^-)4 



So tar we liave tested the leniperature-coetïieients of 7^. We can 

 also lest equation (5) directly, namely by for instance calculating 

 (Ï from it, and by comparing the values obtained thus with the 

 values of o calculated in anothei- way. When we again omit 



the factor e '^^ and when we put |,t o' A =r <6 = -- — (jY=: num- 



ber of molecules per gram-molecule), substituting again 



RT 



a 



Pf-, 



V 



for 



V — b, and neglecting n bv the side of -, we find : 



V 



1) For these substances the values for -^777 also for 0° G. have been calculated 



from the empirical formula ofRoDGEE and Thoepe, though they are solid at this 

 temperature. 



