters and glal^ 

 veflels. 



In fome of the preliminary experiments, I obtained a fmall 

 portion of zinc ; but, having received, through the kindnefs of 

 Mr. R. Phillips, of Lombard-flreet, fome pure cryftals of the 

 ore, I found that the zinc had proceeded from blende, which 

 was imperceptibly mixed in the fpecimens which I had firit 

 examined* 



DefcHption 



