CONTEXTS. 



Page. 



Abt. 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 ; hy L. V. Piesson . 380 



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



the Littoral Plain ; by A. M. Edwaeds 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. Mobelaxd _• 392 



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



Pextield ..-. 393 



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



XLVIII. — Influence of Free Nitric Acid and Aqua Regia 



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



Beownikg 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. Dakton 1 407 



LI. — Electrical Oscillations of Low Frequency and their 



Resonance ; by M. I. Pupix 420 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Properties of free Hydroxvlamine, L. deBruyn: Tri- 

 sulphide and the Pentasulpinde of Boron, Moissax, 430. — Oxidation of Differ- 

 ent forms of Carbon. Wiesxer: Bise of Salt-solutions in Filter paper, E. 

 Fischer and Schmidjier, 43J. — Chemical Inactivity at low Temperatures, B. 

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

 "Wilhelm Seheele, Briefe unci Aufzeichnimgen herausgegeben von A. E. 

 Nordexskiold : Simple apparatus for measuring the Index of refraction of 

 Liquids. H. Euoss: Electromagnetic Theory of Color dispersion, H. vox 

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

 Lexard: Representation of Equipotential lines due to a current flowing 

 through a metallic plate, E. Lojijiel: Alternating Currents, F. Bedell and A. 

 C. Crehore, 435. — Die physikalisehe Behandlung unci die Messung hoher 

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

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

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

 son, 436. 



Geology and Mineralogy — Additions to the Palasobotany of the Cretaceous 

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

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

 A. C. Seward : Flora Tertiaria Italica. A. Meschlxelli and X. Squixabol. 438. 

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

 Dawsox: New Tteniopterid Fern and its Allies, D. \Thite, ■139.— Bryozoa of 

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

 Florida, \Y. H. Dall: Petrographische Untersuchungen ah argentinischen 

 Graniten, 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 — HodgkiDS Fund Prizes: Mechanics of the 

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

 sox : Jean-Servais Stas, 442. 



