146 Intelligence and Miscellaneous Articles. 



by M. Donders, and he found it to be re 6 . If a tuning-fork be 

 timed for this note, we ascertain, in fact, that it is increased whilst 

 the mouth passes from E to I ; at least I have been able to assure my- 

 self that the increase occurs before the mouth is exactly arranged for 

 the I. Hence the true characteristic of I must be higher. By 

 constructing tuning-forks more and more acute, I ascertained that this 

 note was approached ; it was finally found to be si b 6 ; with tuning- 

 forks still higher, it is immediately felt that the limit has been passed. 



For OU M. Donders had given fa 3 . Thisnote can undoubtedly be 

 strengthened by the mouth, but it is only in departing very little 

 from the position O ; and one feels that the note of OU must be much 

 more grave. M. Helmholtz assigns fa 2 to OU. However, a tuning- 

 fork fa 2 does not resound before the mouth arranged for OU, which 

 M. Helmholtz accounts for by the smallness of the opening of the 

 mouth ; but it seemed to me that this smallness of the opening, 

 while rendering a very energetic increase impossible, must still admit 

 an appreciable increase in the intensity of the sound. Having more- 

 over ascertained the simple ratios which exist between the notes of 

 the vowels O, A, E, I, ascending by octaves, I thought that this 

 law would extend to the vowel OU. I verified this hypothesis 

 circumstantially by means of a tuning-fork, the pitch of which 

 could be raised by means of slides ; I was thus able to assure myself 

 that the characteristic note of OU (such as I ordinarily pronounce 

 it) was really (sib) 2 ; for the maximum of resonance always occurred 

 between 440 and 460 simple vibrations. 



For the pronunciation of the Germans of the North (to which the 

 experiments of M. Helmholtz also refer), the vowels are then cha- 

 racterized as follows : — 



OU O A E I 



(sib) 2 , (si» 3 , (sib) 4 ,~: (sib) 5 , (sib) 6 ; 



or, in round numbers of simple vibrations, 450, 900, 1800, 3600, 

 7200. 



It seems to me more than probable that we must seek, in the sim- 

 plicity of these ratios, the physiological cause which makes us find 

 nearly always the same five vowels in the different languages, 

 although the human voice can produce an indefinite number, as the 

 simple ratios between the numbers of vibrations explain the existence 

 of the same musical intervals among most nations. 



It is some time since I obtained these results; but I wished to 

 have them verified by several eminent physiologists, whose approba 

 tion has encouraged me to publish them. — Comptes Rendus, April 25, 

 1870. 



COMPRESSIBILITY OF GASES UNDER HIGH PRESSURES. 

 BY M. L. CAILLETET. 



In order to obtain very high pressures applicable to the experi- 

 ments in which I am engaged, after numerous trials I fixed upon 

 an apparatus which consisted of a hollow steel cylinder firmly 



