CONTENTS OF VOL. XLI. FIFTH SERIES. Vll 



Notices respecting New Books : — 



Dr. H. du Bois's The Magnetic Circuit 517 



Hermann Grrassmann's Ausdehnungslehre 518 



Mr. A. H. Barker's Graphical Calculus 519 



Proceedings of the Geological Society : — 



Mr. G. W. Lamplugh on the Speeton Series in Yorkshire 



and Lincolnshire 519 



Eev. Edwin Hill on Transported Boulder Clay 521 



Dr. Henry Hicks on the Morte Slates and Associated 



Beds in North Devon and West Somerset 521 



Prof. T. "W. Edgeworth David on Evidences of Glacial 



Action in Australia in Permo-Carboniferous Time. . . . 522 

 Mr. Alfred Harker on certain Granophyres, modified by 

 the Incorporation of Gabbro Fragments, in Strath 



(Skye) 523 



Prof. E. Hull on the Geology of the Nile Valley, and 

 on the Evidence of the greater Volume of that River 



at a former Period 524 



On the Diffusion of Metals, by Prof. W. C. Roberts- Austen . 524 

 Rbntgen Rays not present in Sunlight, by M. Carey Lea . . . 528 

 On a new Areometer, by L.-N. Vandervy ver 530 



Index 532 



PLATES. 



I. & H. Illustrative of Prof. A. W. Witkowski's Paper on the Thermo- 

 dynamic Properties of Air. 



