CONTENTS OF VOL. XXVII. — FOURTH SERIES. 



NUMBER CLXXXI.— MARCH. 



Page 



M. G. Quincke on the Optical Properties of the Metals 161 



Mr. T. Tate on the Magnitude of a Drop of Liquid formed 



under different circumstances 176 



Mr. S. V. Wood, Jun., on the Formation of the River- and other 



Valleys of the East of England. (With a Map.) 180 



Mr. E. V. Neale on the Traces of a Spiral Structure in the Solar 



System 190 



Prof. Reusch on some Properties of Ice 192 



Dr. W. J. M. Rankine on the Dynamical Theory of Heat 194 



Mr. J. Croll on supposed Objections to the Dynamical Theory 



of Heat 196 



MM. F. Reich and Th. Richter on Indium , 199 



Mr. C. Tomlinson's Experiments on the Electrical Fly. (With 



a Plate.) 202 



Mr. A. B. Northcote on Parathionic Acid 218 



Chief Justice Cockle on Differential Covariants 225 



Notices respecting New Books : — M. G. Kirchhoff's Researches 

 on the Solar Spectrum and the Spectra of the Chemical Ele- 

 ments 229 



Proceedings of the Royal Society : — 



Mr. E. J. Lowe on Ozone 229 



The Astronomer Royal on the Diurnal Inequalities of Ter- 

 restrial Magnetism, as deduced from observations made 

 at the Royal Observatory, Greenwich, from 1841 to 1857. 234 

 Note on the Earth's Climate in Palaeozoic times, by T. Sterry 



Hunt, F.R.S 236 



On the Intensity of Solar Radiation in different Seasons, by 



Father A. Secchi 237 



On the Electrical Properties of Pyroxyline-paper and Gun- 

 cotton, by B. Silliman, Jun 240 



NUMBER CLXXXIL— APRIL. 



Prof Magnus on the Condensation of Vapours on the Surfaces 



of Solid Bodies. (With a Plate.) 241 



Prof. Magnus on the Influence of Condensation in Experiments 



upon Diathermancy 249 



Prof. Maxwell on Reciprocal Figures and Diagrams of Forces. 250 

 Prof. Clausius on the Difference between Active and Ordinary 



Oxygen 261 



Mr. J. J. Waterston on the Application of the Vapour-density 



system of Notation to express Chemical Reactions 273 



Mr. H. Norton on Fractional Values for the Heptagon and 



Circle 281 



