Residual Valence of Various Molecules 



481 



by the following circumstance: From the formula 

 a = ((S 2 S + 2 )/(S 2))PV* and the formula 



a = M((S 2 S + 2)/(S 2))RT 2 /'(T C - - T) 1 /'/^ </.) we 

 have V' = MR(T C - - T)'/>T 2 /V(di d,)P e . If now we com- 

 pute d c of oxygen by this formula from the densities of liquid 

 and vapor oxygen found by Mathias . and Onnes, we find 

 indeed a constant value for d c , but a density nearly 3 percent 

 higher than that computed by the rectilinear diameter law, 

 as follows: 



TABLE II 



Computation of the critical density of oxygen from the densities 

 at different temperatures, t 



118.8 0.4413 



120.4 0.4428 



-140.2 0.4437 



154.51 0.4427 



d c computed by Mathias and Onnes by the rectilinear diameter 

 law was 0.4299. 



The deviation with pentane was in the opposite direction. 

 d c was found by S. Young to be 0.2323. If it is calculated 

 by the foregoing method from Young's density figures we have 



o 0.2235 

 160 0.2265 



In this case the result was about 3 percent too low. 



With octane the computed and found values agree very 

 well, as follows, using Young's density figures at various 

 temperatures. 



