SMITH. 



EXPANSION OF ETHER AND ALCOHOL. 



453 



This lack of information makes it difficult to compare my values of a 

 with those obtained from his data, and it becomes necessary to take up 

 the question of the effect of a small amount of water on the compressi- 

 bility and on the expansibility of alcohol. The latter part of the 

 problem has been examined by Dupre and Page,^*^ and moreover, the 

 necessary information is to be had from tables ^^ on the specific gravity 

 of mixtures of alcohol and water. Each of these sources of information 

 indicates that the difference between the coefficients of expansion of 

 absolute alcohol and that of alcohol which contains 0.5 per cent water 



ao 



40 



CO 



80 



100 



Curve I. 



would not be so much as one per cent of either coefficient and may be 

 neglected here. These facts are brought out clearly by Curve I, in 

 which e X lOMs plotted as ordinate and per cent of alcohol as abscissa. 

 The points surrounded by circles are from the data of Dupri^ and 

 Page and the points marked with crosses are from the tables of den- 

 sities of mixtures of alcohol and water. It is seen that each set of 

 values gives essentially the same curve ; and for points between 99 per 

 cent and 100 per cent alcohol the tangent to the curve makes only a 

 small angle with the axis of abscissae. 



The information heretofore available on the change in compressibility 

 with the presence of water is by no means satisfactory. Pagliani ^^ has 



" Pliil. Trans. 159, 591. 



« Jour, de Phys. (2) 10, 589 (1891). 



" Landolt and Bornstein. 



