Mercurial

a. [Lat. mercurialis, from Mercurius, Mercury; It. mercuriale, Sp. mercurial, Fr. mercuriel.]

1. Having the qualities fabled to belong to Mercury; active; sprightly; full of fire or vigor; as, a mercurial youth; a mercurial nation.
2. Pertaining to Mercury, as god of trade; hence, money-making; crafty. “The mercurial wand of commerce.” J. Q. Adams.
3. Pertaining to quicksilver; containing quicksilver; consisting of mercury; as, mercurial preparations or medicines.