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Alchemy symbols. Historical artwork of alchemy symbols and their explanation, taken from an 18th- century German publication. The chemicals shown are potassium nitrate (salpeter), copper (koper), ammonium chloride (salarmonacum), allaun verlecht (a metal alloy), sodium choride (salcomunis), mercury (queck silber) and sulphur (sulphur). Alchemy was the pseudo-scientific predecessor to chemistry, which among other ideas is best known for its practitioners' hunt for the Philosopher's Stone, which would impart eternal life and the ability to turn base metals into gold.
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