And the second "i" in aluminum.
IUPAC says it should be that way.
Actually: a little history here. The history of element 22 name is sorta weird. It was initially referred to as alumin, but the discoverer changed the name to aluminum, then to aluminium to match the naming of other metals.
Aluminium is popular everywhere but the USA. When the IUPAC made their decision, they sided with us Americans on the spelling of sulfur (sulphur is the norm elsewhere).
So at least there's that.
After reading "Eats, Shoots, and Leaves" I have grown to like some of the stylings from olde Mum Angleterre.
Oh bleh. Not that thing.
http://www.newyorker.com/magazine/2004/06/28/bad-comma
How can you read that? it's all in italics! augh!
Anyway, I like the oxford comma, where appropriate. Commas go in and out of style and nowadays they are "out". I add a comma where I would naturally pause when speaking, unless a semicolon makes more sense.