My Essay on Death led me to make a conscientious enquiry into the present position of the great mystery, an enquiry which I have endeavoured to render as complete as possible. I had hoped that a single volume would be able to contain the result of these investigations, which, I may say at once, will teach nothing to those who have been over the same ground and which have nothing to recommend them except their sincerity, their impartiality and a certain scrupulous accuracy. But, as I proceeded, I saw the field widening under my feet, so much so that I have been obliged to divide my work into two almost equal parts. The first is now published and is a brief study of veridical apparitions and hallucinations and haunted houses, or, if you will, the phantasms of the living and the dead; of those manifestations which have been oddly and not very appropriately described as "psychometric"; of the knowledge of the future: presentiments, omens, premonitions, precognitions and the rest; and lastly of the Elberfeld horses. In the second, which will be published later, I shall treat of the miracles of Lourdes and other places, the phenomena of so called materialization, of the divining-rod and of fluidic asepsis, not unmindful withal of a diamond dust of the miraculous that hangs over the greater marvels in that strange atmosphere into which we are about to pass.