LITERARY NOTICES. 



Nagel, W. (Herausgeber). Handbuch der Physiologic des Menchen. Dritter 

 Band (Physiologic dcr Sinnc;, Erstc Halftc, XII -\~ 282, 1904. Braun- 



sc/nveig, Vieweg und SoJin. 



This first installment of Nagel's "Handbuch" forms a little more 

 than a third of the volume devoted to sense-physiology, and, except 

 for two short introductory articles on the doctrine of specific energies 

 (Nagel, Berlin, pp. 1-15), and the psychology of the senses (v. Kries, 

 Freiburg, pp. 16-29), it is confined to physiological optics. Schenck 

 (Marburg) presents dioptrics and the accommodation of the eye (pp. 

 30-90) ; Nagel, the effects of light on the retina (pp. 1-108) ; and v. 

 Kries, visual sensation (pp. 109-282). Visual perception, and the nu- 

 trition and the protective organs of the eye are left for the second half 

 of the volume and will not, therefore, be considered in the present 

 review. 



Both introductory articles deal with certain concepts common to 

 all the senses. To place Johannes Muller's doctrine of specific en- 

 ergies beyond dispute, it would be necessary to show that different 

 stimuli, acting on the same nerve, produce the same sensation. Nagel 

 mentions that the only really clear confirmation of this kind is the 

 taste sensations that result when the chorda in the caviim tympani is 

 mechanically, electrically or chemically stimulated He concludes 

 that while the doctrine, with certain reservations in the case of the 

 lower senses, is doubtless in general valid, the efforts, dating from 

 Helmholtz, to show the existence of separate nerves with correspon- 

 dent specific energies within the individual sense-organs are not success- 

 ful ; for the differences in sensation may just as well be due to the differ- 

 ences in the outward stimuli as to the specific energies of the ner ve 

 fibers themselves. 



V. Kries's introductory discussion of the psychology of the senses 

 is important chiefly as a general estimate of the value of psychological 

 analysis for sense-physiology, a question which receives repeatedly 

 more specific attention in his longer article on visual sensation. Of 

 special interest is his view of the theoretical possibility of measuring 

 sensations (Fechner's Psychophysic Law), and his treatment of the 

 theory of specific comparisons, i.e. comparisons between sensations 



