Notices respecting New Books. 77 



real cause of the disagreeable effect of beats upon the ear is no doubt 

 that suggested by Helmholtz when he compares it to the unpleasant 

 effect produced on the eye by frequent alternations of light and dark- 

 ness. Resultant tones, on the other hand, are probably perceived, just 

 as though they were primary tones, through the agency of quite a dis- 

 tinct set of ear-fibres (Corti's fibres) from those affected by the gene- 

 rating tones. In the same lecture (p. 301), speaking of the unsa- 

 tisfactory musical character of simple tones, such as the tones of 

 tuning-forks or of stopped-diapason organ-pipes, Professor Tyndall 

 contents himself with saying that such tones " would be like pure 



water, flat and dull, and would not satisfy the demand of 



the ear for brightness and energy." The reason of this — namely 

 that, with such tones, the difference between pure and impure inter- 

 vals is revealed to the ear only by resultant tones, generally of the 

 second or third order — is not alluded to. On pages 305 and 306 

 Professor Tyndall has reproduced Helmholtz's diagrams showing 

 the relative degrees of consonance and dissonance resulting from the 

 combination of the tone middle c with every possible tone up to 

 treble c, and of the latter with every tone up to c in alto. In the 

 explanation of these diagrams, it should have been stated, not 

 only that the marks es and as " are the German names of a flat third 

 and flat sixth," but also that b stands for a flat seventh, our bfy and 

 b \ being respectively represented in German musical notation by b 

 and h. 



The value of the book for educational purposes is much increased 

 by a short summary, following each lecture, of the most important 

 facts or principles that have been stated in it. But for easy refer- 

 ence to particular points it requires a greatly improved index. 



Professor Tyndall has in this work introduced several terms which 

 are new to the English vocabulary of acoustics. Overtones and re- 

 sultant tones are, we think, excellent English equivalents for the 

 German Obertbne and Combinationstone, and we receive them grate- 

 fully. We cannot, however, say as much for clangtint as English for 

 Klangfarbe. Our objections to this term are several. In the first 

 place, it appears to us unnecessary, the word quality having already 

 a perfectly well-understood technical meaning coincident with that 

 of the proposed new word. Secondly, the German word Klangfarbe 

 is itself objectionable, being founded upon a false analogy, the pro- 

 perty of sound which corresponds to the colour of light being pitch 

 and not quality. Lastly, Klang in German is used for sounds of all 

 kinds, and cannot be correctly translated by clang, which already im- 

 plies a special quality in the sound to which it is applied. To 

 speak of the clang of a flute, for instance, is almost a contradictio in 

 adjecto. 



