Category:Menstruum

Men"stru*um, n.; pl. E. Menstruums, L. Menstrua. Etym: [L. menstruus. See Menstruous.]

Defn: Any substance which dissolves a solid body; a solvent. The proper menstruum to dissolve metal. Bacon. All liquors are called menstruums which are used as dissolvents, or to extract the virtues of ingredients by infusion or decoction. Quincy.

Note: The use is supposed to have originated in some notion of the old chemists about the influence of the moon in the preparation of dissolvents. Johnson.