OBSERVATIONS.
The process here delivered is taken from M. Stahl. The design of that ingenious Chymist's inquiry was to discover how Moses could burn the golden calf, which the Israelites had set up and worshipped while he was on the mount; how he could afterwards reduce that calf to powder, throw it into the water which the people used, and make all who had apostatized drink thereof, as related in the Book of Exodus.
M. Stahl, having first observed that Gold is absolutely unalterable and indestructible by the force of fire alone, be it ever so violent, concludes, that without a miracle Moses could not possibly perform the above-mentioned operations on the golden calf any way but by mixing with the Gold some matter qualified to alter and dissolve it. He then takes notice, that pure Sulphur does not act upon Gold at all, and that many other substances, which are thought capable of dividing and dissolving it, cannot however do it so completely as is necessary to render that metal susceptible of the effects related. He then gives the method of dissolving it by Liver of Sulphur, described in the process.
Liver of Sulphur dissolves likewise all the other metals: but M. Stahl observes, that it attenuates Gold more than any other metallic substance, and unites with it much more intimately than with the rest. This appears from what happens, on attempting to dissolve in water any of the mixts resulting from the union of another metal with the Liver of Sulphur: for then the metal separates, and appears in the form of a powder or fine calx; whereas, when Gold is united with Liver of Sulphur, the whole compound dissolves in water so perfectly, that the Gold even passes with the Liver of Sulphur through the pores of filtering paper.
If an Acid be poured into a solution of this combination of Gold with Liver of Sulphur, the Acid unites with the Alkali of the Hepar, and the Gold falls to the bottom of the liquor along with the Sulphur, which doth not quit it. The Sulphur thus precipitated with the Gold is easily carried off by a slight torrefaction, after which the Gold remains exceedingly comminuted. The Sulphur of this compound may also be destroyed by torrefaction, without the trouble of a previous solution and precipitation, and then also the Gold remains so attenuated as to be miscible with liquors, and floats on them, or swims in them, in such a manner that it may easily be swallowed with them in drinking. From all this M. Stahl concludes there is great reason to believe it was by means of the Liver of Sulphur that Moses divided, and in a manner calcined, the golden calf, so that he could mingle it with water, and make the Israelites drink it.
PROCESS IV.
To separate Gold from all other metallic Substances by means of Antimony.
Having put the Gold you intend to purify into a crucible, set it in a melting furnace, cover it, and make the Gold flow. When the metal is in fusion cast upon it, by a little at a time, twice its weight of pure crude Antimony in powder, and after each projection cover the crucible again immediately: this done keep the matter in fusion for a few minutes. When you perceive that the metallic mixture is perfectly melted, and that its surface begins to sparkle, pour it out into a hollow iron cone, previously heated, and smeared on the inside with tallow. Immediately strike with a hammer the floor on which the cone stands; and when all is cold, or at least sufficiently fixed, invert the cone and strike it: the whole metallic mass will fall out, and the under part thereof, which was at the point of the cone, will be a Regulus more or less yellow as the Gold was more or less pure. On striking the metallic mass the Regulus will freely part from the sulphureous crust at top.
Return this Regulus into the crucible, and melt it. Less fire will do now than was required before. Add the same quantity of Antimony, and proceed as at first. Repeat the same operation a third time, if your Gold be very impure.