PREFACE. 



The several chapters comprising this report represent the various 

 lines of investigation pursued under the direction of the late Professor 

 Harry C. Jones during the year 1915-16 and in the case of the work 

 of Davis and Johnson continued in 1916-17. Although somewhat 

 diverse in nature, they all bear directly or indirectly upon the concep- 

 tions of solution in general and of solvation in particular which have 

 been developed in this laboratory during the past fifteen years. 



Dr. Hulburt and Dr. Hutchinson have measured the absorption 

 coefficient of solutions of a number of salts in differents solvents for 

 monochromatic radiation. They have calculated from this the molec- 

 ular absorption coefficient for such solutions and have made a careful 

 comparative study of the molecular absorption-concentration curves. 



The investigation of formamid as a solvent, begun by Davis and 

 Putnam, has been continued by Dr. Davis and Dr. Johnson. In addi- 

 tion to observing the behavior of a series of nitrates and formates in 

 this solvent, they have determined the conductivity and viscosity of 

 solutions of a number of salts of the organic acids and have also studied 

 several representative salts in mixtures of formamid with ethyl alcohol. 



Dr. Davis has also made some observations on the viscosity of 

 caesium salts in binary mixtures of glycerol and of formamid with water. 



Dr. Lloyd and Dr. Pardee have extended the work in absolute ethyl 

 alcohol to include a study of the conductivities of the sodium salts of a 

 number of organic acids and have succeeded in applying the formula of 

 Noyes and Johnston for aqueous solutions to the calculation of disso- 

 ciation in this solvent. 



Dr. Ordeman has completed his study of the relative dissociating 

 power of free and combined water reported on in part in Publication 

 No. 230 of the Carnegie Institution of Washington. 



Dr. Connolly has investigated the different chemical activity of free 

 and semi-combined water, using as an illustration the effect of neutral 

 salts in the hydrolysis of acetic anhydride. A preliminary paper on 

 this work is also to be found in Publication No. 230. 



The results of all these investigations, which have been carried out 

 with aid of generous grants from the Carnegie Institution of Washing- 

 ton, are recorded in this volume. The writer also wishes to thank 

 that Institution for making possible the completion of certain investi- 

 gations left unfinished by the untimely death of Professor Jones, and 

 the Chemical Staff of this University for their courtesy in extending 

 the facilities of the laboratory. 



PAUL B. DAVIS. 



THE JOHNS HOPKINS UNIVERSITY, June 1917. 



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