CONTENTS OF VOL. XXXV. FOURTH SERIKS. V 



Page 



On Curves fulfilling the Equation ^ + ftf =0, by W. J. Mac- 



dx dy~ 



quorn Rankine, F.R.S. &c 244 



NUMBER CCXXXV1L— APRIL. 



Dr. E. J. Mills on certain Cobaltamines 245 



Mr. C. J. Woodward on the Synthesis of White Light from the 



Colours of the Spectrum 261 



M. R. Riihlmann on the Alteration produced by Heat in 

 the Velocity of Propagation of Light in Water. (With a 



Plate.) 262 



Dr. M. Simpson on the Direct Transformation of Chloriodide 



of Ethylene into Glycol 282 



Prof. F. Guthrie on the Conduction of Heat by Liquids 283 



Sir William Thomson on Mr. C. F. Varley's Reciprocal Elec- 



trophorus 287 



M. P. A. Favre's Electrolytic Investigations 289 



Mr. C. Hockin on a Lecture-Experiment 299 



Notices respecting New Books : — Mr. A. W. Cunningham's 

 Notes on the History, Methods, and Technological import- 

 ance of Descriptive Geometry, compiled with reference to 

 Technical Education in France, Germany, and Great Britain. 301 

 Proceedings of the Royal Society : — 



The Rev. F. Bashforth on the Resistance of the Air to the 

 Motion of Elongated Projectiles having variously formed 



Heads 301 



Mr. J. A. Longridge on the Resistance of the Air to Rifled 



Projectiles 304 



Proceedings of the Royal Institution : — 



Prof. H. E. Roscoe on Vanadium, one of the Trivalent 



Group of Elements 307 



Proceedings of the Geological Society : — 



Mr. J. W. Judd on the Speeton Clay 314 



Prof. J. Phillips on the Hessle Drift 315 



The Duke of Argyll on the Geological Structure of Argyll- 

 shire 315 



Mr. C. Babbage on the Parallel Roads of Glen Roy .... 316 

 Mr. D. Mackintosh on the Origin of smoothed, rounded, and 

 hollowed surfaces of Limestone and Granite, on an appa- 

 rent oblique lamination in Granite, and on the Encroach- 

 ment of the Sea in the Bristol Channel 317 



Mr. T. M'K. Hughes on the two Plains of Hertfordshire 



and their Gravels 317 



On the Duration of Induction-currents, by P. Blaserna 318 



