THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH SERIES.] 



NOVEMBER 1910. 



LXXXIX. On the Critical Phenomena of Ether. 

 By F. B. Young, B.A., B.Sc* 



IT has been observed by numerous investigators that when 

 a liquid in contact with its vapour is heated to the 

 critical temperature of vaporization, the meniscus disappears 

 whilst the density o£ the liquid is still distinctly greater than 

 that of the vapour, and that this difference o£ density may 

 persist for an appreciable time even if the temperature is 

 still further raised. According to the simple theory of 

 continuity of state, the liquid and vapour should become 

 identical at the critical temperature f. Various explanations 

 of this phenomenon have been offered, some of which are 

 intended to reconcile it with Andrews's theory, whilst others 

 utilize it as evidence of the insufficiency of that theory. The 

 chief views which have been presented are the following : — 



A. Explanations involving no modification of Andrews's 

 Theory, 

 (i.) Gouy (1) points out that owing to the influence of 

 gravity the pressure in the substance is not uniform 

 but increases from the top downwards. Since the 

 substance when exactly at its critical state is quite 

 abnormally compressible, an appreciable discontinuity 

 may be produced in the density of the substance at 

 that level at which the pressure is equal to the critical 

 pressure. 



* Communicated by Prof. A. P. Chattock. 



t S. Young has shown this to he true in the case of normal pentane 

 (Trans. Chem. Soc. vol. lxxi. p. 446, 1897). 



PhiL Mag. S. 6. Vol. 20. No. 119. Xov. 1910. 3 G 



L 



