CONTENTS of N° 262.— Fourth Series. 



XLV. On the present state of the question as to the Limits of the 

 Jurassic and Cretaceous Periods. By F. J. Pictet page 321 



XLVI. An Improvement in Filtration. By Prof. John C. Draper, 

 M.D., College of the City of New York 335 



XLVI I. Note on the Temperature and Heating-powers of Flames. 

 By W. M. Watts, D.Sc 337 



XLVIII. Note on the Atomic Volume of Solid Substances. By 

 James Dewar, F.R.S.E., Chemical Demonstrator in the University, 

 Lecturer on Chemistry, Veterinary College, Edinburgh 339 



XLIX. Note on Inverted Sugar. By James Dewar, F.R.S.E., 

 Chemical Demonstrator in the University, Lecturer on Chemistry, 

 Veterinary College, Edinburgh 345 



L. On the Theory of the Variation of Temperature in Gases in 

 consequence of Changes in their Density and Pressure. By the Rev. 

 J. M. Heath 347 



LI. The Province of Mineral Chemistry. By Hermann Kolbe. . 348 



LII. On the Course of Geodesic Lines on the Earth's Surface. By 

 Captain A. R. Clarke, R.E., F.R.S 352 



LIII. Goodricke's Theory of Algol. By T. S. Aldis, M.A., Late 

 Scholar of Trinity College, Cambridge 363 



LIV. On the Spectra of some Gases under High Pressures. By M. 

 A. Wullner 365 



LV. Description of a New portable Mercurial Barometer. By J. 

 A. Calantarients 371 



LVI. Proceedings of Learned Societies : — 



Royal Society : — Mr. George Gore on Fluoride of Silver. — 

 Part I. ; Mr. E. J. Stone on the Heating-powers of Arctur us 

 and a Lyrae ; Mr. Richard A. Proctor on certain Drifting 

 Motions of the Stars 374-383 



Geological Society 383 



LVI I. Intelligence and Miscellaneous Articles : — 



On a new kind of Electrical Dust-figures, by Professor von 



Bezold 392 



Action of Sodium on Acetic Ether, 394 



On the Periods of certain Meteoric Rings, by Daniel Kirkwood. 394 

 On the Diathermancy of a Series of Substances for Obscure 



Heat, by Dr. Schultz-Sellack 396 



On the Influence of Sounding-vibrations on the Magnetism of 



Iron, by Dr. E. Warburg 398 



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 post-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Red 

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