midnight
`` Touchy , eh ? '' sniffed Septemas Scudmore . `` Not strange at all . Studious inclination , close application to work , baffling researches , midnight oil -- these things irritate the nerves and make a man crusty . But then , I do n't think you ever hurt yourself by close application to work . You must be naturally irritable . '' Professor Scotch pranced up and down the room like an angry bantam .