CONTENTS TO VOLUME XXXI. 



Nimiber 181. 



Page 



Art. I. — Gravity Determinations at Sea ; by L. A. Bauer.. 1 

 II.— Stratigraphy of a Deep "Well at Waverly, Ohio ; by R. 



S. Bassler - 19 



III. — Solid Solution in Minerals with Special Reference to 



Nephelite; by H. W. Foote and W. M. Bradley 25 



IV. — Fossil Evidence of the Age of the Virginia Piedmont 



Slates ; by T. L. Watson and S. L. Powell 1 33 



V.— Native Gold from Gold Harbour, Queen Charlotte 



Islands ; by R. P. D. Graham 45 



VI.— Natramblygonite, a New Mineral ; by W. T. Schaller 48 



VII.— New Emission Theory of Light ; by J. Trowbridge. 51 



VIII.— Origin and Peopling of the Deep Sea; by J. 



Walther - — 55 



IX. — Camels of the Harrison Beds, with Three New Species ; 



by F. B. Loomis --- 65 



William Henry Brewer -- 71 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Preparation of Metallic Radium, E. Ebler : Reduc- 

 tion of Oxide of Iron by Solid Carbon, Charpy and Bonnerot, 75. — 

 Action of Light upon an Electric Cell, H. Pelabon : Sterilization of Large 

 Quantities of Water by Ultra-violet Rays, Helbronner and Reckling- 

 hausen, 76. — Refrigeration by Mixtures of Liquids, J. Duclaux : The 

 Relations between Chemical Constitution and Some Physical Properties, 

 S. Smiles : Positive Rays, W. Wien, 77. — Deflections by Electrostatic 

 and Magnetic Fields of Radium B after Recoil from Radium, A. S. 

 Russ, etc. : Energy Distribution of Diffraction Gratings, A. Trow- 

 bridge and R. W. Wood : Modification in Magnetic Fields of Lines of 

 the Light emitted by the Electric Spark, G. A. Hemsalech : Electric 

 Motors, H. M. Hobart, 78. 



Geology and Natural History — Grundziige der Palaontologie, K. A. v. 

 Zittel, 78.— Notes on Ordovician Trilobites, II, III and IV, P. E. Ray- 

 mond : Preliminary List of the Fauna of the Allegheny and Conemaugh 

 Series in Western Pennsylvania, P. E. Raymond : The British Carbonif- 

 erous Orthotetinas, I. Thomas, 79. — Geological Excursion in the Grand 

 Canyon District, D. W. Johnson : Aufbaii des Gebirges in der Umgebung 

 der Strassburger Hutte an der Scesaplana, W. v. Seidlitz : Granites of 

 the Southeastern Atlantic States, T. L. Watson : The Volcanic Rocks of 

 Victoria, E. W. Skeats, 80. — Analcite Rocks, G. W. Tyrrell : Morganite, 

 a Rose-colored Beryl, G. Kunz, 81. — Tables for the Determination of 

 Minerals by Physical Properties : The Subantarctic Islands of New Zea- 

 land : British Nudibranchiate Mollusca, with Figures of the Species ; 

 Part viii. Supplementary, 82. — Medusae of the World, A. G. Mayer: 

 An Introduction to Zoology, R. W. Hegner, 83.— Animal Study: with 

 Directions for Laboratory and Field Work, W. H. D. Meier : Methods of 

 Attracting Birds, G. H. Trafton : Second Report on the Hymeniales of 

 Connecticut, E. A. White, 84. 



