462 



NATURE 



[August 9, 19 17 



It would greatly facilitate the work of a student 

 if a reference were gi^^^en in the margin to the 

 chart, which should be consulted in all cases where 

 directions are given for plotting courses or bear- 

 ings, etc. 



On chart vi, the isobar between 28" 78 and 29*09 

 should be 28*94, and not 28"24. 



Dr. Fowler omits to notice the great advantage 

 of the "knot," It combines a measure of a time 

 with a measure of distance — one knot signifying 

 one nautical mile per hour, ten knots ten nautical 

 miles p>er hour. ^ 



MENTAL ASPECT OF SOUND. 



The Psychology of Sound. By Dr. H. J. Watt. 

 Pp. vii + 241. (Cambridge: At the University 

 Press, 1917.) Price 105. 6d. net. 



THIS volume is written by a psychologist of 

 repute, who is a lecturer on psychology in 

 the University of Glasgow. It is one of the 

 most important presentations of the sense of hear- 

 ing since the time of Helmholtz. It is true that 

 Dr. Watt discusses hearing more from the psycho- 

 logical than from the physiological point of view ; 

 he is less interested in the physiological mechanism 

 than in the mental experiences associated with 

 hearing. Still, the author is familiar with 

 physiological theories regarding hearing and the 

 cochlea. In the eighth chapter he gives an ex- 

 cellent critical account of all the physiological 

 theories from Helmholtz onwards, and discards 

 them more or less in favour of a theory of his 

 own, which he thinks reconciles psychological and 

 physiological data better than any other. 



His theory, briefly stated, is that the basilar 

 membrane does not act as a resonance apparatus, 

 but when a sound wave enters the cochlea from 

 the stapes there are variations of pressure at 

 points of the basilar membrane — positive and 

 negative pressures — positive when the pressure is 

 increased by the stapes, negative when the pres- 

 sure is diminished and backward; and the nega- 

 tive pressure "dissipates itself in all directions." 

 It is not easy to understand the illustrative dia- 

 gram on p. 164. There remains the doubt whether 

 an accurate analysis can be made of motions in 

 a space of such small dimensions as the scala inter- 

 media. Nor is it easy to see what is gained over 

 the resonance theory by the resolution of motions 

 into positive and negative pressures. 



Limits of space forbid giving a detailed account 

 of many of the author's views. Pitch is primarily 

 a variation of auality, or it includes that withi" 

 it. Physiologists have used the term " quality " 

 with a different meaning, and they prefer a 

 "quantitative classification" of pitch. Pitch, in 

 our view, depends on the number of pressures on 

 the. auditory mechanism, or the duration of each 

 pressure, and this fits in with a theory of rcr 

 sonance. Again, the word "mass," as apolied to 

 tones, is liable to lead to confusion. " Bi-tonal 

 mass" is a term difficult to understand ; the mean- 

 ine: of tone or blending of tones is clearer if we 

 think of the fusion of two or more waves to form 



NO. 2493, VOL. 99] 



one. There is an important chapter on the 

 analysis of tonal sequences, and interesting ex- 

 planations are given of experiences on this sub- 

 ject. The author discusses melody and the 

 formation of scales. " Intensity is not, as is often 

 supposed, the direct basis of auditory localisa- 

 tions, but only the indirect basis. It is required to 

 provide a means whereby the predominance of 

 one order over others may be attained." There 

 must be a predominant order. This is difficult to 

 understand. Surely it is easier to regard intensity 

 as the result of greater or less stimulation? The 

 author gives an admirable summary of his con- 

 clusions. His most important point is that the 

 cochlea has few of the characters of an analytic 

 apparatus, and thus much of the resonance theory 

 is discounted. 



This is undoubtedly a book on psychology, but 

 it will indirectly be of much service to the physio- 

 logist. The physiologist has to explain how the 

 ear works, and he confines himself to the 

 mechanism. The psychologist adds to this, 

 mainly by introspective methods, an attempt to 

 explain the experiences associated with hearing, 

 and the feelings that arise from these. Psychology 

 and physiology are distinct departments of 

 science, and each must be investigated by its own 

 methods. The danger is to allow one province 

 to encroach on the other. One has to remember 

 also that when we listen to a tone, or a com- 

 bination of tones, as in music, we have to do 

 not only Avith the cochlea, but with neural pro- 

 cesses in the brain and elsewhere. The psycholo- 

 gist may be able to frame theories that will explain 

 these experiences, but neither he nor the physiolo- 

 gist can tell us much of the neural phenomena. 

 We do not accuse Dr. Watt of mysticism. He is 

 too learned a psychologist to fall into this error. 

 An extensive bibliography, enumerating no fewer 

 than 159 separate works, shows how he has drunk 

 deeply at the well-springs of both psychology and 

 phvsiology. Not a little in this book will awaken 

 reflection. There is an excellent index. 



J. G. M. 



OUR BOOKSHELF. 



Cotton Spinning. By W. Scott Taggart. Vol. iii. 



Fourth edition. Pp. xxviii + 462. (London: 



Macmillan and Co., Ltd., 1916.) Price los. 

 net. 



Mr. Scott Taggart's treatise has become a stan- 

 dard book of reference on cotton spinning, and 

 deservedly so ; the illustrations are excellent, the 

 descriptions of the various pieces of mechanism 

 are clear and adequate, and the scheme of the 

 work is based upon the regular sequence of the 

 movements dealt with. 



Vol. iii. is devoted to mule and ring spin- 

 ning, to winding, doubling, reeling, gassing, 

 bundling, mill planning, and humidity. It also 

 contains a chapter on " L^seful Information." fo j 

 most cases attention has been given to the rela- 

 tive importance of the several sections into which 

 the treatise is divided, but more care might, uitn 



