Nine Books on the Nature of Things

The death and mortification of metals is the removal of their bodily structure and sulphurous fatness, which can be taken from them in many ways: by calcination, reverberation, dissolution, cementation and sublimation. Metallic calcination is of more than one kind. One occurs through salt, one through sulphur, one through aquae fortes, and one through common Mercury and living Mercury. Calcination through salt requires the metal to be beaten into extremely thin plates, layered with salt and cemented. For calcination through sulphur, the metal is beaten into plates, layered with sulphur and reverberated. Through aquae fortes, it is granulated, dissolved in aqua fortis and precipitated in it. Calcination through common Mercury likewise requires metal plates: place Mercury in an earthen vessel narrow above and broad below, then in a moderate charcoal fire gently blown until Mercury begins to fume and a white cloud emerges from the vessel’s mouth. Put the plated metal over its mouth: common Mercury penetrates it and makes it brittle like coal. Calcination through living Mercury requires the metal to be cut into small pieces, beaten into plates or granulated and amalgamated with Mercury. Afterward squeeze the Mercury through a skin, and the metal remains in the skin in the form of calx or sand.