In the 18th century, some scientists and would-be scientists travelled around the country giving demonstrations for the gentry of the latest things in natural philosophy as well as plenty of classics. It was a good way of securing patronage (pots of cash for serious experiments). They'd put alarm clocks under bell jars and pump the air out to make them stop ringing, or produce hydrogen and explode it, or re-animate frogs legs with a voltaic pile. Hours of creepy fun.
The best part is that it's not necessary to understand the underlying physics or biology to get these experiments to work, leaving you free to concentrate on their presentation. In many ways, the
genuine seances that came a century later are intimately related to those demonstrations. They certainly led directly to the public lectures by the likes of Faraday at the Royal Society.
There's a famous painting by Joseph Wright, which shows someone looking suspiciously like Peter Stringfellow doing the bell jar on an unfortunate songbird for a well-to-do family:
http://bit.ly/tPkhk