VI CONTENTS. 



Page 

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

 berland and Durham (concluded) 273 



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



Shortest Twilight {concluded) 277 



Mr. J. MacCullagh on a Difficulty in the Theory of the Attrac- 

 tion of Spheroids . . * 282 



Rev. H. Moseley on a New Principle in Statics, called the 



" Principle of least Pressure " 285 



Sir D. Brewster's Notice respecting certain Changes of Colour 



in the Choroid Coat of the Eyes of Animals 288 



Proceedings of the Royal Astronomical Society 290 



. Zoological Society 293 



— — Royal Society of Edinburgh 303 



. , Royal Geological Society of Cornwall — 305 



Early Anticipation of Phrenology — Composition of Phosphu- 



retted Hydrogen 308 



Metallic Phosphurets 310 



M. Pelletier on Aricina, Santaline, Sarcocoline, &c 311 



Preparation of Formic Acid 313 



Mr. H. H. Watson's Experiments on the Action of Lime on 



certain Solutions of Carbonate of Potash 314? 



Proposed Modification of the Patent Laws 316 



Death of Thomas Allan, Esq., of Lauriston, F.R.S. L. & E. 



F.L.S.&c.&c : 317 



Mr. C. Gould's Description of a new and interesting Object 



for theMicroscope 318 



Occultations of Fixed Stars by the Moon, in October and No- 

 vember 1833 319 



Meteorological Observations 320 



NUMBER XVII.— NOVEMBER. 



Mr. A. Trevelyan on the Vibration of heated Metals; including 

 a Letter on the same Subject by Dr. W. Knight 321 



Mr. R. Potter's Particulars of a Series of Experiments and 

 Calculations undertaken with a View to determine the Velo- 

 city with which Light traverses Transparent Media 333 



Mr. J. O.Westwood's Descriptions of several new British Forms 

 amongst the Parasitic Hymenopterous Insects (continued). . 342 



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

 Species of Araneidce 344. 



T. R. F. on Mr. Talbot's Proposed Method of ascertaining the 

 greatest Depth of the Ocean 352 



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

 Series (concluded) 353 



New Books : — Young's Elements of Plane and Spherical Tri- 

 gonometry, with its Applications to the Principles of Navi- 



