SMITH. 



EXPANSION OF ETHER AND ALCOHOL. 



457 



would get by extrapolating from the values previously obtained from 

 the data of Amagat. It is true that the [490] now placed at the head 

 of the 40° column is slightly larger than the numbers beneath it would 

 lead one to expect, and a still greater divergence in the same direction 

 is to be observed at the head of the 80° column. Moreover, these dis- 

 crepancies would have been considerably greater if a possibly too great 

 allowance (3 per cent) had not been made for the greater impurity of 

 the alcohol used in the research of this paper as compared with the 

 alcohol used by Amagat. But at the most they are hardly great 

 enough to give certain evidence of any noteworthy change in the con- 



TABLE XVI. 

 Alcohol. 



dition of the alcohol in approaching and passing into the superheated 

 condition. 



It appears in Table XV that a' decreases and that a increases with 

 rising temperature. Here, as in the case of ether, we find it interest- 

 ing to follow the change of each of these quantities as far as we can, in 

 order to see how nearly they approach each other in the neighborhood of 

 the critical temperature, which for alcohol is about 243° C. We should 

 of course expect them to approach the same limit in approaching the 

 critical temperature and pressure. The values of a' given in Table 

 XVI were calculated from the evaporation data of alcohol as given by 

 Ramsay and Young. It appears from this table that a' continues to 

 decrease until the critical temperature is approximately reached. 



I have made an attempt to obtain values of a at temperatures not 

 very far from the critical temperature. Ramsay and Young have with 



