CONTENTS 
Page 
Physics. — Supeeposed or Duplicated Spectrum Fringes . . . By Carl Bams 149 
Chemistry. — An Electromagnetic Hypothesis of the Kinetics of Heterogene- 
ous Equilibrium, and of the Structure of Liquids . By William D. Harkins 152 
Chemistry.— Hydrogen OvERVOLT AGE . ByDunganA.MacInnesqndLeonAdlerlGO 
Physics.— An Approximate Law of Energy Distribution in the General X-Ray 
Spectrum . . ... By David L. Webster 163 
Genetics. — Linear Arrangement of Genes and Double Crossing Over • . 
By Harold H. Plough 167 
Genetics. — ^The Spatial Relations of Genes 
By A.H. Sturtevant, C. B. Bridges, and T. H. Morgan 168 
Physics.— A Complete Apparatus for Absolute Acoustical Measurements . . 
By Arthur Gordon Webster 173 
National Research Council.— Extract of Minutes of Joint Meeting of the 
Executive Board of the National Research Council with the Council of 
THE National Academy of Sciences 180 
— ■ Minutes of Joint Meeting of the Executive Board and the Council of 
THE National Academy of Sciences 189 
