CONTENTS. V 



Geology and Mineralogy — Note respecting the term Agnotozoic, T. C. Chamber- 

 lin, 254. — Contributions to the Paleontology of Brazil, Charles A. White: 

 Arkansas Geological Survey : Fossils of Littleton, New Hampshire : Palaeo- 

 lithic Man in Northwest Middlesex, J. A. Brown, 255. — Organization of the 

 Fossil Plants of the Coal Measures, W. C. Williamson : Catalogue of the Fos- 

 sil Mammalia in the British Museum, E. Ltdekker: Geological Evidences of 

 Evolution, A. Heilpein, 256. — Kilauea: Allgemeine und chemische Geologie, 

 J. Roth: Mineral Resources of the United States, D. T. Day Native Plat- 

 inum from Canada, G. C. Hoffmann, 257. — Shepard Collection of Minerals: 

 Natural Gas, 258. 



Botany — Respiratory Organs of Plants, L. Jost: Combination of the Auxanome- 

 ter with the Clinostat, Albrecht, 258. — Die natiirlichen Pflanzenfamilien, A. 

 Engler and K. Prantl, 259.- — Botanical Necrology for the year 1887, 260.. 



Miscellaneous Scientific Intelligence — Hann's Meteorological Atlas, 263. — New 

 Meteorites, 264. 



Number 208. 



Page 



Aet. XXII. — The Absolute Wave-length of Light ; by L. 



Bell. Part I 265 



XXIII. — History of the changes in the Mt. Loa Craters ; by 



J. D. Dana. (With Plates IV and V) 282 



XXIV. — The Electromotive Force of Magnetization ; by 



E. L. Nichols and W. S. 'Franklin .... 290 



XXV. — Notes on certain rare Copper Minerals from Utah ; 



by W. F. Hillebeand and H. S. Washington 298 



XXVI. — The Taconic System of Emmons, and the use of 



the name Taconic in Geologic nomenclature ; by C. D. 



Walcott. (With Plate III) 307 



XXVII. — Three Formations of the Middle Atlantic Slope ; 



by W. J. McGee 328 



XXVIII. — Diorite Dike at Forest of Dean, Orange County, 



N. Y. ; by J. F. Kemp 331 



XXIX. — New Lecture Apparatus for determination of Re- 

 flection and Refraction ; by W. L. Stevens 332 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Spectrum of the Residual Glow, Ckookes, 334. — Pres- 

 ence of Chlorine in Oxygen prepared from Potassium chlorate, Bellamy : 

 Interaction of zinc and sulphuric acid, Muir and Adie, 335. — Organic Analysis, 

 A. B. Prescott: Practical Physics, B. Stewart and W. W. H. Gek, 336. — 

 Spectrum of the oxyhydrogen flame, G. D. Liveing and J. Dewar : Application 

 of the Electrolysis of Copper to the Measurement of Electric Currents, Gray : 

 Influence of light upon electrical discharges : Wave-lengths of standard lines, 

 P. Kurlbatjm, 337. 



Geology and Natural History. — Distribution of strain in the Earth's crust resulting 

 from secular cooling, C. Davison and G. H. Darwin, 338. — Lavas of Krakatoa: 

 Geologie von Bayern, K. W. von G umbel: Recent contributions to our knowl- 

 edge of the vegetable cell, 341. 



