My mistake, I did not know that "SHARP S" stands for the "Eszett" German 
letter.

There is a font (Myriad Web on my system) that proposes a (wrong) glyph 
for this code point. According to
http://www.tcl.tk/software/tcltk/whatsnew.tml#i18n
"""
Tk guarantees to find a way to display any Unicode character regardless 
of the font you selected, as long as there is some font in the system 
that contains the Unicode character
"""
but Tk does not guarantee that the font will display the correct 
character...