CONTENTS OF THE SECOND VOLUME. 



CHAPTER VI. 



ON THE KINETIC OR MECHANICAL VIEW ( OP NATURE. 



The idea of motion in ancient philosophy, 3 ; Descartes' development of the 

 kinetic view, 6 ; Huygens and Newton, 7 ; Revival of the kinetic view 

 in the nineteenth century, 7 ; Young and Fresnel, 8 ; Undulatory and 

 emission theories, 11 ; Both theories kinetic, 11 ; Undulatory theory 

 prepared by acoustics, 12; Newton's authority on the side of the emission 

 theory, 14 ; But also suggests the other theory, 15 ; Biot, Brewster, 

 and Laplace against the undulatory theory, 16 ; Euler, the successor of 

 Huygens, 16; Young, 16; His "general law of the interference of 

 light," 18 ; Theory of the luminiferous ether, 18 ; Brougham's attack on 

 Young, 19 ; Augustin Fresnel, 21 ; Difficulties presented by the polar- 

 isation of light, 22 ; Fresnel's Memoir on Diffraction, 25 ; Young and 

 Fresnel introduce the conception of transverse vibrations, 28 ; Mechani- 

 cal difference between light and sound, 30 ; The properties of the ether, 

 31 ; Other kinetic theories, 34 ; Kinetic theory of gases, 34 ; Vortex 

 motion, 35 ; Faraday's researches, 35 ; Problems as to the nature of the 

 ether, 36 ; The theory of elasticity, 40 ; The problem of the ether may 

 be treated mathematically, 44 ; or experimentally, 44 ; Necessity of 

 combining the two methods, 44 ; Spectrum analysis, 45 ; The clue 

 furnished by the phenomena on which it depends, 47 ; Sir G. Stokes, 

 47 ; Gustav Kirchhoff, 48 ; Explanation of fluorescence, 52 ; View of the 

 ether as an " elastic solid," 54 ; Lord Kelvin's researches, 55 ; Tyndall's 

 4 Heat,' 57 ; Lord Kelvin's vortex theory of matter, 57 ; Helmholtz's 

 investigations, 58 ; Earlier researches on vortex motion, 61 ; Influence 

 of Helmholtz's investigations in England, 62 ; Difficulties of the vortex 

 ring theory, 64 ; Modern view of electrical phenomena : Faraday, 66 ; 



