SMITH. — EXPANSION OF ETHER AND ALCOHOL. 



445 



its former temperature and a new series of observations commenced. 

 The cross section of the tube E F (Figure 8) being large, no correction 

 was made for the surface film which adhered to its sides. 



Tables VI and VII show the results for ethyl ether and ethyl alcohol 

 respectively. In these tables P is the vapor-pressure, in centimeters of 

 mercury, of the liquid at the corresponding temperature t, and p is the 

 external pressure, in centimeters of mercury, on the liquid. 



TABLE VII. 

 Expansion of Ethyl Alcohol in the Superheated State. 



It will be observed from an examination of these tables that the 

 mean of the results obtained under the same conditions has in all cases 

 a probable error of less than one per cent. 



Compressibility. 



The piezometer, after having been filled, was inserted into the cylin- 

 drical brass tube which had been previously filled with water. Both 

 were then placed in position in the water-bath. The connections 

 were made with the pressure-gauge in the usual way. After the tem- 

 perature of the water-bath had been raised to the desired value and 

 allowed to become constant, it was determined by means of the same 

 Baudin thermometer used in the work on expansion. From an initial 

 value somewhat less than the vapor-pressure of the liquid in the bulb 

 of the piezometer, the pressure was decreased about 40 cm. of mercury 

 and the corresponding change of volume was read. The pressure was 



