THE 



s 



LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JANUARY 1894. 



I. Note on the Generalizations of Van der Waals regarding 

 ti Corresponding" Temperatures, Pressures, and Volumes. 

 By Sydney Young, D.Sc, F.R.S., Professor of Chemistry, 

 University College, Bristol*, 



IN a paper read before the Physical Society in November 

 1891, and published under the above title in the Philo- 

 sophical Magazine for February 1892 (xxxiii. p. 153), the 

 absolute temperatures and the molecular volumes (as liquid 

 and saturated vapour) of eleven compounds were compared with 

 those of fluorbenzene at a series of corresponding pressures. 



It was pointed out, however (p. 155), that a better mode 

 of procedure in many respects would have been to give the 

 temperatures, pressures, and volumes of each of the twelve 

 substances in terms of its critical constants ; but as the 

 critical volumes of several of the compounds had not been 

 directly determined, and as none of them were known with 

 accuracy, the method had to be abandoned. 



Since then it has been shown by M. Mathias that the 

 critical densities — and therefore the volumes — may be deter- 

 mined with great accuracy by the method of Cailletet and 



* Commumcated by the Physical Society: read November 10, 1893. 

 Pltil. Mag. S. 5. Vol. 37. No. 22-4. Jan, 1894. B 



