CONTENTS. 



Page 

 Art. XXXI. — The Silicates of Strontium and Barium: by 



P. Eskola, , 331 



Art. XXXII. — Sedimentation in Lake Louise, Alberta, 



Canada; by W. A. Johnston, . , 376 



Art. XXXIII. — Imbricated Structure in River-gravels; by 



W. A. Johnston, -. 387 



Art. XXXIV. — Zircon as Criterion of Igneous or Sedimen- 

 tary Metamorphics ; by P. Armstrong, 391 



Art. XXXY. — The Minnesota Devonian and its Relationship 

 to the General Devonian Problem of North America; by 

 C. R. Stauffer, 396 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics. — A New Method of Separating Arsenic from All Other 

 Metals, L. Moser and J. Ehrlich: A New Volumetric Method as Applied 

 to Certain Problems in Inorganic Chemistry, P. Dutoit and E. Orofet, 

 413. — Theories of Organic Chemistry, F. Henrich: The Chemistry of 

 Combustion, J. N. Friend. 414 — Petroleum, Where and How to Find it, 

 A. Blum: The Heavier Constituents of the Atmosphere, J. J. Thomson: 

 The Corrosion of Iron and Steel, 415. — The Mathematical Theory of Prob- 

 abilities, A. Fisher, 417. 



Geology. — The Paleontology of the Zorritos Formation of the North Peruvian 

 Oil Field, E. M. Spieker: The Eecession of the last Ice Sheet in New 

 England, E. Antevs, 417. — A Section of the Paleozoic Formations of the 

 Grand Canyon at the Bass Trail, L. F. Noble: Essentials for the Micro- 

 scopical Determination of Minerals . and Rocks in Thin Sections, A. 

 Johannsen: The Rocks of Mount Everest, 419. — A Newly Found Tennes- 

 see Meteoric Iron, G. P. Merrill: Minor Faulting in the Cayuga Lake 

 Region, E. T. Long, Errata, 420. 



Miscellaneous Scientific Intelligence. — Foundations of Biology, L. L. Woodruff: 

 The Study of Living Things: A Course in Biology for Secondary Schools. 

 W. H. D. Meier, 421. — Field Museum of Natural History, Annual Re- 

 port for 1921: National Academy of Sciences, 422. 



Obituary — A. Smith: F. T. Trouton: D. Sharp: W. Kellner: A. L. Kimball: 

 A. A. Sturley, 423. 



