Ignis fatuous
Some time last year I learned that rue is a plant—or that "rue" names a plant, let's say. It's a bitter herb, used in the making of bitters both non and potable. A relative of the plant is used in Angostura bitters, for instance. Instantly the more common verb, words like "rueful", Housman's poem, &c., became altogether more portentous and unfamiliar. It really had a strong effect on me.
But it turns out the words are actually unrelated. "Rue" the plant comes from Greek 
; "rue" the sorrowful feeling from Old English "hréow". What a disappointment.
Comments
on 2005-07-14 10:05:55.0, Matt Weiner commented:
In Ophelia's mad monologue, "There's rue, for remembrance" is a deliberate pun, I think. Quote perhaps not exact.
"hreow"? Who knew the Old Angles were cats?
and, further, on 2005-07-14 10:11:22.0, ben wolfson commented:
In fact one of the entries for the sorrowful "rue" in the OED is "With punning allusion to RUE n.1".
1500-20 DUNBAR Poems lxiv. 10 Leif nor flour fynd could I nane of rew. 1583 GREENE Mamillia II. Wks. (Grosart) II. 297 Least time and triall make thee account Rue a most bitter hearbe. 1606 J. DAVIES (Heref.) Select Sec. Husband Wks. (Grosart) II. 8/1 So shalt thou But beare thine own Harts-ease, and neuer Rue. 1721 KELLY Scot. Prov. 284 Rue in Thyme should be a Maiden's Posie. 1825 WATERTON Wand. S. Amer. III. 238 They did all in their power to procure balm for me instead of rue. But it would not answer.
and, further, on 2005-07-14 11:29:33.0, Michael commented:
both non and potable
"both potable and non," I should think.
Matt: "...there's rue for you, and here's some for me; we may call it herb of grace o'Sundays; O, you must wear your rue with a difference."
Rue, regret, is the one herb she plans to take. Rue is also an abortifacient.
and, further, on 2005-07-14 11:37:09.0, ben wolfson commented:
"both potable and non," I should think.
That's because you are a lackluster prose stylist and I am the next Thomas Browne.
and, further, on 2005-07-14 11:38:00.0, ben wolfson commented:
Thomas Browne. I worked with the guy who maintains that site one summer when I was writing shell scripts for the Journal of Chemical Physics.
and, further, on 2005-07-14 11:54:26.0, Michael commented:
it's because if you put "portable" first, you understand the "non" when it comes, but the reverse is not true.
and, further, on 2005-07-14 11:59:48.0, ben wolfson commented:
Yes. I understand. But the sheer momentum of my writing carries the reader through his or her moment of wonderment at the bare "non" right through the "potable" (and said reader would continue to career wildly were it not for the all-stopping power of the period) at which point the "non" becomes retrospectively comprehensible; and more than that, a vital realization is effected, videlicet, by putting the "non" first, I advert the attentive reader to the understanding that it is only because of the nonpotable that the potable is noteworthy.
and, further, on 2005-07-14 0:14:04.0, Michael commented:
uh huh.
and, further, on 2005-07-14 0:56:02.0, Standpipe Bridgeplate commented:
Your prose style has elements both un and readable.
and, further, on 2005-07-14 13:21:01.0, dave zacuto commented:
I think your neologistic usage is inadvertentisable.
and, further, on 2005-07-15 7:01:19.0, ben wolfson commented:
Watch it, dave. I know where you live, more or less.