Mercury hath a greater affinity with the Marine than with the Nitrous Acid. The affinity which Mercury hath with the Marine Acid is also greater than that of Gold with the Marine Acid; for unless this Acid be associated either with the Nitrous Acid, or at least with a certain proportion of Phlogiston, it will not dissolve Gold. Hence it comes, that when a solution of Mercury in the Nitrous Acid is dropped into a solution of Gold in _aqua regis_, the Mercury unites with the Acid of Sea-salt, which is an ingredient in the _aqua regis_: but the Marine Acid cannot on this occasion join the Mercury, without deserting the Gold and the Nitrous Acid with which it was united; and then the Gold, which cannot be kept in solution by the Nitrous Acid alone, is forced to quit its solvent and precipitate. The liquor, therefore, that now floats over the Gold thus precipitated, must contain Mercury united with the Acid of Sea-salt: and in fact it yields a true Corrosive Sublimate, which is known to be a combination of Mercury with the Marine Acid. Mercury dissolved in Spirit of Nitre is employed to procure the precipitation we are speaking of; because metallic substances, when so comminuted by an Acid, are much fitter for such experiments than when they are in a concrete form. Gold precipitated in this manner by a metallic substance doth not fulminate. PROCESS III. _To dissolve Gold by Liver of Sulphur._ Mix together equal parts of common Brimstone, and a very strong Fixed Alkali; for instance, Nitre fixed by Charcoal. Put them in a crucible, and melt the mixture, stirring it from time to time with a small rod. There is no occasion to make the fire very brisk; because the Sulphur facilitates the fusion of the Fixed Alkali. Some sulphureous vapours will rise from the crucible; the two substances will mix intimately together, and form a reddish compound. Then throw into the crucible some little pieces of Gold beat into thin plates, so that the whole do not exceed in weight one third part of the Liver of Sulphur: raise the fire a little. As soon as the Liver of Sulphur is perfectly melted, it will begin to dissolve the Gold with ebullition; and will even emit some flashes of fire. In the space of a few minutes the Gold will be entirely dissolved, especially if it was cut and flatted into small thin leaves. _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.