C 306 ] 
afterwards treated in the fame manner as before 
faid, in fpeaking of the grey copper-ores (Se6t. 
xli.), the metal will foon be produced. But, if the 
ore is poor, the produd after the firft fcorification 
muft be brought into fufion, and afterwards melted 
v/ith fome frelh borax, in order to calcine and fco- 
rify the remaining portion of iron ^ after which it 
may be treated as mentioned in Seft, xli* 
The copper will, in this lafl cafe^ be found in a 
very fmall globule. 
SECT. XLIII. 
The copper is not very eafily fcoriffed with this- 
apparatus, when it is melted together with borax 
unlefs it has firft been expofed to the fire by itfelf 
for a while, in order to be calcined. When only 
a little of this metal is diflblved, it inftantly tinges 
the flag of a reddiih brown colour, and moftly 
opaque ; but as foon as this flag is kept in fufion 
for a little while, it becomes quite green and tranf- 
parent : and thus the prefence of the copper may 
be difcovered by the colour, when it is concealed 
in heterogeneous bodies, fo as not to be difcovered 
by any ether experiment. 
SECT. XLIV. 
If metallic copper is melted with borax by a flow 
fire, and only for a very little time, the glafs, or flag.,, 
becomes of a fine tranfparent blue or violet colour, 
inclining more or lefs to the green ^ but this colour 
is not properly owing to the copper, but it may ra- 
ther be to its phlogifton *, becaufe the fame colour 
is to be had in the fame manner from iron : and 
thefe glafles, which are coloured with either of 
thefe two metals, foon lofe their colour, if ex- 
