mercurial

Etymology

Noun sense 1 (“(obsolete) plant known as mercury”) is from Middle English mercurial, from Anglo-Norman mercurial and Old French mercurial, or directly from their etymon, from Mercurius (“the Roman god Mercury”) + -ālis (suffix forming adjectives of relationship from nouns). Later adjective and noun uses may have been directly derived from Latin mercuriālis, whence Middle English mercurial (“under the astrological influence of the planet Mercury”).

noun

1. (obsolete) Any of the plants known as mercury, especially the annual mercury or French mercury (Mercurialis annua).
2. (astrology) A person born under the influence of the planet Mercury; hence, a person having an animated, lively, quick-witted or volatile character.
3. (chemistry) A chemical compound containing mercury.
4. (pharmacology, historical) A preparation of mercury, especially as a treatment for syphilis.
   She had paſſed through the milder Remedies frequently without ſucceſs: upon which account I deſigned Mercurialls; and beginning with Venæſection, afterwards purged her with decoct. epithymi, as it is preſcribed in the method of Cure. … After I had thus evacuated the Plethora, and diſpoſed her body for Mercurialls more operative, I gave her each morning and evening a few grains of Mercur. diaphoret. in a bolus with conſ. lujule and Mithridate, … 1676, Richard Wiseman, “Of Lepra, or Elephantiasis”, in Several Chirurgicall Treatises, London: Printed by E. Flesher and J[ohn] Macock, for R[ichard] Royston[…], and B[enjamin] Took[…], →OCLC, 1st book (A Treatise of Tumours), page 139
   [A] small dose of the mercurial may cause excessive salivation; and, if this discharge be attended by much soreness of throat, it is most difficult to determine whether the salivation is actually the result of the mercurial, or merely symptomatic of the sore throat and cold. If it proceed from the mercurial, there will generally be some tenderness of the gums, a soft and flabby state of the sides of the tongue, and it will generally be more obstinate. 1858, James Copland, “POISONS—Poisoning—Poisoned—Symptoms and Treatment of”, in A Dictionary of Practical Medicine. […] In Three Volumes, volume III, part I, London: Longman, Brown, Green, Longmans, & Roberts, →OCLC, paragraph 580, pages 413–414

