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 NEW BOOKS. 619 question about the value of the work that has been done in exposing the pretensions and frauds of certain persons that have lately preyed upon human credulity. An important paper by Mrs. H. Sidgwick (in the previous Part) on her experience of spiritualistic mediums is here followed up by an elaborate memoir (pp. 381-495) on " The Possibilities of Mai- Observation and Lapse of Memory from a Practical Point of View," the joint- work of Mr. R. Hodgson and Mr. S. J. Davey. Mr. Hodgson (who exploded the Blavatsky imposture) writes a general " Introduction " to the " Experimental Investigation " which he helped Mr. Davey to conduct ; Mr. Davey being a man of first- rate conjuring powers, who has been able to equal (if not surpass) all that has been achieved by professional " mediums " in the way of slate-writing. Never pretending with his sitters to any supernatural powers, and even putting them on their guard against trickery, Mr. Davey has yet been readily credited with thaumaturgic attributes, and the investigation consists mainly in a critical comparison of the written reports furnished by the sitters, of what they saw, fancied they saw or failed to see. Nothing could be more instructive than the evidence thus obtained of the fallibility of human observation and memory, especially under the sway of emotion ; the different emotional moods of the various sitters according as they knew nothing, little or much of the actual conditions under which the phenomena were produced giving to the reports the liveliest diversity of hue. Beside other papers of psychological interest, the Part contains two important researches by Mr. E. Gurney. One on " Stages of Hypnotic Memory " (pp. 51 5-31) adds most striking evidence to what he before adduced in MIND ix. 110 ft'., x. 161 ff., as to the discontinuity of memory between different stages of the hypnotic trance and its continuity between recurrences of the same stage, within limits, however, that are now for the first time approximately defined. The other memoir on " Peculiarities of certain Post-hypnotic States " (pp. 268-323) is still more remarkable for the light it throws, by a protracted series of experiments (some, with planchette, of a quite iiovel description), upon those most puzzling manifestations of " secondary intelligence " that are dis- closed in the performance, more or less unconsciously, within the waking state of orders given in the hypnotic trance. In both memoirs the writer touches, with a skilful hand, on the philosophical implication of the facts, as bearing on the question of personal identity. Essai de Psychologic Generale. Par CHARLES EICHET, Agrege a la Faculte cle Medecine de Paris. Avec figures dans le texte. Paris : F. Alcan, 1887. Pp. xiv., 193. "General psychology," in the author's conception, is a synthesis of psychological facts, viewed in their general aspects, from the knowledge of their ultimate elements made possible by physiology, of which psychology is simply " the obscurest chapter ". A notion of his procedure is given by the order of treatment he adopts, which is as follows : (1) " Irritability," <2) " The Nervous System," (3) " Reflex Movement," (4) " Instinct," (5) "Consciousness," (6) "Sensation," (7) "Memory," (8) "The Idea," (9) " The Will ". " Cellular irritability," which includes both " sensibility " and " motor reaction," may be regarded as " elementary psychical life ". It manifests itself under the three forms of " reflex action," " instinct " and " intelligence ". The characters alike of reflex action and of instinct are " fatality and finality ". That is to say, they take place for the advantage of the organism or the species, but without consciousness of their end. All the distinctions of instinct from reflex action depend on its greater com- plexity. " Instinct, or at least complicated instinct, supposes unintelli- gence, just as intelligence supposes the absence of instinct." Man has