viii Contents. 



XVII. Notes on Some Points in the Theory of Light, . . 7 43?- 



XVIII. On the Prohlem of Total Reflexion, ..... 218 



XIX. On the Dispersion of the Optic Axes, and of the Axes of 



Elasticity in Biaxal Crystals, ..... 221 



XX. On the Law of Double Refraction, ..... 227 



XXI. On the Laws of Metallic Reflexion, and on the Mode of 



making Experiments upon Elliptic Polarization, . . 230 

 XXII. On the attempt lately made by M. Laurent to explain, on 

 mechanical principles, the Phenomenon of Circular Pola- 

 rization in Liquids, ..... . . 249 



XXIII. On Total Reflexion, ..... 250 



PAET II. 



GEOMETRY. 



I. Geometrical Theorems on the Rectification of the Conic Sec- 

 tions, 255 



II. On the Surfaces of the Second Order, 260 



III. Note relative to the comparison of the Arcs of Curves, particu- 



larly of Plane and Spherical Conies, 318 



IV. Note on Surfaces of the Second Order, . 321 



PAET III. 



ROTATION. 



I. On the Rotation of a Solid Body round a Fixed Point; being an 

 account of the late Professor Mac Cullagh's Lectures on that 

 subject. Compiled by the Rev. Samuel Haughton, Fellow of 

 Trinity College, Dublin, 329 



