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from the experiment, that platina is a great deal moredifficult of fusion than flint, and flint a great deal more sothan gypsum; and as no means have been found of push-ing common fire to such a height, as to produce either in'flint or gypsum the least appearance of fusion, without theconcurrence of the saline or earthy parts of the fuel,which serve as a flux for those bodies, though not forplatina; there appears no room to hope, as the authorseems to do towards the end of his memoir, that we shallever be able to melt platina in great furnaces. It followsalso, that the melted drops, which both Mr. Macquer andI obtained in our furnaces, could not be pure platina : forthough it is not to be thought that our sires were of equalintensity with that to which the platina was here exposed,,our drops had suffered a more perfect fusion, than thoseparts appear to have done that were melted in the focusof the burning-glass : the drops likewise had nothing oftire malleability, which platina melted by the burning-glass is laid to poisess in so remarkable a degree, but onthe contrary fell in powder under the hammer. If thefusion in one case was brought about by the mixture ofsome foreign metallic matter with the platina, we cannotbe certain but in the other also the same cause may haveconcurred in a less degree; and consequently it is possiblethat pure platina may require for its fusion a heat stillmore vehement.

From the experiments related in this section I think itmay be concluded, that platina is a silver-coloured metal,of considerable ductility, not fusible by the strongest fits,that can be excited in the furnaces, or sustained by the-vessels, of the chemist or the workman; that it approaches-to gold in one of the reputedly most discriminating cha-racters of that metal, specific weight; and that it agreeswith gold and silver in being fixt and uncalcinable by fire.

SECT,