mutual solvent
A volatile solvent so called because it is
miscible with more than one class of liquids.
Acetone, for example, is miscible with water,
alcohol, and ether, as well as with oil, alcohol,
or ethereal fluids. Such a material is also known
as a coupling agent because it can cause two
ordinarily immiscible liquids to combine with each
other, forming a clear solution. (233 )