tones appreciable by the ear. It is quite true that there is only one octave of colour, but the intercombination between the component colours of that octave in the vast ranges of tones they possess, gives us the almost endless variety of colours which we see in nature and in art, whereas it is scientifically demonstrated that the tones appreciable by the ear are not at all comparable in their number to these.[1]
The second objection as to quality of tone in music not being represented in colour opens up an interesting point. Timbre in music is produced by the admixture, greater or less, of harmonics with the ground-note which is being sounded; or with each of the notes composing a chord. If the vibrations of air producing a given note are recorded by an optical curve by means of a suitable instrument, with a needle attached to a sensitive diaphragm which traces it upon a smoked glass, these harmonics clearly show themselves as small notches or wave crests upon the main line of the pulsations of the diaphragm, being
- ↑ See reference to this in the chapter upon the psychology of the subject.
146