SMITH. — EXPANSION OF ETHER AND ALCOHOL. 



The equation used in finding the values of a' is 



449 





in which, p = the internal work of vaporization, in ergs, 



v^ = " specific volume of the liquid state, in cu. cm., 

 fi = " " " " " saturated vapor " " 



The Value of a in Ether. 



In Table X are given five values of a in ether, calculated by means 

 of my data on compressibility and expansibility. Of these values 

 the first three are for pressures slightly greater than the vapor-pressure, 

 and the last two are at pressures less than the vapor-pressure. 



We have, I believe, no definite information as to the method of 

 purification of the ether used by Amagat. The way in which the 

 ether used by me was purified has already been pointed out. In 

 comparing the values of a obtained from my data with those obtained 

 from the data of Amagat, we must neglect any differences due to 

 difference in purity of the ether used in the two cases. It is doubtful 

 if this would be a source of any considerable error. 



For purposes of comparison the values found by Professor Hall for a 

 and a' in ether are given in the following table. The numbers in 

 brackets to the right of each a-column, are, as stated by Professor 

 Hall, " an attempt to establish a regular gradient of a with varying 

 pressure, corresponding in a general way to the indications of the a- 

 column." 



VOL. XLII. 29 



