( 635 ) 



.r-axis. 



Fis;. 2. 



for the points of this locus may be derived in the following way 



00 



If we write xp = MRT \ (1 —x) log (1 —x) -f ./■ % g ] -f f p<& 



then 



dm J v 



CO 



8 = Wr/;^+j(J)*. 



At infinite volume the value of a = MRT I- — as we saw above. 



1 \ — x 



The locus under consideration must therefore be determined by 



J \dx 



dv = Q. Hence on the line a?= the final value,. a point must 



