info getting lost lost in the gutter on page 219 - I. On the refraction and dispersion of the halogens, halogen acids, ozone, steam, oxides of nitrogen and ammonia

It has long been well known that the refractive indices of simple gaseous compounds do not obey the additive law so closely as those of solids or liquids. From the study of these last Gladstone and Dale, and their followers, succeeded in obtaining refraction equivalents for a large number of the elements which were fairly constant for the same class of compound. But in gases the discrepancies were found to be much wider, and this appeared the more surprising since, in other fields of research, the gaseous state has proved peculiarly favourable for the discovery of simple relations. Accumulation of Data.—The investigation, of which the present paper forms part, was designed to throw light on the cause of these anomalies.