CONTENTS. 



Pa#e 



Art. XXXIV. — Some Experiments with Endothermic 



Gases; by W. G. Mixter ■_ ... 323 



XXXV. — Hypothesis to explain the partial non-explosive 



Combination of Explosive Gases and Gaseous Mixtures ; 



by W. G. Mixter r . 327 



XXXVI. — Occurrence of Paleotrochis in Volcanic Rocks in 



Mexico; by II. S. Williams 335 



XXXVII.— Origin of Paleotrochis ; by J. S. Diller 337 



XXXVIII. — Association of Argillaceous Rocks with Quartz 



Veins in the Region of Diamantina, Brazil; by O. A. 



Derby _ - - . 343 



XXXIX.— Goldschmidtite, a New Mineral; by W. H. Hobbs 357 

 XL. — Hydromica from New Jersey ; by F. W. Clarke and 



N. II. Darton ._ _ ._ 365 



XLI. — Powellite Crystals from Michigan; by C. Palache.. 367 

 XLII. — Volatilization of the Iron Chlorides in Analysis, and 



the Separation of the Oxides of Iron and Aluminum ; by 



F. A. Gooch and F. S. Havens.. 370 



XLIII. — Descriptions of imperfectly known and new Actini- 



ans, with critical notes on other species, V; by A. E. 



Verrill _ 375 



XLI V. — Preliminary Note as to the Cause of Root-Pressure ; 



by R. G. Leayitt _ 381 



XLV. — Study of Some American Fossil Cycads. Part III; 



by G. R. Wieland. (With Plates VIII-X.) 383 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— Low Temperature Experiments, Hempel, 392. — Reduc- 

 tions in Presence of Palladium, Zklinsky: Properties of Metallic Calcium, 

 Moissan, 393. — New Bases from Strychnine, Tafel: History of Physics in' its 

 Elementary Branches including' the Evolution of Physical Laboratories, F. 

 Cajori, 394. — Electrolytic Interrupter, A A. C. Swinton: Measurement of slow 

 electrical oscillations, W. Kon'IG, 395. — Electric waves on wires, W. D. Cool- 

 idge: Absorption of the X-rays by air: Optisehen Instrumente der Firme R. 

 Fuess, C. LeisS; 396. 



Geology and Natural History — Note on a Bridger Eocene Carnivore, 0. C. Marsh : 

 Age of the Franklin White Limestone of Sussex County, N. J., J. E. Wolff 

 and A. H. Brooks, 397.— West Virginia Geological and Economic Survey: 

 Alabama Geological Survey, W. B. Phillips: Development of Lvtoceras and 

 Phylloceras, J. P. Smith: Pre-Cambrian Igneous Rocks of the Fox River Val- 

 ley, Wise, S. Weidman, 398 —West Virginia Geological Survey. I. C. White: 

 New and interesting olivine-melilite-leucite rock, V. Sabatini, 399. — Deuxieme 

 Memoire sur les Algues Marines du Groenland, L. K. Rosexvixge: Mono- 

 graphie des Caulerpes, A. W. Bosse, 400.— Disposition Delesseriearum, J. G. 

 Agaudh, 401. 



Miscellaneous Scientific Intelligence— National Academy of Sciences, 401.— Annual 

 Report of the Board of Regents of the Smithsonian Institution, to July, 1897 : 

 Harper's Scientific Series, 402. 



Obituary— -Dr. Gustav Wiedemann, 402. 



