CONTENTS OK VOL. XII. — FOURTH SERIES. 



Page 

 On a Zeolitic Mineral from the Isle of Skye, Scotland, by J. W. 



Mallet, Ph.D 406 



Meteorological Observations for September 1856 407 



Table 408 



NUMBER LXXXL— DECEMBER. 



The Rev. S. Haughton on Slaty Cleavage, and the Distortion 

 of Fossils 409 



Prof. Stokes's Remarks on Professor Challis's paper, entitled 

 " A Theory of the Composition of Colours," &c 421 



Prof. Clausius oft the Application of the Mechanical Theory 

 of Heat to the Steam-engine (concluded) 426 



Mr. J. N. Hearder on a new Arrangement of the Induction Coil. 443 



Sir W. R. Hamilton's Memorandum respecting a new System 

 of Roots of Unity 446 



Mr. P. J. Martin on the Anticlinal Line of the London and 

 Hampshire Basins 447 



Mr. J. P. Hennessy on the Importance of an Adequate Defini- 

 tion in developing the Theory of Parallel Lines 452 



Prof. Schonbein on the Oxidation of the Constituents of Am- 

 monia by Porous Media, with some Remarks on Nitrification. 457 



Mr. H. Wedgwood's Remarks on a System of Geometry derived 

 from an Analysis of our ideas of Direction and Position . . . . 459 



Prof. Clausius's Reply to a Note of Mr. Joule, contained in the 

 November Number of the Philosophical Magazine 463 



Notices respecting New Books: — M. A. Delesse's Materiaux 

 de Construction de I'Exposition Universelle de 1855 464 



Proceedings of the Royal Society 466 



Geological Society 482 



Note on the Optical Properties of Transparent Bodies submitted 

 to the Action of Magnetism, by M. Verdet 483 



On the possibility of the simultaneous existence of opposite 

 Electrical Currents in the same Conducting Wire, by Professor 

 G. Belli 483 



Measurement of the Speed of a Railway Train by means of 

 Electro-magnetism, by W. C. M'Rea 486 



Meteorological Observations for October 1856 487 



Table 488 



NUMBER LXXXIL— SUPPLEMENT TO VOL. XII. 



M. V. Regnault on the Specific Heat of some Simple Bodies, 

 and on the Isomeric Modifications of Selenium 489 



Mr. C. A. Bentley on an Improved Construction of RuhmkoriF's 

 Induction Coil 519 



