Electrotherapy Museum Movies
The very groovy Turn of the Century Electrotherapy Museum (my new #1 reason to go visit South Florida) has lots of cool stuff online -- violet ray wands (aka portable Tesla coils), quack medical devices, turn of the century patents -- but they also have a whole page of movies, where you can see these and other old electro-medicinal devices and inventions sparking away in all their ethereal glory.
See -- surgical diathermy on a minute steak!
Witness--the power of the violet wand!
Feel -- the sparks of the Xray Coil!