Number 4

A jester had a child born to him, and he sent the boy to the grocer's shop to buy oil and syrup. The grocer took the money, filled the jar with urine, and handed it back. When the child brought it home and the jester saw what it was, he said nothing. Some time later he found the grocer groaning with a toothache. He went off, wrapped a bit of dried filth in a scrap of paper, and gave it to him. When the man put it on his tooth, he asked, 'What was that?' The jester said, 'That's the dregs of the oil you gave me the other day.'