[ 495 J

In regard to the pretensions to the obtaining of gold bythis process, it is' not perhaps unreasonable to suppose,that the remarkable separation of powdery matter in thecementation, and the appearance os some golden grainswhich had been naturally intermingled among those ofthe platina, led men of warm imaginations to anticipatethe further effect of the process, and to make the affertionwhich the above experiments overturn.

IV. Platina with commonsalt.

A n ounce of common fait, dried, was kept in fusionwith a dram of platina, in a close crucible, for an hourand a half. The salt appeared yellowish, and on breakingthe mass, there were found m the middle of it some redcrystalline grains. The platina was all at the bottom ofthe crucible, and preserved its figure, having suffered nochange, except being made very white. The experimentwas repeated with what is called regenerated commonsalt, and the phenomena were exactly the same. Boththese experiments are from Marggraf.

V. Platina with vitriolic salts.

Marggraf mixed a dram of platina with somepure Glaubers sal mirabilc, and kept the mixture in astrong fire for two'hours: the salt sunk through the cru-cible, and left the platina of a dark grey colour: onwaihing the platina with water, and rubbing it in a glassmortar, there separated ‘a little light matter of a brightblackish colour, and what remained was platina un-changed. A dram of platina, and an ounce of vitriolatedtartar, were treated in the same manner: the salt meltedand became reddish; the platina suffered no change, ex-kept that it looked somewhat more grey.

VI. Platina