ON THE THEORY OF SOLUTION. SUT 
the case of calcium chloride, calcium nitrate, and alcohol respectively, 
and these, though they are smaller than in the case of sulphuric acid, are 
far too great to be attributed to experimental error; and the fact that they 
occur sometimes in one direction, sometimes in the other, precludes the 
possibility of attributing them to any constant source of error in the 
instruments used or in the method adopted. 
Remembering that these are the only data which we have at present 
respecting very weak solutions, we must conclude that the hypothesis 
that such solutions exhibit perfect regularity is wholly untenable. 
It is important to observe that when we pass on to stronger solutions, 
where the actual magnitude of the deviations becomes so great that they 
would be revealed by the roughest experiments—deviations of even 70°— 
and where, I believe, even the supporters of the osmotic pressure theory 
would not hesitate to attribute them to the disturbing influence of 
hydrates; these deviations occur in precisely the same irregular manner 
as they do in the case of weak solutions, and must evidently be attributed 
Fig. 2.—Freezing points of sulphuric acid and alcohol solutions. 
Mols. (CglTg0)2 to 100H,0. 
6 8 ; 
Mols. H.S0, to 100H,0. 
to the same cause. The results with alcohol given in fig. 2 illustrate these 
irregularities in a very striking manner. It must also be pointed out that, 
apart from the irregularity of these deviations, their very direction shows 
that they cannot be attributed to the dissolved particles being brought 
within the sphere of each other’s attraction, as in the case of the deviation 
of gases from Boyle’s law, for the result of this would be that their attrac- 
tion on the particles of the solvent would be diminished and the freezing 
point of this latter would consequently be lowered to an abnormally small 
extent, whereas precisely the reverse is the case in nearly every instance 
at present investigated: the freezing points of strong solutions are ab- 
normally low. Various instances of this will be found in the ‘Phil. 
Mag.’ 1890, vol. i. p. 500, that of sulphuric acid, which is illustrated here in 
fig. 2, being by no means the most prominent; while the case of alcohol, 
now for the first time displayed (fig. 2), is the only exception which 
has, so far, been met with, and that is an exception only in the case of 
excessively strong solutions. 
