CONTENTS. Vll 



Number 143. 



Art. XXXV. — Electric Arc between Metallic Electrodes ; 



by W. G. Cady and H. D. Arnold 383 



XXXVI. — Gibbs' Geometrical Presentation of the Phenom- 

 ena of Reflection of Light ; by A. W. Ewell 412 



XXXVII. — Decay of Ionized Nuclei in the Fog Chamber, 



in the Lapse of Time ; by C. Barus 419 



XXXVIII. — Crystallographic Combinations of Calcite from 



West Paterson, X. J. ; by H. P. Whitlock 42G 



XXXIX. — Preparation of Acetamide by the Action of 

 Ammonium Hydroxide and Ethyl Acetate ; by I. K. 

 and M. A. Phelps 429 



XL. — Volumetric Estimation of Potassium as the Cobalti- 



nitrite ; by W. A. Drtjshel 433 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Atomic Weights of Silver, Nitrogen and Sulphur, 

 Richards and Forbes : Atomic Weight of Radium, Mdme. Curie, 439. — 

 Melting-Point of Pure Tungsten, Wartenberg : Solubilities of Inorganic 

 and Organic Substances, A. Seidell : Practical Chemistry for Army and 

 Matriculation Candidates, and for Use in Schools, G. Martin : Elements 

 of Physical Chemistry, H. C. Jones, 440. — Canal Rays, F. Paschen, etc. : 

 Propagation of Plane Electromagnetic Waves over Plane Surfaces and 

 their relation to Wireless Telegraphy, J. Zenneck, 441. — Influence of Mag- 

 netic Fields on the Resistances of Electrolytes, G. Berndt : Change of 

 Resistance in Metal Wires with Occlusion of Oxygen, G. Szivessy : Atlas 

 of Absorption Spectra, H. S. Uhler and R. W. Wood : Bulletin of the 

 Bureau of Standards, S. W. Stratton, 442. 



Geology and Natural History — Devonic Fishes of the New York Formations, 

 C. R. Eastman, 443. — Paleontology of the Niagaran Limestone in the 

 Chicago Area. The Trilobita, S. Weller : Revision der Ostbaltischen 

 Silurischen Trilobiten, F. Schmidt, 445. — Stratigraphy of the Western 

 American Trias, J. P. Smith : Remarks on and Descriptions of new Fossil 

 Unionidse from the Laramie Clays of Montana, R. P. Whitfield, 446. — 

 Palaeontologia Universalis : Die Fossilen Insekten, A. Handlirsch : Illi- 

 nois State Geological Survey, H. F. Bain : Connecticut Geological and Nat- 

 ural History Survey, Bull. No. 8. Bibliography of the Geology of Connec- 

 ticut, H. E. Gregory, 447. — Tables of Minerals including the Uses of 

 Minerals and Statistics of the Domestic Production, S. L. Penpield : New 

 California Minerals, G. D. Lotjderback : Elements of Biology: A Practi- 

 cal Text-Book Correlating Botany, Zoology, and Human Physiology. G. W. 

 Hunter : Elements of Physiology, T. Hough and W. T. Sedgwick, 448. — 

 Young of the Crayfishes Astacus and Cambarus, E. A. Andrews : Evolu- 

 tion and Animal Life, D. S. Jordan and V. L. Kellogg : Report on the 

 Crustacea (Brachyura and Anomura) collected by the Nox-th Pacific Explor- 

 ing Expedition, 1853-1856, W. Stimpson, 449. — Reports on the Scientific 

 Results of the Expedition to the Eastern Tropical Pacific, in charge of 

 Alexander Agassiz, by the U. S. Fish Com, Steamer Albatross, from Oct., 

 1904 to March, 1905, L. M. Garrett, 450. 



Obituary — M. Maurice Loewy, 450. 



