3- In the history of the fusion of platina with lead it hasbeen observed, that lead deposites, in a gentle heat, greatpart of the platina which had been united with it in astrong one. As the part which remains suspended in thelead, might be suspected to differ from that which subsides,a quantity of lead was decanted from fresh parcels of pla-tina in a heat below ignition, and both the decanted metaland the residuums submitted to cupellation separately.The event was the same in all; the metal becoming con-sistent after the lead had been worked off to a certain point,and refusing further scorification.

4. Mixtures of platina and lead, which had been cupelledin an assay furnace as long as they could be kept fluid,were exposed to stronger fires in a blast furnace, by them-selves, with powdered charcoal, with black flux, with bo-rax, with nitre, and with common salt. None of themperfectly melted, or suffered any considerable alteration;they only became somewhat more porous, probably fromthe exudation of some of the lead and a partial liquefactionor .softening of the mass. The immediate contact of burn-ing fuel, agitated by bellows, made some of these mixturesflow after they had refused to melt in crucibles acted onby intense fires : the beads by this means became some-what neater and more compact, but very little of the leadwas separated.

5. The cupelled beads were in general brittle, breakingeasily under the hammer, without stretching in any con-siderable degree. They were of a grey colour both on theupper surface and in the fracture, but pretty bright andwhite on the lower surface, and when ground or filed:they had nothing of the purplish hue, which the mixturesof platina and lead (page 515) had in so remarkable a de-gree; nor does their colour appear anywise altered afterkeeping for ten years in the same circumstances in which

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