> Can anyone explain why Americans insist on calling Aluminium (the
 > metal) Aluminum ?? I have dealt with Alumina before but not with
 > Aluminum. Is this going to be a general trend *pops tongue in
 > cheek* and we will end up with potassum, uranum etc...?

I can't tell you where it started, precisely, but the OED notes that
the discoverer of Al, Sir Humphry Davy, gave it the name ALUMINUM.
Later it was apparently changed (one wonders by whose authority) to
"harmonize best with other names of elements".  Apparently whoever
was given charge of this responsibility failed to execute it completely,
since the original form ALUMINUM is utterly standard in the USA.

The pronunciation of that word in the US has a *totally* different
structure and sound from "the same word" as pronounced elsewhere in
the Commonwealth (and no, I don't know what the actual geographic
distribution is), viz:

  USA  / @ - lu' - mn-n@m /
    o maximum 4 syllables
      o 1st syllable is either a shwa or a syllabic /l/
        - frequently elided
      o 2nd syllable receives main word stress
        - minimal stress (fourth out of four levels) on all others
        - contains high back tense vowel /u/ as in "boot"
        - the only true vowel in the word; the rest are syllabic resonants
      o third syllable is normally a syllabic /n/
      o fourth syllable is frequently a syllabic /m/, though one does
         hear a (centralized) vowel occasionally in the last syllable.
    o syllabic /l/ is velarized in American English.
      o syllabic or not, the /l/ is velarized,
        - not palatalized like the UK variant,
          since it's after a shwa and before a back vowel.

  UK   / ae` lyU mI'n iy @m/
    o FIVE syllables
    o low front /ae/ vowel in first syllable
      o first syllable has secondary stress
    o high back lax /U/ in second
      o occasionally tensed to /u/ when monitoring speech
      o palatal /ly/ present
    o high front lax /I/ in third syllable
      o third syllable has main stress
      o loudest vowel in word
    o high front tense /i -> y/ transition in new fourth syllable
    o fifth syllable identical with American fourth syllable

  These are vastly different words in terms of their pronunciation.
  I was ten years old before I ever noticed the non-US spelling, and
  then merely took it for a typo.  I was considerably older before I
  *heard* how that spelling of that word was pronounced, and then all
  became clear.

  This is, for me, much more interesting as an example of a very
  powerful spelling pronunciation than as a matter of propriety. It
  must have been the spellings that contributed to this distinction,
  because they came first, when the scientific work was done, but
  before the practical applications like electrolysis and machining
  were possible. Both words were made up by scientists, according to
  different (equally logical, but inconsistent) ideas about how one
  should do it.

  According to the OED, and as suggested, the Latin neuter plural
  "alumina", used as a mass noun in English and elsewhere for AlOH, or
  "the earth of alum", as "the French chemical nomenclators of 1787"
  called it, is the source of the singular backformation.  That would
  make a singular that ended in -UM, but which one?  Should it have an
  [I]?  Or should it be a standard consonant-stem form on Lat ALUMIN-
  'alum'?  Obviously, both.

  For purely fortuitous reasons, one spelling convention (the one
  without the [I]) became common here in the U.S. and the other did so
  elsewhere.  Much later, when those who had to actually *say* the
  word did so, it usually came out as some variant or other of one of
  the above, depending on how they interpreted the conventions of
  speaking English spelling aloud.  After all, they hadn't learned it
  at their mothers' knee.

  It's not like alumin(i)um is mentioned in the Bible, you know.
  IMHO, this pronunciation difference has gone *much* too far to
  change. I personally prefer the sound of the UK pronunciation, but
  if I used it in my lectures at a midwestern US university, I'd be
  thought eccentric.  That wouldn't be the first time, and if I
  thought it was useful, like crossing sevens, say, I'd do it anyway.
  But I'd run the risk of simply confusing the students, so why

  Anyway, I doubt there's much of a trend here.  So we don't have to
  mount a 24-hour guard over the [I] in "potassium"; it's likely to
  remain with us a bit longer, since it's been around quite a while
  already and there aren't any vast dialect differences yet.

 -John Lawler                     More grammar
  Linguistics Program   University of Michigan
 "..and, who knows? Maybe the horse will sing."