Vlii CONTENTS. 



Number 156. 



Page 

 Art. XLVII. — Preparation of Urano-XJranic Oxide, U 3 8 , 



and a Standard of Radio-activity ; by II. N". McCoy and 



G. C. Ashman .. 521 



XLV1II. — Telemeter with Micrometer Screw Adjustment ; 



by F. E. Wright ■.. 531 



XLIX. — Device to Aid in the Explanation of Interference 



Phenomena; by F. E. Wright .. _ 536 



L. — Descriptions of Tertiary Plants, II ; by T. D. A. 



COCKERELL -.537 



LI. — Three Contact Minerals from Velardena, Durango, 

 Mexico. ( Gehlenite, Spurrite and Hillebrandite ; ) by 

 F.E.Wright t _ _ 545 



LII. — Volumetric Estimation of Potassium in Animal Fluids; 



by W. A. Drushel 555 



LIII. — Meso-Silurian Deposits of Maryland; by Wm. F. 



Prouty.* _._ .._ 563 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Eate of Production of Helium from Kadium, J. 

 Dewar : Eadium in Tufa Deposits, Schlundt : Compound of Cobalt with 

 Carbon Monoxide, Mond, Hirtz and Cowap, 575. — Cyanide Processes, E. 

 B. Wilson : Magnetic Potation of Electric Discharge, D. N. Mallik : 

 Directive System of Wireless Telegraphy, E. Bellini and A. Tosi : Positive 

 Pays, J. J. Thomson, 576. — Radium Emanation in the Atmosphere near 

 the Earth's Surface, Eve : Absorption of Rontgen Rays, W. Seitz : Zee- 

 man Effect in Solar Vortices, G. A Hale : Study of Stellar Evolution, 

 an Account of some Recent Methods of Astrophysical Research, G. E. 

 Hale, 577. — Korpuskulartheorie der Materie, J. J. Thomson and G. 

 Siebert. — Magneto- und Electro-Optik, W. Voigt : Evolution of Forces, 

 G. Le Bon, 579. — Experimental Electricity, G. F. C. Searle : The New 

 Physics and its Evolution, L. Poincare : Principles of Mechanics, H. 

 Crew, 580. 



Geology and Mineralogy — West Virginia Geological Survey, I. C. White : 

 Florida State Geological Survey, E. H. Sellards, 581. — Wisconsin Geo- 

 logical and Natural History Survey : Geological Survey of Cape of Good 

 Hope, 582. — Bergensfeltet og tilstodende Trakter i senglacial og postglacial 

 Tid, C. F. Kolderup : Mikroskopishe Physiographie der massigen Ge- 

 steine ; Ergussgesteme, H. Rosenbusch, 583. — : Die Fossilen Insekten und 

 die Phylogenie der rezenten Formen, A. Handlirsch : Gahnite, G. M. 

 Flint : Hints for Crystal Drawing, M. Reeks, 584. 



Botany — Systematic Anatomy of the Dicotyledons, H. Solereder, 585. — 

 Text-Book of Botany and Pharmacognosy, H. Kraemer, 586. — Die 

 Gestalts- und Lageveranderung der Pflanzen-Chromatophoren, G. Senn, 

 587. 



Miscellaneous Scientific Intelligence — National Academy of Sciences : 

 National Antarctic Expedition, 1901-1904, 588. — Road Preservation and 

 Dust Prevention, W. P. Judson, 589. — Ostwald's Klassiker der Exakten 

 Wissenschaften : Elementary Dynamics, E. S. Ferry : Plane and Solid 

 Geometry, E. A. Lyman, 590. — Moral Instruction and Training in Schools, 

 M. E. Sadler : Practical Exercises in Physical Geography, W. M. Davis, 

 Twenty-Sixth Annual Report of the Bureau of American Ethnology, 591. 



Obituary — William K. Brooks, 591. 



