ispell/hunspell: Invalid coding system: iso8859-1

[djc]

I'm trying to make hunspell work in "GNU Emacs 24.3.1 (i386-mingw-nt6.1.7601)" 
under Win7. It must be something small, but so far I'm stumped.

Hunspell is set up in the ordinary way, and I've installed several dictionaries 
under hunspell\share\hunspell, including en_US.aff (whose first line is "SET 
ISO8859-1") and en_US.dic. My initialization code includes

================

(setq ispell-local-dictionary-alist
    '((nil
        "[[:alpha:]]"
        "[^[:alpha:]]"
        "[']"
        t
        ("-d" "en_US" "-p" "E:\\Util\\hunspell\\share\\hunspell\\personal.en")
        nil
        iso8859-1)

      ("american"

        "[[:alpha:]]"
        "[^[:alpha:]]"
        "[']"
        t
        ("-d" "en_US" "-p" "E:\\Util\\hunspell\\share\\hunspell\\personal.en")
        nil
        ISO8859-1)
      )

================

When I explicitly set the dictionary to "american" and then invoke ispell in a 
buffer, it returns "Invalid coding system: iso8859-1".

What have I overlooked or what have I set up wrong? Many thanks for help.

djc