On an Experimental Modification of van der Waah's Equation. 135 
From the constants given by Kamerlingh Onnes and Keesom [loc. 
cit.) this expression was evaluated along the isopentane saturation line. As 
the DiETERici values are a little irregular at the critical part of the curve, 
they were smoothed graphically before being used. In each case figures 
are given in cal/° C. and are for the gram-molecule. 
Table VIII. 
Experimental Inversion Curve. 
IF" 
T^^^Msmoothed). 
0-686 
0-5 
-24-0 
1085 
0-679 
0-7 
-22-7 
1-09° 
0-723 
1-0 
-21-3 
1-098 
0-766 
1-3 
-19-8 
1-107 
0-809 
1-6 
-19-1 
1-113 
0-831 
1-8 
-19-4 
1113 
0-853 
1-9 
-19-8 
1-11^ 
0-875 
2-1 
-20-6 
1-107 
0-896 
2-3 
-21-9 
1-10^ 
0-918 
2-6 
-24-0 
1-093 
0-940 
2-9 
-28-2 
1-07^ 
0-961 
3-3 
-34-8 
1-063 
0-983 
3-8 
-53-8 
1-04° 
0-994 
4-4 
-114-4 
l-OP 
1-000 
o 
-4-- 
