ON THE KEFKACTIVE INDEX OF GASEOUS FLUORINE. 



331 



TABLE V. Relative Refractivities of some of the Elements. 



We have pleasure in expressing our thanks to Sir WILUA.M RAMSAY and to 

 Professor TROUTON for assistance throughout the research, to M. MOISSAN for his 

 kindness in supplying the fluorine used in the first series of experiments, and to the 

 Iloyal Society for grants in aid of the expense incurred in the research. 



2 u 



