From the Wikipedia entry on Guignol (the French equivalent of Punch and Judy). My emphasis:
“When hard times fell on the silk trade during the French Revolution, he [Laurent Mourghet, Guignol’s creator] became a peddler, and in 1797 started to practice dentistry, which in those days was simply the pulling of teeth. The service was free; the money was made from the medicines sold afterward to ease the pain. To attract patients, he started setting up a puppet show in front of his dentist’s chair.”