Oct. 20, !88i] 



NATURE 



581 



Music." The book itself may without unfairness be de- 

 scribed as an "arrangement," or rather as a " pot-pourri,'' 

 inasmuch as it reiembles those musical compositions in 

 which some of the fragmentary themes of one or more 

 gre, t masters are dished up for the public in some new or 

 popularised setting, consisting of commonplaces of a more 

 or less florid type. About So per cent, of the pages before 

 us consist of clippings and quotations taken verbatim ct 

 literatim (and in quotation marks be it added) from 

 the works of Helmholtz, Stone, Pole, Tyndall, and Sedley 

 Taylor, interspersed with a connective-tissue woven from 

 the "author's" own brain. We have found this in- 

 genious fabric very remarkable reading, and have gleaned 

 a number of new facts from it. We have learned, for 

 example, that the transmission of verbal messages, prayers, 

 h)mns, and sermons through the telegraph wiie by the 

 telephone must be held to " prove that air is not the only 

 medium through which sound-impulses can pass." We 

 find our author declaring on p. 80 that the reason why so 

 romantic a name as the " s\ ren '' should be applied to so 

 matter-of-fact an instrument docs not appear; while on 

 p. 98 he seems to have made the discovery that the name 

 is a misnomer, because "Homer's Seipjji'eos " («'<:) were 

 not endowed with the power of singing under water as 

 this instrument can. C ur author is very unhappy in 

 dealing with equal temperament, and complains that 

 nearly all writers on temperament, with the exception of 

 Mr. Ellis, describe it as dividing the octave into twelve 

 precisely equal semitones, " without explaining that these 

 semitones are not absolutely equal." That the perfect 

 equality of the theoretically equal temperament is never 

 attained in practice is indeed true; but why does our 

 author find fault with writers on temperament for stating 

 the exact theory ? His accusation again=t Dr. Stone for 

 palpable misuse of language (on p. 359) is utterly out of 

 place, and only shows that the author has not compre- 

 hended the true meaning of a mu^ical interval as defined 

 by a ratio. He appears not to know that if an octave is 

 divided into twelve e>actly equal gecimetrical parts or 

 ratios, the differences between the successive terms of the 

 ratios are not, and canr.ot be, arithmetically equal to one 

 another. Hence his attack on the perfectly unexception- 

 able statements of Ur. Pole and Dr. Stone. The dia- 

 grams w ith which the work is interspersed consist prin- 

 cipally in pictures of syrens and in copies of wave-forms 

 taken from IVlr. Sedley Taylor's "Sound and Music," 

 and spoiled by drawing them as if made up of semicircles 

 pieced together. The wave-form given on p. 266 to illus- 

 trate beats does not show the wave-form of the beat at 

 all : and though the author gives on p. 102 a wave-form 

 which illustrates a beat admirably, he appears not to know 

 it, as he passes it by as being merely one of a few dif- 

 ferent forms of tracing which a vibroscope can register. 

 Rut we have said enough to justify us in having at the 

 outset pronounced "The Student's Helmholtz" to be 

 what we called it — a pot-pourri — or, in the pknn English 

 tongue, a hash. 



Afrika iin Lichte unserer Tage. Bodengestalt und geolo- 

 gischer Bau. (With a Hypsometrical Map.) By Josef 

 Chavanne. (Vienna : A. Hartleben.) 

 The conclusions come to by Herr Chavanne we have 

 already referred to. Africa, he finds, is, on the whole, a 

 high plateau or table-land, crossed here and there by 

 mountain-chains or single ekvations. The plateau com- 

 mences in most places at a remarkably short distance 

 from the sea, the slopes south of the equator being par- 

 ticularly steep. North of the equator the land may be 

 looked upon as a very slightly inclined plane, which, like 

 the southern plateau, is also crossed by separate eleva- 

 tions, some of them being very considerable. The 

 presence of numerous, and for the greater part widely- 

 distributed, kikes is unlike the general physiognomy of 

 the other large continents. By far the most important 



part of the author's work is the excellent hypsometrical 

 map whii'h accompanies the book, and to which we 

 referred a short time ago. Its scale is i : 30,000,000. 

