180 SPECIAL SENSES. 



waves. This fact, which we shall discuss more elaborately 

 farther on, requires little argument for its support. If we 

 suppose a string vibrating a certain number of times in a 

 second, the vibrations being perfectly simple, we should have, 

 according to the laws of vibrating bodies, a simple musical 

 tone ; but, if we suppose that the string subdivides into dif- 

 ferent segments, one of which gives the 3d, another, the 5th, 

 and so on, of the fundamental note, it is evident that the 

 form of the vibrations must be considerably modified. This 

 is the fact ; and, with these modifications in form, the quality, 

 or timbre, of the tone is changed. ."We can illustrate this 

 roughly on the piano. If we strike the note C, we have 

 a certain quality of sound. "We may assume, for sake of ar- 

 gument, that this is a simple tone, though in reality it is 

 complex. We now strike simultaneously the fundamental 

 note, its 3d, 5th, and 8th, making the common chord of C 

 major. The predominant tone is still C, but the addition of 

 the harmonious notes modifies its quality. If we diminish 

 the third by half a tone, we still' have C for the predominant 

 tone, but the quality of the chord is changed to the minor. 

 In this rough illustration, the ear can readily detect the har- 

 monious tones ; but, in the tone of a single string, this cannot 

 be done without practice and close attention. Still, in the 

 tones of single strings, the ear can distinguish the harmonics ; 

 and, what is mofe satisfactory, the existence of harmonics 

 can be actually demonstrated in various ways. 



From what we have just stated, it follows that nearly all 

 musical tones consist, not only of a fundamental sound, but 

 of harmonic vibrations, subordinate to the fundamental and 

 qualifying it in a particular way. These harmonics may be 

 feeble or intense ; certain of them may predominate over 

 others ; some, that are usually present, may be eliminated ; 

 and, in short, they may present great diversity of arrange- 

 ment, and thus the timbre may present an infinite variety. 

 This is one of the elements entering into the composition of 

 tones, and affords a partial explanation of quality. 



