The index of refraction of some soda-limesilica glasses as a function of the composition

Twenty-one soda-sihca and twenty-one soda-lime-silica classes were made in platinum and the index ot refraction and chemical composition of each glass were determined.From the data obtained equations were derived and a diagram was prepared showing the relations between index of refraction and composition of rnese glasses.• J he <? ia S ram makes ^possible to predict with considerable accuracy (1) the index of refraction of any glass, in the range of compositions considered, from its composition and (2) the compositions of the various glasses which have the same index of refraction.Some evidence is presented indicating that index of refraction of the soda-silica glasses may be a simple function of certain soda-silica compounds which may be present in glass.CONTENTS I. Introduction 993 II.Outline of the work ~~~9 94 III.Making the glass 994 IV.Measurement of index of refraction 996 V. Data obtained and results 997 VI. Discussion 1001 VII.Comparison with other data 1002