CONTENTS OF VOL. XLVI. FOURTH SERIES. V 



Page 



Prof. E. Clausius on a new Mechanical Theorem relative to 

 Stationary Motions 236 



Dr. T. C. Charles's Analyses of Coal from the Coal-Measnres 

 in co. Tyrone, and of a Lignite from Ballintoy, co. Antrim. 244 



Lord Bayleigh on the Nodal Lines of a Square Plate 246 



Mr. E. Moon's Eeply to some Eemarks of Professor Challis, 

 " On Objections recently made to the received principles of 

 Hydrodynamics " 247 



Notices respecting New Books : — 



Mr. "W. E. Birt's Mare Serenitatis : its Craterology and 

 principal features 250 



On the Passage of Gases through Colloid Membranes of Ve- 

 getable Origin, by A. Barthelemy 251 



On the Eeflection of Light investigated by M. Potier, by G. 

 Quincke 252 



On Explosions produced by High Tones, by MM. Champion 

 and Pellet 256 



NUMBEE CCCYL— OCTOBEE. 



Mr. E. Guthrie on a Eelation between Heat and Static Elec- 

 tricity 257 



Prof. E. Clausius on a new Mechanical Theorem relative to 



Stationary Motions 266 



Prof. J. D. Dana on some Eesults of the Earth's Contraction 

 from Cooling, including a discussion of the Origin of Moun- 

 tains. — Part IY. Igneous Ejections, Volcanoes 276 



Mr. E. C. Nichols on the Determination of the Specific Heat of 



G-ases and Vapours at Constant Volumes 289 



M. E. Zollner on the Temperature and Physical Constitution 



of the Sun. (Second Memoir.) 290 



Mr. W. E. Birt on the Moon's Libration 305 



Mr. A. Tribe on a Specific-gravity Bottle for Liquids sponta- 

 neously Inflammable in contact with Air 308 



Prof. Challis on the received principles of Hydrodynamics, in 



reply to Mr. Moon 309 



Notices respecting New Books : — 



Mr. E. A. Proctor's The Moon, her Motions, Aspect, 



Scenery, and Physical Condition 312 



Proceedings of the Eoyal Society : — 



Mr. Greville Williams on Emeralds and Beryls. — Part I. 



On the Colouring-matter of the Emerald 314 



Proceedings of the Geological Society : — 



Mr. J. "W. Judd on the Secondary Eocks of Scotland .... 326 



Mr. J. E. Campbell on the Glaciation of Ireland 328 



On Solution of Nitrate of Nickel as an Absorption-Preparation, 

 by Dr. H. Emsmaim 329 



