Why is "Missouri" pronounced with -z-

[sagehen]

>Gerald,
>
>As a graduate student working for Don Lance in the 80s, I did some
>research on the history of the pronunciation of Missouri.   In the 19th
>century, in fact,  [mIsuri] was the preferred pronunciation.  The
>pronunciation [mIzuri] was scorned.  An explanation for the shift from s
>to z in "Missouri" and "possess" in contrast with "Mississippi" is a
>variant of Verner's Law--stress on the following syllable.
>
>I believe Don covered this in one of his articles on the pronunciation
>of Missouri ((1985, Missouri Folklore Society Journal or 1999 Names) but
>I am not certain.
>
>Virtually, Terry
~~~~~~~~~~
What makes the "Mizzouree" / "Mizzourah" distinction?  My mother, b. St.
Louis 1905, always said "Mizzouree."
A. Murie