( 862 ) 
If we represent the volume of the layer between Ma, (€) and 
bona (e+ de) by ef) de, gs) being a determined function of e and 
we imagine an ensemble in which the density in the mentioned 
layer amounts to f(s), this ensemble will be identical with the real 
ensemble if 
f{e) ef*) de 
- we. ) ; — e—ke EQ) : - = ° e (16) 
7 (€,) en “0 
From (16) results 
GRAN EN PAE oe (eg) —— ie (EE) 
developing for small values of (¢—«,) we get 
d loc ; de : y 
(ee) ( ee 2) Er ( ee | | i 
et 1E 2 
de 
d* log f (&)> dp j 
4 ener) a =) +( =) | = Hee), 
we” Sn EE 
Therefore 
d log f (€) a dp(e) 
Ei ty dé EE 
de 
and 
Ld? log A a8 gs) ee 
de? JZ de? 2E) 
In first approximation 
= aes 4) 
S(&) =F (8) ¢ nh EN 
If we suppose that this formula is true for all values of ¢ and 
: d? log 7 (€) : : 
that therefore ER be put 0, we find for the number of 
LE 
systems having the energy between ¢ and e + de 
d2) Vise (2) +? 
e ti 
d: k 
Ie zie le. 
; de Y 
ag le F dz Jz=%z ee i ‘ 
Putting {- pe) = — ande le) e = Ne® we find for 
de El 6) 
this number. 
FP — 
„ror tole) 
Ne dE rs bY ae et. (CEN 
so the ensemble is canonical. The relation to be adopted between # and 
