REPORT OF EXECUTIVE COMMITTEE. 107 



three times normal to a few hundredths normal, have been employed 

 and the molecular lowering of the freezing-point of water produced 

 by them has been determined. The refractivities, densities, and 

 conductivities of the above solutions have also been measured. In 

 all, more than a thousand solutions have been brought within the 

 range of this investigation. The results all point to the correctness 

 of the theory advanced some three years ago by Dr. Jones, that in 

 concentrated solutions of electrolytes there is combination between 

 the dissolved substance and the solvent. There are hydrates formed. 

 A general relation was established between the amount of water 

 of crystallization of electrolytes and the magnitude of the freezing- 

 point lowering produced b}' them. The two were shown to be 

 approximately proportional to one another. This is a necessary 

 consequence of the theory of hydration in concentrated solutions 

 and a beautiful confirmation of it. Those substances that crystallize 

 with the largest amounts of water of crystallization would be the 

 substances that in solution would hold the largest amounts of water 

 in combination, and this would manifest itself by abnormally great 

 freezing-point depression ; and such is the fact. An enormous field 

 of work is thus opened up, which will be pushed forward as rapidly- 

 as possible. 



W. L. Miller, University of Toronto, Toronto, Canada. Grant 

 No. 155. For the study of electric migrations 171 sohitio7is of weak 

 acids. $500- 



Professor Miller submitted an abstract of a long report by Mr. 

 W. J. McBain, who conducted the experiments on the electric 

 migrations in solutions of weak acids. 



Abstract of Report. — Mr. McBain has determined the transport in 

 half-, tenth-, and fiftieth-normal acetic acid, and in tenth-normal 

 propionic acid, and finds about 0.3 as the transport number for the 

 acet-ion and the propion-ion in place of o.i , as called for by the The- 

 ory of Solutions. Experiments with solutions in which acetic acid 

 was mixed with sodium acetate or sulphuric acid show that the " un- 

 dissociated " acetic acid does not move during the electrolyses; and 

 this conclusion is confirmed by experiments with solutions of cad- 

 mium sulphate in mixtures of acetone and water, where the acetone 

 was found to remain practicall}^ stationary during the electrolyses. 

 An attempt to reconcile these results with the theory by assuming 

 " h\-drated " ions led to the conclusion that the hydrogen ion mu.st 

 be hydrated (at least 90 H.^O for each H) in decinormal acid, and 



