CONTENTS 



Art. XXXVI. — Ordovician-Silurian Contact in the Ripley 



Island Area of Southern Indiana, with notes on the age 



of the Cincinnati geanticline ; by A. F. Foerste. 



(With Plate XVII) -. 321 



XXXVIL— Crystallographic Study of Millerite ; by C. 



Palache and H. O. Wood. _;. ._ _. 343 



XXXVIII. — Unconformity of the Cretaceous on Older Rocks 



in Central New Mexico ; by C. R. Keyes 360 



XXXIX. — Peculiar Occurrence of Bitumen and Evidence as 



to its Origin ; by W. C. Morgan and M. C. Tallmon. 



(With Plates XVIII and XIX) 363 



XL. — Radio-activity of Natural Waters ; by B. B. Boltwood 378 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Action of Radium Emanations on Diamond, W. 

 Crookes, 388. — Radio-active Lead, Radio- tellurium, and Polonium, 

 Debierne, 389. — Condensation of Helium and Hydrogen by Charcoal, J. 

 Dewar : Riechstoffe, G. Cohen : Volumetric Analysis, F. Sutton, 390 — 

 Emanation of Radium, W. Ramsay : Emanations — Radiations, Berthelot : 

 Conduction of Electricity through high Vacua, R. J. Strutt : Negative 

 Ions from Heated Metals and Oxides, A. Wehnelt, 391. — Electro- chemical 

 Equivalent of Silver, G. Van Dijk and J. Kunst : Electric Effect of 

 Rotating a Dielectric in a Magnetic Field, H. A. Wilson : Radio-active 

 Gas from Crude Petroleum, E. F. Burton, 392. — Absorption of Water 

 Vapor in the Infra-red Solar Spectrum, F. E. Fowle : Action of Wood 

 on a Photographic Plate in the Dark, W. J. Russell, 393. 



Geology and Mineralogy — U. S. Geological Survey, 394. — Baraboo Iron- 

 bearing District, Wisconsin, S. Weidman, 395. — Chemical Survey of the 

 Waters of Illinois, A. W. Palmer: Submerged Tributary of* the St. 

 Lawrence, H. S. Poole : Sands and Sediments, T. M. Reade and P. 

 Holland : Palseontologia Universalis, 396. — Interferenz Erscheinungen 

 im polarisirten Licht ; photographisch aufgenommen, H. Hauswaldt : Tab- 

 leau systematique des Mineraux classes d'appres leurs proprietes chimiques 

 et cristallographiques, P. Groth ; Traduit de la quatrieme Edition alle- 

 mande, MM. E. Joukowsky and F. A. Pearce, 397. — Introduction to the 

 Study of Meteorites, with a list of the Meteorites represented in the Collec- 

 tion of the British Museum of Natural History on January 1, 1904, L. 

 Fletcher : Manual of the Chemical Analysis of Rocks, H. S. Washington, 

 398. — Notes on the Rocks of Nugsuaks Peninsula and its environs, Green- 

 land, W. C. Phelan : Ueber den Kali-Syenit des Piz Giuf und Umgebung 

 und seine Ganggefolgschaft, F. Weber, 399. 



Miscellaneous Scientific Intelligence — Harvard College Observatory, 399. — 

 Study of a Lunar Crater, W. H. Pickering, 400. — Field Columbian 

 Museum, Publication 95, Zoological Series, D. G. Elliot : Statistical 

 Methods with special reference to Biological Variation, C. B. Davenport, 

 401. — Catalogus Mammalium, tarn viventium quam fossilium, E.-L. 

 Troussart : Beitraege zur Chemischen Physiologie und Pathologie, F. 

 Hofmeister : Ostwald's Klassiker der exakten Wissenschaften, 402. 



