A symbol used by alchemists to represent horse dung.
Horse dung was used in the process of Digestion and Putrification, both of which involve putting the substance in a flask submerged up to the neck in a barrel of rotting horse dung. The dung, which produces heat as it decomposes, will maintain a steady temperature at about 120°F, encouraging chemical reactions in the flask.
Modern equipment allows for more sanitary means of incubating substances for long periods of time.
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