BEAD-PROOF, a term used by our distillers to express that sort of proof of the standard strength of spirituous liquors which consists in their exhibiting, when shaken in a phial or poured into a glass, a crown of bubbles on the surface for some time thereafter. This, however, is a fallacious rule as to the degree of strength, because any thing that increases the tenacity of the spirit will give it this proof, although it be under the due strength.