CONTENTS. 



Page 



Art. XXIV. — Origin of Coral Reefs and Islands ; by J. D. 



Daxa, 169 



XXV". — Quartz-twin from Albemarle County, Virginia ; by 



W. G. Brown, 191 



XXVI. — Impact Friction and Faulting ; by G. F. Becker, 194 

 XXVII. — Transmission oi Light by Wire Gauze Screens ; 



by S. P. Langley, "... 210 



XXVIII. — Geological Relations of the Gypsum Deposits in 



Cayuga County, N. Y. ; by S. G. Williams, 212 



XXIX. — Variation of the Magnetic permeability of Nickel 



at different temperatures ; by C. A. Perkins, 218 



XXX. — Enlargements of Hornblende fragments ; by C. R. 



Van Hise, , 231 



XXXI, — Three Masses of Meteoric Iron from Glorieta Moun- 

 tain, near Canoncito, Santa Fe County, New Mexico; 



by G. F. Kunz. (With four plates), 235 



SCIENTIFIC INTELLIGENCE. 



Physics. — ''Transfer-resistance" in Electrolytic and Voltaic Cells, G-. Gore, 238. 

 — Electrical Resistance of the new alloy Platinoid, Bottomley : Annual change 

 of the Aurora Borealis, 240.— Note on a preliminary Comparison between the 

 Dates of Cyclonic Storms in Great Britain and those of Magnetic Disturbances 

 at the Kew Observatory, B. Stewart and W. L. Carpenter : Properties of 

 Matter, P. G. Tait : Mathematical theory of Electricity and Magnetism, H. W. 

 Watson and S. H. Burbuby, 241. 



Geology and Natural History. — Report of Progress of the Geological and Natural 

 History Survey of Canada during the years 1882-83-84, A. R. C Selayyn, 241. 

 — Aralo-Caspian and Mediterranean Basins, T. P. Jamieson, 243. — Union 

 Group, Pacific Ocean. — Spiralis major and Sp. Randalli of Newberry, large 

 Screw-like fossils from the Chemung group of Northern Pennsylvania and 

 Southern New York, J. S. Newberry : Geological Map of the United States, 

 W. J. McGee : Maefarlane's Geological Railway Guide, 244. — Impact Friction 

 and Faulting, G. F. Becker: Plantes a Fourmis, 245. — Lloyd's Drugs and 

 Medicines of North America : Transactions and Proceedings of the New 

 Zealand Institute for 1884: Revision of the North American Species of the 

 Genus Scleria, N. L. Britton, 246. — Beitrag zur Kenntniss der Sarraceniaceen, 

 P. Zippeber: Charles "Wright, 247. 



Miscellaneous Scientific Intelligence. — Transactions of the Connecticut Academy 

 of Arts and Sciences: Catalogue of Scientific and Technical Periodicals (1665 

 to 1882) together with Chronological Tables and a Library Check-List, H. C. 

 Bolton, 247. — Contributions to North American Ethnology, J. W. Powell : 

 Microscope in Botany, a Guide for the Microscopic Investigation of Vegetable 

 Substances. J. Y\\ Behress. 248. 



Obituary. — Henri Feesca : Henri Milne Edwards : W. C. Kerr, 248. 



