Vlll CONTENTS. 



Number 24. 



Page 



Aet. 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 .. 413 



XLIV.— Sapphires from Montana, with special reference to 

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

 Kunz ._. _ _ 417 



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



by L. Y. Pirsson 421 



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



H. Pratt 424 



XLYII. — Electrical Measurement by Alternating Currents ; 



by H. A. Rowland 429 



XLYIII. — 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 Hemptinne, 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. P. 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 

 Wilsing: 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. 



