[8] “Smith coal is nothing else than that of the blacksmith or brewer’s coal; and grind it with clean rainwater; that one must temper with fairly short gum water and is then reasonably fluid to use in several ways, as seen here.” Boogert. 1692. Klaer lightende Spiegel der Verfkonst, Bibliothèque Méjanes in Aix-en-Provence, MS 1389 (1228): Without page number.