Reading about "gamboge" I got to thinking about "gamgee" as in the name of the hobbit Sam Gamgee. In a note in the very last page of the Appendices to LOTR, Tolkien says of the name Gamgee that no reference to the name "Cotton" was intended. So I looked it up, and it turns out "Gamgee-tissue" is an absorbent cotton-wool for dressing wounds, and takes its name from one "S. Gamgee" (1828-86)!

Neat. There's a little more here:

http://fan.theonering.net/lasselanta/mirth/trivia.shtml

Thanks for the link, jheem. It's just a pity that the link to a "millionaire" quiz about LotR wasn't for real.