CONTENTS TO VOLUME XXVII. 



N^ ber 157. 



Page 

 Art. I. — Diopside and its Relations to Calcium and Magne- 

 sium Metasilicates ; by E. T. Allen and VV. P. White. 

 With Optical Study ; by F. E. Wright and E. S. 



Larsen. (With Plate I) 1 



II— California Earthquake of 1906; by G-. K. Gilbert 48 



III— Descriptions of Tertiary Insects ; by T. D. A. Cock- 



erell. Part V __. 53 



IV. — Electrolytic Estimation of Lead and of Manganese by 

 the Use of the Filtering Crucible ; by F. A. Gooch and 



F. B. Beyer 59 



V. — Specific Radio-Activity of Thorium and its Products ; 



by G. C. Ashman . 65 



VI. — Coronas with Mercury Light ; by C. Barus 73 



SCIENTIFIC INTELLIGENCE. 



Chemistry mid Physics— Attempt to Produce a Compound of Argon, Fischer 

 and Iliovici : Explosive Crystallization, Weston, 82. — Constituents of 

 Ytterbium, A. v. Welsbach : New Form of " Tin Infection," von Hass- 

 linger : Heat Evolved by Radium, von Schweidler and Hess, 83. — 

 Positive Rays, W. Wien : Speclral Intensity of Canal Rays, J. Stark and 

 W. Stenberg : Canal Rays, J. Stark : Potential Measurements in the 

 dark Cathode Space, W. Westphal, 84. — Elements of Physics, Nichols 

 and Franklin : Text-Book of Physics, 85. 



Geology — Publications of the United States Geological Survey, 86. — Canada 

 Geological Survey : North Carolina Geological and Economic Survey, 

 87.— Report of the State Geologist of Vermont for 1907-8 : Thirty- 

 second Annual Report, Indiana Department of Geology, 88. — Illinois 

 State Geological Survey, Year-Book for 1907 : New Zealand Geolog- 

 ical Survey : Report on the Eruptions of the Soufriere in St. Vincent in 

 1902. and on a Visit to Montagne Pelee in Martinique, T. Anderson and 

 J. S. Flett, 89. —Geology and Ore deposits of the Coeur d' Alene District, 

 Idaho, 90. — Geologie der Steinkohlenlager, Dannenberg : Geology of 

 Coal and Coal-mining, W. Gibson : Physical History of the Earth in Out- 

 line, J. B. Babbitt: Triassic Ichthyosauria. with special reference to 

 American Forms, J. C. Merriam, 91. — Fossil Vertebrates in the American 

 Museum of Natural History, Part I — Fishes, L. Httssakof, 92. — Conrad 

 Fissure, B. Brown : Four-horned Pelycosaurian from the Permian of 

 Texas, W. D. Matthew : Osteology of Blastomeryx and Phylogeny of the 

 American Cervidae, W. D. Matthew : Rhinoceroses from the Oligocene 

 and Miocene deposits of North Dakota and Montana, E. Douglass, 93. — 

 Fossil Horses from North Dakota and Montana, E. Douglass : Some Oli- 

 gocene Lizards, E. -Douglass : Preliminary Notes on Some American 

 Chalicotheres, 0. A. Peterson, 94. 



Botany and Zoology — Harvard Botanical Station in Cuba, 94. — Handbuch 

 der Bluten-biologie, P. Knuth : Convenient Clearing and Mounting Agent, 

 96. — Economic Zoology : Text-book of the Principles of Animal Histology, 

 IT. Dahlgren and W. A. Kepner : Archiv. fur Zellforschung, R. Gold- 

 schmidt : Ueber die Eibildung bei der Milbe Pediculopsis graminum, 97. 



Miscellaneous Scientific Intelligence — Artificial Daylight for Use with the 

 Microscope, F. E. Wright : Ion ; A Journal of Electrotonics, Atomistics, 

 Ionology, Radio-activity and Raumchemistry, 98. — Life and Letters of 

 Herbert Spencer, D. Duncan, 99. — American Association for the Advance- 

 ment of Science : Nature of Enzyme Action : Rivista di Scienza, 100. 



Obituary— 0. W. Gibbs : W. E. Ayrton, 100. 



