  A refractometry taking measuring of Brewster angles for birefringent
materials is proposed. The technique is based on the angular scanning of the
reflected power of p-polarized light and the determination of the two specific
minimums at the Brewster angles for the two orthogonal orientations of the
optical axis of the material. In these configurations, the testing light does
not experience the birefringent in the material, assuming the state of ordinary
or extraordinary rays alternately to orientation of the optical axis. The
origin and influence on the measurement of the nonzero residual power at
Brewster angle are accentuated.
