CONTENTS OF VOL. XX. 



NUMBER CXXVIII.— JANUARY, 1842. 



Page 



Prof. Hess's Abstract of Thermometrical Researches 1 



Mr. W. G. Armstrong on the Cause of the Electricity of Efflu- 

 ent Steam 5 



The Rev. P. Kelland on Mossotti's Theory of Molecular Action 8 

 Prof. Booth on the Rotation of a rigid Body round a fixed 



Point 10 



Prof. Grove on a Voltaic Process for Etching Daguerreotype 



Plates 18 



Mr. J. D. Smith and Dr. Brett's Additional Remarks on the al- 

 leged Conversion of Carbon into Silicon 24 



Messrs. W. Francis and H. Croft's Notices of the Results of 



the Labours of Continental Chemists (continued) 33 



On the Magnetic Influence of the Lunar Spectrum, in relation 



to a new Theory of Terrestrial Magnetism 39 



Mr. G. A. Rowell on the Connexion of Electricity with Eva- 

 poration 45 



Mr. Ivory's Remarks on Sir J. W. Lubbock's " Theory of Heat 



and Vapours" 46 



Proceedings of the Geological Society 49 



London Electrical Society 64 



• American Philosophical Society 67 



Scientific Congress at Florence 69 



On the Theory of Electrolysis : — Suggestion of a new Experi- 

 ment 72 



On the Fusion of Silica and Carbon, by H. Prater 72 



Composition of Wolfram 73 



On the Gases disengaged by Marine Plants, by M. Aime .... 74 



On some Nitrous Compounds 75 



On Arseniuretted Hydrogen, by M. H. Rose 76 



Native Bromide of Silver, and Analyses 77 



Meteorological Observations for November 1841 79 



Meteorological Observations made at the Apartments of the 

 Royal Society by the Assistant Secretary, Mr. Roberton; 

 by Mr. Thompson at the Garden of the Horticultural Society 

 at Chiswick, near London ; by Mr. Veall at Boston ; by the 

 Rev. W. Dunbar at Applegarth Manse, Dumfries-shire ; and 

 by the Rev. C. Clouston at Sandwick Manse, Orkney .... 80 



NUMBER CXXIX.— FEBRUARY. 



Mr. Ivory on Mixed Gases 81 



Mr. J. Bryce's Notice of the Discovery of some remains of the 



Ichthyosaurus in Ireland 83 



a 2 



