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Alchemical Symbols - Mineral substances

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Nitre. Saltpeter, Potassium Nitrate. Made by lixiviation. A pile of soil rich in animal dung was exposed to the air (through protected from rain) and a crust of Nitre formed on the windward side of the pile. When purified by recrystallisation this formed a white crystalline powder. It is a powerful oxidising agent. When heated with Vitriol (sulphuric acid), produces the 'strong water' Aqua Fortis (nitric acid).

Quicklime. Produced by burning chalk or limestone. It is a powerful desiccating agent as it reacts strongly with water to produce slaked lime, that is lime whose thirst has been quenched. Calcium Oxide. Pure white powder. Very reactive when heated with most substances.

Sal ammoniac. Ammonium Chloride. Probably originally made from ammonia rich urine and salt. A white granular and fibrous solid, which has the property that it will sublimate at a relatively low temperature. That is, if heated in a flask it will not melt but turn into a white vapour which will rise in the flask and condense in the cooler neck, back to the characteristic fibrous crystals of Sal ammoniac.

Tartar. Found in the lees of wine. Often scraped from the insides of wine barrels. Now known as Potassium Hydrogen Tartrate. When reacted with calcined antimony this formed Tartar Emetic, a powerful emetic used in medicine, though with significant danger, for it is a poisonous substance.

Cinnabar. The main ore of Mercury, from which the metal is extracted by distillation. It is a heavy red powder. Mercuric sulphide. When used as a pigment it is called vermillion.

Marchasite. Iron Pyrites, or Iron disulphide. A hard yellow substance resembling brass. The term Marchasite is also sometimes applied to Bismuth.

Minium. Red Lead, an oxide of Lead.

Litharge. A pale or reddish yellow substance. Lead monoxide.

Realgar. Mineral ore of arsenic. Red brittle vitreous or crystalline solid, which sublimes like Sal ammoniac. Arsenic disulphide.

Orpiment or Auripigment. A bright yellow ore of Arsenic used as a pigment under the name of King's Yellow. Arsenic trisulphide.