Special thanks to contributor Sarah Spencer, studying Psychology at Richmond. She nominated this word, one I use personally but have not yet covered here.
August proves generally hot in Central Virginia, and even if nearly all modern thermometers do not use toxic mercury, the mercury does begin to rise and fall more than in July. Our most mercurial months, October and March, lie in wait. Our metaphor refers to these quick rises or drops, but not merely in temperature. A mercurial person shifts moods as fast as temperatures in Fall or Spring.
The OED is acting up today, but I got as far as seeing a 14th Century date of first recorded use, as well as the definitions “having a lively, volatile, or restless nature.” I have encountered the rather dainty term in literature; it also appears in journalistic pieces about public figures with thin skins; it gives us a polite alternative to calling someone a “brat,” or a “jerk.” Not all mercurial persons are mean; one might shift back and forth from giddy to sad without hurting anyone else. A mercurial child (if not your own) who throws a tantrum in a store can be humorous.
Ultimately, our term goes back to the fleet-footed Roman god Mercury, who lent his name to quicksilver, the element found in older thermometers.
Thanks, Sarah. I hope you can avoid mercurial persons, except in a professional capacity, even if we cannot avoid mercurial weather.
This blog will roll on into better weather and the start of classes, so send words and metaphors of interest by e-mail (jessid -at- richmond -dot- edu) or by leaving a comment below.
See all of our Metaphors of the Month here and Words of the Week here.
Image courtesy of Wikipedia Commons.