%

[ 6o 3 ]

quantity os whitish powder, probably silver, remaining atthe bottom of the vessel. The gold-coloured solution be-ing poured into a solution of green vitriol, a precipitatelike that of gold soon fell. Aster standing till next day,that the precipitate might fully settle, greatest part of theliquor was decanted off, and the remainder, with the pre-cipitate, poured upon a filter: when the liquor had runthrough, the powder was washed on the filter with freshportions of water. When dry, the filter with the preci-pitate were put into an assay crucible, and kept red hot till.no more flame or smoke appeared. Some nitre was thenthrown in by little and little : at first a flight figurationarose ; at length the whole appeared in quiet fusion, andbeing poured out into a mould, I obtained a lump of highcoloured, malleable, pure gold, weighing between eighteenand nineteen grains.

SECT. XL

Of the mineral hijlory of Plat in a.

O F the mineral history of this metal very little is asyet known with any certainty. Though new toEurope, the history even of its discovery is as obscure asthat of the metals of most ancient use : it may be pre-sumed, that the little advantage which promised to resultfrom it, on account of its want of fusibility, occasioned itat first to be neglected •, and that the fraudulent purposes,to which it was afterwards found to be applicable, occa-sioned the knowledge of it to be concealed.

It is supposed by some, that platina is the produce of theEast Indies as well as of theWest, and that its analogy withgold has been known also for a considerable time in theformer as well as in the latter. The foundation of thissuspicion is, that the late professor s’Gravesande had in his

I i i i possession