"I have devoted the last two and a half years solely to the investigation of this phenomenon: that I have studied thousands of cases and read reports both ancient and modern; that I have studied with an unbiased mind things which seemed possible, and things that seemed impossible, and that I feel as qualified to speak as any ‘expert’ who after a few weeks, or even days, of research calmly announces the once-and-for-all solution, and returns thence to his normal activities."