Re: an experiment with di

	I'd like to add a note about charge in dielectrics.  One of
the older toys here is avery small Van de Graaf generator, puts out
a 5" spark and only about 2 microamps current.  One experiment I
sometimes show visitors is this:
	A thin polystyrene drinking glass (solid plastic, not
foam) is placed over one's fist and then the sparks are allowed
to strike the outside of the glass.  Taking the think away from
the coil and putting the other hand to the outside of the glass
results in quite a nice spark and a really solid twitch!!!!!
	Putting the glass down before discharging it doesn't
make any difference, at least if it sits for only a few minutes.
"The charge is really (or appears to be) in the dielectric"!
Then, of course, there are electets and the good old standby,
the electrophorous.
Ed Phillips