dispersion of the optic axes

Dispersion \Dis*per"sion\, n. [CF. F. dispersion.]
   1. The act or process of scattering or dispersing, or the
      state of being scattered or separated; as, the Jews in
      their dispersion retained their rites and ceremonies; a
      great dispersion of the human family took place at the
      building of Babel.
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            The days of your slaughter and of your dispersions
            are accomplished.                     --Jer. xxv.
                                                  34.
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   2. (Opt.) The separation of light into its different colored
      rays, arising from their different refrangibilities.
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   {Dispersion of the optic axes} (Crystallog.), the separation
      of the optic axes in biaxial crystals, due to the fact
      that the axial angle has different values for the
      different colors of the spectrum.
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