1609 ]

I repeated the experiment, with some variation, think-ing to obtain a more perfect resolution of the emery byvitrefying it with the lead. Two ounces of fine emery,and six ounces of minium, were well mixed together, andurged with a strong fire, in a close crucible, for an hour :they melted into an uniform dark brownish glass. Theglass was powdered, mixed with four ounces of fixt alca-line fait and some powdered charcoal, and put into a freshcrucible, with some common salt on the surface: Thefire was pretty strongly excited, but the fusion was not soperfect as could be wished, and only about two ounces oflead were found revived. This lead had suffered nearlythe same change as that in the foregoing experiment, andlike it, gave no appearance of platina on being cupelled.

It seems to follow from these experiments, that the emeryemployed in them contained no platina; but as it is not tobe supposed that all emerys are of one composition, othersorts may deserve to be submitted to the same trials. A-sgold is contained in some parcels of common minerals, andby no means in all the individuals of any one species; pla-tina may possibly in like manner be found in some Euro-pean ores, though there is not the least footstep of it inother parcels of the fame kind of ore.

SECT. XII.

General Observations.

H E foregoing history has brought us acquainted

JL. with a mineral substance, whose metallic aspect,great weight, malleability, and perfect miscibility with allthe common metallic bodies, are sufficient characters of itsbeing a true metal : — which abides fixt and uncalcinedin the strongest fires, is nowise scorified by nitre, or bylead or bismuth, nor dissolved by vitreous bodies, and which

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