Liquids of High Refractive Index

Abstract

IN a previous letter to NATURE¹ under this title, we gave values for the refractive index of phenyldi-iodoarsine as measured by us. Our attention has now been directed to the fact that the properties of this compound had already been accurately measured and published in a valuable paper on ” The Optical Properties of Arsenic” by Gryszkiewitz–Trochimowski and Sikorski² which had appeared six years previously. We had unfortunately overlooked this paper owing to the fact that in none of the abstracts or collective indexes which we consulted as a guide to the relevant literature was there any mention of the above compound in connexion with these authors. The figures for phenyldi-iodoarsine given by the Polish workers (n_D^14.5 1.8527 ; d₄^14.5 2.6264) are higher than those we communicated, but agree closely with those we have recently obtained with the purer samples now commercially available