[ 161 3 
liquor underneath remained coloured as at firff. 
Compofitions of platina and gold being diflolved in 
aqua-regis, and treated in the fame manner, the whole 
of the gold was imbibed by the oil, and the whole 
of the platina remained diflolved in the acid. The 
oil, loaded with the gold, appeared of a fine yellow 
colour, and, on {landing for a few hours, threw off 
great part of its contents, in bright yellow films, to 
the tides of the glafs. Sundry other diftilled oils 
were made trial of, with the fame event. The gold 
is eafily recovered, by fetting the oil on fire ; and, 
when thoroughly burnt out, melting the refiduum 
with borax, as in the preceding experiment. After 
the feparation of the oil employed at firft, it may 
be proper, for the greater fecurity, to add a little 
more ; which, if any part of the gold fhould hap- 
pen to have been left in the liquor, will effectually 
take it up. 
3. The experiment was repeated likewife with 
the fubtile fluid, prepared from vinous fpirits with 
the vitriolic acid, called by the chemifts asther. The 
feparation fucceeded in the fame manner as before ; 
the sether receiving nothing from pure platina, but 
inftantly taking up the gold from a mixture of the 
two. It is obfervable, that the gold imbibed by this 
fluid is kept permanently diflolved by it ; without 
feparating or reviving, as it does from the common 
eflential oils and vinous fpirits. 
4. The liquors remaining in thefe experiments, 
after the extraction of the gold, appear on all trials 
the fame with the common folutions of platina ; 
and readily betray their being impregnated with that 
mineral by their colour, by the precipitation with 
Vol. 50. Y tin, 
