Emily Dickinson Lexicon

MER-CU'RI-AL, a. [From Mercury; L. mercurialis.]

1. Formed under the influence of Mercury; active; sprightly; full of fire or vigor; as, a mercurial youth; a mercurial nation. Bacon. Swift.
2. Pertaining to quicksilver; containing quicksilver, or consisting of mercury; as, mercurial preparations or medicines.
3. Relating to Mercury as god of trade. The mercurial wand of commerce. J. Q. Adams.