SMITH. — EXPANSION OF ETHER AND ALCOHOL. 



451 



as against 543 for 22° in Table X, and the 60° column would begin 

 with the number 532. Interpolation between 542 for 20° and 532 

 for 60° would give 537 for 40°, whereas Table X gives 537 for 39°. 

 This closeness of agreement is highly satisfactory from one point of 

 view, though it fails to reveal any change of especial interest occurring 

 at or near the point of passage into the superheated condition. 



In Professor Hall's paper the values of a' which were calculated 

 from Regnault's evaporation data are not given for temperatures above 

 100° C. In Table XII below are given a number of values of a' which 

 I have calculated from the probably more accurate evaporation data 



TABLE XII. 

 Ether. 



found by Ramsay and Young. ^^ These values are considerably less 

 than the corresponding values obtained from the data of Regnault. 

 This discrepancy is accounted for by the fact that the latent heat of 

 vaporization of ether as given by Ramsay and Young is less than the 

 corresponding value given by Regnault. Now each value of a' given 

 in Table XI is smaller than the value which we have found for a 

 under like conditions of temperature and pressure. The reduction 

 now made in the values of a' by the adoption of Ramsay and Young's 

 data will make the difference between a and a' larger than before. 

 Moreover, a comparison of Table XII with the 198° part of Table XI 

 may seem to indicate that the two values do not approach the same 



" Phil. Trans. (1886), p. 123. 



