493 



melts namely at the ordinary pressure (see inter alia p. 64 — 65) 

 exactly at 4200° C. abs. (Acoording to accurate spectrometrical deter- 

 minations). Though the contents of the said treatise is pretty confused 

 and incoherent from a physico-chemical point of view, and very little 

 indeed can be concluded from what is stated for other pressures, yet 

 this one fact — viz. 7^^ = 4200 — seems pretty firmly established. 

 But then the critical temperature lies certainly not below 6000 a 

 7000° abs., and \/ak must be at least == 32 . IO-2, when hk = 

 100 . 10-^, as we found before (in I). For the formula 



8 ah 



27 ^>fc 

 in which (see earlier papers) the factor A at a temperature of 6470° 

 (see below), where y = 2,ll, has the value 0,781, so that with 

 R = l : 273,09 we get: 



Tk = 80,915 X 0,781 - r= 63,19 — , 



then gives : 



1024. 10-* 



7'i. = 63,19 X— = 6470° abs. 



* 10.10-4 



27 f y \ 

 We remind of the fact that the factor A is = , in 



8-/-iVr+V 



which y represents the reduced coefficient of direction of the imaginary 

 straight diameter between D^ and Z>, in a Z), T-diagram ^). 



It is now the question whether the value of y is confirmed to 

 some extent by another way. We derived before that bk • b„ = 2/ 

 (see "New Relations"!). As bk is expressed in so-called "normal" 

 units, the value of bk must still be multiplied by 22412, and this 

 product divided by the atomic weight A, to obtain bjc in cm', per 

 gramme. i\.nd as 6, = Vo = 1 • -öj, we get : 



bt X 22412 X A 



2y =. ^— , 



so that D^ can be calculated from 



2y X A 



D.= 



bk X 22412 



in which (cf. also "New Relations" III) 2y can be calculated in 

 approximation from the formula 



2y= 1 -4- 0,04 I/7V. 



We, therefore, calculate the value 1 + 0,04 X 00,4 = 4,22 for 



I) See for all this ray series of papers : "A New Relation, etc." in These Proc. 

 of March 26, April 23, May 29 and Sept. 26 1914; resp p. 808, 924, 1047 and 

 451 ; especially i. 



