Vika, my guess is that you're probably right about the sleeping pills; plus, I imagine that under sedation, we move less, and so instead of turning onto our side and resuming nose-breathing, we might lie on our backs and mouth-breathe the whole time.

WW, thanks for this thread--I had completely forgotten this use of mordant, and had to LIU in Atomica:
mor·dant (môr'dnt)
adj.

Bitingly sarcastic: mordant satire.
Incisive and trenchant: an inquisitor's mordant questioning.
Bitingly painful.
Serving to fix colors in dyeing.
n.
A reagent, such as tannic acid, that fixes dyes to cells, tissues, or textiles or other materials.
A corrosive substance, such as an acid, used in etching.
tr.v., -dant·ed, -dant·ing, -dants.
To treat with a mordant.

[French, from Old French, present participle of mordre, to bite, from Vulgar Latin *mordere, from Latin mordēre.]

mor'dan·cy n.
mor'dant·ly adv.
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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2000 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.