Vibrations are a typical metaphor for impressions. Bodies undoubtedly emit a range of emanations that we now call energy radiations and whose vibratory properties are referred to as frequencies. Just as music or audible sounds convey thought to the ear in sound frequencies ranging from 60 to 6000 cycles per second, and color in art and all things visible is conveyed to the eye in light frequencies ranging from 400 to 800 milli-micron wave lengths, there must be a range of frequencies in which otherwise unexpressed thoughts are projected from one brain to another. Vibrations are psychic pulsations or magnetic waves, according to occultists.