98 



NATURE 



[March 25, 1920 



tively rare. The Mesozoic and Tertiary rocks, 

 however, are rich in silicified and other petrified 

 woods, many of which belong- to the coniferous 

 genera. The determination of these woods is a 

 particularly difficult branch of palaeontological re- 

 search, demanding^ great patience and knowledge 

 of the finer points of plant structure. Wood deter- 

 minations are often — indeed generally — neglected, 

 •owing to the difficulty of mastering the technique ; 

 but, as Prof. Seward truly says, "the student 

 •cannot afford to neglect this line of inquiry if he 

 (desires to obtain a comprehensive view " of the 

 essentials of palajontological plant history. In 

 the present volume a considerable proportion of 

 the space is allotted to the careful and critical con- 

 sideration of the species based on secondary wood. 



The terminology of this section is not entirely 

 that adopted by other leading workers in this 

 field, but tends perhaps to simpler grouping of 

 the subject by the elimination of certain "genera " 

 which are based on distinctions too subtle for 

 secure determination, such, for instance, as the 

 Phyllocladoxylon of Gothan. The elimination of 

 doubtful genera, principally those which have 

 names suggestive of affinities remote from those 

 with which they properly are really to be asso- 

 ciated, on the whole tends towards the clarifying 

 of the science. 



In conclusion, one can only urge every geologist 

 and every botanist not only to possess himself of 

 Prof. Seward's text-book, but also to acquaint 

 liimself with its contents. 



The Nature of Musical Sound. 

 The Foundations of Music. By Dr. Henry J. 

 Watt. Pp. xvi + 239. (Cambridge : At the 

 University Press, 1919.) Price 185. net. 



THE author unfolds a new theory to account 

 for the fact that certain combinations of 

 sound, called concords, are "pleasant," while 

 others, called discords, are "unpleasant." In 

 place of the ancient theory by which the " harmony 

 of numbers " in the sense of proportions of string- 

 length to pitch has dominated these questions 

 since the days of Pythagoras, he considers that 

 sound possesses "volume," an attribute some- 

 what difficult to grasp at first sight. So far as 

 we can understand the new theory, the volume 

 of a low sound contains within itself the volumes 

 of all sounds higher than itself; the proportions 

 of the various volumes coincide with the well- 

 known proportions of those of pitch. Hence the 

 volume of the sound represented by C is exactly 

 double that of the next C above it, and the volume 

 of G, lying between the two, is two-thirds that 

 of the lower C. 



NO. 2630, VOL. 105] 



As the lesser volume is contained in the greater^ 

 there is " fusion " of volume when two sounds are 

 heard together. This fusion being complete in 

 the octave, the two sounds coalesce to such an 

 extent as sometimes to be heard as one sound. 

 We are to understand, then (so far as we can 

 make out), that the octave is the " pleasantest " 

 interval. Next come fifths and thirds as pleasant 

 intervals ; and the di.scords, the volumes of which 

 do not fuse with the root volume, are classified 

 as "unpleasant " (pp. 24 et seq.), or words to that 

 effect. We confess that this theory is so novel 

 that we find it hard to grasp. To the musician 

 a discord is not an "unpleasant" part of his raw 

 material ; it is simply a chord that requires to 

 be " resolved " into a succeeding chord. It has, 

 therefore, the element of motion, while the con- 

 cord suggests repose. 



The theory of fusion raises the ancient question 

 of the prohibition of consecutive fifths and 

 octaves. The author discusses at great length all 

 the well-known attempts at explanation, and adds 

 his own. Probably the prohibitions are merely 

 conventions, as suggested by Cyril Scott, quoted 

 in a footnote on p. 132. In the tenth century 

 Hucbald says of the ancient organum of his day : 

 " If sung with suitable slowness, you will see 

 that it produces a sweet concord." The present 

 reviewer, wishing to scoff at the notion that suc- 

 cessions of fifths and octaves could "produce a 

 sweet concord," asked the choir of the Plainsong 

 Society to sing a specimen of tenth-century 

 organum. To his and their surprise they found 

 Hucbald entirely vindicated. And Dr. Watt 

 shows (p. 84) that Gevaert, making a similar experi- 

 ment at Ghent in 1871, found exactly the same 

 result: "The impression made on the audience 

 was profound." 



The only example Dr. Watt gives in musical 

 notation (p. 120) is a series of consecutive fifths 

 by Karg-Elert, played very slowly on the softest 

 organ stop. He offers an explanation of its 

 " beauty " ; we think, however, that the same 

 passage, if sung or played rapidly and loudly, 

 would be anything but beautiful. 



Dr. W^att revives the old controversy as to 

 whether the interval of the fourth is a concord 

 or discord. W^e thought that musicians had long 

 settled that the fourth from the bass, since it 

 requires resolution, is a discord, while the fourth 

 from any other voice is a concord, since it does 

 not require to move. 



The book ends with chapters on "The Object- 

 ivity of Beauty" and ".Esthetics as a Pure 

 Science." To those wishing to investigate the 

 nature of sound, its new outlook should prove 

 interesting. 



