CONTENTS OF VOL. IV. FIFTH SERIES. V 



The Rev. S. Earnshaw on the Finite Integrals of certain Par- 

 tial Differential Equations which present themselves in Phy- 

 sical Investigations , 213 



Mr. E. H. M. Bosanquet on the Theory of Sound 216 



IVIr. Gr. J. Stoney on the Nature of what is commonly termed 



a ''Vacuum '' 222 



Notices respecting New Books : — 



Messrs. T. M. Goodeve and C. P. B. Shelley on the Whit- 

 worth Measuring Machine, including Descriptions of 

 the Surface-plates, Gauges, and other Measuring In- 

 struments made by Sir Joseph Whitworth, Bart., C.E., 



E.E.S., D.C.L., LL.D., &c 223 



Proceedings of the Eoyal Society : — 



Mr. F. Galton on the Process of Verifying Thermometers 



at the Kevv Observatory 226 



Mr. W. Spottiswoode on Stratified and Unstratified Forms 



of the Jar-Discharge 231 



Proceedings of the Geological Society : — 



Prof. A. Daubree on Points of Similarity between Zeoli tic 

 and Siliceous Incrustations of recent formation by 

 Thermal Springs and those observed in Amygdaloid 



and other altered Volcanic Eocks 234 



Mr. D. Mackintosh on a number of new Sections around 

 the Estuary of the Dee which exhibit Phenomena having 

 an important bearing on the Origin of Boulder-clay 



and the Sequence of Glacial Events 236 



Messrs. W. Gunn and C. T. Clough on the Discovery of 



Silurian Beds in Teesdale 236 



Mr. G. M. Dawson on the Superficial Geology of British 



Columbia 237 



On the Electrical and Capillary Properties of Mercury in con- 

 tact with different Aqueous Solutions, by M. Lippmann . . 238 

 Note on the Effect of Chromatic Aberration in Distant Vision, 

 by B. Thompson Lowne, F.E.C.S., Lecturer on Physiology 



in the Middlesex Hospital Medical School 239 



On some remarkable Phenomena in Geissler Tubes, by MM. 

 Eeitlinger and von Urbanitzki 240 



NIJMBEE XXV.— OCTOBEE. 



Dr. W. Eamsay on PicoKne and its Derivatives 241 



Mr. E. S. Brough on the Diameter of the Wire to be employed 

 in winding an Electromagnet in order to produce the Maxi- 

 mum Magnetic Effect 253 



Mr. M. M. Pattison Muir on Chemical Classification 257 



Mr. T. T. P. Bruce Warren on the Determination of Tempera- 

 ture-coefficients for Insulating Envelopes 272 



