ble to the human eye. Immediately below the line of infra-red, at the point where the human vision ceases to record color-impressions, there begins a series of vibrations which we can only feel as warmth; and still lower down the scale is another series which the human ear records in the form of sound. Yet we know of a certainty that these vibrations are also potential color-waves, that each note of music carries its own special color-note, whose quality and beauty, alas! may never be known to man, owing to the limited range of his vision.
However, no one can with certainty affirm that this may not be one of the joys that await future generations. Nothing is beyond the range of possibility. Already, by means of the fluoroscope, we are able to extend our vision somewhat, and peer over a little into