 The elevations are marked in eight different tints of 

 brown, showing so many grades and altitudes from zero 

 upwards. Thus at one glance we see the African con- 

 tinent rising as a rule from o to 600 metres in the 

 northern half, while, in the southern half, elevations from 

 goo-1200 metres are the rule. The greatest heights — 

 those of 1 500-2000 metres and more — are packed close 

 together on the east side, between the suuthern end of 

 the Red Sea and the Zambesi River, and only occur 

 again in the extreme south-east (Natal) and far up in the 

 north-west (.Atlas). The text of the book is well written ; 

 the author's descriptions are always attractive, to the 

 point, and free from all superfluous wordiness. 



LETTERS TO THE EDITOR 



[The Editor docs not hold hi msitf responsible for opinions expressed 

 by his correspondents. A'either can he undertalie to return, 

 or to correspond with the writers of, rejected manuscripts. 

 No tiolice is taken of anonymous communications. 



[ Tlie Editor urgently requests correspondents to keep their tetters 

 as short as possible. The prissiire on his space is so great 

 that il is impossible othenvise to ensure the appearance ev n 

 ofcommunicaticns containing interesting and ncvel facts.] 



Struggle of Parts in the Organism 



The review of Dr. Roux's work on the " Struggle of Parts in 

 the Organism " by Mr. Geo. J. Roinanes which appears in your 

 nun.ber t.f .September 29 (p. 505) contains .-ome p.nssages which, 

 I venture to ihink, are hardly con istint with the furpoie to 

 which the c ilumns cf Naturk are devctefl. I understand that 

 purpose to be the di-cu'sion of scieniificfnct* and^cientific laws, 

 pr. perly so called. I >hould he die last to deny ihat these facts 

 and these laws may have, and indeed mu^t have, their own ultir 

 mate bearing upcn therlogi', whether natural or revealed. But 

 it is not the | urpo e of a purely scientific journal to enter upon 

 this discu-.^ion ; it !■; r ne which cannot be there pursued without 

 involving c ntioversits alien to the spirit in which phy-i. al 

 science ouyht to be studied at d explained. 



And if even temperate discu sion upin the subject ought to 

 be avoided in a purely scientific journal, still more ought there 

 to he a ^cnipulcus abstention from dogmatic utterances whithare 

 hostile to theolrgical opinions, and which are unsupported by 

 iven the jcmblarce of argunr.ent. 



In the passages to which X refer Mr. Romanes a serfs that to 

 the whrile "argimient from design" in nature an '*end has 

 coir.e " — as the re.-ult tf Mr. Parwin's Theory of Evolution — 

 that the "fountains of this great deep have been broken up by 

 the p'Wer of one man," ard that "never in the history of 

 thought has a change been effected of a comparable magnitude 

 and im| ortance." 



As an expiression of the rpinion of Mr. Romtnes that the 

 Darwinian ihe( ry ought to put an end to the " argument from 

 design," this assertion may I:e allow-ed to pa;s. But as the 

 asseriitnof a fact I venture to say that- it has no foundation. 

 There are many minds, iriclacing some of thf ."^e most distin- 

 guished in science, who not only fail to see any conti'adiction 

 between tvolution and design, but who hold that the doctrine of 

 evolution and the facts on which it is founded have supj lied 

 richer illustrations than were ever before accessible of the opera- 

 tions of design in nature. 



I ^hould le transgressing my own rule Wire I to defend this 

 view in your columns. I shall theref. re content myself with 

 saying that no possible amount ( f discovei-y concerning the 

 physical causes of natural phenomena can affect the argument 

 that the combination and co-ordination of these causes which 

 produce the "apparent" effects of purpose are really and truly 

 what they seem to be — the work of Mind and Will. 



In ver.i ry, October 4 ARGYLL 



Solar Chemistry 

 The re;earches of Mr. Lockyer, and others, summarised by 

 him in recent numbers of Nature, have to a gi'eat extent com- 

 plicated the aspect of this gi-and problem, which appeared so 



