When almost any organic substance—for example, wood, flesh, hair, leaves, eggs—is gradually heated, various materials are driven off sequentially by the heat, leaving behind a solid residue. Jābir interprets this practical experiment as the separation of a compound substance into its component elements. The “fire” distills off as a flammable and/or colored substance, the “air” as an oily one, and the “water” as a watery one; the “earth” remains behind as the residue.
