a second by an electric spark of a duration far shorter than that of any musical note. If we take two such electric sparks of different colours and allow them to appear in a darkened space, the eye will, notwithstanding, be perfectly capable of distinguishing between their respective colours. No musical note at all approaches an electric spark as to its shortness of duration, and therefore the whole contention as to the inferiority of the eye in this respect falls to the ground. This, however, should be frankly admitted, namely, that rapid colour changes are at first fatiguing, and that to appreciate them in colour-music requires some training and experience. At first there is a sensation of dazzle, but, as previously stated, this gradually disappears, and is after a time, with most people, entirely lost. So much so is this the case that, as pointed out, the preference for slow compositions soon gives place to the desire for more and more rapid ones.
A difficulty that occurred to the mind of a musical critic was that in music the high notes, namely those of rapid vibrations, are
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