506 SECTIONAL ADDRESSES. 
prominence. By its dielectric constant the solvent determines the magni- 
tude of the interionic forces. By its power of solvating the ions it exerts 
a decisive influence on the extent to which they form ion pairs or 
undissociated molecules. And lastly by its viscosity, as well as by the 
extent of solvation, it determines the mobilities of the ions. The task 
of the immediate future is to discover the precise nature and extent of 
the solvent atmosphere around the ions which exerts such an important 
influence on their properties. And so to-day we find ourselves face to 
face with a new phase of the problem, and we can repeat with Faraday 
the words near the close of his great paper on electrolysis: ‘ Indeed, it is 
the great beauty of our science, CHEMISTRY, that advancement in it, 
whether in a degree great or small, instead of exhausting the subjects of 
research, opens the doors to further and more abundant knowledge, 
overflowing with beauty and utility, to those who will be at the easy 
personal pains of undertaking its experimental investigation.’ 
