"That pocket-piece of yours," said the doctor, "reminds me that I have an interesting one of my own; perhaps you can tell me what it is." He took from his pocket a silver coin and handed it to Jennings, as he spoke. One edge had been flattened, and a hole pierced in it. "Ah! an old Spanish piece," said Jennings, "evidently of the time of Pope Leo Fourth, sometime in the sixteenth century. A very interesting piece. Where did you get it?" "There is a curious story connected with that coin," meditatively remarked Dr. Watson; "perhaps you would like to hear it." [Illustration: ONE EDGE HAD BEEN FLATTENED AND A HOLE PIERCED IN IT.] We had been dining with Watson and were now comfortably seated in the library before an old-fashioned open fire. It was snowing outside, making the warm, bright study all the more cheerful by contrast. "Perhaps you remember," said Watson, "that during the winter of 1886 I devoted much more of my time than usual to the Insane Asylum. I was very much interested in testing the value of hypnotism for insane patients, especially mild cases and those having illusions and insistent ideas. I had been quite successful in one case--a woman who had tried to starve herself to death under the impression that the devil commanded her not to eat was greatly benefited by post-hypnotic suggestion. Suggesting that the devil would not come any more induced pronounced hysteria, but when hypnotized, and told that the devil commanded her to eat, instead of to abstain from food, she took nourishment readily, and soon developed an extraordinary appetite. "An immediate improvement in her condition was noticeable, and as her general bodily health improved, the illusions became less and less frequent, and she was discharged from the asylum as cured in less than three months." Watson paused and gazed meditatively at the end of his cigar. "Ever tried to hypnotize an insane person, Jennings?" "Not that I remember." "You, Morris?" "Can't say that I have." "Hm! Well, sometimes you succeed, and sometimes you don't; more often you don't. There was one patient, a man by the name of Allen, who had been a sailor. He was subject to fits of extreme melancholia, and at times was positively dangerous, as he imagined some one was trying to poison him. "I never succeeded in hypnotizing him, although I tried repeatedly. However, I saw him every day, and as his general health improved, his attacks of melancholia became less frequent. He seemed grateful to me for taking an interest in him, and often talked with me about his early life and the out-of-the-way countries he had visited. Shortly after I was called away and did not return to the asylum for two weeks, and when I did go back I found that Allen was dead. He had cut his throat one afternoon with a large pocket-knife and made a mighty clean job of it, too.