My favorite class in high school was physics. We learned a lot, and part of that learning was playing with the demonstration equipment.
To teach us something about static electricity and electrical capacitors, the teacher had us join hands with him and form a human chain between the two electrodes of the static electricity generator (d’Arsonval machine) . Each electrode had a low-capacity capacitor (Leyden jar) attached to it, to store and build up the voltage from the generator.
As one student cranked the generator, the small electric current ran through those of us who made up the human chain between the electrodes. The current ran through our hands, arms, and bodies. We felt nothing.
Then the instructor had each of us unclasp one hand from an adjoining person, allowing the capacitors to accumulate some charge. We were to unclasp, then immediately clasp again. Everyone felt a tiny electric jolt as hands were reclasped.
Pat Mulligan was in the chain. Pat was not an electricity enthusiast, except as it lit his room, cooked his meals, and kept his food cold.
Pat became a lawyer.
When Pat released his clasp, he was reluctant to reach out and grab hands again. He reached for the other hand tentatively, then drew his hand away.
The teacher shouted, “Pat, take the hand! The charge is building up in the capacitors!”
Slowly, tentatively, Pat moved his hand closer to his partner’s hand.
Suddenly a bright blue flash appeared between Pat’s hand and his partner’s. It was about six inches long.
We all felt a strong, though harmless jolt as the capacitors discharged through us.
Our arms all jerked upward and we let go of our partners’ hands.
Then we all had a good laugh.
No harm done, except to Pat Mulligan’s ego.