First published in 1918. By the author of the Sherlock Holmes stories. The book begins: The subject of psychical research is one upon which I have thought more and about which I have been slower to form my opinion, than upon any other subject whatever. Every now and then as one jogs along through life some small incident happens which very forcibly brings home the fact that time passes and that first youth and then middle age are slipping away. Such a one occurred the other day. There is a column in that excellent little paper, Light, which is devoted to what was recorded on the corresponding date a generation--that is thirty years--ago. As I read over this column recently I had quite a start as I saw my own name, and read the reprint of a letter which I had written in 1887, detailing some interesting spiritual experience which had occurred in a seance.