CONTENTS. 



Page 



Aet. XIX. — Effect of High Pressures on the Physical and 



Chemical Behavior of Solids ; by J. Johnston and L. H. 



Adams ._ 205 



XX. — Coefficients and Exponent of the Radiation Equation, 



K 10 = cT 10 a , in the Earth's Atmosphere ; by F. H. 



Bigelow 254 



XXI. — Simple Screw Micrometer ; by C. Barus 267 



XXII. — -Pseudomorphs of Limonite after Marcasite ; by H. B. 



North .. _._ _ _ 270 



XXIII. — Floating Islands of Halemaumau ; byF. A. Perret 273 

 XXIV.— Hydrolysis of Alkyl Metallic Sulphates ; by G. A. 



LlNHART 283 



XXV. — Delafossite, a Cuprous Metaferrite from Bisbee, 



Arizona ; by A. F. Rogers _ 290 



XXVI. — Electric Charges of the a- and /?-Rays ; by J. 



Danysz and W. Duane 295 



XXVII. — Resolution of Interference Fringes ; by C. Barus 308 



XXVIII. — Purification of Barinm Sulphate precipitated in 

 the Determination of Barium ; by F. A. Gooch and 

 D. U.Hill 311 



XXIX.— Significance of the Piltdown Skull ; by G. G. Mac- 

 Curdy ,_ 315 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Decomposition of Silicates, W. Hempel : Presence 

 of Manganese in Animals, Bertrand and Medigreceanu : General Method 

 for the Preparation of the Ammonium Salts of Organic Acids, Keiser and 

 McMaster, 321. — Behavior of Nitroglycerine when Heated, Snelling and 

 Storm : Illustration of the Luminosity of Phosphorus, O. F. Twiss : 

 Eecent Advances in Organic Chemistry, A. W. Stewart : Eeview Ques- 

 tions and Problems in Chemistry, M. S. H. Unger, 322. — Spectrum of 

 Ionium, A. S. Eussell and E. Eossi : Excitation of y-Eays by o-Eays, J. 

 Chadwick, 323. — Direct Determination of the Mean Free Path of Gas 

 Molecules, J. Franck and G. Hertz, 324. — Der energetisch Imperativ, W. 

 Ostwald : Abstract-Bulletin of the Physical Laboratory of the National 

 Electric Lamp Association, 326. —A B C of Hydrodynamics, E. de Villamil: 

 Geometrical Optics, S. Percival : Introduction to Mathematical Physics, 

 E. A. Houston : Practical Measurements in Eadio-Activity, W. Makower 

 and H. Geiger, 328.— Physical Eeview and American Physical Society, 329. 



Geology and Natural History — Publications of the United States Geological 

 Survey, 329. — Second Annual Eeport of the Director of the Bureau of 

 Mines, 330. — Cambrian Brachiopoda, C. D. Walcott, 331.— United States 

 of North America, E. Blackwelder, 332. — Untersuchungen liber die 

 Gezeiten der festen Erde und die hypothetische Magmaschicht, W. 

 Schweydar : Variations of Glaciers in 1911 : New Zealand Department of 

 Mines, 333, 334. — Determinative Mineralogy, J. V. Lewis : Dana's Con- 

 firmation of Darwin's Theory of Coral Eeef s, 334. —German Central- Africa 

 Expedition, Botany, 335. 



Miscellaneous Scientific Intelligence — Transactions of the Astronomical Obser- 

 vatory of Yale University, 335. — Bedrock, a Quarterly Journal : Outline of 

 Courses in Botany, Microscopy, and Pharmacognosy, H. Kraemer, 336. 



Obituary— F. Teller : M. L. P. Cailletet : M. L. Teisserenc de Bort : 

 P. Gordan : E. Collett : A. Witkowski : Earl of Crawford : W. G. 

 Wright : O. Schoetensack. 



