3 o'clock
He made baby laugh yesterday when I was explaining to him about the Standard Bread . We 'll just put `` 1 loaf 3 . A remittance at your earliest convenience will oblige . '' That 'll mean that 1 person is invited for 3 o'clock , and on the back we 'll write where and why in invisible ink . Lemon juice , you know . And the baker 's boy shall be told to ask to see the people -- just as they do when they _ really _ mean earliest convenience -- and then he shall just whisper : `` Deadly secret . Lemon juice .