86 AVERAGES IN A CANONICAL ENSEMBLE. 



as many times as we choose, and in any order, the average 

 value of the result will be zero. Or, if we apply the same 

 operators to u, and finally take the average value, it will be the 

 same as the value obtained by writing the sign of average 

 separately as u, and on e, A , A 2 , etc., in all the operators. 



If u is independent of the momenta, formulae similar to 

 the preceding, but having e q in place of e, may be derived 

 from equation (179). 



