128 ON THE VISCOSITY OF AQUEOUS SOLUTIONS.—BARNES. 
it should be noted, with the ionization constants obtained for the 
simple solutions), is very satisfactory, especially in the case of 
solutions of potassium chloride and sodium chloride and solu- 
tions of potassium sulphate and sodium sulphate, where the 
differences are all within the limit of experimental error. In the 
case of the stronger solutions of potassium chloride and barium 
chloride and of potassium sulphate and copper sulphate, the 
differences are not within the limit of error; but a close agree- 
ment, as was pointed out in the beginning, could not be 
expected. It will be noticed, however, that the differences in 
these cases diminish and approach the experimental error as 
concentration diminishes. Observations on the viscosity of 
weaker solutions of these salts were not available. 
From these results, therefore, it may be concluded, that the 
viscosity of mixtures of dilute solutions of the salts under con- 
sideration can be predicted, by the aid of the dissociation theory, 
within the limit of experimental error, from data as to the vis- 
cosity and conductivity of the constituent solutions only. 
