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oils appear to be more sluggish than the aether in takinglip the gold, and hence require to be well shaken withthe solution. ,

Rectified spirit of wine mingles uniformly with theacid solution, and does not, for a time, occasion anyother apparent change than rendering its colour moredilute. When the solution of gold has been inspissatedto dryness, the metal, with the acid that remains com-bined with it, dissolves in spirit of wine : if the men-struum was either the pure marine acid, or a mixture ofthe pure nitrous and marine acids, or a mixture of thenitrous acid and sal ammoniac, the inspissated matter dis-solves totally in the vinous spirit : if the aqua regia wasmade by dissolving sea fait in aqua fortis, or by dissol-ving nitre in spirit of fait, the neutral saline com-pounds contained in these menstrua not being disso-luble in vinous spirits, remain perfectly white afterthe extraction of the gold. From all these mixtures,as from essential oils, the gold separates by degrees, thoughless speedily. On standing for some days, especially ifthe glass is but lightly covered, the metal is seen floatingin fine bright yellow pellicles upon the surface. Theaddition of a little essential oil to the spirit hastens theseparation of the gold.

Here it may be observed, that many of those, whohave busied themselves in the pursuit of medicinal pre-parations from gold, have been greatly deceived in theresult of their operations, from not being acquaintedwith the above properties of the metal. Finding that es-sential oils imbibe gold from aqua regia, and receive withthe gold a high colour, and that rectified spirit of wine,by digestion with the oil, dissolves it, and becomes im-pregnated with its colour; they imagined they had thusobtained an aurum potabile, or true tincture of the gold,

which