CM. xv.] THE COMPOSITION OF MIND. 125 



composed. The tone asserts itself to be complete!} homo 

 geneous. All that mere introspection could discover in 

 consciousness would be an apparently simple sensation of 

 musical tone. Yet into the composition of this sensation 

 there enter a thousand or several thousand psychical states 

 answering to the presence of as many elementary sounds 

 with their maxima and minima of intensity. And if any 

 one of these elementary sub-conscious psychical states were 

 absent, the character of the conscious sensation would be 

 different from what it is. 



But this is not all. Every musical tone has a timbre or 

 quality of its own, according as it proceeds from a piano, a 

 violin, a flute, or any other instrument. Now, Helrnholtz 

 has proved that the quality of any tone is due solely to the 

 number and combinations of certain higher and fainter tones 

 which accompany it. Along with the fundamental note 

 there are heard sundry harmonic notes, due to vibrations 

 from two to ten times more rapid than those which con 

 stitute the fundamental note. When any note is sounded 

 on the piano, the first six harmonics are sounded with it ; 

 when the same note is sounded on the violin, by means of 

 the bow, the first six harmonics are sounded so feebly as to 

 be overpowered by the seventh, eighth, ninth, and tenth; 

 and this is the only cause of the difference in quality of tone 

 between the piano and the violin. Now, by an effort of 

 attention these harmonic over-tones may be recognized as 

 distinct sensations when two or three notes are slowly 

 struck. But in ordinarily rapid playing they are not dis 

 tinctly recognized. Their only effect is to impart to the 

 tones that peculiar quality which enables the ear to re 

 cognize the instrument from which they emanate. Thus 

 our apparently simple sensations of musical sound are enor 

 mously complex. When F-in-alt is sounded on the violin, 

 there are produced, in the course of a single second, several 

 thousand psychical states which together make up the sen- 



