Water doesn't boil at 100 Degrees

The consistently excellent history of science blog Ether Wave Propaganda directs our attention to Cambridge Professor Hasok Chang's brief discussion of the boiling point of water:

We all learn at school that pure water always boils at 100°C (212°F), under normal atmospheric pressure. Like surprisingly many things that "everybody knows", this is a myth. We ought to stop perpetuating this myth in schools and universities and in everyday life: not only is it incorrect, but it also conveys misleading ideas about the nature of scientific knowledge. And unlike some other myths, it does not serve sufficiently useful functions.