C 295 ] 
lently on it, thefe phcenomena ought not to be 
confounded with each other. 
SECT. XXXIII. 
The ores being thus calcined, the metals con-^ 
tained in them may be difeovered, either by being 
melted alone, or with fluxes : when they fhew 
themfelves, either in their pure metallic ftate, or 
by tinging the flag with colours peculiar to each 
of them. In thefe experiments it is not to be ex- 
pe6led, that the quantity of metal contained in 
the ore thould be exaddy determined ; this mufl: 
be done in larger laboratories. This cannot, how- 
ever, be looked upon as any defed, flnee it is luf- 
ficient for a mineralifl, only to find out what fort 
of metal is contained in the ore. There is ano- 
ther circumftance, which I am forry to fay, is a 
more real defed in our little laboratory, which is, 
that fome ores are not at all able to be tried in it, 
by fo fmali an apparatus : for inftance, the gold 
ore called Pyrites aureus^ which confifts of gold, 
iron, and fulphur. The greateft quantity of gold, 
which this ore contains, is about one ounce, or 
one ounce and an half out of one hundred pounds 
pf the ore, the reft being iron and fulphur ; and 
as only a very fmali bit is allowed for thefe experi- 
ments, (Sedl. xvi. xxxi.) the gold contained there- 
in, can hardly be difeerned by the eye, even if it 
could be extraded, but it goes along with the 
iron in the flag, tliis lafl: metal being in fo large a 
quantity in proportion to the other, and botli of 
them having a comniicible power with each other. 
All the kinds of Blende, Blackjack, which are 
rnineralifed zink ores, containing zink, fulphur, 
and iron, cannot be tried this way, becaufe they 
cannon be perfcdly calcined, and befides, the zink 
fiks 
