CONTENTS OF VOL. XLVIII. FIFTH SERIES. Vll 



NUMBER CCXC V.— DECEMBER. 



Page 

 Mr. Bruce Y. Hill on Accidental Double Refraction in Liquids. 485 

 Mr. Arthur W. Warrington on Hydrometers of Total Immer- 

 sion 498 



Mr. G. A. Schott on the Determination of the Point of Maxi- 

 mum Density of a Liquid by the Hydrometer of Total 



Immersion 506 



Prof. H. L. Callendar on a Practical Thermometric Standard. 519 

 Prof. J. J. Thomson on the Masses of the Ions in Gases at 



Low Pressures 547 



Prof. C. G. Knott and Prof. T. Gray on Reflexion and 



Refraction of Elastic Waves 507 



Notices respecting New Books : — 



Prof. H. Crew's The Elements of Physics 569 



Proceedings of the Geological Society: — 



Mr. W. Gibson and Dr. Wheelton Hind on a Series of 

 Agglomerates, Ashes, and Tuffs in the Carboniferous 



Limestone Series of Congleton Edge 570 



Mr. E. J. Garwood on the Glacial Phenomena of Spits- 

 bergen 571 



Dr. C. Davison on the Cornish Earthquakes of March 



29th to April 2nd, 1898 571 



Prof. T. T. Groom on the Geological Structure of 

 Portions of the Malvern and Abberley Hills 572 



Index 573 



