CONTENTS. V 



Page 



Separation of Lime and Magnesia, by Dobereiner 247 



Mode in which some Salts act in Hydrogen Gas, by Wohler 248 



On Cubebin, by MM. Capetaine and Soubeiran 249 



Anhydrous Phosphoric Acid, by M. Marchand 250 



Cinnamic and Formic ^Ethers, by M. Marchand 251 



Analysis of Hailstones, by M. Girardin 252 



Veratric Acid, by M. Merck 253 



Geological Society of France 254 



Gauss on the Theory of Magnetism 254 



Scientific Books 254 



Meteorological Observations for July 1839 255 



Table 256 



NUMBER XCVL— OCTOBER. 



Mr. Lyell on the tubular Cavities filled with Gravel and Sand 

 called " Sand-pipes," in the Chalk near Norwich 257 



Dr. J. W. Draper on the Use of a Secondary Wire as a Measure 

 of the Relative Tension of Electric Currents 266 



Rev. E. Craig on the Configuration of the Scales of Butterflies' 

 Wings, as exhibited in the Microscope 279 



Mr. J. Marsh on a new Method of distinguishing Arsenic from 

 Antimony, in cases of suspected poisoning by the former 

 substance 282 



Mr. Halliwell's Account of a few Independent Notices of Ame- 

 rica by Middle-age Writers 284 



Mr. J. Rigg on the Corollary deduced by Professor J, Thomson, 

 from the Proposition demonstrated by him in the Number for 

 July 285 



Notice respecting Lantanium. Extracted from a Letter of Pro- 

 fessor Berzelius to Professor Kersten of Freiberg 286 



Mr. Grove on a small Voltaic Battery of great energy ; some 

 Observations on Voltaic Combinations and forms of Ar- 

 rangement ; and on the Inactivity of a Copper positive Elec- 

 trode in Nitro-sulphuric Acid 287 



Rev. D. Williams on the Geological Position of the Culm- and 

 Plant-bearing Beds of Devon and Cornwall 293 



Col. R. Wright's Meteorological Observations in Colombia be- 

 tween the Years 1 820 and 1830 297 



Mr. J. Ferguson on the Cause of the Holes that occur perfo- 

 rating sheets of Melting Ice 305 



Mr. L. 'I'hompson on the Separation of Lime from Magnesia, 

 and on the Assay of Gold 309 



Mr. S. M. Drach on the Use of Barometrical Formulae for de- 

 termining the Heights of Mountains 310 



Proceedings of the Royal Society 312 



British Association for the Advancement of Science; Ninth 

 Meeting (at Birmingham) 330 



