70 O. V. L. Charlier 



and we conclude that T is proportional to and depends moreover on a single 

 parameter . 



The integration may be performed tirst regarding and leads then to an 

 integrallogarithmus. 



It is, however, preferable to begin with the integration regarding . We 

 make the following change of variables: 



X = p^' 



(160) 

 so that 



and 



dxdy 



(161) 



' 0 u 



0 



The constant before the integral may also be written in the form 



aK ' 



The logarithm under the sign of integration may be removed through inte- 

 gration by parts. We have, indeed, 



de ^(4 + 2?/) -2//2 



^ —= — ye 



dy 



The application of this formula gives 



0 



33 .y^ 



eoV^J ^""^^^ 



Putting 



(162) 



we get 



y = 2t 



