Gurney shares, therefore, with Janet and Binet, the {311} credit of demonstrating the simultaneous existence of two different strata of consciousness, ignorant of each other, in the same person. The 'extra-consciousness,' as one may call it, can be kept on tap, as it were, by the method of automatic writing. This discovery marks a new era in experimental psychology, and it is impossible to overrate its importance. But Gurney's greatest piece of work is his laborious 'Phantasms of the Living.' As an example of the drudgery stowed away in the volumes, it may suffice to say that in looking up the proofs for the alleged physical phenomena of witchcraft, Gurney reports a careful search through two hundred and sixty books on the subject, with the result of finding no first-hand evidence recorded in the trials except the confessions of the victims themselves; and these, of course, are presumptively due to either torture or hallucination. This statement, made in an unobtrusive note, is only one instance of the care displayed throughout the volumes. In the course of these, Gurney discusses about seven hundred cases of apparitions which he collected. A large number of these were 'veridical,' in the sense of coinciding with some calamity happening to the person who appeared. Gurney's explanation is that the mind of the person undergoing the calamity was at that moment able to impress the mind of the percipient with an hallucination. Apparitions, on this 'telepathic' theory, may be called 'objective' facts, although they are not 'material' facts. In order to test the likelihood of such veridical hallucinations being due to mere chance, Gurney instituted the 'census of hallucinations,' which has been continued with the result of obtaining answers from over twenty-five thousand persons, asked {312} at random in different countries whether, when in good health and awake, they had ever heard a voice, seen a form, or felt a touch which no material presence could account for. The result seems to be, roughly speaking, that in England about one adult in ten has had such an experience at least once in his life, and that of the experiences themselves a large number coincide with some distant event. The question is, Is the frequency of these latter cases too great to be deemed fortuitous, and must we suppose an occult connection between the two events? Mr. and Mrs. Sidgwick have worked out this problem on the basis of the English returns, seventeen thousand in number, with a care and thoroughness that leave nothing to be desired. Their conclusion is that the cases where the apparition of a person is seen on the day of his death are four hundred and forty times too numerous to be ascribed to chance. The reasoning employed to calculate this number is simple enough. If there be only a fortuitous connection between the death of an individual and the occurrence of his apparition to some one at a distance, the death is no more likely to