Benjamin Franklin used a Leyden jar to store energy for kitestring which attracted lightning discharge. He was lucky he didn't get killed. Another scientist in Europe who copied him did get killed.

Here are some uRLs:

Leyden jars ;http://www.alaska.net/~natnkell/history.htm

Electric eels http://www.sciencenet.org.uk/database/Biology/0104/b00906d.html

Electic eel: http://www.sidwell.edu/us/science/21bio/fish/organ.html

I used to have some very high current capacitors to make flashes with xenon tubes such as are used on aircraft flashing lights. If I remember right, they were rated a couple hundred farads. Discharge from one of those could kill. I used them to make flash for camera in early fifties.