846 REPORTS ON THE STATE OF SCIENCE.—1912. Vil. 
Bancroft ® discussed the question of the identity of fusion and solu- 
bility curves, and adduced evidence in support of his contention that 
they are not to be considered as identical. 
1897 Storltenbecker 2*, continued his studies of mixed hydrated 
’ erystals,* and concluded that it is not permissible to regard the 
isolation of any particularly stable hydrate as connoting the existence of 
the solute solely in that state of hydration: other less stable hydrates 
must be recognised as being present in solution. Other views in favour 
of union taking place between solvent and solute are to be found in a 
publication by Talmadge,*? which deals with the solubility of solids in 
vapours. 
McIntosh ** studied the solubility of mercuric chloride, it having been 
observed previously that the solubility graph exhibits a break at a tem- 
perature which is different with different solvents. It was pointed out 
that this should not be the case if the change of direction of the curve 
is due to a change from one modification of mercuric chloride to another. 
The author found that from a solution in methylic alcohol a compound 
HgCl,,CH,OH crystallises out below 35° C., and he considers it 
probable that the salt forms similar compounds with other solvents. A 
further publication ** by the same author is devoted to a general discus- 
sion of the relation between solubility and freezing-point. 
The problems presented by the dissolution of an electrolyte in a solu- 
tion of another electrolyte—both of which give an ‘ion’ in common 
when in solution—were discussed by Hoitsema*° from the standpoint 
of the electrolytic dissociation hypothesis. He concluded that unless 
interaction occurs between the two substances the concentration of the 
one must be lowered by the addition of the other, but that it cannot 
sink below the value for the non-dissociated part of the salt. 
Fock ** brought forward results of an investigation of the equili- 
brium obtaining between saturated solutions of a number of pairs of iso- 
morphous salts and showed that Nernst’s law of solubility is incorrect, 
saturation being dependent upon both dissociated and undissociated salt. 
In place of Nernst’s law that the molecular concentration of the un- 
dissociated portion is constant, it was suggested that the sum of the 
concentration of the undissociated and the square of the concentration 
of the ‘ions ’ is constant. 
The soundness of Nernst’s law was further contested by Fock.‘* 
The equation given by Jahn} representing the absorption of gases by 
solutions of electrolytes was subjected to exhaustive tests and confirmed 
by Roth.?® 
Noyes and Whitney 2" regarded solubility as a diffusion phenome- 
non. They measured the rate of dissolution in water of benzoic acid 
1898 and of lead chloride when in stick form, and concluded *° that the 
“~" yate at which a solid substance dissolves in its own solution is 
proportional to the difference between the concentration of that solution 
and the concentration of the saturated solution. Noyes and his colla- 
borators *°» ®* gave considerable attention to the verification of the 
theory of solubility influence as deduced from the electrolytic dissocia- 
* Vide Part I. R. 238. + Vide Part I. R. 240. 
