CONTENTS. Vll 



Number 269. 



Page 



Art. XLI. — Deportment of Charcoal with the Halogens, 



Nitrogen, Sulphur, and Oxygen; by W. G. Mixter 363 



XLII. — Note on some Volcanic Rocks from Gough's Island, 



South Atlantic ; by L. V. Pirsson . 380 



XLIII. — Champlain(?) deposit of Diatomaeese belonging to 



the Littoral Plain; by A. M. Edwards 385 



XLIV. — Refraction of Light upon the Snow ; by A. W. 



Whitney 389 



XLV. — Value of the force exerted by a current of Electricity 



in a circular conductor on a unit magnetic pole at its 



center; by S. T. Moreland 392 



XL VI. — Cookeite from Paris and Hebron, Maine; by S. L. 



Pentteld .. 393 



XLVII, — Mineralogical Notes ; by S. L. Penfield 396 



XL VIII. — Influence of Free Nitric Acid and Aqua Regia 



on the Precipitation of Barium as Sulphate; by P. E. 



Browning 399 



XLIX. — Rose-colored Lime- and Alumina-bearing Variety 



of Talc ; by W. H. Hobbs 404 



L. — The Magothy Formation of Northeastern Maryland ; by 



N. H. Darton . ... 407 



LI. — Electrical Oscillations of Low Frequency and their 



Resonance ; by M. I. Putin 420 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Properties of free Hydroxylamine, L. de Bruyn : Tri- 

 sulphide and the Pentasulphide of Boron, Moissan, 430. — Oxidation of Differ- 

 ent forms of Carbon, Wiesner: Rise of Salt-solutions in Filter paper, E. 

 Fischer and Schmidmek, 431. — Chemical Inactivity at low Temperatures, R. 

 Pictet, 432.— Berzelius und Liebig, Ihre Briefe von 1831-1845, 433. — Carl 

 Wilhelm Scheele, Briefe und Aufzeichnungen herausgegeben von A. E. 

 Nordenskiold : Simple apparatus for measuring the Index of refraction of 

 Liquids, H. Ruoss: Electromagnetic Theory of Color dispersion, H. von 

 Helmholtz, 434. — Penetration of thin metallic screens by Phosphorescent rays, 

 Lenard: Representation of Equipotential lines due to a current flowing 

 through a metallic plate, K. Lommel: Alternating Currents, F. Bedell and A. 

 C. Crehore, 435. — Die physikalische Behandlung und die Messung hoher 

 Temperaturen, C. Barus: Hiilfsbuch fur die Ausfiihrung elektrischer Mes- 

 sungen, A. Heydweiller: Practical Physics, R. T. Glazebrook and W. N. 

 Shaw : Elementary Treatise on Physics, Experimental and Applied, E. Atkin- 

 son, 436. 



Geology and Mineralogy — Additions to the Paleobotany of the Cretaceous 

 Formation on Staten Island, A. Hollick: Organization of the Fossil Plants of 

 the Coal-Measures, W. C. Williamson, 437. — Fossil Plants as Tests of Climate, 

 A. C. Seward : Flora Tertiaria Italica, A. Meschinelli and X. Squinabol. 438. 

 — Correlation of Early Cretaceous Floras in Canada and United States, J. W. 

 Dawson: New Tasmopterid Fern and its Allies, D. White, 439. — Bryozoa of 

 the Lower Silurian in Minnesota, E. O. Ulrich, 440. — Tertiary Mollusks of 

 Florida, W. H. Dall: Petrographische TJntersuchungen an argentinischen 

 Gfaniten, J. Romberg: Phonolite in Great Britain: Catalogue of American 

 Localities of Minerals, E. S. Dana, 441. — Repertorium der Mineralogischen und 

 Krystallographischen Literatur, 1885-91, P. Groth, 442. 



Miscellaneous Scientific Intelligence — Hodgkins Fund Prizes: Mechanics of the 

 Earth's Atmosphere. C. Abbe: Manual of Irrigation Engineering, H. M. Wil- 

 son: Jean-Servais Stas, 442. 



