Vlll CONTENTS OF VOL. III. FIFTH SERIES. 



Page 



Mr. B. E. Baynes on the Steam and Hoar-frost Lines of 



Water-Substance 512 



Mr. O. J. Lodge on a Modification of Mance's Method of 



measuring Battery Resistance. (Plate V.) 515 



Mr. N. S. Maskelyne on Ludlamite 525 



Notices respecting New Books : — 



Mr. A. H. G. Hobson's Amateur Mechanic's Practical 

 Handbook, describing the different Tools required in 

 the Workshop, the Uses of them, and How to Use them ; 

 also Examples of different kinds of Work, with full De- 

 scriptions and Drawings 526 



Mr. W. Whitaker's Geology of the Eastern End of Essex. 527 

 Proceedings of the Royal Society: — 



Dr. W. Huggins on the Photographic Spectra of Stars . . 527 

 Mr. G. E. Fitzgerald on the Eotation of the Plane of Po- 

 larization of Light by Reflection from the Pole of a 



Magnet 529 



Mr. H. Tomlinson on the Increase in Resistance to the 

 Passage of an Electric Current produced on Wires by 



Stretching 532 



Mr. W. Spottiswoode on Stratified Discharges. — III. On 

 a rapid Contact-breaker, and the Phenomena of the 



Elow 535 



Proceedings of the Geological Society : — 



Prof. E. Hull on the Upper Limit of the essentially 

 Marine Beds of the Carboniferous System, and the 

 necessity for the establishment of a ' Middle Carboni- 

 ferous Group 539 



Mr. H. K. Jordan on Coal-pebbles and their Derivation. 541 

 On the Employment of a Silvered Glass as a Camera Lucida, 



by A. Terquem 541 



Note on the Sensation of Colour, by C. S. Peirce 543 



On Accidental Double Refraction, by J. Mace 547 



PLATES. 



I. Illustrative of Mr. W. J. Lewis's Paper on Crystall#grapkical Forms 

 of Glaucodoie. 



II. Illustrative of Dr. K. Heumarm's Paper on the Theory of Luminous 

 Flames. 



III. Illustrative of Mr. J. E. Harrisons Paper on the Supposed Diather- 



mancy of Bock-Salt. 



IV. Illustrative of Mr. W. J. Lewis's Paper on the Crystallography of 



Barium Nitrate. 



V. Illustrative of Mr. 0. J. Lodge's Paper on a Modification of Mance's 

 Method of measuring Batterv Resistance. 



