CONTENTS TO VOLUME XIX. 



Number 109. 



Page 

 Art. 1. — Submarine Great Canyon of the Hudson River ; by 



J. W. Spencer 1 



IT. — Radio-activity of Underground Air; by H. M. 



Dadotjrian 16 



III. — Types of Limb-Structure in the Triassic Ichthyosauria ; 



by J. C. Merriam . 23 



IV. — Interaction of Hydrochloric Acid and Potassium Per- 

 manganate in the Presence of Ferric Chloride ; by J. 

 Brown . 31 



V. — Crystal Drawing ; by S. L. Peneield . _ 39 



VI. — Anemiopsis Californica (Nutt.) H. et A. An anatomi- 

 cal Study ; by T. Holm 76 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Production of Pure Sodium Hydroxide for Labora- 

 tory Uses, F. W. Kuster : Production of Magnetic Alloys from Non- 

 Magnetic Metals, E. A. Hadfield : Ozobenzol, Harries and Weiss, 83. — 

 Concerning Emanium, Giesel : School Chemistry, E. Avery : Application 

 of Some General Organic Eeactions, Lassar-Cohn, 84. — Influence of Glass 

 Walls of Geissler Tubes on Stratified Discharges in Hydrogen, E. Gehrcke : 

 Phosphorescence, P. Lenard and V. Klatt: Color Changes in Gold Pre- 

 parations, F. Kirchner and E. Zsigmondy : Spectra of Hydrogen, Helium, 

 Air, Nitrogen, and Oxygen in the Ultra- Violet, J. Schniederjost, 85. — 

 Pressure of Light, A. Bartoli : Notes on X-Light, W. Eollins, 86. 



Geology and Mineralogy — Indiana Geological Survey, W. S. Blatchley, 87. 

 — Geological Map of Indiana, T. C. Hopkins : Geological Survey of New 

 Jersey, H. B. Kummel : Eecent Seismological Investigations in Japan, 

 Dairoku Kikuchi, 88. — Earthquakes, in the Light of the New Seismology, 

 C. E. Dutton : Minerals of Japan, T. Wada, 89. — Brief notices of some 

 recently described Minerals, 90. 



Miscellaneous Scientific Intelligence — Annual Eeport of the Eegents of the 

 Smithsonian Institution : Bulletin of the Bureau of Standards, 91. — 

 National Academy of Sciences : American Association for the Advance- 

 ment of Science, 92. 



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