IV CONTEXTS. 



Number 134. 



Page 

 Art. VII. — Ultimate Disintegration Products of the Radio- 

 active Elements. Part IE. Disintegration Products of 



Uranium ; by B. B. Boltwood 78 



VIII. — Dike of Diabase in the Potsdam Sandstone in the 



Valley of Virginia ; by T. L. Watson 89 



IX. — A Spectrum of the Rontgen Rays from a Focus Tube, 

 and the Relative Selective Absorption of Rontgen Rays 

 in Certain Metals. A preliminary note ; by J. M. 



Adams. (With Plate I) .. ._ 81 



X. — Limeless Ocean of Pre-Cambrian Time ; by R. A. Daly 93 

 XI. — Occurrence, in the Rocky Mountains, of an Upper 



Devonian Fauna with Clymenia; by P. E. Raymond ._ 116 

 XII. — Wasatch and Wind River Rodents ; by F. B. Loomis 123 

 XIII. — Descriptions of the two genera of tubicolous Anne- 

 lids, Paravermilia and Pseudovermilia, with species from 



Bermuda referable to them ; by K. J. Bush . . . 131 



XIV. — Titration of Mercnrous Salts with Potassium Per- 

 manganate ; by D. L. Randall 137 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— Occurrence of Argon with Helium in a Mineral, 

 Kitchen and Winterson : Researches on High Percentage Ozone Gas, E. 

 Ladenburg, 141. — Determination of Halogens in Organic Compounds, 

 Stepanow : Cause of the Phosphorescence of Chlorophane, G. Urbain, 

 142. — Comparison of the Optical Temperature Scale with the Nitrogen 

 Thermometer up to 1600°, L. Holborn and S. Valentiner : Light Im- 

 pressions on Photographic Plates, P. H. Eykman and A. P. H. Trivelli : 

 Ratio of the Energy of the Rontgen Rays to the Energy of the exciting 

 Cathode Rays, E. Carter, 143.— Scientific Papers of J. Willard Gibbs, 

 with Preface by H. A. Bxjmstead and R. G. Van Name, 144. — Electron 

 Theory, E. E. Fotjrnier d'Albe, 145. — Lehrbuch der Optik. P. Drude. 



Geology and Mineralogy — Maryland Geological Survey, W. B. Clark. 14C. — 

 Fifth Report of the Vermont State Geologist, 148. — Geologie und Palseon- 

 tologie von Ostasien, etc., T. Lorenz : Geology and Paleontology of the 

 Schoharie Valley, A. W. Grabau : Cephalopoda of the Beekmantown and 

 Chazy Formations, R. Ruedemann, 148. — Geology of the Penn Yan-Ham- 

 mondsport Quadrangles, D. D. Luther : Carboniferous and Permo-Carbon- 

 iferous Invertebrata of New South Wales, E. Etheredge and W. S. Dun : 

 Geology and Underground Waters of the Arkansas Valley, Colo., N. H. 

 Darton : Geol. History of Mt. Greylock, T. N. Dale : Treatise on Rocks, 

 Rock-weathering and Soils, G. P. Merrill, 149. — Facetted Pebbles, Lis- 

 boa : Die Kristallinen Schiefer, V. Grubenmann, 150. — Rock Minerals: 

 their Chemical and Physical Characters, etc., J. P. Iddings, 152. — Das 

 Salz : dessen Vorkommen und Verwertung. J. O. F. von Buschman : 

 Chemische Krystallographie, P. Groth, 153. 



Botany and Zoology — Sinnesorgane im Pflanzenreich, G. Haberlandt, 154 : 

 Principles of Botany, J. Y. Bergen and B. M. Davis : Second Report of 

 Wellcome Reseai-ch Laboratories, Khartoum, A. Balfour, 156. — Animal 

 Micrology; Practical Exercises in Microscopical Methods, M. F. Guyer, 156. 



Miscellaneous Scientific Intelligence — Carnegie Institution of Washington, 

 Year Book No. 5, 1906, 156. — Report of the Librarian of Congress, etc., 

 1906 : Physikalische Chemie der Zelle, R. Hoeber, 158. — Differential Equa- 

 tions, D. F. Campbell : Seismological Committee, 159. — Smithsonian Insti- 

 tution : American Forestry Association : Celebration of the 200th Anniver- 

 sary of the Birth of Benjamin Franklin : Amer. Philosophical Society, 160. 



