m~ Index XI-XX, now ready. Price $1.00. 



CONTENTS 



Page 



Art. I. — Relative Proportion of Radium and Uranium in 

 Radio- Active Minerals; by E. Rutherford and B. B. 

 Boltwood 1 



II. — Measurement of Radium in Minerals by the y-Radiation; 



by A. S. Eve _ 4 



III. — Absorption of the a-Rays from Polonium; by M. Levin 8 



IV. — Thermal Constants of Acetylene ; by W. G. Mixter.. 13 



V.— Modification of the Lasaulx Method for Observing Inter- 

 ference Figures under the Microscope; by F. E. Wright 19 



VI. — Datolite from Westfield, Massachusetts ; by E. H. 



Kraus and C. W. Cook 21 



VII. — Russian Carboniferous and Permian compared with 

 those of India and America; by C. Schuchert. (With 

 Plate I) -. 29 



VIII. — Note on two interesting Pseudomorphs in the McGill 

 University Mineral Collection ; by R. P. D. Graham, 

 B.A. 47 



IX. — Estacado Aerolite ; by K. S. Howard and J. M. 



Davison , 55 



X.— Stibiotantalite ; by S. L. Penfield and W. E. Ford ., 61 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— Properties of Liquid Nitrogen, H. Erdmann: Oxida- 

 tion of Ammonia to Nitrates and Nitrites, Schmidt and Booker, 78. — 

 Detection and Determination of Small Quantities of Iron, A. Mouneyrat: 

 Quantitative Determination of Acetone, A. Jolles : Avogadro and Dalton, 

 A. N. Meldrum, 79. — Electric Discharge in Gases, H. Sieveking,""80. — 

 Note on the computed drop of pressure in adiabatic expansion, C. Barus: 

 Meteorologische Optik, J. M. Pernter : Leitfadeii der Wetterkunde, E. 

 Bornstein, 81. — Refraktionstafeln, L. de Ball: Shaft Governors, 82. 



Geology and Mineralogy — Preliminary Report of the State Earthquake Inves- 

 tigation Commission, 82. — United States Geological Survey, 84. — Pleisto- 

 cene Geology of Mooers Quadrangle, etc., J. B. Woodworth, 86. — Geology 

 and Water Resources of Oklahoma, C. N. Gould : Bulletins of the Geo- 

 logical Survey of Virginia, 87. — La Sierra de Cordoba, W. Bodenbender : 

 Columbia University: Constitution of the Silicates, Tschermak, 88. — 

 Chemical Crystallography, Groth and Marshall : Geometrische Kristal- 

 lographie, E. Sommerpeldt : Mines du Transvaal, G. Moreau : Polarisa- 

 tionsmikroskops, E. Weinschenk, 89. — Tabellen zur mikroskopischen 

 Bestimmung der Mineralien nach ihrem Breckungsinc3 a x : Mineralogie des 

 Departements du Rhone etde la Loire, F. Gonnard: Studien uber Meteori- 

 ten, C. Klein, 90. 



Miscellaneous Scientific Intelligence — Plaster-plaques for Museums, G. L. 

 Goodale, 90. — American Association for the Advancement of Science, 92. 

 — Memoirs of the National Academy of Sciences, Brooks and Cowles : 

 Zeitschrift fur Gletscherkunde, E. Bruckner : Publications of the Field 

 Columbian Museum, 93. — Carnegie Institution of Washington : Personal 

 Hygiene designed for Undergraduates, A. A. Woodhull : Bulletin of the 

 Agricultural Experiment Station, Japan, 94. 



Obituary — Dr. Ernst Schellwien, 94. 



