title: Partial dispersion of glasses. Part 3.
abstract: The formula describing the dependence of the refractive index of glasses on lambda by means of the delta function defined in an earlier paper is transformed to a system based on the values n(2) - n(1) and n(m), meaning the main dispersion and the refractive index for a medium wavelength, respectively. The delta function becomes zero throughout for normal glasses. It is shown under what conditions the established delta function can be simplified to a linear function of the wavelength or even to a single suitable value delta(0). The accuracy of the diverse formulas is discussed by examples.
authors.forename: W
authors.initials: W
authors.lastname: Geffcken