CONTENTS 
■ Page 
Physics. — Path Differences Within Which Spectrum Interferences are 
Observable By Carl Barus 609 
Physics. — Non-Reversed Spectra of Restricted Coincidence . By Carl Barus 614 
Chemistry. — The Equilibrium Between Acids and Bases in Sea Water . . . 
By Lawrence J. Henderson and Edwin J. Cohn 618 
Biology. — An Apparent Correspondence Between the Chemistry of Igneous 
Magmas and of Organic Metabolism By Henry S. Washington 623 
\Botany. — ^The Oaks of America By William Trelease 626 
Mathematics. — A Set of Independent Postulates for Cyclic Order .... 
By Edward F. Huntington 630 
Psychology. — A New Method op Studying Ideational and Allied Forms op 
Behavior in Man and Other Animals ...... By Robert M, Yerkes 631 
Chemistry. — Electrical Conduction in Dilute Amalgams 
By Gilbert N. Lewis and Thomas B. Hine 634 
Psychology. — Ideational Behavior of Monkeys and Apes. By Robert M. Yerkes 639 
Chemistry. — ^The Osmotic Pressure and Lowering of the Freezing-Point of 
Mixtures of Salts with One Another and with Non-Electrolyt£s in 
Aqueous Solutions . By William D. Harkins, R. E. Hall, and W. A. Roberts 642 
Mathematics. — Certain General Properties of Functions . By Henry Blumberg 646 
Paleontology. — Sphenacodon Marsh, A Permocarboniferous Theromorph Rep- 
tile from New Mexico By Samuel W. Williston 650 
Biology. — On Volume in Biology By Lawrence J. Henderson 654 
