Beaumontague is a composition of iron borings, brimstone, pitch, sal-ammoniac, rosin, and beeswax, which is used to fill up cracks and flaws in an iron casting, to give an appearance of solidity.
Beaumontague
Chambers's Encyclopaedia, Volume 2: Beaugency to Cataract, p. 3
Source scan(s): p. 0012