Notices respecting New Books. 319 



would open the necessary communication, and especially cross 

 fractures combined with two orthogonal shifts, as in the figure. 

 This may easily be illustrated with four books, laid corner 

 to corner and shifted as shown. Indeed a steam-tight envelope 

 can only be maintained under great compression, and any dis- 

 turbance would tend to allow a passage through it. Thus the 

 difficulty of getting the heat up from below seems capable of 

 being explained away ; and many of the phenomena of meta- 

 morphism may be accounted for by the percolation of steam and 

 highly heated water, which, not having reached the surface at a 

 sufficient temperature, may have failed to establish a volcanic vent. 



XXXVII. Notices respecting Neio Books. 



On the Sensations of Tones as a Physiological Basis for the Theory of 

 Music. By Heemaits" L. F. Helmholtz, 31. D. Translated, with 

 the Author's sanction, from the Third German Edition, with Addi- 

 tional Isotes and an Additional Appendix , by Alexander J. Ellis, 

 F.M.JS. 



TTTE have now before us the translation of the third edition of 

 * * Prof. Helmholtz's ' Toncmpfindungen ' by Mr. Ellis. Though 

 the English scientific public has for some time been acquainted with 

 the principles and methods of this work through Mr. Sedley 

 Taylor's able exposition, it was a want much felt that we had no 

 translation of the original Treatise. 



This want has now been supplied in a clear and forcible trans- 

 lation, which, besides the advantage of easy and pleasant English, 

 has the additional advantage of avoiding such words as timbre, and 

 clang, and clangtint, which we agree with Mr. Ellis in considering 

 unnecessary as our scientific nomenclature now stands. 



The purpose of this book is to give, so far as this is possible, 

 a physical explanation of music and of the physical materials at 

 the command of the musician. 



It sets forth how much our organs of hearing can do, w r hat 

 objective facts are presented to them, and how from the two we 

 can explain the analysis of Sounds, Concord and Discord, Melody 

 and Harmony. 



The first section of the w 7 ork discusses partial tones, with their 

 influence on quality of tone, and also the physiology of the ear, 

 with the object of discovering how we are able to analyze and 

 combine sounds. The waves of the sea are seen moving across 

 each other and coalescing, then separating again, and each pur- 

 suing its own path; the whole process of interference is here 

 apparent to the eye, but the ear cannot so survey the waves of 

 sound. The passages of the ear are so small compared with the 

 waves of sound, that only those motions in the directions of the 

 axis are available for disturbing the air in it. But though the 

 ear cannot survey the process of interference, it yet possesses the 



