CONTENTS. 



Page 



Art. XXII. — A young Tortoise, Ohrysemys fiicta, with two 



heads ; by E. H. Barbour. With Plate V 227 



XXIIL— The Structure of Florida ; by L. C. Johnson 230 



XXIV. — Analysis of a Soil from Washington Territory, and 

 some remarks on the utility of Soil-analysis ; by E. A. 

 Schneider 236 



XXV. — Rosetown Extension of the Cortlandt Series ; by J. 



F.Kemp... 247 



XXVI. — The Contact-Metamorphism produced in the ad- 

 joining Mica schists and Limestones by the Massive 

 Rocks of the " Cortlandt Series," near Peekskill, N. Y.; 

 by G. H. Williams. With Plate VI 254 



XX VII.— The Sedentary Habits of Platyceras; by C. R. 



Keyes 269 



XXVIII. — Edisonite, a fourth form of Titanic acid; by W. 



E. Hidden 272 



XXIX. — Two new masses of Meteoric Iron ; by G. F. Kttnz. 



With Plate VII __. 275 



XXX. — Experiments on the Effect of Magnetic Force on the 

 Equipotential Lines of an Electric Current; by E. H. 

 Hall 277 



XXXI. — The Compression of Powdered Solids; by W. 



Spring 286 



XXXII. — Preliminary notice of Beryllonite, a new mineral ; 



by E. S. Dana 290 



SCIENTIFIC INTELLIGENCE. 



Physics. — Infra-red Solar Spectrum, Abney, 291. — Photometry of Color, Aexet: 

 Heat Measurement, vox Helmholtz, 292.— Ether Calorimeter, Neesen: Elec- 

 trolysis of Water, von Helmholtz. 293. 



Geology and Natural History. — Explosive volcanic eruption in Japan, J. S. Mans- 

 field, 293. — American Geological Society: Cambrian Trilobites from Sardinia, 

 Gr. Meneghini, 294. — Bibliography of the Foraminifera, Recent and Fossil, 

 C. D. Sherbcrx : Decomposition of Native Iron Sulphides, A. A. Julien: 

 Rock-Forming Minerals, F. Rutley: Uraninite. W. F. Hillebrand: Heather 

 in Townsend, Mass., Ball, 295. — Insect Life, 296. — Fauna of British India, 

 W. T. Blanford: Entomology for Beginners, A. S. Packard, 291. 



Miscellaneous Scientific Intelligence. — American Association for the Advancement 

 of Science, 291. — India in 1887, as seen by Robert Wallace, 302. —Eclectic 

 Physical Geography. R. Hinman, 303. 



Obituary. — Silas Stearns, 303.— R. Clausius: Richard A. ProClOR: Philip 

 Henry Gosse: M. Henri Debrat, 304. 



APPENDIX. 

 Index to the Writings of Dr. Asa G-ray. 



