[ S 8o ]

.of mercury, to gold than platina, and to platina thanlead i

III. Platina:

Lead:

Iron.

One ounce of a mixture of iron and platina, and twoounces of lead, were covered with black flux, and urgedwith a pretty strong fire, but which did not prove sufficientfor the fusion of the platina and iron: the lead beingpoured off into a cylindrical mould, the lower part of thecylinder looked of a duller hue than the lead was at first,and proved specifically heavier, in the proportion of 11,598to 11,386. The lumps of iron and platina were mixedwith the lead a second time, and exposed to a strong firetill the whole came into perfect fusion: on cooling thecrucible too hastily in water, the fluid matter exploded andthrew off the cover, and the lead was found reduced intosmall filaments, filling the crucible, which before was notone fourth part full. The iron regulus at the bottom wasin a round, smooth, very hard lump, and seemed to retain,a considerable portion of the platina. The lead, meltedinto a mass with a little resin, appeared, from its specificgravity, and more manifestly on cupellation, to have im-bibed more of the platina than the iron retained.

Cast iron being dropt into a melted mixture of platina'and lead covered with black flux, and the sire kept upstrong till the iron melted, most of the platina appeared tobe retained by the lead, and very little if any of it to betaken up by the iron. It was judged at first that this didnot happen from the platina having less affinity to ironthan to lead, but from its not having come sufficiently incontact with the iron; for we have elsewhere seen thatgreat part. of the platina finks to the bottom even of th©lead, and the iron floats on the surface of the lead.

A. mixture