Certain Effects Produced by Chilling Glass*

Abstract

Data are secured from the heating curves for chilled and annealed glasses which appear to show. (1) That cooling glass slowly through the annealing range allows some molecular readjustment which may include the formation of large molecules or aggregates, while cooling it rapidly prevents such readjustments, (2) That these readjustments appear to change such characteristics of the glass as its density, refractive index, homogeneity, stability, etc., and (3) That heating glass for long periods at a given temperature allows the glass to come to a condition of equilibrium which, over a wide range, varies with the treating temperature.The data on which these conclusions are based are obtained by a method of curve analysis used to compare changes in the form of the heating curves caused by different heat treatments of the glass.