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pretty remarkable manner ; tire gold to become dissolublein the pure marine acid, which gold by itself resists; andthe tin to become easily vitrescible, though otherwise itcan scarce be vitrefied at all y I treated platina and tin inthe same manner.

Two parts of the picked grains of platina and threeparts of tin were melted together, the mixture reduced in-to powder in a clean iron mortar, and a hundred and sixtygrains of the powder set in a cupel, under a muffle, insuch a heat as is employed for the cupellation of silver.The cupel being taken out, the matter appeared of a darkpurplish colour, and part of it stuck together into a lump.It was then put into an unglazed porcelain saucer, setagain under the muffle, and stirred every now and thenfor two hours : here and there some grains appeared glow-ing, like bits of burning coal ; a phenomenon which tinusually exhibits in its calcination. The powder, whencold, looked of a mixed greyish-reddish colour, the redprevailing : it weighed thirteen grains more than at first,so that it had gained an increase of about one twelfth, ex-clusive of part of it which had stuck both to the cupel andto the roughiih surface of the unglazed saucer.

A part of the calx was urged in a covered crucible, witha strong fire in a blast furnace, above an hour. It did notin the least melt, and baked together but very slightly : itscolour was darkened almost to a black. Both the red andthe black calces, digested in spirit of salt, gave pretty deepyellow tinctures, like diluted solutions of platina in aquaregiaj whereas neither the grains of platina, nor the tincalcined by itself, give any colour to the acid.

II. Separation of Mercury from platina.

Some quicksilver, which by long trituration with pla-tina had dissolved a part of the metal, was put into an iron

ladle,