"A MORTAL ANTIPATHY" was a truly hazardous experiment. A very wise and very distinguished physician who is as much at home in literature as he is in science and the practice of medicine, wrote to me in referring to this story: "I should have been afraid of my subject." He did not explain himself, but I can easily understand that he felt the improbability of the physiological or pathological occurrence on which the story is founded to be so great that the narrative could hardly be rendered plausible. I felt the difficulty for myself as well as for my readers, and it was only by recalling for our consideration a series of extraordinary but well-authenticated facts of somewhat similar character that I could hope to gain any serious attention to so strange a narrative.