10 The Kinetic Theory conception of Matter [OH. i 



Twenty years later ideas of the same nature seem to have occurred 

 independently to Hooke, the recognition of whose work in the foundation 

 of the Kinetic Theory is due to Professor Tait*. 



The next advance in the theory is due to Daniel Bernoulli f, who fre- 

 quently is credited with having been the first to make the discoveries of 

 Gassendi and Hooke. In his Hydrodynamica, published in 1738, he points 

 out that the elasticity of a gas may be regarded as due to the impacts of 

 particles on the boundary. He deduces Boyle's law for the relation be- 

 tween pressure and volume, and attempts to find a general relation between 

 pressure and volume when the finite size of the molecules, supposed abso- 

 lutely hard and spherical, is taken into account. 



After Bernoulli, there is little to record for almost a century. Then we 

 find that in rapid succession HerapathJ (1821), Waterston (1845), Joule 

 (1848), Kronig ! (1856), and Clausius (1857) take up the subject. Waterston 

 attempted to -ternm a scientific mathematical theory of the subject; but 

 his paper, which was presented to the Royal Society in 1845, contained 

 certain inaccuracies, and was for this reason not published in the Philo- 

 sophical Transactions until 18921F, when Lord Rayleigh had it published 

 on account of its historical interest. Clausius, in his first paper**, calculates 

 accurately the relation between temperature, pressure and volume, and also 

 the value of the ratio of the two specific heats for a gas in which the 

 energy of the molecules is wholly one of translation. In 1859, Clerk 

 Maxwell was added to the number of contributors to the theory, reading 

 a paper on the subject before the British Association at Aberdeen -f-f-. It 

 has been suggested that Maxwell was first led to take an interest in the 

 subject by his investigations on the motion of Saturn's rings, which gained 

 for him the Adams Prize in 1857 Jj. In the hands of Clausius and Maxwell 

 the theory developed with great rapidity, so that to write the history of the 

 subject from this time, would be hardly less than to give an account of 

 the theory in its present form. Among the more prominent contributors 

 to the theory since the time of Clausius and Maxwell may be mentioned 

 Boltzmann, Kirchhoff, Van der Waals and Lorentz on the continent, and in 

 England Tait, Lord Rayleigh and Burbury. 



* "Hooke's Anticipation of the Kinetic Theory." Proc. Edin. Roy. Soc., March 16, 1885. 

 Tait's Collected Works, n. p. 122. 



t Daniel Bernoulli, Hydrodynamica. Argentoria, 1738. Sectio decima, " De affectionibus 

 atque motibus fluidorum elasticorum, praecipue autem aeris." 



J Annals of Philosophy, [2], i. p. 273. 



British Association Beport, 1848, Part n. p. 21 ; Memoirs of the Manchester Literary and 

 Philosophical Society, [2], ix. p. 107. 



|| Poggendorff's Annalen. IT Phil. Trans. CLXXXIII. p. 1. 



** "Ueber die Art der Bewegung welche wir Warme nennen," Fogg. Annalen, c. p. 353. 



ft Phil. Mag. Jan. and July, 1860. Collected Works, i. p. 377. 



JJ See W. D. Niven, preface to Maxwell's Collected Works, p. xv. 



