CONTENTS 
Astronomy — Evidence of Stream Motion Afforded by the Faint Stars Near 
THE Orion Nebula By Adriaan van Maamn 225 
Astronomy — On the Use of the Spectroscopic Method for Determining the 
Parallaxes of the Brighter Stars . . ByW. S. Adams and G. Str'dmberg 228 
Astronomy. — Relation of Color to Intrinsic Luminosity in Stars of the Same 
Spectral Type By Frederick H. Seares 232 
Astronomy — The Motions in Space of Some Stars of High Radial Velocity . . 
By W. S, Adams and A. H. Joy 239 
Astronomy. — ^Deviations of the Sun's General Magnetic Field from That of a 
Uniformly Magnetized Sphere 
By F. H. Seares, A, van Maanen, and F. Ellerman 242 
Physiology. — On the Problem of the Production of Fat from Protein in the 
Dog . By H. V. Atkinson and Graham Lusk 246 
Mathematics. — On the Twist in Conformed Mapping . , . By T. H. Gronwall 248 
Paleontology. — Seventeen Skeletons of Moropus; Probable Habits of this 
Animal By Henry Fairfield Oshorn 250 
Chemistry — ^The Structure of Atoms and the Octet Theory of Valence , . . 
By Irving Langmuir 252 
Physics. — A New Instrument for Measuring Pressures in a Gun 
ByA.G. Webster and L. T. E. Thompson 259 
Physics. — On the Angle of Repose of Wet Sand By A. G. Webster 263 
Paleontology. — Pal^eomastodon, The Ancestors of the Long- Jawed Mastodons 
Only By Henry Fairfield Osborn 265 
Physics. — The Elongation Due to Magnetization By C. Barus 267 
Mathematics. — Groups Involving Only Two Operators Which are Squares . 
By A. G.Miller 272 
Physics. — ^Acoustical Impedance and the Theory of Horns and of the Phono- 
graph By Arthur Gordon Webster 275 
Botany. — Phenomena of Cell Division in the Cambium of Arborescent Gym- 
nosperms and Their Cytological Significance . . By Irving W. Bailey 283 
Physics. — On the Possible Form of the Equation of State of Powder Gases . . 
By A. G. Webster 286 
Physics. — The Relative Adsorption of Mixtures of Oxygen and Nitrogen in 
Cocoanut Shell Charcoal . . By Harvey B, Lemon and Kathryn Blodgett 289 
Mathematics. — Real Hypersurfaces Contained in Abelian Varieties 
By S. Lefschetz 296 
National Research Council. — Extracts from the Minutes of the Meeting of 
the Executive Board 299 
