2l8 REPORTS ON INVESTIGATIONS AND PROJECTS. 



The writer has been assisted, in the investigations here reported, by Drs. 

 W. W. Holland and E. G. Zies and Messrs. W. M. Clark and C. N. Myers. 



Noyes, Arthur A., Massachusetts Institute of Technology, Boston, Massa- 

 chusetts. Grant No. 625. Researches upon the physical properties of 

 aqueous solutions in relation to the ionic theory. (For previous reports 

 see Year Books Nos. 2-8.) $3,000 



During the past year the several lines of investigation described in pre- 

 vious reports have been continued. It may be recalled that the general object 

 of these researches is to develop the Ionic Theory of Solutions, or at any rate 

 the empirical principles expressing the phenomena involved, in such a way 

 as to account for the unexplained anomalies which aqueous solutions of 

 strong electrolytes exhibit. 



The special subjects that have been under investigation are: (1) the trans- 

 ference numbers of tri-ionic salts (especially of thallous sulphate and lead 

 nitrate), by Dr. K. G. Falk, with the purpose of determining whether inter- 

 mediate ions, such as T1S0 4 _ or PbN0 3 + , exist in considerable quantity ; 

 (2) the electrical conductivity of mixtures of salts, by Mr. A. C. Melcher, 

 Dr. W. C. Bray, and Mr. F. L. Hunt, with the purpose of establishing the 

 general law governing the ionization of salts; and (3) the solubility of salts 

 in the presence of other salts, by Dr. W. D. Harkins, with the purpose of 

 determining empirically the form of the law of solubility-effect which must 

 be substituted for the inexact mass-action form of that law. 



A systematic, critical review of existing data bearing on the properties of 

 solutions in their relations to the Ionic Theory has also been begun with the 

 aid of Dr. K. G. Falk; and a first paper of the series, dealing with freezing- 

 point lowerings, has already been published (Jour. Amer. Chem. Soc, vol. 

 32, pp. 1011-1030). 



During the past year articles describing the work previously completed 

 and reported on in earlier volumes of this Year Book have also been pub- 

 lished as follows : 



(1) The solubility of silver chloride, barium sulphate, and calcium sulphate at 



high temperatures, by A. C. Melcher (Jour. Amer. Chem. Soc, vol. 32, pp. 

 50-66). 



(2) The hydrolysis of ammonium acetate and the ionization of water at high 



temperatures, by A. A. Noyes, Yogoro Kato, and R. B. Sosman (Jour. 

 Amer. Chem. Soc, vol. 32, pp. 159-178). 



(3) The ionization of salts in mixtures with no common ion, by M. S. Sherrill 



(Jour. Amer. Chem. Soc, vol. 32, pp. 741-748). 



