176 Dr. F. A. Lindemanti on tlie 



slightly if at all in two isotopes, so that the difference of the* 



9a 2 Tv 9cc 9 2 Tv 

 correction terms — — - — must be small and may 



be neglected. One may therefore write 



It has been shown that the atomic heat may be repre- 

 sented with remarkable accuracy by 



d 9RT|V 



C "'~dT 





where {1=—^ as before, except that v m is defined somewhat 



differently from v the frequency of the atom *. v m is, however,. 

 very nearly equal to v and may almost certainly be identified 

 with it. This equation naturally holds equally well if the 



' ; Nullpunktsenergie " — -, corresponding to continuous ab- 



sorbtion, is taken into account, for then 



Taking this value therefore 



P% Jo T Wjo **— 1 Mi Jo « r — 1 



^^rrd^c^dx _rd tl c^x*d x 



+ g I d/ji, — g I ^! J + (?i - i 2 ) 

 -C^dpCv-avdoc 9. v ,. . . 



J/i-2 A 6 . * — x ° 



* P. Debye, ^Lrcra. d. 1%-s. xiv. p. 789 (1912) ; W. Nernst & F. A. 

 Lindemaim, Sitzungsber. d. Akad. d. W. L. 11, p. 1160. 



