CONTENTS. 



Page 



Art. XLII. — A Microsclerometer, for determining the Hard- 

 ness of Minerals ; by T. A. Jaggar, Jr. (With Plate 

 XII.). ._ 399 



XLIII. — Recent Observations on European Dinosaurs ; by 



O. C. Marsh _ _ 41 3 



XLIV. — Sapphires from Montana, with special reference to 

 those from Yogo Gulch iu Fergus County; by G. F. 

 Kunz 1 . .. _ 417 



XLV. — Corundum-bearing Rock from Yogo Gulch, Montana ; 



by L. V. Pirsson 421 



XLVI. — Crystallography of the Montana Sapphires; by J. 



H. Pratt.. _ .... 424 



XLVII. — Electrical Measurement by Alternating Currents ; 



by II. A.Rowland 429 



XL VIII. — The alleged Jurassic of Texas. A Reply to Pro- 

 fessor Jules Marcou ; by R. T. Hill _ 449 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— Thermal Phenomena attending Change in Rotatory- 

 Power, Brown and Pickering, 470. — Chemical Action of Electrical Oscilla- 

 tions, De Hemptixne. 471. — Explosion of Chlorine Peroxide with Carbon Mon- 

 oxide. Dixon, 472. — Absorption of Nitrogen by Carbon compounds under the 

 influence of the silent Electric Discharge, Berthelot: Manual of Qualitative 

 Analysis. C. R. Fresenius, 473. — Delay in spark discharges, E. Warburg: 

 Photoelectric relations of Fluorspar and of Selenium, G-. C. Schmidt, 474. — 

 Magnetic method of showing metallic iron: Spectra of certain stars, Vogel and 

 Wilsixg : Structure of the Cathode Light and the nature of the Lenard Rays. 

 Goldstein: New Nicol Prism. 475. 



Geology and Natural History — Observations on Baffinland, R. Bell, 476. — Inter- 

 national Geological Congress, 477. — Mineral Resources of the United States, 

 1895, D. T. Day: Descriptive Catalogue of Useful Fiber Plants of the World, 

 including the structural and economic classifications of fibers', C. R. Dodge, 478. 



Miscellaneous Scientific Intelligence— Natural Academy of Sciences, 479. — Cordoba 

 Photographs, B. A. Gould : November Meteors : Sixteenth Annual Report 

 of the Bureau of American Ethnology. J. W. Powell, 480.— Field Columbian 

 Museum : American Journal of Physiology, 481. 



Index, 482. 



