CONTENTS. 



Page 



Art. XXXVIII. — Carbon and Oxygen in the Sun ; by J. 



Trowbridge _ 329 



XXXIX. — Determination of the Division Errors of a Straight 



Scale ; by H. Jacoby 333 



XL. — Studies upon the Cyperacese; by T. Holm. (With 



Plate IX) _ _. 348 



XLI. — Bearpaw Mountains of Montana ; by W. H. Weed 



and L. V. Pirsson . _ 351 



XLII. — Rontgen Rays not Present in Sunlight ; by M. C. Lea 363 

 XLIII. — Potomac River Section of the Middle Atlantic Coast 



Eocene ; by W. B. Clark _ _ 365 



XLIV. — Ischian Trachytes; by H. S. Washington.. 375 



XLV. — Numerical Relations existing between the Atomic 



Weights of the Elements ; by M. C. Lea 386 



XLVI. — Crocoite from Tasmania; by C. Palache 389 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Investigations with sulphide of nitrogen, Clever and 

 Muthmann, 391. — Manganese carbide, Moissan : Preparation of pure stron 

 tium compounds. Sorensen. 392. — New class of compounds of metallic salts 

 with ammonia, Wiede and Hofmann : Influence of light on the form of dis 

 charge of a Holtz machine, Elster and Geitel : Fluorescence of Vapors 

 E. Wiedemann and G. C. Schmidt, 393. — Interference of Electric Waves 

 Viktor von Lang : Rontgen's Discovery : Temperature of the Carbons of the 

 Electric Arc, Wilson and Gray, 394. — Melting points of some of the metals 

 S. W. Holman, R.'R. Lawrence and L. Barr, 395. 



Geology and Natural History — Economic Geology of the Mercur Mining District, 

 Utah, J. E. Spurr, 395. — Catalogue of the Fossil Fishes in the British Museum 

 Part ill, A. S. Woodward, 396. — Catalogue of the Mesozoic Plants in the De 

 partment of Geology of the British Museum, Part II, A. C. Seward: Catalogue 

 of the Perciform Fishes in the British Museum, G. A. Boulenger, 397. — De 

 scriptive Catalogue of the Spiders of Burma, preserved in the British Museum, 

 T. Thorell: Duration of Niagara Falls and the History of the Great Lakes 

 J. W. Spencer: Illinois State Museum : Oblique Bedding in Limestones, 398.— 

 Geological History of the Chautauqua (N. T.) Grape Belt, R. S. Tarr: Geolog 

 ical Literature : Norges Geologiske Undersogelse : Eruptionsfolge der triadi 

 schen Eruptivgesteine bei Predazzo in Siidtyrol, W. C. Brogger, 399. — Mica 

 Peridotites in Bengal, T. H. Holland: Zusammenstellung petrographischer 

 Untersuchungsmethoden nebst Angabe der Literatur, E. Cohen, 40u. — Jadeite 

 from Thibet, M. Bauer : Dictionary of the Names of Minerals including their 

 History and Etymology, A. H. Chester: Mineralogie de la France et de ses 

 Colonies, A. Lacroiz: Mineralogy, F. Rutley, 401. — Determination des Felds- 

 paths dans les plaques minces, A. Michel-Levy : Allgemeine Krystallbeschreib- 

 ung auf Grund einer vereinfachten Methode des Krystallzeichnens, A. Nies, 402. 



Miscellaneous Scientific Intelligence — Diurnal Periodicity of Earthquakes, C. 

 Davison, 402. — Transactions of the American Microscopical Society : Hand- 

 book of Arctic Discoveries, A. W. Greely, 403.— James Clerk Maxwell and 

 Modern Physics, R T. Glazebrook : North American Birds, H. Nehrling : 

 Ostwald's Klassiker der exacten Wissenschaften, 404. 



