452 



NATURE 



ISept 23, 1875 



has not stopped here. In chemistry, when a discovery 

 has been made of the constitution of a compound body, by 

 analysing it into its constituent elements, the efforts of the 

 chemist are naturally turned to the converse process of 

 proving the same proposition by synthesis, or by combi- 

 ning the single elements and showing that they will produce 

 the compound. This proof has not been wanting in the 

 present case, for Helmholtz has succeeded in combining 

 simple sounds together in such a way as to produce imi- 

 tations not only of vocal sounds, but of many other pecu- 

 liar qualities of tone ; not perfectly, from the extreme 

 difficulty of imitating exactly all the minute shades of 

 difference that enter into the combination, but still with 

 enough success to demonstrate the general argument. 



We have given especial prominence to Helmholtz's 

 discoveries on the nature of musical sounds, because this 

 is in reality the great feature of his work, by which it 

 first acquired its fame, and by which his name will here- 

 after be honoured. But the physical part of the book 

 contains much beside this that is important and interest- 

 ing. His explanations on the general phenomena of 

 acoustics are most lucid, and often very original ; and 

 his descriptions of the mechanism and action of the 

 organs of hearing, coming from one of the highest autho- 

 rities in physiology, are exceedingly instructive and 

 valuable. 



In Part II. the author enters into an investigation of 

 what are called beats— z. subject which has been hereto- 

 fore very obscure— and also of other acoustical pheno- 

 mena called " combination tones," which, though known 

 since the time of Tartini, have not been thoroughly 

 understood till Helmholtz gave their explanation. Into 

 these matters we have not, however, space to follow the 

 author : those who are interested in them can refer to the 

 book for themselves. 



Before we leave the physical part of the work it will be 

 only just to testify to the excellence of the translation. 

 Mr. Ellis is so well known as a philologist and a man of 

 science, that his competence to deal with the work in a 

 literary and scientific point of view requires no comment, 

 and English readers may be satisfied that in this transla- 

 tion they have the original faithfully put before them. 

 His work has evidently been a labour of love, and he 

 deserves the highest credit for the trouble he has taken 

 over it. 



At the same time all men are fallible, and when a great 

 authority condescends to do a work that could hardly be 

 expected from him, we must not be unprepared for some 

 little waywardness on his part, and there are a few things 

 which we would rather have seen otherwise done. The 

 title of the book is unfortunate ; for, although no doubt 

 "The Sensations of Tone" is a correct translation of 

 " Tonempfindungen," yet to many English ears it will, we 

 fear, sound strange and unintelligible from the fact that 

 we are hardly accustomed in our language to understand 

 the word " tone " in the sense here intended. The English 

 title certainly does not give to the English reader anything 

 like the same idea as the original title, " Die Lehre von 

 den Tonempfindungen," does to an educated German. 

 The strict rendering of a German phrase does not always 

 correctly represent the original ; for example, in speaking 

 of the clever little tract of Hauslick, "Ueber das Musicka- 

 lisch Schone," Mr. EUis translates it, " On the musically 



beautiful," whereas, as every reader of the tract well knows, 

 the more appropriate expression in English would be " On 

 the beautiful in music." 



But the chief fault we' have to find in the translation is 

 the rendering of a term which of all others is the most 

 important in the whole work, and in which the translator 

 has, we conceive, taken a liberty not altogether justifiable. 

 Helmholtz, in describing the compound nature of musical 

 sounds, has called all the sounds above the fundamental 

 one by the name of " obertone,'.' a word exceedingly 

 appropriate, useful, and expressive, 'inasmuch as it at once 

 defines and includes all these sounds in one appellation. 

 Prof. Tyndall, in his resume of Helmholtz's discoveries, 

 has most naturally and with great propriety translated 

 this term by the word "overtones." It exactly expresses 

 the German in the simplest way, and it is as perfectly 

 admissible into English as " overcoat " or " overseer." 



Unluckily, Mr. Ellis is either too proud to adopt this 

 word or has taken otherwise a dislike to it ; for, on the 

 ground that he does not consider it good English, he sub- 

 stitutes for it the expression " upper partial tones." This 

 is not only clumsy and roundabout, but it is imperfect and 

 wrong, inasmuch as it does not include, as the original 

 expression does, the ivhole of the sounds above the funda- 

 mental, and gives no means of distinguishing higher 

 overtones from the lower ones. As these overtones play 

 such an exceedingly important part in Helmholtz's work, 

 we cannot but consider, with all respect to Mr. Ellis, this 

 rendering a blot on the translation which we very much 

 regret. 



We must reserve our ^notice of the musical portion of 

 Helmholtz's work till a future opportunity. 



OUR BOOK SHELF 



Guide to the Geology of London and the Neis^hbour- 

 hood (Geological Survey of England and Wales). By 

 William Whitaker, B.A., F.G.S. (London : Messrs. 

 Longmans and Co., 1875.) 



It is a matter of great satisfaction to geologists that the 

 Geological Survey are again giving to the public some of 

 the accumulated stores of information of which they are 

 necessarily possessed, by resuming the series of large 

 and complete memoirs which had been in abeyance for 

 many years before the publication of " Whitaker's Geo- 

 logy of the London Basin," Part I., in 1872— a series now 

 so well continued by the works of Judd and Topley. 

 These, however, are comparatively expensive, and enter 

 into minute details, so that although the whole of the 

 information contained in the small book under notice has 

 already been given at greater length in Mr. Whitaker's 

 work mentioned above, or will be in a similar promised 

 pubUcation on the " Drifts of the London Basin," it will 

 be of great use to a large number of persons who would 

 not care for a more detailed description. A special Geo- 

 logical Map of London and its Environs, with all the 

 Drift beds indicated, has lately been published, and for 

 the last two years the Geological Model of London on a 

 six-inch scale has been the admiration of all visitors to 

 the Jermyn Street Museum : the pamphlet now before us 

 is designed as a handbook to these. It commences with 

 a description of the construction of the model, a matter of 

 no small difficulty, considering the accuracy of the repre- 

 sentation. The description of the various formations which 

 enter into the London area, with their resulting features 

 and scenery, though necessarily short, contains the cream 

 of all the known facts, and what is better still, the reasons 

 for all the not self-obvious determinations of the age and 



