Metals are calcined and, as soon as they have completely lost their metallic sulfur by calcination, the destroyed metal, or rather its components remaining in the fire, is transformed.
This is most commonly achieved by pouring well prepared metallic lime into concentrated hydrochloric acid as described above and digestion in a closed vessel until no trace of a dissolution appears any more. The hydrochloric acid absorbs the metallic salt, it absorbs the coloring earth and forms with it a “sympathetic ink” 30.
The talciform earth is separated from this solution, after leaving it for a few days in a cool place. At the bottom of the vase we find the metallic salt in pretty crystals. They are removed, rinsed with distilled water, and the solution (or sympathetic ink) is allowed to stand until it no longer contains crystals. Then the coloring earth is precipitated by means of pure lye salts which have been dissolved in water, and it is separated from the spirit of salt which, after several new affusions of distilled water, lets it appear visibly, precisely. like the other two parts.
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