Ylll CONTENTS. 



Number 192. 



Page 



Art. XLIII. — Emission of Electrons by Metals under the 



Influence of Alpha Rays ; by H. A. Bumstead 403 



XLIV. — Some Minerals from Beaver County, Utah ; by B. 



S. Butler and W. T. Schaller .,__ 418 



XLV. — Method of Determining- the Density of Minerals by 

 means of Rohrbach's Solution having a Standard Refrac- 

 tive Index ; by H. E. Merwin 425 



XLVI. — Quartz and Fluorite as Standards of Density and 



Refractive Index ; by H. E. Merwin 429 



XLVII.— Williamsonian Tribe ; by G. R. Wieland 433 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Arsenides of Iron and Manganese, Hilpekt and 

 Dieckmann : Enrichment of Eadio-active Substances by Adsorption. 

 Eblee and Fellner : Fluorides of Vanadium, 0. Ruff and H. Lickfett : 

 A Constituent of Mineral Coal, A. Pictet aud L. Ramseyer, 467. — Techni- 

 cal Analysis of Brass and the Non-ferrous Alloys, W. B. Price and R. K. 

 Meade : Allen's Commercial Organic Analysis : Electro-Analysis, E. F. 

 Smith, 468. — Disintegration Products of Uranium, G. N. Antonoff, 469 — 

 Method of making Visible the Paths of Ionizing Particles through a Gas, 

 C. T. R. Wilson, 470. — Dynamical Nature of the Molecular Systems 

 which emit Spectra of the Banded Type, E. T. Whittaker, 472. 



Geology and Natural History — Recent Contributions on Cycadophytans, G. 

 R. Wieland, 473. — Botanical Expedition to Newfoundland and Southern 

 Labrador, M. L. Fernald, 476. — Topographic and Geologic Survey of 

 Pennsylvania, R. R. Hice : Virginia Geological Survey Bulletin No. VI, 

 477. — Hexahydrite, a New Mineral, A. A. Johnston, 478. 



Miscellaneous Scientific Intelligence — A Study of Chiriquian Antiquities, G. 

 G. MacCurdy, 478. — National Academy of Sciences, 479. — American 

 Association for the Advancement of Science, 489. 



Obituary — L. J. Troost : A. Michel-Levy : H. Risley : F. Ameghino, 480. 

 Index to Volume XXXII, 481. 



