CONTENTS. V 



Page 



NUMBER XV.— SEPTEMBER. 



Mr. Faraday's Experimental Researches in Electricity. — Third 



Series 161 



Mr. J. Barton on the Inflection of Light, in Reply to Pro- 

 fessor Powell ] 72 



Mr. T. S. Davies on Bernoulli's Solution of the Problem of 



Shortest Twilight 179 



Rev. J. Challis's Theory of the Correction to be applied to a 



Ball-Pendulum for the Reduction to a Vacuum 185 



Mr. J. Blackwall's Characters of some undescribed Genera 



and Species of Araneidce 187 



Mr. J. MacCullagh's Additional Note on Conical Refraction 197 



Rev. T. J. Hussey's Catalogue of Comets (continued) 198 



Mr. N. J. Winch's Contributions to the Geology of Northum- 

 berland and Durham (continued) 200 



Mr. C. Wheatstone's Remarks on one of Mr. Talbot's proposed 



Philosophical Experiments 204 



Mr. J. Prideaux's Experimental Contributions towards the 



Theory of Thermo-electricity 205 



Proceedings of the Royal Society 215 



Geological Society 219 



Royal Astronomical Society 231 



Philosophical Society of Cambridge .... 235 



Compounds of Chromic Acid with Metallic Chlorides 235 



On Fossil-bone Caverns 237 



Mr. Edmonds, Jun., on the Visibility of Stars by Day ....... 238 



Leybourn's Mathematical Repository 239 



Meteorological Observations 240 



NUMBER XVI.— OCTOBER. 



Mr. Faraday's Notice of a Means of preparing the Organs 

 of Respiration, so as considerably to extend the Time of 

 Holding the Breath; with Remarks on its Application, in 

 Cases in which it is required to enter an irrespirable Atmo- 

 sphere, and on the Precautions necessary to be observed in 

 such Cases 241 



Mr. G. Fairholme's Observations on the Nature of Coal, and 

 on the Manner in which the various Strata of the Coal-mea- 

 sures must probably liave been deposited 245 



Mr. Faraday's Experimental Researches in Electricity. — 

 Third Series (continued) 253 



Mr. J. Prideaux's Experimental Contributions towards the 

 Theory of Thermo-electricity 262 



