82 ILLINOIS ACADEMY OF SCIENCE 
ing up on going into solution he ascribed to the collisions due to 
molecular motion in the solution. Fortunately for Clausius, 
at the same time Williamson was working on the subject of 
etherification and came to the same conclusion independently. 
This theory of Clausius dominated chemistry for many years, 
in fact until Arrhenius came forward with the one which is 
familiar to you all. This theory may be stated thus : 
When a substance is dissolved in water and conducts the 
electric current, it is dissociated into ions more or less com- 
pletely, depending on the dilution, and that the degree of this 
dissociation may be calculated from (1) the conductance of 
the solution, (2) the lowering of the freezing point or raising 
of the boiling point, and (3) the osmotic pressure. 
Let us now consider first some of the reasons, in a general 
way, why this theory is favored, after which we will take up 
some of the objections, and then consider some of the very 
recent work. 
THINGS IN FAVOR OF THE THEORY 
1. Many aqueous solutions conduct and many non-aqueous do 
not. 
2. When a current is passed through a solution of an electrolyte 
there is an immediate production of discomposition products. 
3. Many or most electrolytes show too great a lowering of the 
freezing point, raising of the boiling point, and too great an osmotic 
pressure. 
4. All or nearly all strong bases when neutralized by strong 
acids show the same heat of neutralization. 
5. The instantaneous interaction of chemicals when electrolytes 
and the slow or lack of action when they are not. 
6. Some gases, when dissolving in water, do not obey Henry's 
Law. 
7. The hindering of a reaction by adding something that will give 
like ions. 
8. Most substances dissociate more as the dilution is increased. 
9. Faraday's Law. 
OBJECTIONS TO THE THEORY 
1. Non-aqueous solutions do conduct. 
2. In some solutions the conductivity does not increase on dilu- 
tion. 
3. In some the dilution makes the conductivity increase, some in- 
crease then decrease, some decrease, and some decrease then in- 
crease. 
4. There are instantaneous reactions in non-aqueous solutions. 
5. Neutralization of non-aqueous solution does not always give 
the same heat of reaction. 
6. The degree of dissociation as calculated by the three different 
methods do not always agree. 
