xviii CONTENTS. 



PAGE 



The functions of the energy del d log Fand log Fas analogues of 



temperature and entropy 169-172 



The functions of the energy de / cty and <p as analogues of tempera- 

 ture and entropy 1 72-1 78 



Merits of the different systems 178-183 



If a system of a great number of degrees of freedom is microcanon- 

 ically distributed in phase, any very small part of it may be re- 

 garded as canonically distributed 183 



Units of and rj compared with those of temperature and 

 entropy 183-186 



CHAPTER XV. 



SYSTEMS COMPOSED OF MOLECULES. 



Generic and specific definitions of a phase 187-189 



Statistical equilibrium with respect to phases generically defined 



and with respect to phases specifically defined 189 



Grand ensembles, petit ensembles 189,190 



Grand ensemble canonically distributed 190-193 



Q must be finite 193 



Equilibrium with respect to gain or loss of molecules .... 194-197 

 Average value of any quantity in grand ensemble canonically dis- 

 tributed 198 



Differential equation identical in form with fundamental differen- 

 tial equation in thermodynamics 199, 200 



Average value of number of any kind of molecules (i>) . . . . 201 



Average value of (v-v)* 201,202 



Comparison of indices 203-206 



When the number of particles in a system is to be treated as 

 variable, the average index of probability for phases generically 

 defined corresponds to entropy 206 



