CONTENTS. 7 



9 



CHAPTER VI. 



THE CONDUCTIVITY AND VISCOSITY OF CERTAIN RUBIDIUM AND AMMONIUM SALTS IN 

 TERNARY MIXTURES OF GLYCEROL, ACETONE, AND WATER AT 15, 25, AND 35. 



Page. 



Introduction 117 



Experimental 119 



Apparatus 119 



Thermostats * 119 



Conductivity Apparatus 120 



Viscosity Apparatus 120 



Volumetric Apparatus 120 



Solvents 120 



Salts 122 



Solutions 122 



Procedure 122 



Viscosity Data 123 



Conductivity Data 127 



Discussion of Results 131 



Summary 140 



CHAPTER VII. 



DISCUSSION OF EVIDENCE ON THE SOLVATE THEORY OF SOLUTION OBTAINED IN THE 

 LABORATORIES OF THE JOHNS HOPKINS UNIVERSITY. 



Earlier Work 141 



Relation between Lowering of the Freezing-point of Water and Water of Crystalli- 

 zation of the Dissolved Substance 143 



Approximate Composition of the Hydrates formed by Various Substances in Solution 145 

 Relation between the Minima in the Freezing-point Curves and the Minima in the 



Boiling-point Curves 147 



Relation between Water of Crystallization and Temperature of Crystallization. . . . 148 

 Hydrate Theory in Aqueous Solutions becomes the Solvate Theory in Solutions in 



General 149 



Temperature Coefficients of Conductivity and Hydration 151 



Relation between the Hydration of the Ions and Their Ionic Volumes 155 



Hydration of the Ions and the Velocities with which They Move 157 



Dissociation as Measured by the Freezing-point Method and by the Conductivity 



Method 158 



Effect of one Salt with Hydrating Power on the Hydrates formed by a Second Salt 



in the Same Solution 161 



Investigations in Mixed Solvents 162 



Spectroscopic Evidence Bearing on the Solvate Theory of Solution 170 



Work of Jones and Uhler 170 



Work of Jones and Anderson 172 



Work of Jones and Strong 175 



Absorption Spectra of Neodymium Salts 178 



a Bands 180 



Effect of Rise in Temperature 181 



Spectrophotography of Chemical Reactions 183 



Work of Jones and Guy on the Absorption Spectra of Solutions 185 



Work of Jones, Shaeff er, and Paulus 188 



Summary of the Lines of Evidence obtained in this Laboratory bearing on the 



Solvate Theory of Solution ". 189 



How the present Solvate Theory of Solution differs from the older Hydrate Theory . . 190 



Significance of the Solvate Theory of Solution 192 



The Solvate Theory and the Theory of Electrolytic Dissociation 193 



Does the Solvate Theory help to explain any of the Apparent Exceptions to the 



Theory of Electrolytic Dissociation? 194 



Does the Solvate Theory aid us in Explaining the Facts of Chemistry in General 



and Physical Chemistry in Particular? 196 



Why is the Nature of Solutions of such Vital Importance not only for Chemistry 



but for Science in General? 197 



Bibliography 199 



Papers 199 



Monographs 202 



