606 



-2 



while (30) becomes: 



C=^CJl-0Ab7t-^^^ + 0,163 r(3^ ...i 



b. For (f {>•) = c)—^ we obtain : 



(Ar)B = 0.6070 

 B = B^ |l-0,9105t(7^5 — 0.0789t-^ — 0.0093r-^- O.OOlO '-^^'^.. 



(;= C^j I -0,728 r^-; + 0,298 '-^...|. . 



c. Ill (ig. I B and 6' have been represented as functions of 

 t(ii) according to the above formulae, while />^ , resp. C'^ have been 

 taken = 1. 



(36) 



(37) 



(38) 

 (39) 



Fig- 1. 

 We see tiiat within the represented range of temperature C is 



j)0sitive. 6' decreases with rising temperature, in a considerably less 

 degree however than B. 



How the behaviour will be towards lowei- temperatures it is 

 impossible to say before more terms of Jhe developments into series 

 will have been calculated. When following terms do not change 

 this result, the terms here calculated would cause a minimum of 6', ^) 

 after which 6' would rise again, so that it is not improbable that C 

 remains positive up to a domain of considerably lower temperatures 

 than those to which fig. J refers. 



While for the two laws of force considered the curves of B are 

 nearly the same above the BoYLK-point, the coefficient 6' decreases 

 with the tonperature for q = 5 much more rapidly than for ^ =: 4, 

 at least in the beginning. 



1) Gomp. the representation of the values of C for helium in H. Kamerlingh 

 Onnes and \V. H. Keesom. Die Zustandsgleichung. Leiden. Suppl. N". 23, § 88, Fig. 15. 



