Vlll CONTENTS. 



Number 270. 



Page 



Art. XXVII. — Generalized Relativity and Gravitation ; by 



E. WoOLARD 425 



XX VIII.— An Unusual Mastodon ; by F. B. Loomis 438 



XXIX. — A Restoration of Neocalamites ; by E. W. Berry 445 



XXX.— The Origin of Chert ; by F. M. Van Tuyl ..., 449 



XXXI. — A Larofe Parasuchian from theTriassic of Pennsyl- 

 vania ; by W. J. Sinclair , . 457 



XXXII. — Augite from Stromboli ; by S. Kozu and H. S. 



Washington -.. - 463 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Use of Metallic Silver as a Reducing Agent in the 

 Volumetric Estimation of Iron, G. Edgar and A. R. Kemp : Iodimetric 

 Estimation of Copper and Iron, H. Ley, 470. — Chemistry in the Home, 

 H. T. Weed: Chemistry, First Stage, F. P. Armitage, 471. — Publications 

 of the Yerkes Observatory, G. E. Hale, etc., 472. — Axial Aberrations of 

 Lenses, E. D. Tillyer and H. I. Shultz, 474. 



Geology and Mineralogy — Publications of the United States Geological Sur- 

 vey, G. 0. Smith, 475. — United States Bureau of Mines, V. H. Manning: 

 Geology and Ore Deposits of the Virgilina District of Virginia and North 

 Carolina, F. B. Laney, 476. — Tin Deposits near Irish Creek, Virginia, H. 

 G. Ferguson : New Mineral Names, w. E. Ford, 477. — Geological Society 

 of London, 478. — A Geological Handbook to Northern France, W. M. 

 Davis, 479. 



Miscellaneous Scientific Intelligence — National Academy of Sciences, 479.— 

 Carnegie Institution of Washington, Year Book, No. 16, R. S. Woodward, 

 480. — Carnegie Foundation for the Advancement of Teaching, Twelfth 

 Annual Report of the President and Treasurer, H. S. Pritchett and R. A. 

 Franks, 483. — Soil Physics and Management, J. G. Mosier and A. F. 

 Gcstafson : Elementary Economic Geography, C. R. Dryer, 484. — A 

 Laboratory Outline of Neurology, C. J. Herrick and E. C. Crosby, 485. 



Obi/nary — G. K. Gilbert: G. J. Hinde, 485. 



Index, 486. 



