sulfur hexafluoride

it's good for a laugh
( manolith hooray for me, Mon 11 May 2009, 9:58, archived)

I thought that was Dinitrogen monoxide

( Maximinimus you stick around I'll make it worth your while, Mon 11 May 2009, 9:59, archived)

clever

( manolith hooray for me, Mon 11 May 2009, 10:00, archived)