I could swear I’m used to seeing “gasses,” but I went to look it up online and I see many places and some dictionaries happily using “gases.” This seems startlingly new to me.
Is this something that’s in transition, or have I been reading too many British chemistry papers, or is the Web full of nitwits?
This is a case of English not conforming to its own rules, again… personally I would prefer the spelling “Gasses” be used as it does not imply in any way a hard “A” sound should be used, however “Gases” is the correct spelling.
Both are correct. I believe the -ss- is the older way, to conform with the need to show that the “a” is pronouced as a short vowel, but the more modern way is to simply add the -s or -es regardless of syllable quality.
As was brought up in another thread, “busses” is still acceptable, and is my preferred spelling for the same reason that “gasses” is my preferred spelling. I’m accustomed (in the welding world) to seeing both “gases” and “gasses” depending upon the nation of origin.
The OED lists the plural as “gases” with no mention of an alternative. It gives several citations for “gases”, with the earliest from 1791. There is one citation for “Gasses” from 1779, but in that case, the singular was also spelled “Gass”.