"I answer, and proudly maintain, "That this increase of weight comes from the air, thickened and made heavy, and in some measure rendered adhesive in the vessel by the violent and long—continued heat of the furnace—which air mixes with the calx (its union being assisted by the continual stirring), and attaches itself to its smallest particles—no otherwise than as water, when sand is thrown into it, makes it heavier by moistening it, and adhering to its smallest grains.""