fondonEtymologyCompare French fondant (“flux”).nounA large copper vessel used for hot amalgamation.“The diameter of the copper bottom of the fondon is from 5 feet 6 inches to 7 feet 6 inches, and, instead of the necessary motion being imparted to the charge by a wooden stirrer, worked by hand, it is obtained by blocks of copper dragged over the bottom by an arrangement similar to the arms of an arrastra.”