■616 The Earl of Berkeley and Dr. C. V. Burton 



on 



and we put q—pj — P', then the pressure on the solvent 



changes from 



to 



p — r — s — — dm 



.and so the work done on the solvent is 



-(M +dm)L ^dp, 



with these two pressures as the limits ; that is 



~du BP c 

 ~^BrM 



In the third operation, the work done on the solution is 

 — p's'dm, 

 and that on the solvent is 



In the fourth operation, the work done on the solution is 



dm 



dm 



}■ 



and that on the solvent is 



P^ 



H-M 1 q^—dq. 

 Jp-p 03 



On summing up and dividing by dm, and equating to 

 zero, we get 



(V iV-P' 



= l «t/p — 1 t«^. 



Jo Jp-P 



. . . (28) 



This, on taking the upper limits ?/ and p r — P' equal 

 respectively to /? + dp and p — Y+dp— ^— <^>, becomes 



sdp == ul dp — . — dp\ 



or 





(29) 



