CONTENTS OF VOL. XXXI. FIFTH SERIES. Vll 



Page 

 Notices respecting New Books : — 



Mr. L. Clark's Dictionary of Metric and other useful 



Measures 436 



Dr. W. M. Watts's Index of Spectra 436 



Mr. C. Langdon-Davies's The Phonopore and the Simplex 



Pkonopore Telegraph 437 



Czermak's Reduction Tables for Readings by the Gauss- 



Poggendorif Mirror Method 43S 



Dr. C. V. Burton's Introduction to Dynamics, including 



Kinematics, Kinetics, and Statics 4.38 



Proceedings of the Geological Society :— 



Mr. W. H. Penning on the Geology of the Southern 



Transvaal 439 



Miss Catherine A. Raisin on the Lower Limit of the 



Cambrian Series in N.W. Caernarvonshire 440 



Some Remarks on the Kinetic Theory of Gases, by S. Tolver 



Preston 441 



The Lightning Discharge, by S. Tolver Preston 443 



Electrical Observations on the Hoher Sonnblick, bv Profs. 



Elster and Geitel 446 



On the Absorption-Spectrum, and the Colour of Liquid 



Oxygen, by K. Olszewski 447 



On a Peculiar Case in the Refraction of Organic Compounds, 

 by R. Nasini and T. Costa 448 



NUMBER CXCIIL— JUNE. 

 Mr. J. Brown on the Role of the Cation in Voltaic Com- 

 binations ; particularly those containing Chlorides of Iodine 



and Bromine 449 



Mr. W. T. A. Emtage on a Method of Determining the Velo- 

 cities of Propagation of Disturbances in Elastic Media. . . . 464 



Mr. H. M. Vernon on Manganese Tetrachloride 469 



Mr. T. Mellard Reade on his Theory of the Origin of Moun- 

 tain-Ranges by Sedimentary Loading and Cumulative Re- 

 current Expansion : in Answer to Recent Criticisms .... 485 

 Mr. M. Carey Lea on Allotropic Silver. — Part III. Blue 



Silver, soluble and insoluble forms 497 



Mr. J. Swinburne on the Electrometer as a Wattmeter .... 504 

 Mr. J. Wimshurst on an Alternating and Experimental 



Influence-Machine 507 



Prof. A. Anderson on the Eocometry of Diverging Lens- 

 Combinations 511 



Notices respecting New Books : — 



Mr. W. J. Macdonald's Higher Geometry 513 



Mr. R. C. J. Nixon's Supplement to " Euclid revised " . 513 



Mr. H. M. Taylor's Pitt Press Euclid 514 



Messrs. J. Blaikie and W. Thomson's Geometrical De- 

 ductions 514 



E. de Fodor's Die Elektrischen Verbrauchsinesser .... 514 



