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uncoloured, and left the metal white and bright. Thepowders separated in the cementation were treated in thesame manner, and the sublimation repeated thirty timeswith fresh quantities of the salt: in the first sublimations,ferrugineous yellow flowers arose, but at last the salt re-ceived no tinge, and the powder remained of a greyishcolour.

Mr. Marggras gives an account of an experiment of thefame kind, in which he takes notice of some phenomena,which either did not occur, or were not attended to, inmine. He threw into a red hot crucible four, ounces ofnitre, and one ounce, or four hundred and eighty grains, ofplatina : no detonation happened, but a considerable fumearose. The fire being continued, with care to prevent thefalling in of any piece of coal, the matter, after some time,,begun to swell up, and a portion of it being taken outlooked greenish : it afterwards turned to a deep olive green,and grew considerably tough and thick : aster some hoursof strong fire, it proved as thick as pap. The thick mat-ter was taken out while hot with an iron spatula : it wasof a deep oiive-green colour. As much as possible of whatadhered to the crucible was collected, and set to digestwith the other in distilled water : next day the whole wasas thick as gel!y. Being then diluted with more water,stirred about, and suffered to settle, the liquid was pouredoff, and this repeated till all the lighter parts were washedover : this light matter, separated from the saline liquorby filtration, well washed on the filter with hot water, anddried, weighed two hundred and twenty-five grams : itwas of a dark grey colour, and by strong calcination undera muffle became black like pitch. The more ponderouspart was ground in a glass mortar, by which some morebecame fine enough to be washed over : this was of a clearbrown colour, and amounted to thirty grains. The pla-tina ,