64 
Mr. Hatchett’s Analysis of a 
ii. 
If suddenly heated on charcoal, by the blowpipe, it crackles 
and splits ; but, when gradually exposed to the flame, it liquefies, 
and, upon cooling, assumes a dull metallic gray colour. 
When the globule was longer exposed to heat, white fumes 
(which at first had a sulphureous odour) were evolved, and 
partly settled on the charcoal. 
Ebullition prevailed during the discharge of these white fumes ; 
and the globule gradually suffered considerable diminution, re- 
maining at length tranquil, and of a very dark gray colour. 
Upon examination, this appeared to be principally sulphuret 
of lead, which, like a crust, enveloped a minute globule of me- 
tallic copper, so malleable as to bear to be flattened by a hammer. 
hi. 
Some of the ore, finely powdered, was put into a matrass, and 
nitric acid diluted with an equal portion of water was poured 
on it. Upon being digested in a low heat, a considerable part 
was dissolved, with much effervescence. Some sulphur, which 
floated, was separated; and the clear liquor, which was bluish 
green, was decanted from the residuum at the bottom of the 
vessel. 
A great part of the excess of acid being expelled from the 
solution, it was largely diluted with distilled water, and some 
dissolved muriate of soda was added ; but this did not produce 
any alteration in the transparency of the liquor. A solution of 
sulphate of soda was then poured in, and formed a very copious 
precipitate of sulphate of lead. 
When this had been separated, the liquor was saturated with 
ammonia ; by which it was changed to a deep blue colour. A 
