232 



Mr. William Sutherland on th 



le 



is interesting, as it relates to temperatures both above and 

 below the critical. The values of the constants are B = 54, 

 /3=-692. 



Table XIX. 



Carbonic Dioxide below critical volume. 



Volume 



70° C { P ressure > ex P- ■ 

 ' \ „ calc. 



nj-op f Pressure, exp.. 

 ' \ „ calc. 



i qo n { Pressure, exp.. 

 " \ ,, calc. 



1-526. 



1-203. 



1115. 



1-027. 



150 

 152 



274 

 266 







69 

 69 



126 

 120 



187 

 184 



320 



320 







99 

 97 



200 



20S 



The agreement is within the limit of experimental error at 

 the high pressures. Cailletet and Mathias have determined 

 (Compt. Rend, cii.) the density of liquid C0 2 at various tem- 

 peratures under the pressure of saturation. Here is a com- 

 parison with a couple of their results : — 



Temperature . . . —34°. 0°. 



Volume— Cailletet and Mathias . '946 1-087 

 „ Equation "943 1*086 



As far as compound gases are concerned, the applicability 

 of the form for volumes below the critical has now been de- 

 monstrated in two typical cases. The elementary gases have 

 now to be considered as to their behaviour below the critical 

 volume. The data are again those furnished by Amagat 

 (Co7npt. Mend. cvii. and Phil. Mag. Dec. 1888) on the com- 

 pressibility of these gases between 760 and 2280 metres of 

 mercury. Our study of these bodies above the critical volume 

 has given us the knowledge that the internal virial term below 

 k must be l/v, and the kinetic-energy term at the critical 

 volume is 3RT/2, and with these guides the complete form 

 required is soon found from the experimental numbers. It is 



(8 



jw= jRT(l + &**" 





with the following values for the 



additional constants 



and b : — 





h. 



0. b. 



Hydrogen ... 12 



4-3 -480 



Nitrogen . . . 2' 64 



•81 -420 



Oxygen . . . 1*78 



•604 -4415 



Methane . . . [5*51] 



[1-59] [-447] 



