Vlll CONTENTS. 



Number 6. 



Page 



Art. XL VII. — Color Relations of Atoms, Ions and Mole- 

 cules ; by M. C. Lea. Part II 405 



XL VIII. — Gravimetric Determination of Selenium; by A. 



W. Peirce _ ___ 416 



XLIX— Extinct Felida3 of North America; by G. I. 



Adams. (With Plates X, XI, XII.) 419 



L. — Age of the Igneous Rocks of the Yellowstone National 



Park ; by A. Hague 445 



LI. — Occurrence of Pollucite, Mangano-Columbite and Mi- 



crolite at Rumford, Maine ; by H. W. Foots 457 



LII. — Device for Simplifying the Drawing of Crystal Forms ; 



by A. J. Moses 462 



LIII. — Concerning Crookes Tubes ; by C. C. Hutchixs and 



F. C. Robinson _._ 463 



LIV. — Researches on the Runtgen Rays ; by A. M. Mayer 467 



LV. — Pithecanthropus erectus, from the Tertiary of 



Java; by O. C. Marsh. (With Plate XIII.) 475 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Molecular weight of sulphur, Orndorff and Terrasse : 

 Absorption of the Rontgen rays by chemical compounds, NovAk and Sulc, 

 483. — Dictionary of Chemical Solubilities, Inorganic, A. M. Comey: Fermenta- 

 tions, P. Schutzenberger, 484. — Repertoire cles Reactives Speciaux, F. Jean 

 and G. Mercier: Existence of two Orthophthalic Acids, W. T. H. Howe: Na- 

 ture of the X-Rays, D. A. Goldhajvimer, 485. — Recent work with Rontgen Rays, 

 486. — Diminution of the intensity of Sound with the distance, K. L. Schaefer, 

 487. 



Geology and Natural History — Fifteenth Annual Report of the United States 

 Geological Survey, 487. — Topographical maps of the United States Geological 

 Survey : Summary Description of the Geology of Pennsylvania, 488. — Geology 

 of the Road-Building Stones of Massachusetts, with some. Consideration of 

 Similar Material from other parts of the United States, N. S. Shaler: Univer- 

 sity Geological Survey of Kansas, conducted under authority of the Board of 

 Regents of the University of Kansas, E. Ha worth, 489. — Geological Survey of 

 Canada, 490. — Tierreich, eine Zusammenstellung und Kennzeichnung der 

 rezenten Tierformen. Comparative Morphology of the Galeodidse, H. M. 

 Bernard, 49 1..— Characese of America, T. F. Allen : Kryp toga men -Flora von 

 Deutschland, Oesterreich und der Schweiz, Hysteriacese, Discomycetes (Peziz- 

 aceae), H. Rehm, 492. — Phycotheca Boreali-Americana, F. S. Collins, I. Holden 

 and W. A. Setchell. 



Miscellaneous Scientific Intelligence — National Academy of Sciences, 493. — New 

 England Meteorological Society, 495. 



