OBSERVATIONS. 6l 
per precipitated by a poliihed iron. The 
quantity of copper now obtained was 
J 35 g ra i ns > or 5 &T i n IO °* Thefe 135 
grains melted with the above-mentioned 
flux, gave a globule of copper which 
weighed 133 grains. 
Grey Cobalt Ore from Dol-coth. 
§ i- 
(a) Half an ounce of this cobalt-ore 
reduced to a fubtile powder, was gradu¬ 
ally diflolved in aqua regia, made of 
equal parts of nitrous and marine acid. 
The folution was brilkly performed, very 
frequent red vapors being expelled, and 
only a grey muddy refiduum, 17 grain 
in weight was left $ this deflagrated 
upon charcoal with a flame, and fmelled 
at firft like fulphur, but afterwards 
{ 
like arfenic ; fome earth remained. 
(b) The 
m 
