478 On a Method of Calculating Solubilities, etc. 



Table VIIL Benzene and Ethyl Alcohol, x = - 0-1297. 



Tables VII and VIII, were calculated by means of the thermodynamic 

 equation 



L T dp 



.s t -s J " dt ' 



using the data of Ramsay and Young* for ethyl alcohol ; of Youngf for 

 benzene ; and Young and Thomas J for methyl acetate. 



It is probable that, in some cases at least, a formula similar to that 

 given above may be used for the calculation of heats of solution and of 

 chemical reaction, but at present the data necessary for testing this are 

 not available. 



Summary. 



1. It is shown that by means of the equation R = R' + c (t' t) 

 (vide p. 471), vapour pressures (Ramsay and Young), solubilities, and 

 the equilibrium constants of chemical reactions can be calculated. 



2. The latent heat of vaporisation of a substance can be calculated 

 from the latent heat of vaporisation of another substance, within a 

 certain range, by means of the empirical equation L l = Lo T./. 



My thanks are due to Professor Ramsay for the advice which he has 

 given during the progress of the present work. 



* ' Phil. Trans.,' 1886, Part I, p. 71. 



f' 'Trans. Chem. Soc.,' 1891, vol. 59, p. 134. 



J Ibid., 1893, vol. 63, p. 1210. 



