[ 6 4S ] 
2. We likewife varied the experiment, inje&ing 
repeatedly pieces of fulphur upon platina ftrongly 
heated ; and conftantly found, that pure fulphur had 
no more effect upon this mineral than on gold itfelf. 
3. As fix’d alcaline falts enable fulphur to diflolve 
gold ; platina was expos’d to the fire with a mixture 
of fulphur and alcali, call’d hepar julphur is. After a 
confiderable heat had been continu’d for fome time, 
and the matter occasionally ftirr’d, very little of the 
platina was found remaining in its proper form ; 
the greateft part being taken up by the fulphureo- 
faline mixture, fo as to diflolve along with it in 
water. 
General Remarks. 
It appears, from the foregoing experiments and 
observations, 
1. That probably this mineral is originally found in 
large, hard mafles, compos’d of true platina, a fub* 
fiance Similar to the black Virginia fand, and another 
ferruginous matter of the emery kind, lome Spar, 
and particles of gold. 
2. That thefe mafles are, not without great labour, 
deduced into Small grains, which are afterwards 
ground with mercury, in order to extradt the gold. 
3. That the pure platina is a white metallic fub- 
fiance, in fome fmall degree malleable : that it is 
nearly as ponderous as gold, equally fix’d and per- 
manent in the fire, equally indeftrudtible by nitre, 
unaffected by fulphur, diffoluble by hepar fulphur is * 
That it is not to be brought into fufion by the great- 
eft degree of fire procurable in the ordinary furnaces^ 
whether expos’d to its adtion in clofe veffels, or in 
contaCt with the fuel ; by itfelf, or with the addition 
of inflammable, Saline, vitreous or earthy fluxes. 
XL Ex- 
