A large part of the material used in this book was sent to the authors as representatives of the Society for Psychical Research; and the book is published with the sanction of the Council of that Society.

The division of authorship has been as follows. As regards the writing and the views expressed, - Mr. Myers is solely responsible for the Introduction, and for the " Note on a Suggested Mode of Psychical Interaction," which immediately precedes the Supplement; and Mr. Gurney is solely responsible for the remainder of the book. But the most difficult and important part of the undertaking - the collection, examination, and appraisal of evidence - has been a joint labour, of which Mr. Podmore has borne so considerable a share that his name could not have been omitted from the title-page.

In the free discussion and criticism which has accompanied the progress of the work, we have enjoyed the constant advice and assistance of Professor and Mrs. Sidgwick, to each of whom we owe more than can be expressed by any conventional phrases of obligation. Whatever errors of judgment or flaws in argument may remain, such blemishes are certainly fewer than they would have been but for this watchful and ever-ready help. Professor and Mrs. Sidgwick have also devoted some time and trouble, during vacations, to the practical work of interviewing informants and obtaining their personal testimony.

In the acknowledgment of our debts, special mention is due to Professor W. F. Barrett. He was to a great extent the pioneer of the movement which it is hoped that this book may carry forward; and the extent of his services in relation, especially, to the subject of experimental Thought-transference will sufficiently appear in the sequel. Mr. Malcolm Guthrie, Professor Oliver J. Lodge, and M. Charles Richet have been most welcome allies in the same branch of the work. Professor Barrett and M, Richet have also supplied several of the non-experimental cases in our collection. Mr. F. Y. Edgeworth has rendered valuable assistance in points relating to the theory of probabilities, a subject on which he is a recognised authority. Among members of our own Society, our warmest thanks are due to Miss Porter, for her well-directed, patient, and energetic assistance in every department of the work; Mr. C. C. Massey has given us the benefit of his counsel; and Mrs. Walwyn, Mr. Hensleigh Wedgwood, the Rev. A. T. Fryer, of Clerkenwell, the Rev. J. A, Macdonald, of Rhyl, and Mr. Richard Hodgson, have aided us greatly in the collection of evidence.

Many other helpers, in this and other countries, we must be content to include in a general expression of gratitude.

Further records of experience will be most welcome, and should be sent to the [office of the Society for Psychical Research].

June, 1886.