VI CONTENTS OF VOL. XLVIII. FOURTH SERIES, 



Page 

 Compound, obtained by the Action of Sulphide of Ammo- 

 nium on the Hydrate of Chloral 247 



Dr. A. Schuster on Unilateral Conductivity 251 



Lord Rayleigh on the Vibrations of Approximately Simple 



Systems 258 



The late W. S. Davis on a simple Method of Illustrating the 

 chief Phenomena of Wave-motion bv means of Flexible 



Cords. (With a Plate.) * 262 



Prof. A. M. Mayer's Eesearches in Acoustics. — Xo. V 266 



Prof. J. J. Miiller on a Mechanical Principle resulting from 



Hamilton's Theory of Motion 274 



Mr. J. O'Kinealy on a New Formula in Definite Integrals . . 295 



Mr. F. Guthrie on an Absolute Galvanometer 296 



Xotices respecting New Books : — 



The Rev. J. F. Twisden's First Lessons in Theoretical 



Mechanics 298 



Mr. E. Butler's Supplement to the First Book of Euclid's 



Elements 300 



Mr. F. Cuthbertson's Euclidian Geometry 300 



Proceedings of the Royal Society : — 



Mr. J. H.X. Hennessey on Displacement of the Solar Spec- 

 trum * 303 



Mr. J. H. X. Hennessey on White Lines in the Solar 



Spectrum 305 



Messrs. Xegretti and Zambra on a Xew Deep-sea Ther- 

 mometer 306 



Proceedings of the Geological Society : — 



Mr. A. B. Wynne on the Physical Geology of the Outer 



Himalayan region of the Upper Punjab, India 310 



Mr. E. J. Dunn on the mode of occurrence of Diamonds 



in South Africa 311 



Mr. J. C. Ward on the Origin of some of the Lake-basins 



of Cumberland 311 



Mr. D. Mackintosh on the Traces of a Great Ice-sheet in 

 the Southern part of the Lake- district and in Xorth 



Wales 313 



Mr. A. W. Edgell on some Lamellibranchs from the Bud- 



leigh-Salterton Pebbles 313 



On the Action of two Elements of a Current, by J. Bertrand. 314 



On Earth-currents, by L. Schwendler, Esq 315 



Experiments on the Dissipation of Electricitv bv Flames, bv 



J. W. Fewkes " 319 



On the Stratification of the Electric Light, by M. Neyreneuf . 320 



DUMBER CCCXIX.— XOYEMBER. 



Mr. H. A . Rowland on the Magnetic Permeability and Maxi- 

 mum of Magnetism of Xiekel and Cobalt 321 



