Tl CONTENTS OF VOL. XXVII. — FIFTH SERIES. 



Dr. G. Gore on the Loss of Voltaic Energy of Electrolytes 

 by Chemical Union 353 



Proceedings of the Geological Society : — 



Dr. J. Prestwich on the Occurrence of Palaeolithic Plint 

 Implements in the neighbourhood of Ightbam, Kent, 



their Distribution and probable Age 359 



Mr. S. S. Buckman on the Cotteswold, Midford, and 



Yeovil Sands, and the Division between Lias and Oolite 360 

 Miss C. A. Raisin on some Nodular Eelstones of the 



Lleyn Peninsula 362 



Mr. A. Johnstone on the Action of Pure Water, and of 

 Water saturated with Carbonic-acid Gas, on the 



Minerals of the Mica family 362 



On the Ophiolite of Thurmau, Warren Co., N.Y., with Re- 

 marks on the Eozoon Canadense, by G. P. Merrill 363 



On Electrodes with dropping Mercurv, by Prof. W. Ostwald . 365 



On Electrolysis, by MM. Violle and Chassagny 366 



On the Electrolytic behaviour of Mica at High Temperatures, 

 by W. H. Schultze 368 



NUMBER CLXVIIL— MAY. 



Mr. J. S. Ames on the Concave Grating in Theory and Prac- 

 tice. (Plate VIII.) 369 



Mr. J. Brown on Helmholtz's Theory of Mercury-dropping 

 Electrodes, and the Difference of Potential between Clean 



Mercury and Electrolytes 384 



Messrs. C. R. Cross and A. S. Williams on the Strength of the 

 Induced Current with a Magneto-Telephone Transmitter as 



Influenced by the Strength of the Magnet 392 



Mr. J. Parker on Diamagnetism and the Concentration of 



Energy 403 



Mr. A. Blytt on the probable Cause of the Displacement of 



Shore-lines, an Attempt at a Geological Chronology 405 



Proceedings of the Geological Society : — 



Mr. G. W. Lamplugh on the Subdivisions of the Speeton 



Clay 429 



Rev. R. Baron on the Geology of Madagascar 431 



Dr. E. H. Hatch on the Petrographical Characters of 



some Rocks collected in Madagascar 432 



Sir J. W. Dawson on the Rocks of the Atlantic Coast of 



Canada 433 



Messrs. Hill and Jukes-Brown on the Occurrence of 

 Colloid Silica in the Lower Chalk of Berkshire and 

 Wiltshire 433 



