The dispersion phenomena of Albite from Alp Rischuna, Switzerland

Abstract

The refractive indices of this mineral for different wave-lengths were determined by the Abbé-Pulfrich total-reflectometer. The dispersion of the glass hemisphere of the instrument was determined by the aid of a highly polished glass prism, the dispersion of the latter being found by the method of minimum deviation. In order to obtain light of definite wave-length Hilger's wave-length spectrometer was used with a Nernst lamp or an electric arc as the source of illumination.