CONTENTS. 



Page. 



Art. I. — Speed of Propagation of the Charleston Earth- 

 quake ; by S. Newcomb and C. E. Dutton 1 



II. — History of the changes in the Mt. Loa Craters; by J. D. 



Dana. Parti. Kilauea,. (Plate I) 15 



III. — Analysis and Composition of Tourmaline; by R. B. 



RlGGS 35 



IV. — Different types of the Devonian System in North 



America; by H. S.Williams 51 



V. — Law of Double Refraction in Iceland Spar ; by C. S. 



Hastings 60 



VI. — Notice of a New Genus of Sauropoda and other new 

 Dinosaurs from the Potomac Formation ; by 0. C. 

 Marsh 89 



VII. — Notice of a New Fossil Sirenian, from California; by 



O. C. Marsh 91 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics.— Decomposition of the Hydrides of the Halogens by Light 

 in presence of Oxygen, Richardson, 73. — Influence of Liquid water in promot- 

 ing the decomposition of Hydrogen chloride, Armstrong, 74. — Concentration 

 of Solutions by Gravity, Gouy and Chaperon, 75.— Percentage of Oxgenin the 

 Air, Hempel: Constitution ' of Selenous Acid, Michaelis and Landmann: 

 Indexing of Chemical Literature, 76. — Mechanical Equivalent of Heat, Diet- 

 erici: Radiation in absolute measure, Bottomley : Maximum of Light Inten- 

 sity in the Solar Spectrum, Mengarixi, 77.— Relation of the wave-length of 

 light to its intensity, Ebert: Brief notice of a paper by Mr. Hallock, Spring, 

 78. — Lessons in Elementary Practical Physics, Stewart and Gee, 79. 



Geology and Natural History. — Communication by Raphael Pumpelly, 79. — Geo- 

 logical history of the Swiss Alps, 80. — Gradual variation in intensity of meta- 

 morphism, 82. — Mission Scientifique du Cap Horn, 83. — The American Geolo- 

 gist : Geology and Mining Industry of Leadville, Colorado, S. F. Emmons : 

 Fifteenth Annual Report on the Geological and Natural History Survey of 

 Minnesota, N. H. Winchell, 84. — New York Paleontology: Annual Report of 

 the Geological Survey of Pennsylvania : Fossil Mammals from the White River 

 formation contained in the Museum of Comparative Zoology, W. B. Scott and 

 H. F. Osborn, 85. — Diatomaceous Earth in Nebraska : The Upper Beaches and 

 Deltas of the Glacial Lake Agassiz, "W. Upham ; Supposed diamonds in a 

 Meteorite: Cryptolite: Grundriss der Bdelsteinkunde, P. Groth: Rivista di 

 Mineralogia e Cristallografia Italiana, R. Panebianco: Catalogue of all recorded 

 Meteorites, 0. W. Huntington, 86. — A chapter in the History of Meteorites, 

 W. Flight: Das pflanzenphysiologische Praktikum, Detmer, 87. 



Miscellaneous Scientific Intelligence. — Proceedings of the Colorado Scientific Society: 

 Relative Proportions of the Steam Engine, W. D. Marks : Modern American 

 Methods of Copper Smelting, E. D. Peters, 88. 



Obituary. — Ferdinand Vandeveer Hatden. 88. 



