xiv CONTENTS 



V. Coexistent Phases 105 



13. The Phase Rule 105 



14. The Relation between Variations of Temperature 



and Pressure in a Univariant System 108 



15. Cases in Which the Number of Degrees of Freedom 



is Greater Than One. (a) Systems of Two or 



More Components in Two Phases Ill 



(6) Systems of Three Components in Three 



Coexistent Phases 115 



\T. Values of the Potentials in Very Dilute Solutions 116 



16. A Priori Considerations 116 



(a) m2 Is Capable of Negative As Well As Posi- 

 tive Values 117 



(6) niils Capable Only of Positive Values 117 



17. Derivation of the Potentials of a Solution from 



Their Values in a Coexistent Vapor Phase 120 



18. Equilibria Involving Dilute Solutions 124 



(a) Osmotic Pressure 124 



(6) Lowering of the Freezing Point 125 



(c) Lowering of the Vapor Pressure of a Solvent 



by an Involatile Solute 127 



VII. The Values of Potentials in Solutions Which Are Not 



Very Dilute 128 



19. Partial Energies, Entropies and Volumes 128 



20. The Activity 131 



21. Determination of Activities from the Vapor Pres- 



sure 132 



22. The Lowering of the Freezing Point 135 



23. Osmotic Pressure of Solutions 138 



VIII. Conditions Relating to the Possible Formation of Masses 



Unlike Any Previously Existing 141 



24. Conditions under Which New Bodies May Be 



Formed 141 



25. Generalized Statement of the Conditions of Equi- 



librium 145 



IX. The Internal Stability of Homogeneous Fluids 146 



26. General Tests of Stability 146 



27. Condition of Stability at Constant Temperature 



and Pressure 148 



28. Condition of Stability Referred to the Pressure of 



Phases for Which the Temperature and Poten- 

 tials Are the Same as Those of the Phase in 



Question 150 



X. Stability in Respect to Continuous Changes of Phase. . . 152 



29. General Remarks 152 



30. Condition with Respect to the Variation of the 



Energy 153 



