CONTENTS OF VOL. XXVI. FOURTH SERIES. V 



Page 

 Dr. Hofmann on the Composition of the Blue Derivatives 

 of the Tertiary Monamines derived from Cinchonine . . 230 

 On the Electrical Conductivity of Thallium, by M. Lucien 



De la Rive 236 



On the Magnetical Deportment of some Cyanogen Compounds 



of Iron, Nickel, and Cobalt, by Dr. J. Wiesener 238 



Researches on the Optical Properties developed in Transparent 

 Bodies by the action of Magnetism, by M. Verdet 238 



NUMBER CLXXV.— OCTOBER. 



Prof. Bunsen on Caesium. (With a Plate.) 241 



Mr. J.J. Waters ton on Chemical Notation in conformity with 



the Dynamical Theory of Heat and Gases 248 



Dr. J. Miiller on the Determination of the Length of the Waves 



of certain bright Lines in the Spectrum 259 



Archdeacon Pratt on the Stability of Arches 262 



M. L. v. Karolyi on the Products of the Combustion of Gun- 

 cotton and Gunpowder under circumstances analogous to 



those which occur in practice 266 



Prof. Challis on Newton's " Foundation of all Philosophy " . . 280 



Prof. Sylvester on a Theorem of the Integral Calculus 293 



Mr. G . B. Jerrard on a Question arising from a recent Mathe- 

 matical Controversy 294 



Mr. B. S. Proctor on the Focal Adjustment of the Eye. (With 



a Plate.) 295 



Mr. W. J. M. Rankine : Abstract of an Investigation on Plane 



Water-lines. (With a Plate.) 303 



Notices respecting New Books : — Mr. H. Watts's Dictionary of 



Chemistry and the Allied Branches of other Sciences 306 



Proceedings of the Royal Society :— 



Dr. A. Smith on the Absorption of Gases by Charcoal . . 311 

 Dr. Phillips on the Telescopic Appearance of the Planet Mars. 312 



Mr. W. Crookes on Thallium 317 



Mr. W. Huggins and Dr. W. A. Miller on the Lines in 



the Spectra of some of the Fixed Stars 319 



Proceedings of the Geological Society : — 



Dr. Dawson on the Devonian Plants of Maine, Gaspe, and 



New York, and on a new species of Dendrerpeton .... 321 

 Mr. J. W. Salter on the Upper Old Red Sandstone and the 



Upper Devonian Rocks 321 



Mr. J. Prestwich on the Section at Moulin-Quignon .... 322 

 On the Earth's Climate in Palaeozoic Times, by T. Sterry Hunt, 



M.A., F.R.S 323 



On some Phenomena produced by the Refractive Power of the 



Eye, by A. Claudet, F.R.S 324 



On the Conservation of Energy, by Philip Kelland, Esq 326 



The Star Chromatoscope : an Instrument to examine and com- 

 pare the Rays of the Stars, by A. Claudet, F.R.S 327 



