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and solution os chalk in aqua fortis, were found by Marg-graf to produce no precipitation or apparent change in di-luted solution of platina.

Sal ammoniac, one of the ingredients to which the men-struum owed its power of dissolving the platina at first,precipitated great part of it in form of a reddish or yellow-ish powder, nearly similar to that thrown down by alcalies.It is observable, that though neither sal ammoniac nor al-calies, separately, occasioned a complete precipitation, theliquor still remaining of a high colour ; yet when one wasadded to the solution remaining after the action of theother, a new precipitate fell, which left the liquorcolourless.

X. Solution of platina, with vinous spirits.

As gold is revived from its solutions by vinous spirits,and made to rife in yellow films to the surface; I mixeda solution of platina with a large proportion of highlyrectified spirit of wine, and exposed the mixture for manydays to the fun, in a wide-mouthed glass slightly coveredwith paper to keep out dust: there was no appearance ofany yellow skin, nor was any other alteration perceived,than that the platina had begun to crystallize from theevaporation of the fluid.

Suspecting that though the liquor should really containgold, yet the platina might strongly retain the gold andprevent its being separated by the spirit, I mixed three orfour drops of solution of gold with two hundred drops ofsolution of platina, and after shaking them well together,added some rectified spirit of wine: the whole being ex-posed as above to the fun, a golden film was in a few daysobserved upon the surface.

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XI. Solution