BRIDGMAX. — THERMODYNAMIC PROPERTIES OF LIQUIDS. 



57 



The volume of ether as a function of pressure and temperature is 

 shown in Table IX and in Figure 13. 



For the initial compressibility at 20° and 40° we have values of 

 Amagat^'^; O.O3IS4, and 0.0c218 respectively. There are also measure- 

 ments by Avenarius^s at 20° and 40°; O.O3I9I, and O.O3232, respec- 



23456789 10 U 12 

 Pressure, kgm. / cm.^ x 10"' 

 Rther 



FiGURE 13. Ether. Volume at 20°, 40°, 60°, and 80° plotted against 

 pressure. The lower curve gives volume at 20°. The curves for the higher 

 temperatures could not be extended to the origin because of the low boiling 

 point. 



tively. The values needed to give the changes of volume listed in the 

 table are O.O3I7O, and O.O32I5. The mean values finally adopted were 

 O.O3I84, and O.O322O. There are also other measurements by Grimaldi^^ 

 and Amagat at temperatures considerably above the normal boiling 

 point, and at accordingly increased pressures, 20 kgm. or so. It was 

 not attempted to make connections with these values. 



Cp has been measured by Regnault*^, who gives 20.97 at 0°, and 

 21.69 at 30°; by Sutherland*^, whose values are 27.35 at 80°, and 

 31.86 at 120°; and by de Heen*^ who found 32.59 at 140°, and 41.27 at 



37 Amagat, 1. c, (1877). 



38 Avenarius, Bull. Ace. St. Pet., 10 (1877). 



39 Grimaldi, N. Cim., 19, 7 (1886). 



40 Regnault, 1. c. (1862). 



41 Sutherland, 1. c. 



42 de Heen, Bull de Belg., 15, 522 (1888). 



