The Cannon Assistant's Tale
The cannon is a stupid man, says his assistant. He tries to make precious metals from common metals, but he is never successful. The cannon is obsessed with his work, and spends all of his money on his fruitless attempts. There is another cannon who is downright corrupt, and convinced a priest to give up all of his money. He sold the priest a potion that would turn mercury to silver, and made a convincing show using sleight-of-hand. The potion doesn't work for the priest, and he is humiliated and poor.