[ 647 ] 
no change could be perceiv’d either in it, or in the 
platina. 
3. The glafs being cut off, a little above the li- 
quid, the heat was gradually increas’d, till the liquor, 
which now began to evaporate, had, in five or fix 
hours, totally exhal’d, and the platina become dry, 
and red-hot. When grown cold, wafifd with water, 
and exficcated, it was found exactly of the fame 
weight as at firft, and its grains not divided, or ap- 
parently alter’d. 
Remark. Platina appears therefore to entirely re- 
fill: the vitriolic acid ; which, by one or other of the 
above proceffes,diffolves or corrodes every other known 
metallic body except gold. 
Experiment 2. 
Platina with the Marine Acid. 
1. Weak and ffrong fpirits of fait being digefied, 
feparately, with one-third their weight of platina, in 
a gentle heat, for feveral hours, the liquors remain'd 
uncolour’d, the platina unalter’d, and undiminilh'd. 
The heat was afterwards increas’d, and the liquors 
kept ffrongly boiling till they had totally exhal’d, 
without occafioning any fenfible change in the pla- 
tina. 
2. Three ounces of a mixture of two parts decre- 
pitated fea-falt and three parts of vitriol highly cal- 
'cin’d, were prefs’d fmooth into a crucible ; an ounce 
of platina fpread evenly upon the furface, and cover’d 
with fome more of the mixture ; the crucible clofely 
luted, and kept in a moderate red heat for feveral 
hours. On examining it when grown cold, the faline 
2 mixture 
