A Theory of Solutions. 163 
for granted that only single molecules of the solvent are able 
to join with the ions or the single molecules of a non- 
electrolyte, and finally reflecting that the process of dissocia- 
tion of the dissolved body is connected with the dissociation 
of the complex molecules of the solvent, we understand why 
one ion or one molecule respectively is united with one mole- 
cule of the solvent. 
Thus the osmotic laws are the result of these considerations 
founded on empirical investigations. 
We suppose, like Arrhenius, that the molecules of a 
dissolved electrolyte dissociate, but there is a great difference 
between our views. We believe thai even in the most diluted 
solutions in one moment every dissociation for instance 
of a molecule NaCl is followed by an association of Na and 
Cl. There will be a chain of dissociations and associations, 
and not only a series of dissociations. 
Arrhenius’s coefficient of dissociation is given by the relation 
of the number of particles of the electrolyte which are joined 
with 2, 3, &c. single molecules of the solvent and the number 
of tts particles which are joined with one molecule of the solvent 
or none. We think it is not improbable that even at the 
moment when the ions are joined every ion takes hold of its 
particle of the solvent, excepting in stronger solutions 
where it will occur that 2, 3 ions or one molecule of them 
have only one single molecule of the solvent at their disposal. 
In my former publications I have shown that the phenomena 
of contraction which arise by dissolving different bodies in 
water support these ideas. The contraction of one gramme- 
molecule of the most different nonelectrolytes (non-associated) 
in water seems to be nearly the same, the contraction pro- 
duced by a gramme-molecule of a binary electrolyte reaches 
nearly double the amount, &. But further investigations 
are desirable in this direction. 
We think that we can explain by our theory many pheno- 
mena better than by that of Arrhenius. Take the case of the 
catalysis of a solution of sugar by acids. Only the single 
molecules of water are ‘‘ active,” or able to invert the mole- 
cules of sugar, and the number of these active molecules 
increases with rise of temperature, and especially in the 
presence of an acid which according to its intensity increases 
the number of the active molecules of the solvent. 
But in the first place we shali try whether we cannot 
succeed in deriving the known formula of Rudolphi-van’t 
rs 
Hoff * me =K with the help of our theory, for every 
* Rudolphi, Zettschr. Physik. Chem. xvii. p. 385 (1895), and van’t 
Hoff, cbed. xviii. p. 300 (1895). 
M 2 
