Notices respecting New Boohs. 283 



Professor G-oldschmidt, do not altogether agree with him and 

 think that, numerous as these fibres are, they are not so numberless 

 as to account satisfactorily for the minute gradations which are 

 perceptible ; the author believes the drum of the ear to play a very 

 important part. There can be no doubt that the appreciation of 

 musical tones depends wholly on the brain, which can, indeed, act 

 quite independently of the organ of hearing ; for do we not think, 

 even dream, of tones ? 



The second chapter is taken up with the Harmony of Colours, and 

 is analogous to the first chapter, but with some important modifica- 

 tions necessitated by the dissimilarity of the organs by means of which 

 our senses are affected. Since the eye, unlike the ear, has a range 

 of less than a single octave, and, if unaided, is incapable of resolving 

 a composite wave into its constituent parts, there is nothing con- 

 nected with light which corresponds to music ; and the discussion 

 must, therefore, proceed on different lines. The extent of our 

 knowledge of the constitution of matter has been vastly increased 

 by the discovery of the spectroscope. Much of what it has shown 

 us we understand ; but there still remains much which is not yet 

 explained. Many writers have endeavoured to trace a relation 

 between the spectral lines of the same elementary substance, and 

 also between the different elementary spectra, but as yet with 

 little success. If Professor Groldschmidt's principle of compli- 

 cation reveals the existence of some .-uch periodicity in the 

 elementary spectra, and determines for each the fundamental line 

 which corresponds to the tonic in a musical scale, a great step will 

 have been made towards the elucidation of the phenomena. In 

 the present work the author, however, merely deals with the fringe 

 of the subject ; he shows that the Praunhof'er lines in the solar 

 spectrum, with the exception of Gr, form a series of the falling 

 harmony type, and so do the lines in the spectrum of hydrogen. 

 Possibly he intends to discuss the subject at greater length in a 

 separate paper. 



The remaining sections of this chapter deal successively with 

 the various theories of colour-vision which have been put forward, 

 especially that of Young and Helmholtz, and the evolution of 

 colour-vision in Man and its development in children. 



In the concluding chapter it is briefly shown that the symmetry 

 involved in the law of complication is discernible in the characters 

 of the lower organisms, in corals and in plants ; and further, that 

 the methods of subdividing units of length, weights, and measures, 

 and systems of money, all conform to the same principle. _ 



"We have already mentioned that the later paper, " IJber har- 

 monische Analyse von Musikstiicken," is an expansion of the 

 section in the earlier work treating of the Harmony of Tones, 

 though the discussion is a little different. Since a knowledge of 

 crystallography is not among the ordinary qualifications of 

 musicians, the author has wisely based the discussion on the 

 diatonic scale, and not on the development of faces on a crystal. 

 He here shows that the transformations from the wave-lengths 



