PREFACE. 



The investigations discussed in this monograph might seem, at first 

 sight, to deal with a variety of subjects, some of which have no very close 

 relation to the others; but nearly all of these lines of work were sug- 

 gested by the solvate theory of solution as proposed here about fifteen 

 years ago, and have been carried out with the specific purpose of 

 ascertaining their bearing on this theory. 



Dr. Davis studied the viscosities of solutions of cesium salts in mixed 

 solvents, and in mixtures of the associated liquids water, formic acid, 

 and acetic acid, in its relation to the theory of viscosity proposed by 

 Jones several years ago. 



Dr. Davis and Dr. Putnam investigated the dissociating power of 

 formamid as a solvent, in connection with its bearing on a theory of the 

 relation between the dissociating power of a solvent and other physical 

 properties of that liquid; namely, its dielectric constant and its own 

 association. 



Dr. Shaeffer and Dr. Paulus used the new spectroscope constructed 

 to study the nature of "solvent bands," to determine the constants of 

 indicators a quantity absolutely essential to the scientific use of these 

 substances in quantitative analysis. 



This work was extended by Dr. Paulus and Mr. Hutchinson to the 

 indicator, corallin. 



Having found such a marked difference between the physical behavior 

 towards light of free and of combined water, Dr. J. E. L. Holmes took 

 up the study of a reaction effected by the ions of water the saponifica- 

 tion of an ester to see whether any difference in the chemical activity 

 of free and of combined water could be detected. It seems that such 

 a difference exists, combined water having apparently greater chemical 

 activity than free water. 



This work was extended by Mr. Connolly to another reaction which 

 proceeds much more rapidly the Irydration of acetic anhydride. 

 This work has not yet been extended sufficiently to justify any final 

 conclusion. 



The work begun two years ago on the conductivities of organic acids 

 in ethyl alcohol, was greatly extended by Dr. Lloyd and Mr. Wiesel, 

 comprising the study of nearly forty of the more common organic acids 

 in this solvent. The aim of this work is to arrive at a knowledge of the 

 dissociation of these substances by alcohol, and the degree of solvation 

 of these compounds in alcohol. 



Dr. Watkins has extended work begun in this laboratory about a 

 dozen years ago on the conductivity and dissociation of salts by water. 

 He has studied a number of the less common salts, and has obtained 

 very accurate results which, in general, confirm the conclusions drawn 

 from our earlier work in this field. 



in 



