GENERAL DISCUSSION OF RESULTS. 207 



ions in the two solutions. Conductivity is a function of the number of the ions and 

 the velocities with which they move. When the numbers are constant we eliminate 

 this factor, and conductivity is then a function of the relative velocities of the ions. 

 The velocity is conditioned by the mass and volume of the ions, and by the fluidity, 

 which is the reciprocal of the viscosity of the solvent. If the masses and volumes 

 of the ions in two different solvents are constant, then ionic velocities in the two 

 solvents should vary as the fluidities of these solvents. The ratio between jjl in 

 the two solvents should be the same as the ratio between the fluidities of these sol- 

 vents. This, however, was found not to be the case. This shows that the mass 

 and probably the volume of the solvated ion must differ in the solutions in the two 

 solvents. The ratio between the values of fx M in two solvents, when compared with 

 the ratio of their fluidities, gives some idea of the relative solvation of the ion in ques- 

 tion in the two solvents. 



RESULTS OBTAINED BY MAHIN. 



A fairly large amount of work had been done in my laboratory on the condition 

 of salts in binary mixtures of certain solvents. The first work by Dr. Mahin had 

 to do with the condition of salts in ternary mixtures of solvents, such as water, 

 methyl alcohol, ethyl alcohol, and acetone. It was, of course, impossible to predict 

 in advance whether any new principles would come to light as the result of the mutual 

 action of three solvents upon one another. The salt used for this work was lithium 

 nitrate. The conductivity of this salt in varying ternary mixtures of the above- 

 named solvents was measured over a wide range in dilution. The viscosities of a 

 number of these mixtures were also determined at and 25, and for various per- 

 centages of acetone, methyl alcohol, and water, of acetone, ethyl alcohol, and water, 

 and for methyl alcohol, ethyl alcohol, and water. 



It would seem, from this preliminary work with ternary mixtures of the various 

 solvents, that the conductivities and viscosities are about what would be expected 

 from the solutions in binary mixtures of these same solvents. Further work is being 

 done in my laboratory on the properties of salts in ternary mixtures of these various 

 solvents. Acetone is an unusual solvent in most of its properties. Substances 

 dissolved in acetone are largely polymerized and, at the same time, some of the mole- 

 cules are broken down into ions. This has led to confusion, in that it has been 

 assumed that solutions in acetone as the solvent do not conduct themselves as solu- 

 tions in other solvents. Jones carefully studied the point raised by Dutoit and 

 Frederick, that certain substances dissolved in acetone have normal molecular 

 weights, and yet show very considerable conductivity. These were found not to 

 have normal molecular weights in acetone at any dilution that could be studied by 

 the boiling-point method. It seemed highly desirable to measure the conductivi- 

 ties of substances dissolved in acetone over as wide a range of dilution as was possible. 

 At very high dilutions the associate molecules should break down into simple 

 molecules, and these then dissociate in the usual way. 



Acetone is, furthermore, a solvent with small viscosity, and the viscosities of 

 mixtures of acetone with the alcohols and with water were determined. The con- 

 ductivities of solutions of salts in these mixtures were also measured at various 



