I have so often in my life been on the very edge of ghost-seeing, and felt so perfectly certain that the least encouragement on my part would set them before me, and that nothing but a resolute effort of will would save me from such a visitation, that I have become convinced that of the people who have seen apparitions, one half have--as I should term it--chosen to do so. I have all my life suffered from a tendency to imaginary terrors, and have always felt sure that a determined exercise of self-control would effectually keep them from having the dominion over me. The most distressing form of nervous excitement that I have ever experienced was one that for many years I was very liable to, and which always recurred when I was in a state of unusual exaltation or depression of spirits; both which states in me were either directly caused or greatly aggravated by certain electrical conditions of the atmosphere, which seemed to affect my whole nervous system as if I had been some machine expressly constructed for showing and testing the power of such influences on the human economy. I habitually read while combing and brushing my hair at night, and though I made no use of my looking-glass while thus employed, having my eyes fixed on my book, I sat (for purposes of general convenience) at my toilet table in front of the mirror. While engrossed in my book it has frequently happened to me accidentally to raise my eyes and suddenly to fix them on my own image in the glass, when a feeling of startled surprise, as if I had not known I was there and did not immediately recognize my own reflection, would cause me to remain looking at myself, the intentness with which I did so increasing as the face appeared to me not my own; and under this curious fascination my countenance has altered, becoming gradually so dreadful, so much more dreadful in expression than any human face I ever saw or could describe, while it was next to impossible for me to turn my eyes away from the hideous vision confronting me, that I have felt more than once that unless by the strongest effort of will I immediately averted my head, I should certainly become insane. Of course I was myself a party to this strange fascination of terror, and must, no doubt, have exercised some power of volition in the assumption of the expression that my face gradually presented, and which was in no sense a distortion or grimace, but a terrible look suggestive of despair and desperate wickedness, the memory of which even now affects me painfully. But though in some measure voluntary, I do not think I was conscious at the time that the process was so; and I have never been able to determine the precise nature of this nervous affection, which, beginning thus in a startled feeling of sudden surprise, went on to such a climax of fascinated terror.