_La Géométrie Générale et les Jugements Synthétiques a priori_ is a reply by M. G. Lechalas to an article by M. Renouvier in the _Critique Philosophique_ criticising M. Calinon's theory of geometrical spaces embodied in the system of "general geometry." While showing that spaces with three dimensions are rationally included in a space with four dimensions, M. Lechalas recognises the impossibility of establishing such a geometry, seeing that we have no figure that answers to what a four-dimensional space would be, as well as the purely formal character of the presentations of non-Euclidian figures. (Paris: F. Alcan.) ZEITSCHRIFT FÜR PSYCHOLOGIE UND PHYSIOLOGIE DER SINNESORGANE. Vol. I, No. 2. CONTENTS: UEBER DIE WAHRNEHMUNG UND LOKALISATION VON SCHWEBUNGEN UND DIFFERENZTÖNEN. By _Carl L. Schaefer_. DIE ASSOCIATION SUCCESSIVER VORSTELLUNGEN. By _H. Münsterberg_. BRIEFE VON G. TH. FECHNER: UEBER NEGATIVE EMPFINDUNGSWERTE. (Concluded.) Edited by _W. Preyer_. LITERATUR-BERICHT. The results of Mr. Schaefer's researches are that for the localisation of the vibrations of two tones, in the case of their unequal relative intensity, the direction and distance of the relatively louder tone are determinate. If the relative intensity of the primary tones is equal, the vibrations are heard to proceed from the region between the two sounding points. Differential tones are heard between the ears, when the sounding sources are in the median plane; but when both primary tones come from the same side, in or immediately before the ear on that side; and in case of unequal intensity, when both come from different sides, on the side of the softer sound. Prof. Münsterberg concludes that there is no _successive_ association of ideas; when successively appearing, they are received singly into the memory. The letters of Fechner are continued from No. 1. ZEITSCHRIFT FÜR PSYCHOLOGIE UND PHYSIOLOGIE DER SINNESORGANE. Vol. I, No. 3. CONTENTS: UEBER DIE KLEINSTEN WAHRNEHMBAREN GESICHTSWINKEL IN DEN VERSCHIEDENEN TEILEN DES SPEKTRUMS. By _W. Uhthoff_. DIE ÆSTHETISCHEN GEFUEHLE. By _A. Döring_. BESPRECHUNGEN: (1) A. Mosso's und A. Maggiora's "Ueber die Gesetze der Ermüdung." (2) Münsterberg's "Beitraege zur Experimentellen Psychologie." LITERATUR-BERICHT. Dr. Uhthoff, in order to determine the least visual angle of perception, has employed a grating in a pure-monochromatic spectral field. His results were that the angles in the different parts of the spectrum are essentially equal. Æsthetic emotions, Mr. Döring contends, proceed from the unhindered play of the functions of psychical faculties; their contrary, from the inhibition of the same.