1060 



And üiiallv for y = 0,50 (7'r=;0), where h is invariable, we should 

 find />:/>„=! for all values of ??: z-^, (/^—^>i,) : (y--i;J always bein<i- = 0. 



Let MS in conclusion review according- to what law or approxi- 

 mate law the found value of x^ — i.e. of the final direction of the 

 curve h^f[v) — varies with y or T. 



From (38/>) follows ,r„ = (2y-l) X --77 Lx ^^^. We shall 



see that here the factor of 2y — 1 is almost constant between 

 7 = 0,75 and 7 = 0,55. 



7 = 0.90 10.75 0.70 0.65 0.60 0.55 ] 0.50 



.To = 0.386 0.263 0.215 0.164 0.110 0.0543 

 jrf,:(2> — l) = 0.482l 0.526 0.538 0.547 0.551 0.543 0.5 



If 0,482 foi- y = 0,9 and 0,5 for y=0,5 is excepted, the mean 

 value of the other values is 0,541, and we may therefore write 

 with some accuracy : 



I Am r~^A = 0,54 (2y— 1). 



V' — ^«y« 

 Hut seeing that 2y— 1 = 0,038 J/T, we have also: 



Lira -^^ = 0,02 \/l\ (39) 



which according to the above will therefore also hold all alom/ the 

 final part of the curve b=f{v), from values of r == 0,7 y^.- {ov = Vo. 



For Argon at temperatures < Tk only y = 0,75 (T=150) and 

 7 =z 0,70 (2"= 100) should practically be taken into account, be- 

 cause the observations have not been carried further than jT = 90 

 (absolute). If we thus consider an isotherm for Argon below the 

 critical point, we may assume that (provided it be not too near Tk) 

 the value of h will practically agree with b,, at the vapour volume, 

 and that at the ll([uid volume the /;-value will satisfy the above 

 equation (39). 



If (39) is written in the reduced form 



and if it is taken into account that h-.Vk^?, v:Vk = n, and 

 r„ : Vk = «0 = iio = 1 • 2 (1 + 7k), then for Argon : 



(^_V.):(n — 7.) = 0,02l/T , (n < 0,7) . . (40) 



when yjc = 0,75 is taken. 



