6o 
MINERALOGICAL 
of copper than the common alkaline 
fluxes: but the analyfis of copper ores 
In the moift way, according to the fol¬ 
lowing experiments, is /till the moft ac¬ 
curate. 
(a) Half an ounce of this copper ore, 
pulverized, and properly calcined, loft 
14 grains. It was then mixed with an 
equal weight of calcined borax, half 
its weight of white pounded glafs, and 
1-4th of rofin; and after all, being 
gradually heated in a crucible lined 
with charcoal, covered with common 
fait, was melted in a ftrong heat during 
half an hour. Under an uniformly 
fufed blackifh grey fcoria was found a 
globule of copper, which weighed 71 
grains, which is 29^ in 100. 
(b) Upon half an ounce of the fame 
copper ore, calcined, was poured two 
ounces of ftrong concentrated acid of 
vitriol. The mixture was diftilled to 
drynefs: what remained was wafhed with 
water, the folution filtred, and the cop¬ 
per 
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