i 704] 



Mills — Molecular Attraction. 



167 



f these constants. The relation is so full of possibilities 

 ad for its adequate consideration will require so extended an 

 Avestigation that we postpone the discussion for a separate 

 aper. 

 Again, combining- equations 6 and 8 we obtain: 



SP 



ST 



287500 log v 



^ m Y — v' 



Owing to the inaccuracy of Crompton's equation at low 



por pressures at such points equation 15 cannot give accu- 



te results. But as the critical temperature is approached 



1 believe that this equation offers the most accurate method 



SP 

 it available for finding the ^7p-> g^ing" results far better 



an could be obtained from direct observations of the pres- 

 ire even when the observations are afterwards smoothed. 

 |[n Table 23 we apply the equation to isopentane corn- 

 ring the results obtained by its aid with those obtained 

 :'»m Biot's formula. 



1 V 



log ~v 



it the critical temperature the fraction == assumes the 



leterminate form — . Evaluating by diifentiating the 



nerator and denominator we find the limit approached at 



. . 4343 



critical temperature to be — ^ — , 0.4343 being the modu- 



of the Naperian system of logarithms. Therefore we 

 'e at the critical temperature, 



SP _ 124860 

 ST 



] 



mV 



ery simple relation. For isopentane we thus get the 



. SP 

 les of -p- r as 405.9, a result in exact accord with the 



ues 397 to 407 as given by Dr. Young 1 , and thus confirm- 

 x Proc. Phys. Soc, 1894-95, p. 950. 



