[ 57° I

transparent, like Macquers. The platina was in a fiatcake, coated with the semivitrified matter of the cupeland glassy drops from the muffle, so that nothing could beiudged from the weight: it broke pretty easily under thehammer, and did not seem to differ from that of formercupellations.

16. What was here wanting in the continuance, I en-deavoured to supply by a repetition of the fire. The pla-tina, pounded and waffled, was placed under a fresh muf-fle, on a scorifying dish; and the heat kept up in its fullviolence, chiefly with wood and charcoal, for fourteenhours. Greatest part of the platina stuck so firmly tothe diffl, in virtue of part of the lead which had exudedand vitrefied, as not to be got off without pounding thevessel. Where the platina on the diffl was struck with ahammer, or rubbed with a steel burnisher, it stretched, andacquired a continuous surface like silver or tin leaf. Afterthe powder had been passed through a fine sieve, and waffl-ed, on beating it again some broad flat grains appeared,which stretched easily under the hammer, and on beingsqueezed with a pair of plyers, bent almost double : oneof these bore to be opened, and bent again in several di-rections, without cracking. This powder, whose particlesappeared so ductile and flexible, I tried to reunite into amass, by urging it with a vehement sire, in a covered cru-cible, for four hours : it cohered into a button, of the formof the crucible, not at all sticking to the vessel, and freefrom discolourment: the button broke from a blow or twoof a hammer, but not very easily, filed tolerably smooth,and burnished like fine silver.

17. I cupelled four parcels of platina, with thrice theirquantity of lead, till they would no longer continue fluidin a good assay furnace ; and repeated the cupellation onfresh cupels, with the fame quantity of lead, a second and

a third