CONTENTS 
^ Page 
Astronomy. — Some Problems of Sidereal Astronomy . By Henry N orris Russell 391 
Astronomy. — On the Spectral Lines op a Pulsating Star ........ 
By Harlow Shapley and Seth B. Nicholson 417 
Chemistry.— Ethylene Chlorhydrin By M. Gomberg 424 
Chemistry. — Studies op the Constitution op Steel . By Mward D. Campbell 426 
Genetics.— Inheritance of Quantity and Quality op Milk Production in Dairy 
Cattle By W. E. Castle 428 
Astronomy. — Studies of Magnitudes in Star Clusters, X. Spectral Type B 
AND THE Local Stellar System By Harlow Shapley 434 
Chemistry. — ^Influence of Ions on the Electrification and Rate of Diffusion 
OF Water Tbhough Membranes By Jacques Loeb 440 
National Research Council. — ^Meeting of the Interim Committee 447 
Minutes op Joint Meeting op the Executive Board op The National Research 
Council with the Council op the National Academy of Sciences . . . 452 
National Academy of Sciences. — Report of the Annual Meeting, 1919 . . . 479 
National Academy of Sciences. — ^Awaed op Medals 492 
National Academy of Sciences. — Research Grants prom Trust Funds of the 
Academy 492 
