I had known that J. B. Van Helmont (1577-1644) invented the word gas based on Greek χάος ‘chaos’—it makes sense if you know that in Dutch, the letter g is pronounced kh—but I had no idea he also created blas for “a supposed ‘flatus’ or influence of the stars, producing changes of weather” (OED). You can read all about it, with a funny quote from Richard Franck’s Northern Memoirs, Calculated for the Meridian of Scotland; To Which is Added, The Contemplative and Practical Angler. Writ in the Year 1658, at Mark Liberman’s post at the Log, and the comment thread there brings up the question of the family name Degas, originally De Gas: Ray Girvan points out that “Degas’ paternal grandfather, Rene-Hilaire De Gas, was a baker from Orléans” and the commune Gas “is very close to Orléans.” To which Bryn LaFollette adds:
Well, that leads to the question of where the commune Gas gets its name. There is surprisingly little information on either the French or English Wikipedia pages, nor on any of the easily found pages on les communes de France.
Of course, it may be that there is no known etymology for the name of such an obscure commune, but I’ll bet Brichot would have a theory.