v j CONTENTS. 



Niimroer 40. 



Page 



Art XXV— Glacial Lakes Newberry, Warren and Dana, 

 'in Central New York; by H. L. Faieohild. (With 

 Plate VI) 249 



XXVI.— Rapid Method "for the Determination of the 

 Amount of Soluble Mineral Matter in a Soil ; by T. H. 

 Means - - ;.- - - 264 



XXVII.— New Type of Telescope Objective especially 



adapted for Spectroscopic Use ; by C. S. Hastings.... 267 



XXVIII.— Phenocrysts of Intrusive Igneous Rocks; by L. 



V. Pirsson -- t 2* 71 



XXIX.— Occurrence, Origin and Chemical Composition of 



Chromite; by J. H. Pratt... 281 



XXX.— Influence* of Hydrochloric Acid in Titrations by 

 Sodium Thiosulphate, with special reference to the Esti- 

 mation of Selenious Acid; by J. T. Norton, Jr 287 



XXXI— Rock-forming Biotites and Amphiboles; by H. W. 



Turner . - 294 



XXXII.— One little known and one hitherto unknown species 



of Saurocephalus; by 0. P. Hay 299 



XXXIII.— Some American Fossil Cycads. Part II ; by G. 



R. Wieland. (With Plate VII.) 305 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— Luminous and Chemical Energy, Berthelot, 309. — 

 Homogeneity of Helium, Ramsay and Travers: Properties of Ozone, Laden- 

 burg, 310.— Preparation of Alkali Nitrites, Divers: Composition of American 

 Petroleum, Young : Electrical waves along wires, A. Sommerfeld, 311. — 

 Polarization and hysteresis in dielectrics, W. Schaufelberger: New method 

 of showing electric waves, A. Neugschwender : Separation of long waves of 

 heat by means of quartz prisms, H. Rubens and E. Aschkinass: Theory of 

 conduction of electricity through gases by charged ions, J. J. Thomson: Hall 

 phenomenon and the theory of Lorentz. Poincare\ 312. — Relation of the Sur- 

 face Tension and Specific Gravity of certain Aqueous Solutions to their State of 

 Ionization, K. H. Archbald : Cause of the Absence of Coloration in certain 

 Limpid Natural Waters, W. Spring, 313. — Text-Book of General Physics for 

 the use of Colleges and Scientific Schools.. C. S. Bastings and E. E. Beach, 314. 



Geohxju and Mineralogy — New facts regarding Devonian Fishes, C. R. East- 

 man, 314. — Geological Sketch of San Clemente Island, W. S. T. Smith: Geol- 

 ogy of the Edwards plateau and Rio Grande plain, etc., R. T. Hill and T. W. 

 Vaugiian, 315.— South Dakota Geological Survey, Bulletin No. 2, J. E. Todd: 

 Crater Lake, Oregon, J. S. Diller: International Geological Congress: Inter- 

 national Geographical Congress, 316.— Funafuti, W. J. Sollas: Petrograph- 

 ical and Geological Investigations of certain Transvaal Norites, Gabbros, and 

 Pyroxenites, J. A. L. Henderson, 317. — Occurrence of Corundum, T. H. Hol- 

 land and W. G. Miller, 318. — Minerals in Rock Sections, L. Mel. Luquer: 

 New Mineral Names, 319. 



Miscellaneous Scientific Intelligence — Benjamin Apthorp Gould Fund, 320. — An- 

 nual Report of the Board of Regents of the Smithsonian Institution for the 

 year ending June 30, 1896: Second Washington Catalogue of Stars, 321.— 

 Zoological Results based on material from New Britain, New Guinea, Loyalty 

 Island and elsewhere, collected during- the years 1895-97, A. Willey: Select 

 Bibliography of Chemistry, 1492-1897, H. C. Bolton: Biological Laboratory, 



