CONTENTS OF VOL. XXVIII. FIFTH SERIES. V 



NUMBER CLXXIL— SEPTEMBER. p age 



Prof. E. Wiedemann on the Mechanics of Luminosity. 

 (Plate III.) 149 



Messrs. J. T. Bottomley and A. Tanakadate on the Thermo- 

 electric Position of Platinoid 163 



Mr. Charles Tomlinson on the Theory of Hail. (Plate V.) . . 169 

 Dr. Charles V. Burton on Endless Availability ; and on a 



Restriction to the Application of Carnot's Principle 185 



Lord Rayleigh on Achromatic Interference-Bands 189 



Mr. A. Tanakadate on the Thermal Effect due to Reversals 



of Magnetization in Soft Iron. (Plates VI.-VHI.) 207 



Notices respecting New Books : — 



Prof. R. H. Smith's Graphics, or the Art of Calculation 

 by Drawing Lines, applied especially to Mechanical 



Engineering. Part 1 218 



On Leidenfrost's Phenomenon, by K. S. Kristensen 220 



Determination of the Change which the Internal Friction of 

 Air experiences at different Temperatures and under 

 Various Pressures, by P. De Heen 220 



NUMBER CLXXI1L— OCTOBER, 



Mr. R. F. D'Arcy on the Viscosity of Solutions. (Plate XI.) 221 



Prof. Silvanus P. Thompson's Notes on Geometrical Optics. 



—Part 1 232 



Prof. E. Wiedemann on the Mechanics of Luminosity ...... 248 



Rev. T. Pelham Dale on a Relation existing between the 

 Density and Refraction of Gaseous Elements, and also of 

 some of their Compounds ; with a Note by Prof. Riicker . . 268 



Mr. James C. McConnel on Diffraction- Colours, with special 

 reference to Coronae and Iridescent Clouds. (Plate X.) . . 272 



Dr. G. Gore on the Molecular Constitution of Isomeric 

 Solutions &c 289 



Prof. H. A. Rowland on the Ratio of the Electrostatic to the 

 Electromagnetic Units of Electricity 304 



Mr. Edward B. Rosa on the Determination of v, the Ratio of 

 the Electromagnetic to the Electrostatic Unit 315 



Dr. Edmond van Aubel on the Electrical Resistance of 

 Bismuth 332 



Notices respecting New Books : — 



Mr. Grant Allen's Force and Energy. A Theory of 

 Dynamics 349 



On the Dependence of the Electromotive Position of Pal- 

 ladium on the Quantity of Hydrogen it contains, by Max 

 Thoma ' , ' 351 



