CONTENTS OF VOL. XXXT. FOURTH SERIES. V 



Page 



Dr. Rankine on the Expansion of Saturated Vapours 197 



Dr. Rankine on Saturated Vapours 199 



Mr. D. D. Heath on Secular Local Changes in the Sea-level. . 201 

 Prof. Guthrie's Speculation concerning the relation between the 

 Axial Rotation of the Earth, and the Resistance, Elasticity, 



and Weight of Solar ^Ether 210 



Prof. Sylvester on an improved form of Statement of the New 

 Rule for the Separation of the Roots of an Algebraical Equa- 

 tion, with a Postscript containing a New Theorem 214 



Prof. Challis on the Solution of a Problem in the Calculus of 



Variations by a New Method 218 



Mr. J. Broughton on some Properties of Soap-bubbles 228 



Proceedings of the Cambridge Philosophical Society : — 



Dr. Drosier on the Functions of the Air-cells, and the Me- 

 chanism of Respiration, in Birds 230 



Proceedings of the Royal Society : — 



Mr. W. Huggins on the Spectrum of Comet 1, 1866 233 



Mr. B. Stewart on the Secular Change of Magnetic Dip, 



as recorded at the Kew Observatory 235 



Proceedings of the Geological Society : — 



Mr. R. A. C. Godwin- Austen on Belgian Geology 237 



On the Changes which Stretching and the passage of a Voltaic 

 Current produce in a Magnetic Bar, by M. Villari of Naples. 239 



On the Heat of Friction, by Prof. Josiah P. Cooke, Jun 241 



Note regarding the decrease of Actinic Effect near the circum- 

 ference of the Sun, as shown by the Kew Pictures, by Messrs. 

 Warren De la Rue, Stewart, and Loewy 243 



NUMBER CCIX.— APRIL. 



Dr. Stevelly on the Composition of Forces 245 



Dr.Heddle on the occurrence of Wulfenite in Kirkcudbrightshire 253 

 M. E. Edlund on the Heat disengaged by Induction-currents, 

 and on the relation between this disengagement of Heat and 



the mechanical force employed to produce it 253 



Mr. J. M. Wilson on the Diminution of Direct Solar Heat in the 



Upper Regions of the Atmosphere 261 



Prof. Norton on Molecular Physics 265 



Prof. J. A. Wanklyn on the Doctrine of Uniform and Constant 



Saturation 283 



Prof. Sylvester on the Periodical Changes of Orbit, under certain 

 circumstances, of a particle acted on by a central force, and on 

 Vectorial Coordinates, &c, together with a new Theory of 

 the Analogues to the Cartesian Ovals in Space, being a 



Sequel to "Astronomical Prolusions " 287 



Mr. J. Croll on the Physical Cause of the Submergence and 

 Emergence of the Land during the Glacial Epoch. With a 



Note by Professor W. Thomson, F.R.S 301 



Dr. Atkinson's Chemical Notices from Foreign Journals 306 



