162 Prof. W. Ramsav aud Miss E. Aston. [June 14, 



June 14, 1894. 

 The LORD KELVIN, D.C.L., LL.D., President, in the Chair. 



Mr. William Bateson, Mr. George Albert Boulenger, Professor 

 Hugh Longbourne Callendar, Professor William Watson Cheyne, 

 Mr. Robert Edmund Proude, Mr. Augustus Edward Hough Love, 

 Mr. Francis Cranmer Penrose, Dr. Dukinfield Henry Scott, the Rev. 

 Frederick John Smith, Mr. Joseph Wilson Swan, and Mr. Victor 

 Herbert Veley were admitted into the Society. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The following Papers were read : 



I. " The Molecular Surface-energy of the Esters, showing its 

 Variation with Chemical Constitution." By Professor W. 

 RAMSAY, Ph.D., F.R.S., and Miss EMILY ASTON, B.Sc. 

 Received April 26, 1894. 



The investigation of the thermal relations of a series of esters by 

 Professor Young* has made it possible to determine their molecular 

 surface-energies between ordinary temperature and their critical 

 points ; for the two important constants required for the calculation 

 of these properties, the densities of the liquids and of their vapours 

 in the saturated state (their orthobaric volumes) have been carefully 

 determined by him. Professor Young has had the kindness to place 

 his specimens at our disposal ; their purity is sufficiently guaranteed 

 by the proofs afforded in his paper. Before using them they were 

 tested for acidity, to ensure that no hydrolysis had occurred during 

 accidental exposure ; but in no case was the reaction acid. 



The chief question to which an answer was sought was : Do these 

 bodies confirm the general law of which experimental proof was fur- 

 nished by one of the authors in conjunction with Dr. Shields, which 

 may be thus stated 



At approximately equal intervals of temperature below their critical 

 temperatures all normal liquids possess equal molecular surface-energy ? 



The analogy of this law with that of Boyle is very striking; the 

 latter may be expressed in almost identical terms 



* ' Trans. Cliem. Soc.,' vol. 63, p. 1191. 



