18 Oapt. A. C. Egerton on the 



In the case of: tungsten, they have assumed a greater 

 atomic heat than given above, about 7 5, which changes 

 the value of X to 218000. 



This is in better accordance with the observations of 

 Corbino (Atti R.Accad. Lincei, 1912, xxi. pp. 346 & 188), 

 who finds a value for C„=7 , 8, which remains fairly constant 

 over a wide range of temperatures (2000° C.)*. 



It has already been pointed out that calculation of 

 the constants in the above way leads to results without 

 physical significance, but the knowledge of the change 

 of specific heat at high temperature is insufficient to 

 permit of the rational method providing a reliable value 

 for the constants of these metals. 



In the case of tungsten, from the melting-point formula 

 /3v may be taken as 301. 



At 2400° abs., 



f =0-125 and ^^° = 14-648 and *g^ = 3-2041. 

 9 a'v 121.9-7.290 n ' 1A _ 5 



° ' and <H)583aT* = 0-04.11. 



p = 5-0 . 10" 8 ; logp = -10-182 atmos. 



Xo_ 218 000 



an 4-571T"" 4-571. 2400" iy ' b7i >" 

 so that 



0=- 10-182 + 19-872- 8-450 + 3-204 + 0*041. 

 .-. = 4-48. 



For platinum, j3v has been measured from the specific 

 heat and has a value 220. From the melting-point, the 

 value 223 has been calculated. Taking j3v = 220, 



^ = 0-11 and Ar-Ao = 15 . 372 and WW = g.^ 



3a = 27 . 10 " 6 (see Nernst, Z.S. f. FJektrochem. xvii. 

 p. 819, 1911), 

 v = 9-1, 

 K = 0-40. 10" 12 ; 



* For platinum some measurements of c have also been made at 

 high temperatures. Konigsberger ( Verh. d. Phys. Ges. xiv. pp. 275, 540, 

 1912) giv r es the following figures : — 



773° c p - 6*57, c v = 6'56 ; 

 1173° c p = 7-39, c v = 6-79. 



