T hermodynamical Theory of Solutions. 31 



from the absorption of a-rays, that a hydrogen atom contains 

 only 1 electron outside the positively charged nucleus, and 

 that a helium atom only contains 2 electrons outside the 

 nucleus ; the latter was necessarily to be expected from 

 Rutherford's theory. 



These questions and some further information about the 

 constitution o£ atoms which may be got from experiments on 

 the absorption of a-rays, will be discussed in more detail in 

 a later paper. 



I wish to express my sincere thanks to Prof. Rutherford 

 for the kind interest he has taken in this work, and for the 

 helpful advice he has given me. 



Physical Laboratories, 



The University, Manchester, 



August 1912. 



III. On the Application of the Theory of Chemical Potential 

 to the T hermodynamical Theory of Solutions. By S. A. 

 Shorter, P.Sc, Assistant Lecturer in Physics in the Uni- 

 versity of Leeds. — Part III. The Action of Gravity on a 

 :y Solution. The Solute Potential. Extension of the Theory* \ 



IN the parts of the present communication dealing with 

 the action of gravity on a solution, and with the solute 

 potential, the following new symbols will be used : — 



Gr, the potential o£ gravity (defined so as to increase 

 downwards) ; 



yjri(p, 0), the chemical potential of the solid solute ; 

 &o(s,p, 0) = ~-f (s, p, 6) ; 



Si(*, p, 0) =^f(s, p, 6) ; 



?i(s, P ,e)=^f(s,p,0); 



li{s, p, 6) the heat of solution. 



The new symbols used in the last section will be defined as- 

 they occur in the text. 



* Communicated by the Author. 



V. 



P 