adj

1. (comparable) Having a lively or volatile character; animated, changeable, quick-witted.
   his mercurial temperament
   [Y]our Mercuriall wit hath mangonized a Gigantean fury with an humble hue. 1642, Thomas Barton, “Section II”, in ΑΠΟΔΕΙΞΙΣ ΤΟΥ ΑΝΤΙΤΕΙΧΙΣΜΑΤΟΣ. [APODEIXIS TOU ANTITEICHISMATOS.] Or, A Tryall of the Covnter-scarfe, Made 1642.[…], London: Printed by Thomas Purslow, for Andrew Crooke,[…], published 1643, →OCLC, page 16
   When the ſoule bringeth its fire deſire out of its owne ſelfe-will into the Love-deſire of God; and goeth out of its owne ſelfneſſe, and ſinketh into the mercy and compaſſion of God, and caſteth it ſelfe into the death of Chriſt; and willeth no longer the fire-ſource, but deſireth in its fire-life to be dead in the death of Chriſt; then the poyſon of the Mercuriall life dyeth in the will of iniquity, and there ariſeth a new twigge, and budding of love-deſire. 1649, Jacob Behmen [i.e., Jakob Böhme], “The Nineteenth Epistle”, in J[ohn] E[llistone], transl., The Epistles of Jacob Behmen: Aliter, Tevtonicvs Philosophvs. […] Translated out of the German Language, London: Printed by Matthew Simmons[…], →OCLC, paragraph 24, page 149
   From the natural Mercurial Briskneſs of her Sally Salisbury's] Temper, a ſedentary Life had ever been her Averſion, wherefore ſhe rather choſe to follow the Fortunes of a Wheel-Barrow, than thoſe of a Diſtaff; … 1723, Charles Walker, “Of Her Birth, Education, and First Setting Out in the World”, in Authentick Memoirs of the Life Intrigues and Adventures of the Celebrated Sally Salisbury.[…], London: [s.n.], →OCLC, pages 11–12
   Lebanon has shown once again that it is a land of dazzling deals and mercurial personalities, including in the realm of the national presidency itself. 22 October 2016, Rami G[eorge] Khouri, “Lebanese Oligarchy Preserves Its Interests Once Again”, in Al Jazeera, archived from the original on 2018-08-01
2. (not comparable, astrology) Pertaining to the astrological influence of the planet Mercury; having the characteristics of a person under such influence (see adjective sense 1).
   The Sun to the Terms of Mercury. It inclineth the native to be Mercurial, given to ſtudy Arts and Sciences, and to delight in reading, and to follow his Calling with chearfulneſs. 1682, Joseph Blagrave, “[The Effects of Directions.] The Sun Directed unto Promittors.”, in Obadiah Blagrave, editor, Blagrave’s Introduction to Astrology. In Three Parts.[…], London: Printed by E. Tyler, and R. Holt, for Obadiah Blagrave,[…], →OCLC, part III, page 254
   6thly, The ☽ separates from a △ of ♂︎, and applies to ☍ of ☿, lord of the 3d; which intimated that some neighbour of the querent, either with a letter, words, or cross information, would wholly destroy the querent's hopes; and that mercurial men, viz. scholars or divines, would be his enemies: … 1852, William Lilly, Zadkiel [pseudonym; Richard James Morrison], “Of the Ninth House and Its Questions. Long Journeys, Voyages, Arts, Science, Church Preferment, Law, &c.”, in An Introduction to Astrology[…]: A Grammar of Astrology, and Tables for Calculating Nativities.[…], London: H[enry] G[eorge] Bohn,[…], →OCLC, page 268
3. (not comparable, astronomy) Pertaining to the planet Mercury.
4. (not comparable, chemistry) Of or pertaining to the element mercury or quicksilver; containing mercury.
   Beware alſo of Mercuriall lotions, I meane any which haue Mercurie Sublimate Precipitat or otherwiſe prepared in them, for though they haue good qualities, yet they are vpon my knowledge and experience dangerous, … 1617, John Woodall, “Of the Small Siringe”, in The Svrgions Mate, or A Treatise Discouering Faithfully and Plainely the due Contents of the Svrgions Chest, the Uses of the Instruments, the Vertues and Operations of the Medicines, the Cures of the Most Frequent Diseases at Sea:[…], London: Printed by Edward Griffin for Laurence Lisle,[…], →OCLC, page 22
   … Dr. Francis Fuller, … upon wearing a Quick-ſilver Girdle, for the Cure of the Itch, (and that after an inconſiderate and raſh manner) was brought under a violent Spaſmodick Diſtemper, which was ſupposed by himſelf and others to be owing to ſome Mercurial Particles lodg'd in ſome excretory Ducts of the Brain. 1734, T[homas] K[night], A Critical Dissertation upon the Manner of the Preparation of Mercurial Medicines, and Their Operation on Human Bodies; particularly Those Most in Fashion:[…], London: Printed for Harmen Noorthouck[…], →OCLC, page 52
   If to theſe we add the inconveniences inſeparable from mercurial preparations, and which are always the conſequences of their uſe; if we conſider the ſmall number of patients to whom mercury may be exhibited with ſafety, … the uſe of mercurial medicines will be confined within very narrow limits. 1773, Henry Saffory, The Inefficacy of All Mercurial Preparations in the Cure of Venereal and Scorbutic Disorders, Proved from Reason and Experience,[…], London: Printed for the author; and sold by T. Evans,[…], and Mr. Southern,[…], →OCLC, pages 31–32
   [I]n the month of May, a mercurial thermometer, having its bulb covered with paper, and blackened in a similar manner to the spirit one, was inclosed in a square bottle of thin glass, four inches wide, to protect it from the wind. 1828, John Richardson, “[Appendix.] No. III. Observations on Solar Radiation”, in John Franklin, Narrative of a Second Expedition to the Shores of the Polar Sea, in the Years 1825, 1826, and 1827,[…], London: John Murray,[…], →OCLC, pages cix–cx
5. (not comparable, medicine) Caused by the action of mercury or a mercury compound.
   I ſaw in the Year 1709. a notable inſtance, where a Phyſician order'd the Patient to be Bled five times in a Mercurial Salivation in a Caſe not Venereal; when he did ſpit at the rate of ℔ iv. per diem, and it was at the height, and yet notwithſtanding it did continue for all this, and the Patient eſcap'd with his Life. 1712, J. White, “Farther Indications of Right Blood-letting in Fevers,[…]”, in De Recta Sanguinis Missione: Or, New and Exact Observations of Fevers.[…], London: Printed by D[aniel] Brown[e][…], A[ndrew] Bell[…], and W[illiam] Innys[…], →OCLC, page 140
   The last exciting cause of the mercurial ulcer, which I shall now mention, is the use of the knife or of the caustic, during a mercurial course, to wounds made or enlarged at this time; for the great additional irritation, which the operation must produce, disposes such wounds to take on easily the mercurial disease. 1810, Andrew Mathias, “Section II. The Exciting Causes of the Mercurial Disease.”, in The Mercurial Disease. An Inquiry into the History and Nature of the Disease Produced in the Human Constitution by the Use of Mercury, with Observations on Its Connexion with the Lues Venerea, London: Printed for Becket and Porter,[…]; John Murray,[…]; and J[oseph] Johnson and Co.,[…], →OCLC, page 84
6. (not comparable, Roman mythology) Pertaining to Mercury, the Roman god of, among other things, commerce, financial gain, communication, and thieves and trickery; hence (comparable), money-making; crafty.
   [Benjamin] Franklin, the mechanic of his own fortune, … tendering, from the self-created nation, to the mightiest monarchs of Europe, the olive-branch of peace, the mercurial wand of commerce, and the amulet of protection and safety to the man of peace on the pathless ocean from the inexorable cruelty and merciless rapacity of war; … 8 February 1843, John Quincey Adams, “Presentation of Washington’s Sword and Franklin’s Staff”, in [Francis Preston] Blair, [John C.] Rives, editors, The Congressional Globe: […] (United States House of Representatives, 27th Congress, 3rd session), volume XII, number 16, Washington, D.C.: Published by Blair and Rives; […], published 10 February 1843, →OCLC, pages 254–255