Little Jimmy had been sent early to bed, but he could not sleep. Presently he called out to his mother in plaintive tones, "Mummy, bring me a glass of water, I'm so thirsty." No reply being vouchsafed him, he repeated his request after a short interval. And this time received an abrupt answer, "If you don't be quiet I'll come up to slap you." Suddenly a thought struck him and still in plaintive voice he cried, "Mummy, when you come to slap me, bring me a glass of water."