EXPANSION AND COMPRESSIBILITY OF ETHER AND 



OF ALCOHOL IN THE NEIGHBORHOOD OF 



THEIR BOILING POINTS. 



By Alpheus W. Smith. 



Presented by E. H. Hall, May 9, 1906. Received October 30, 1906. 

 [For a summary of the results reached in this paper, see p. 458.] 



Introduction. 



This subject was suggested to the writer by Professor Hall, to whom 

 it became of interest in his work on the van der Waals a in ethyl 

 ether and in ethyl alcohol. In obtaining values of the van der "Waals 

 a by one of the methods employed in that paper ^ Professor Hall 

 found it desirable to know both the coefficient of expansion and the 

 coefficient of compressibility of these liquids just before they change 

 into the vapor state. 



The investigators who have concerned themselves with the coeffi- 

 cients of expansion and of compressibility of liquids have for the most 

 part used large differences of temperature and of pressure in produc- 

 ing the change of volume in the liquid, so that every coefficient is 

 the average coefficient over a considerable range of temperature and 

 of pressure. Such data do not give us with certainty the coefficient 

 of expansion and of compressibility at a particular temperature and at 

 a pressure differing but little from the vapor pressure of the liquid 

 at that temperature. 



I, therefore, undertook to find by means of new measurements both 

 the coefficient of expansion and the coefficient of compressibility of the 

 two liquids in question at pressures which were only slightly greater 

 and at those which were somewhat less than the vapor pressure of the 

 liquid at the temperature used, — i.e., the coefficient of expansion 

 and the coefficient of compressibility of these liquids just before they 

 reach their boiling conditions, and these same coefficients when the 

 liquids are in the superheated state. 



1 Boltzmann-Festschrift. 1904. 



