82 



NATURE 



[SEPTEMBER 15, 192 1 



symptom has also been generally recognised. Nodule- 

 formation, however, occurs in many cases other than 

 those in which it is merely a secondary symptom of 

 brown bast. 



The occurrence of diseased sieve-tubes in brown bast 

 tissue, prior to the appearance of the disease in or ad- 

 jacent to the latex vessels, has not been previously 

 recorded, and if this is corroborated it may lead to 

 further advance in our knowledge of this disease. 



The statement that the diseased laticiferous tissue is 

 enclosed in "stone-cell pockets " formed by the activi- 

 ties of wound cambiums is at variance with the 

 results obtained by workers in the East generally. 

 Occasionally stone-cell groups, which are abundant in 

 normal cortex, are fortuitously enclosed within the 

 nodule cambium at the time of its inception. The 

 nodule cambium by its subsequent division lays down 

 wood elements on the inside and cortical elements on 

 the outside. It is a striking characteristic of cortex 

 overlying old nodules, and presumably entirely derived 

 from the nodule cambium, that stone-cells are com- 

 pletely absent. G. Bryce, 



Asst. Botanist and Mycologist. 



Department of Agriculture, Peradeniya, Ceylon, 

 July 21. 



Mr. Bryce is quite correct in his reference to the 

 work of Bateson and others. In a brief note, how- 

 ever, historical reference to the bibliography . of 

 "brown bast" and related phenomena was not con- 

 templated for a moment. The work of Sanderson and 

 Sutcliffe was mentioned in consequence of the recent 

 publication of their book on "Brown Bast." With 

 the Editor's permission, it is proposed to deal further 

 with the subject of this disease in a future issue of 

 Nature. The Writer of the Note. 



The Nature of Vowel Sounds. 



If you will permit me to refer at this late date to 

 Prof. Scriptui'e's articles in Nature of January 13 

 and 20 last on the nature of vowel sounds, I should 

 like to emphasise the great service that the writer 

 has done in pointing out that the ordinary methods of 

 harmonic analysis are not necessarily adequate for the 

 determination of the composition of a given tone, and 

 may, indeed, give quite a false representation of the 

 facts, because the sound may have inharmonic com- 

 ponents. At the same time, it is doubtful whether his 

 note in Nature of March 3. (p. 12) in reply to another 

 correspondent, interpreting some of Prof. Miller's 

 results in this field, are justifiable. Prof. Miller's 

 curves are evidently harmonic, from the fact that they 

 repeat themselves very faithfully at regular intervals 

 and establish without much doubt that vowel sounds 

 (and some others) at least can be so produced that they 

 are susceptible of harmonic analysis, whether they are 

 always of such nature or not. The fact that Prof. 

 Scripture finds the quality of the voice constantly 

 changing in speech is not a matter of surprise, any 

 more than that the human face and form rarely 

 remain exactly the same for two seconds at a time 

 in waking hours ; it need not preclude us, however, 

 from seeking to maintain a given quality for a time 

 for purposes of analysis and record, any more than 

 the latter fact prevents us from sitting for portraits. 



There is, however, a point in the first article that is 

 open to distinct criticism. The author says (p. 633) : — 

 " In the analyses of vowel waves the fundamental is 

 indicated as weak, or often almost lacking. . . . We 

 all know that this is the strongest tone of all." It 

 takes all the point out of scientific research if we are 

 going to discard its plain results for what "we all 

 know," especially if the fact of *' knowledge " stands 

 on such weak grounds as does the one here referred 



NO. 2707, VOL. 108] 



to. All that we are justified in saying is that a com- 

 plex note is by common judgment considered as 

 having the pitch of its fundamental ; this may 

 happen in cases in which the fundamental is 

 known to be weaker than the upper partial or 

 partials — a fact for which we have the authority 

 of Ohm, Helmholtz, and the late Lord Rayleigh 

 ("Theory of Sound," val. i, sec. 26). When 

 Prof. Scripture states that fundamentals are " not 

 of the nature of sine vibrations," he deprives us of 

 any rational definition of the term ; we could build 

 up his type of fundamental vibration from a number 

 of sine vibrations of shorter period, and thus produce 

 a sound of low pitch from a number of high-pitched 

 ones. 



What I believe to be the true interpretation of Prof. 

 Scripture's results and those of others in this field — 

 in fact, the inescapable conclusion — is that the funda- 

 mental is, indeed, extremely weak in many of the tones 

 produced by the voice and other musical instruments, 

 and that it is further masked in the records by the 

 comparative lack of sensitiveness of the ordinary 

 recording apparatus in the lower ranges. We must 

 then also conclude that there is something in the 

 physiology or psychology of hearing, or in both com- 

 bined, whereby the lowest component of a complex 

 tone, the fundamental, fixes for the hearer the pitch 

 of the whole tone, while the presence or absence of 

 certain upper partials and their relative strength deter- 

 mines Its qualit3^ 



The glottal puff theory is not inconsistent with the 

 harmonic theory. Helmholtz accepted it and stated it 

 very clearly, as seen in the following extract from 

 his " Tonempfindungen " (Ellis's translation, p. 103): 

 — " In order to understand the composition of vowel 

 tones we must, in the first place, bear in. mind that 

 the source of their sound lies in the vocal chords, 

 and that when the voice is heard these chords act as 

 membranous tongues, and, like all tongues, produce 

 a series of decidedly discontinuous and sharply 

 separated pulses of air (Ltiftstdsse), which, on being 

 represented as a sum of simple vibrations, must con- 

 sist of a very large number of them, and hence be 

 received by the ear as a very long series of partials 

 belonging to a compound musical tone." There 

 remains to be applied a positive test, which, as Prof. 

 Scripture points out, should not be dependent on the 

 harmonic analysis of curves to determine whether or 

 not Helmholtz was right in concluding that the 

 partials of the voice tones are harmonic. 



With reference to another point in the articles, it 

 seems to me to be no more justifiable to say that the 

 difference between tlie voice of a Caruso and that of 

 a costermonger lies solely in the vocal chords than it 

 would be to say that the tone of a reed instrument 

 depends only on the reed, without reference to the 

 size, shape, material, etc., of the rest of the instru- 

 ment, e.g. that the difference between a bassoon and 

 an oboe is only a difference of reeds. 



Preston Edwards. 



Clark LTniversity, Worcester, Mass., July n. 



The first essential point of the interesting com- 

 munication of Mr. Preston Edwards lies in the ques- 

 tion of the weakness of the fundamental in the tone 

 of a vowel. This tone is that of the larynx, or the 

 voice tone. To the ear this is always the pre- 

 dominating tone. We may not be able to distinguish 

 what vowel a singer is producing, but if we can 

 hear him at all we hear the tone he is singing — that 

 is, the tone from his larynx. When a larynx from 

 a freshly killed animal is subjected .to a blast of air 

 and the vocal chords are brought together, a strong 

 tone is produced. 



