CONTENTS. VU 



Number 29. 



Page 



Art. XLI. — Some Conditions affecting Geyser Eruption ; by 



T. A. Jaggar, Jr. * 323 



XLII. — Properties of Seasoned Magnets made of Self-Harden- 

 ing Steel ; by B. O. Peirce 334 



XLIII. — Curious Inversion in the Wave Mechanism of the 



Electromagnetic Theory of Light ; by C. Barus 343 



XLIV. — Determination of Plagioclase Feldspars in Rock 



Sections; by G. F. Becker. (With Plate III.) 349 



XL V. — Some Lava Flows of the Western Slope of the Sierra 



Nevada, California ; by F. L. Ransome 355 



XLVI. — Krennerite, from Cripple Creek, Colorado ; by A. 



H. Chester 315 



XL VII. — Some new Jurassic Vertebrates from Wyoming ; 



by W. C. Knight 378 



XL VIII. — Estimation of Manganese separated as the Car- 

 bonate ; by M. Austin 382 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — New Methods for Measuring Gases, Bleier. 385. — Influ- 

 ence of the Rontgen Radiation on the Velocity and Rate of Recombination of 

 the Ions of Gases, 386. — Connection between Fluorescence and Chemical Com- 

 position, R. E. Meyer: New method of preparing pure Iodine, Lean and 

 Whatmough, 387. — Borid.es of Calcium, Barium and Strontium, Moissan and 

 Williams: Arrangement of Atoms in Space, Van't Hoff, 388. — College Course 

 of Laboratory Experiments in General Physics, S. W. Stratton and R. H. 

 Mitlikan, 389. — Text-book of Physical Chemistry, C. L. Speyers: Tutorial 

 Chemistry, G. H. Bailey. 390. — The ultra-red spectrum, H. Rubens and E. 

 Aschkinass: Transparency of fluids for heat rays of great wave-length. H. 

 Rubens and E. Aschkinass : Electrical resistance standards. W. Jaeger and 

 K. Kahle: Electric equilibrium between uranium and an insulated metal in its 

 neighborhood, Kelvin. 391. 



Geology and Mineralogy — L'echelle reduite des experiences geologiques permet- 

 elle leur application aux phenomenes de la nature? W. Prinz, 392. — Geological 

 survey of the TVitwatersrand, Southern Transvaal, F. H. Hatch: Revised Text- 

 Book of Geology by James D. Dana, edited by Wm. N. Rice: Genus Lepido- 

 phloios, J. TV. Dawson, 393 — Geological Survey of Georgia : Geological Survey 

 of India, 394. 



Miscellaneous Scientific Intelligence — Report of the National Academy of Sciences 

 for the year 1897, 395.— National Academy of Sciences, 396. — American Asso- 

 ciation for the Advancement of Science, 397. — Science Abstracts, 398. 



Obituary — Prof. Jules Marcou. 



