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cipitate of the same appearance with that which tin throwsdown from common solutions of platina. The rest of thepowder was cupelled with lead: it left a rough, flatted,bright mass, which would no longer melt, and which ex-actly resembled those obtained in cupelling crude platinawith lead.

Mercury is supposed to have a greater affinity to leadthan to any other metallic body, gold and silver excepted.In this experiment it (hewed a greater affinity to platinathan to lead, since it retained much of the platina, afterthe lead, which was at first in much larger proportion,had been almost all thrown out.

II. Mercury:

Gold:

Platina.

A mixture of one part of platina and two of gold,which proved very white and brittle, was well nealed, andcautiously flatted into thin plates, which were thrown redhot into boiling quicksilver. On grinding and washingwith water, a powder separated, copiously at first, and bydegrees more sparingly. After the process had been con-tinued about twenty-four hours, there was no further se-paration, except of a little blackish matter into which apart of the mercury itself is always changed in these kindsof operations. The amalgam, which looked bright, wasput into a crucible, and the quicksilver being evaporatedby moderate heat, there remained a spongy mass, of a highcolour, which being melted and cast into an ingot, provedvery soft and malleable, and not distinguishable by the eyefrom the pure gold made use of. How far this process isapplicable to the separation of platina from gold in theway of business, will be considered in the following section.It is sufficient here to have established the greater affinity

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