[ 6 55 ] 
1. A folution of platina was mix’d with a large 
proportion of highly-redtified fpirit of wine, and ex- 
pos’d for many days to the fun, in a wide-mouth’d 
glafs, flightly cover’d with paper, fo as to keep out 
duft. There was no appearance of any yellow Ikin j 
nor any other alteration, than that the platina had be- 
gun to cryftallize from the evaporation of the fluid. 
2. A drop or two of a folution of gold being 
added to a large quantity of a mixture of folution of 
platina and fpirit of wine, and the whole expos’d as 
above to the fun ; a golden film was in a few days 
obferv’d upon the fur face. 
Remark. It follows from this experiment, and 
the foregoing one with tin, that platina contains no 
gold and that it cannot, any more than the common 
metallic or other foluble fubftances, prevent a fmall 
proportion of gold mix’d with it from being dis- 
coverable. 
Experiment 6. 
j. The fpirits of fal ammoniac, prepar’d both by 
quicklime and by fix’d alcaline falts, added to fo- 
lutions of platina diluted with diftill’d water, preci- 
pitated a fine red fparkling powder j which, exfic- 
cated, and expos’d to the fire in an iron ladle, became 
blackilh ; without at all fulminating, which calces 
of gold, prepar’d in the fame manner, do violently. 
On walhing fome of this precipitate upon a filter, by 
repeated affufions of water, the greateft part of it dif- 
folv’d ; only a fmall quantity of a blackilh matter 
remaining, and the liquor palling through of a deep, 
bright, golden colour, A very large quantity of the 
