CONTENTS OF VOL. XXV. 



(FOURTH SERIES.) 



NUMBER CLXV.— JANUARY 1863. 



Page 

 Prof. W. Thomson on the Secular Cooling of the Earth. (With 



a Plate.) I 



Prof. Dove on a New Photometer 14 



Mr. T. S. Hunt on the Nature of Nitrogen, and the Theory of 



Nitrification 27 



Mr. J. Burgess on the Measurement of Altitudes by means of 



the Temperature at which Water Boils 29 



Dr. Draper on the Motions of Camphor towards .the Light. ... 38 

 Prof. Maskelyne and Dr. Lang's Mineralogical Notes. (With 



Three Plates.) 39 



Mr. A. Cayley on a Tactical Theorem relating to the Triads of 



Fifteen Things 59 



Mr. A. Cayley on a Theorem relating to Surfaces 61 



Prof. Neumann on the Calorific Conductibility of Solids .... 63 

 Proceedings of the Royal Society : — 



Dr. Fairbairn and Mr. T. Tate on the Law of Expansion of 



Superheated Steam 65 



Mr. W. De la Rue on the Total Solar Eclipse of July 18, 



1860 69 



On the Use of the Weights and Measures of the Metric System. 74 

 Experimental Determination of the Velocity of Light : Descrip- 

 tion of the Apparatus, by M. Leon Foucault 76 



On the Phenomena of Transport through Porous Bodies; appli- 

 cation to direct Analysis : Dialysis, by M. Em. Guinet 80 



NUMBER CLXVI.— FEBRUARY. 



Mr. J. Ball on the Formation of Alpine Valleys and Alpine 



Lakes 81 



Mr. D. Forbes on the Chemical Composition of some Chilian 



Minerals 103 



Mr. C. Tomlinson on the Motion of Camphor towards the Light. 114 



Prof. Challis on the Zodiacal Light 117 



Prof. Emerson on the Perception of Relief 125 



o 



M. A. J. Angstrom on a New Method of determining the Ther- 

 mal Conductibility of Bodies 130 



Prof. Rose on the Composition of Samarskite 142 



