title: Relation between refractive index and density of glasses resulting from annealing compared with corresponding relation resulting from compression.
abstract: The change in refractive index and associated change in density of glasses on annealing has been determined by Tool, Tilton, and Saunders. The corresponding changes for the same glasses, produced by hydrostatic compression are presented here and compared with those of Tool et al. It is found that, for a given increase in density on annealing, the increase in index is greater than for the same measured increase in density on compression. The results are interpreted in terms of equations developed by Lorentz-Lorenz, Pockels, and Mueller to show, first, that in all cases, whether from annealing or compression, there is a decrease in polarizability and an increase in density (these results are in agreement with those of previous investigators) and, second, that the decrease in polarizability for a given increase in density is greater on compression than on annealing.
authors.affiliation: National Bureau of Standards,Washington, DC 20234, USA.
authors.forename: S
authors.initials: S
authors.lastname: Spinner
authors.forename: R M
authors.initials: RM
authors.lastname: Waxler