The publication in the _British Journal of Photography_ of Mr. Taylor’s Paper, with the proceedings of the meeting at which it was read, has aroused a wide-spread and deep interest in the subject. The principal portions of it, and, in some instances the whole of the Paper, together with editorial comments, have subsequently appeared in newspapers and journals in Canada, Australia, India, America, and other countries. As his experiments will be a matter of historical interest, many scientific men will be pleased to have his Paper in this book form, with the reproductions of two of the psychic pictures which he obtained on his photographic plates. The term “spirit photographs” is generally used to describe photographs of psychic entities who cannot be seen by ordinary persons, but can be photographed by a medium, or with the help of a medium, and with the co-operation of these unseen entities. Such portraits are obtained both indoors and in the open air, with and without a background, by natural light and by artificial light; and, in the case of “materialised” forms at séances, which are visible to every person present, the portraits have sometimes been taken by light produced by the spirits, the exact nature of which is unknown. The following may serve as a rough classification of what are called spirit photographs:— 1. Portraits of psychical entities not seen by normal vision. 2. Pictures of objects not seen nor thought of by the sitter or by the medium or operator; such as flowers, words, crosses, crowns, lights, and various emblematic objects. 3. Pictures which have the appearance of being copied from statues, paintings, or drawings. Sometimes these are busts or heads only. The flatness in some photographs of this class is supposed, by persons who have _not_ investigated the subject, to be proof that the photographs are produced in a fraudulent manner. 4. Pictures of what are called materialised forms visible to normal sight. 5. Pictures of the “wraith” or “double” of persons still in the body. 6. Portraits on plates which developers have failed to bring into view, but that can be seen and described by clairvoyants and by mediums when in trance and whose descriptions agree, though made independently. There are, also, portraits that cannot be classed as photographs, as they have not been taken by the agency of a camera, or by exposing the prepared plate previous to development of the image. Those who desire further information than is contained in this volume on the subject of spirit photography should read the following:— A series of important articles by the late Mr. Stainton Moses (M.A. Oxon), in _Human Nature_, Vols. VIII. and IX., 1874-75. The volumes may be had on loan from the Library of the Spiritual Institution, 15 Southampton Row, W.C., or from the Library of the Spiritual Alliance, 2 Duke Street, Charing Cross. The subscription to either Library is a guinea a year.