68 
Mr. Hatchett’s Analysis of a 
Grains. 
A. Sulphur - 
34 - 
B. Oxide of antimony 
63. 
C. Sulphate of lead 
120.20 
D. Iron - 
2.40 
E. Black oxide of copper 
32. 
But the metals composing this triple sulphuret are evidently 
in the metallic state ; and white oxide of antimony precipitated 
from muriatic acid by water, is to metallic antimony as 130 to 
100 ; therefore, the 63 grains of the oxide must be estimated at 
48.46, grains of the metal. 
Again, sulphate of lead is to metallic lead as 141 to 100; 
therefore, 120.20 grains of the former are = 85.24 grains of the 
latter. And, lastly, black oxide of copper contains 20 per cent. 
of oxygen; consequently, 32 grains of the black oxide are =1 
25.60 grains of metallic copper. 
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 
1957 ° 
Loss - 4.30 
Or, per cent. 
Sulphur 
17. 
Antimony 
24.23 
Lead 
42.62 
Iron 
1.20 
Copper 
12.80 
9 7-85 
Loss - 2.15 
