Proceedings of the American Academy of Arts and Sciences. 

 Vol. XL. No. 0. — Skptembeu, 1904. 



A QUANTITATIVE BE TERMINATION OF THE ANOMA- 

 LOUS DISPERSION OF SODIUM VAPOR IN THE 

 VISIBLE AND ULTRA-VIOLET REGIONS. 



By K. W. Wood. 



With Thkee Plates. 



Investigations on Light and Heat made or publishkd, wholly or in part, with Appropriations 

 from tub kuuford fund. 



