So long as the particles are all very small in comparison with the wave-length, there is complete polarization in the perpendicular direction; but when the size is such that obliquity sets in, the degree of obliquity will vary with the size of the particles, and the polarization will be complete only on the very unlikely condition that the size is the same for them all.
The investigation of this question upon the elastic solid theory will depend upon how we suppose the solid to vary from one optical medium to another.