12 



NATURE 



[March 3, 1921 



plication to the cyclones of middle and higher lati- 

 tudes, as it presupposes simple whirls like the sym- 

 metrical cyclone of the tropics. J. von Hann. 

 Vienna, February. 



The Ascent of Mount Everest. 



The opportunity which mountaineers and geo- 

 graphers have long looked for of approaching Mount 

 Everest from the north has at last arrived. The 

 Tibetan Government has given its consent for the 

 dispatch of an expedition to explore the mountain. 

 The expedition is now being organised by a com- 

 bined committee of the Royal Geographical Society 

 and the Alpine Club, and an attempt will be made 

 to ascend this the highest mountain in the world. 



The cost of the expedition is estimated at about 

 lOjOooZ, Already a quarter of this amount has been 

 raised among the members of the two societies. But 

 the expedition will have to leave England very shortly, 

 and it is essential to its success that the equipment 

 shall be the best possible, and that no financial un- 

 certainty shall delay the organisation in India of a 

 picked corps of Himalayan porters and of an adequate 

 transport service. Heavy initial outlay is therefore 

 involved, and we now appeal to the general public, 

 confident that it will wish to further an enterprise 

 the successful accomplishment of which will bring 

 so much credit to this country. 



Subscriptions should be sent to the Treasurer, Royal 

 Geographical Society, Kensington Gore, S.W.7, or 

 to the Bank of Liverpool and Martins (Cocks, Bid- 

 dulph, and Co. 's branch), 43 Charing Cross, S.W.i. 

 Francis YounghLisband, 

 President, Royal Geographical Society. 



J. N. Collie, 

 President, Alpine Club. 



February 23. 



I 



Pure Organic Chemicals. 



am glad to see that the writer of the leading 



article in Nature of February 24 directs attention to 

 the concern with which research workers view the 

 possibility of foreign organic chemicals being restricted 

 or excluded by legislation in the interests of British 

 manufacturers. 



The latter are not yet in a position to supply many 

 materials in that state of unquestioned purity such 

 as one associates with the old firms of Merck and 

 Kahlbaum in Germany and Poulenc Freres in France. 



As an illustration I may mention that I recently 

 ordered a pound of propyl alcohol (as catalogued) from 

 a British firm, and at the same time a like quantity 

 from Poulenc Frferes. The first forwarded a material 

 costing i8s. which consisted of a mixture boiling 

 over a wide range of temperature but containing no 

 propyl alcohol, whereas the French firm supplied a 

 pure sample of nearly constant boiling point costing 

 IIS., including postage. J. B. Cohen. 



The University, Leeds, February 25. 



Nature of Vowei Sounds. 



With regard to the very interesting researches on 

 vowel sounds by Prof. Scripture published in Nature 

 of January 13 (p. 632) and January 20 (p. 664), I beg 

 to be permitted to state that the attempt of Helm- 

 holtz to produce vowels with smooth, simple tones has 

 since been fully confirmed. Using, instead of tuning- 

 forks, bottles caused to sound by currents of air 

 blown over their orifices, which, as is well known, 

 give almost perfectly simple tones, I have been able 

 to demonstrate this myself. The remarkable and 



NO. 2679, VOL. 107] 



extended investigations of Prof. Miller described in his 

 book, " Science of Musical Sound," have fully proved 

 the statement of Helmholtz to be true, as have also 

 the researches of Prof. Stumpff, of Berlin. I am 

 therefore of the opinion that the Helmholtz theory of 

 vowel sounds can scarcely be doubted any longer. Her- 

 mann's and Scripture's method of producing vowels 

 by sending puffs of air through a resonator does not 

 contradict this. Whenever a complex vibration is 

 set up which appears to be a mixture of simple tones 

 corresponding to the sound of a vowel, there will be 

 produced a vowel. However, it is very important 

 to have repeated Hermann's experiments and ex- 

 tended them by using resonators with soft walls. 

 Charles de Wesendonk. 

 H6tel Eden, Montreux, Switzerland. 



The above letter very properly directs attention to the 

 excellent work of Prof. Miller. It is worth while to 

 study Fig. 130 of his book, reproduced below. For the 

 tuning-fork there is only one tone, namely, the funda- 

 mental. For the other instruments the fundamental 

 appears clearly, but for the voice the fundamental is 

 lacking. Thus the strongest tone in a vowel, the voice 

 tone, does not appear in the plot. This is in agreement 

 with the work of Hermann and myself. As explained 

 in Nature of January 13 and 20, this arises from the 

 fact that the voice tone consists of a series of puffs. 



i 



ill. 



1 



_1_ L 



t I . 



I 1 1 1 \ 1 I I I I M I M 



I 2 3 4- S 6 7 8 9 10 IS 



Fig. I. — Distribution of energy in sounds from various sources 



Prof. Miller's plots show that for the musical 

 instruments the harmonics appear strongly at certain 

 places. For the voice, however, the seventh, eighth, 

 and ninth harmonics appear. Three tones in the 

 relations 7:8:9 sounded together would produce a 

 most discordant sound with disturbing beats, and 

 certainly not the clear tone that characterises a 

 vowel. As explained in Nature; such a group of 

 neighbouring harmonics arises from the presence of 

 an inharmonic in this region which can express itself 

 only in this way. 



It is interesting to note that Prof. Miller's results 

 give direct evidence of both elements of the new 

 vowel theory, namely, that the voice tone consists 

 of a series of puffs, and that the vowel tones are 

 independent of the pitch of the voice tone. From 

 Prof. Miller's plots they would appear always to be 

 inharmonic. . E. W. Scripture. 



