430 PHILOSOPHICAL PERIODICALS. koerperchen.' [An excellent paper, whose chief object is to determine the importance for pressure sensation of the magnitude of the stimulus surface. When the effect of velocity of deformation is ruled out, the optimal surface for a single end-organ is about 0*4 sq. mm. This fact, as well as the phenomena following from increase and decrease of surface, can be resumed in the law that for the excitation of a touch corpuscle a certain fall of pressure (expressed by dp/dr, where r is the distance of the given point above the cutaneous surface, and p the pressure at the same point) is necessary at the place of stimulation. The sensation is identical, whether the pressure be push or pull ; in either case the fall of pressure is the adequate stimulus of the organ. Its exact measure is impossible ; calibration of sesthesiorneters, etc., can, however, be suitably carried out in terms of an empirical tension unit, 1 gr. mm.] G. Heymans. ' Zur Psychologic der Komik.' [Lipps' general formula is that the insignificant has a large measure of psychical force put at its disposal ; the comic ele- ment is present when an expected significant is replaced by an insignificant, or when something seems significant, but turns out on examination to be insignificant. Heymans accepts the theory ; but adds the cases of dis- covery that an attractive novelty is entirely without interest, of the interruption of a significant by a disparate insignificant, of the sudden solution of an exciting riddle, and of momentary exaltation of a depressed self-estimation.] Litteraturbericht. PHILOSOPHISCHE STUDIEN. Bd. xiv., Heft 4. E. Mosch. 'Zur Methode der richtigen und falschen Faelle im Gebiete der Schallempfin- dungen.' [An investigation of sound intensities by the fall-phonometer, the primary object of which is to better the mathematics of the method of right and wrong cases in the light of the recent work of Bruns, Fechner and Lipps. The instrument was improved, and the procedure without know- ledge secured by the use of four in place of two stimuli. Result : the generalised law of distribution does more justice to the psychological facts than the simple Gauss law. The measure of uncertainty, U, however, has nothing whatever to do with the S. D. or with Weber's law. Whether the a;- values (limits of the different judgments) can do service in this regard remains to be proved.] R. Seyfert. ' Ueber die Auffassung einfachster Baumformen.' [Experiments with triangles. Most accurate apprehension is given with presentation of the figure to the eye, and tracing of contour by eye -movement. Next in rank stands eye-movement alone, without retinal image. Much less accurate, and requiring much more practice, is judgment with constant fixation. Simultaneous movements of hand and arm are usually prejudicial, though with a high degree of practice the reverse may obtain. Apprehension by means of such concomitant movements alone is practicable but inaccurate.] F. Kiesow. ' Zur Psychophysiologie der Mundhoehle.' [The painless region of the cheek is that bounded by the zygomaticus major, the triangularis, and the risorius Santorini (region of the third branch of the trigeminus). Sensitivity to pressure is normal (mechanical and electrical stimula- tion) ; as is the thermal sensitivity (heat and cold). Comparative determinations are given from other portions of the buccal mucous membrane.] F. Kiesow. ' Ein einfacher Apparat zur Bestimmung der Empfindlichkeit von Temperaturpunkten.' F. Kiesow. ' Schmeckver- suche an einzelnen Papillen.' [Experiments on thirty-nine fungiform papillae. Only four refused to react to any of the four stimuli, salt, sugar, quinine, hydrochloric acid. For the rest, great functional variations were observed.] E. W. Weyer. ' Die Zeitschwellen gleichartiger und disparater Sinneseindruecke,' I. [Historical : Exner, Hamlin, Drew (liminal time-interval between impressions) ; Wundt, von Tschisch (time-
