f 
0 
! 
(| 
[le 
} 
Part IT. On Aqueous Solutions. 87 
concentration 2:0 normal. At the low temperatures a dissociation 
of the complex particles, formed of a salt molecule or ion and its 
associated water molecules, takes place. At the higher tempera- 
tures the gradual recovery of the curve is probably due to the 
‘formation of a new type of complex—a solution of ferric oxy- 
chloride or ferric hydroxide in the excess of ferric chloride. All 
the four solutions had sufficiently high concentrations to prevent 
the formation of a precipitate at the higher temperatures. 
| It is not intended that this part of the investigation shall 
establish a quantitative relation between the complexity of mole- 
cular structure and the temperature. Indeed, it has been shown 
‘by Chéneveau* that the viscosity and refractivity methods used 
for the determination of molecular complexity in the liquid state 
do not give identical results, although each mdicates the presence 
of groups composed of solute and solvent particles. The present 
viscosity measurements have been made with the object of verifying 
the prediction of the earlier part of the paper, that the high value 
of the constant B, in the representation of the magnetic suscepti- 
bility of a 2:23 normal solution of ferric chloride as a function of 
the temperature, may be connected with an abnormal variation 
of the viscosity of the solution. Since in a solution there are at 
least several types of particles, the complexity of some changing 
with the temperature, it seems impossible in the present state of 
our knowledge of the viscosity of liquids to derive from it quanti- 
tative information as to the nature of the relation between 
molecular complexity and temperature. For this purpose use has 
been made of the researches of van Laar who has considered the 
general theory of association in the solid and liquid states. 
(5) The Lowering of the Freezing Point of Solutions. 
There is another interesting point in connection with the value 
of the constant B for a 2:0 normal solution of ferric chloride. It 
has been shown that such a solution shows an abnormal value of 
the molecular lowering of the freezing point}. Since the latter 
quantity is directly connected with the constitution of the groups 
of solvent and solute particles, the molecular lowering being 
smaller the greater the complexity of the groups of particles, the 
abnormally low value of the molecular lowering produced by a 2°0 
normal solution of ferric chloride indicates that the groups of 
particles are abnormally complex at this concentration. - These 
* Comptes Rendus, t. cuv., No. 2, 1912, p. 154. 
+ Jones and Getman, Zeits. f. Phys. Chem., Xurx. 1904, pp. 426—433. 
Note: The curve in fig. 7 of the research of Jones and Getman, relating to 
ferric chloride solutions, is drawn inaccurately. Prof. H. C. Jones has kindly 
informed me that the tabulated data are correct and an irregularity still exists for 
a concentration 2:0 normal, when the error of representation has been allowed for. 
