CONTENTS OF VOL. XXVI. FIFTH SERIES. 



Prof. J. Borgmann on the Influence of Light upon Electric 



Discharge 272 



Prof. J. A. Ewing and Mr. W. Low on the Influence of a 

 Plane of Transverse Section on the Magnetic Permeability of 



an Iron Bar 274 



Profs. Liveing and Dewar on the Absorption-spectrum, Lumi- 

 nous and Ultra-violet, of large masses of Oxygen 286 



Dr. E. H. Cook on the Existence of an Undulatory Move- 

 ment accompanying the Electric Spark. (Plate III.) .... 291 

 Mr. W„ Sutherland on the Eecalculation of certain Specific 

 Heats at High Temperatures, and the Specific Heat of 



Water 298 



Notices respecting Xew Books : — 



Mr. A. B. Basset's Treatise on Hydrodynamics 306 



Mr. H. P. Malet's Sunlight 307 



Rev. J. J. Milne's Companion to the Weekly Problem- 

 papers , 308 



Dr. J . Casey's Treatise on Plane Trigonometry 309 



Proceedings of the Geological Society : — 



Mr. J. E. Kilroe on the Directions of Ice-flow in the 



ZS'orth of Ireland 310 



Mr. J. Spencer on the Evidence of Ice-Action in Car- 

 boniferous Times 311 



Miss M. I. Gardiner on the Greensand Bed at the Base 



of the Thanet Sand 311 



Mr. E. Butley on Perlitic Eelsites, probably of Archaean 

 age, from the flanks of the Herefordshire Beacon, and 



on the possible Origin of some Epidosites 312 



Dr. H. J. Johnston-Lavis on the Ejected Blocks of Monte 



Somma 312 



Susceptibilitv and Yerdet's Constant of Liquids, by H. E. J. G. 



Du Bois 314 



Selective Absorption of Metals for Ultra-Yiolet Light, by 



J. Trowbridge and W. C. Sabine 316 



On a kind of Electrical Current produced by Ultra-Yiolet 



Eays, by M. A. Stoletow 317 



Investigations on the Influence of Moisture on the Length of 



certain Woods, and Ivory, by E. Hildebrand 319 



Lecture-Experiment, by M. P. Simon 320 



NTJMBEE CLXL— OCTOBEE. 



Dr. J. Kerr's Experiments on the Birefringent Action of 

 Strained Glass 321 



Messrs. J. Trowbridge and W. C. Sabine on Wave-lengths of 

 Metallic Spectra in the Ultra-Yiolet 342 



Mr. J. Parker on Thermoelectric Phenomena 353 



