CONTENTS OF VOL. XXXI. 



(FOURTH SERIES.) 



NUMBER CCVI.— JANUARY 1866. 



Page 

 Mr. T. R. Edmonds on the Law of Human Mortality expressed 



by a New Formula 1 



Sir David Brewster on the Bands formed by the Superposition 

 of Paragenic Spectra produced by the Grooved Surfaces of 



Glass and Steel.— Part I. (With a Plate.) 22 



Mr. J. Croll on the Excentricity of the Earth's Orbit 26 



Prof. Clausius on the determination of the Disgregation of a 



Body, and on the True Capacity for Heat 28 



Prof. Challis on Hydrodynamics. — Part III , 33 



Mr. R. Edmonds on Earthquakes and extraordinary Agitations 



of the Sea 45 



Prof. Sylvester on Astronomical Prolusions : commencing with 

 an instantaneous proof of Lambert's and Euler's Theorems, 

 and modulating through a construction of the orbit of a hea- 

 venly body from two heliocentric distances, the subtended 

 chord, and the periodic time, and the focal theory of Cartesian 

 Ovals, into a discussion of motion in a circle and its relation 



to planetary motion 52 



Notices respecting New Books : — The Mathematical Writings 



of D. F. Gregory, M.A 76 



Proceedings of the Cambridge Philosophical Society : — 



Prof. Cayley on a new Theorem on the Equilibrium of four 



forces acting on a Solid Body 78 



Prof. Sedgwick on the Geology of the Valley of Dent, with 

 some account of a destructive Avalanche which fell in 



the year 1 752 79 



Mr. J. W. Clark on the Rib of a Whale found near Cromer 81 



Mr. G. F. Browne on some Ice-caves 82 



On the Density of Ozone, by M. Soret 82 



Note of an ExperimentonVoltaicConduction,by J. J. Waterston. 83 

 On the Coloration of Glass by Selenium, by M. J. Pelouze .... 84 



NUMBER CCVII.— FEBRUARY. 



Dr. E. Rose on the Doctrine of Colour-disease 85 



Sir David Brewster on the Bands formed by the Superposition 

 of Paragenic Spectra produced by the Grooved Surfaces of 

 Glass and Steel.— Part II. (With Two Plates.) 98 



