WORK OF E. G. MAHIN. 



It has been shown that water hydrates salts in more concentrated solutions, and 

 that this hydration increases with the dilution, as we would expect from the mass 

 action of the solvent. If in water these salts are solvated, it is evident from the 

 above facts that in methyl alcohol there is a larger mass of the solvent in combina- 

 tion with the ion. This does not necessarily indicate that in the latter case there 

 are more molecules of the solvent in combination with the ion. There may be the 

 same number, or even less, in combination, but the molecules of methyl alcohol being 

 so much heavier might cause the difference in conductivity. In ethyl alcohol also 

 there is a larger molecular mass than in water or in methyl alcohol, but here, again, 

 the difference between the ratios may be due to the heavier molecules of ethyl alcohol. 



It is evident that this factor of solvation at complete dissociation plays a role in 

 our present method for calculating dissociation by means of the conductivity of the 

 solution. Here we employ the equation a=fx v //jL rx . In the above discussion /*, 

 is shown not to be a true function of the actual number of ions present, but is smaller 

 than it ought to be in consideration alone of the number of ions present. Further- 

 more, it has been shown that there is solvation in more concentrated solutions also ; 

 hence, n c is not a function only of the number of ions present in the solution in ques- 

 tion. The deviations of the values of fx v and fx x from the true values are probably 

 of the same order of magnitude, if not very nearly equal, so that the validity of the 

 equation in calculating conductivity is probably not seriously affected. 



FACTS ESTABLISHED.. 



We have measured the conductivities of very dilute solutions of a number of salts 

 in methyl alcohol and ethyl alcohol. 



In most cases the values of fi x were found. These values bear a definite relation 

 to one another. 



It was found that the ratio of the value of /z M for a certain salt in one solvent 

 and the value of /**> for the same salt in another solvent, is nearly constant for salts 

 which are solvated to approximately the same extent. 



In cases where one salt is solvated very much more than another, the value of \x^ 

 is generally less for the more solvated salt. 



We have compared the ratios of //*, for certain salts in two different solvents, with 

 the ratios of the fluidities of these solvents. In all cases the former ratios show a 

 departure from the latter, the value of /*, in the solvent which has the greater 

 molecular mass always being less than we would expect from the ratio of the fluid- 

 ities alone of the two solvents. Those salts which are known to be solvated to the 

 greatest extent show the greatest difference between these ratios. 



Ill 



