origin of the word 'Slav"

[James McDermott]

        Sorry for the late response on the slav/slave/slovo issue, but I've just
come back from my Christmas vacation and want to add my two cents.

        In the early 1920's, my grandfather was a student at Alliance College in
Pennsylvania. His professors gave the same origin as did J.P. Maher for the
word 'Slav'. It derived from 'Slovo' (word) and  was used by the early
Slavs to refer to those with whom they could communicate, i.e. the 'worded'
ones. He was also told that the Germans are called 'niemiecki' meaning 'the
mute ones' because their language was incomprehensible and harsh to the
ears of the early Slavs.

        Does this explanation of 'niemiecki' have any merit, or were my
grandfather's professors indulging in some German-bashing?