“I have some work for you today, my boy,” he said, as soon as the meal was over. “I want you to go to the British Museum and look up the reports of the trials for murder at the Old Bailey during the first ten years of the present century. Among them you will find the trial of a doctor for the murder of one of his patients by giving him an overdose of morphia. I believe that the doctor’s name began with an M, and I fancy that his patient had a title. More than this I cannot tell you, my memory, I regret to say, is not what it used to be. I want you to make a précis of that trial and of the sentence.”