People quite often had mustard footbaths when I was a child. It was supposed to prevent chills. It seemed an odd idea even at the time, but, hey, Coleridge writes about mustard being good for rheumatism, and if it's good enough for Coleridge...
...hm. I've just remembered all those drugs Coleridge used to take.
Well, that argument's fallen flat on its face, then.
Still, never mind, I'd rather use the stuff medicinally than eat it, at least in the form of the pungent paste with which an Englishman traditionally masks the taste of his roast beef.
Mind you, it was quite possible to have the worst of the two worlds: a 1737 medical journal* notes of one poor woman that: Her disease seemed...almost to be cured by mustard vomits.
Oh dear. Such a pity about the almost.
Mustard's strong flavour has given us the expression keen as mustard, of course, and the poet Marston writes splendidly of:
Sharp mustard rime
To purge the snottery of our slimie time.
Which just goes to show how very valuable poetry can be.
Other than that, mustardavelles is a sort of grey woollen cloth, to cut the mustard means to prove fit for purpose (no one is quite sure of the origin of this expression) and the horrible First World War mustard gas, (ClCH2CH2)2S, banned as a weapon by the Geneva Protocol of 1925, has found to be useful in chemotherapy.
Word To Use Today: mustard. This word comes from the French moustarde, from the Latin mustus which means must, the newly pressed juice of grapes. Grape juice used to be used to make mustard.
The weaving town of Montivilliers in Normandy gave us the name of the cloth.
*Before my time.