1910. | with the State of Aggregation of Matter. 107 
V. The adsorption capacity of salts can be correlated with certain physical 
properties of their solutions. The higher the surface tension and the 
greater the viscosity, the smaller the adsorption and the disaggregating 
capacity. These conclusions have been verified experimentally ; the influence 
of these physical properties on the action of salts can, however, be deduced 
from theoretical considerations, the influence of surface tension from the 
general study of adsorption phenomena, and that of viscosity by an extension 
of Nernst’s generalisations on the rate of action in heterogeneous systems. 
VI. The action of salts on systems other than those containing protein 
colloids is similar. Investigations have been made of the action of salts on 
the critical solution temperature of phenol and water, and on the solubility of 
the following crystalline substances :—d.l. leucine, d./. phenylalanine, caffeine, 
benzamide, and p. toluidine. 
VII. The critical solution temperature of phenol and salt solutions is a 
function of the surface tension of the latter. 
VIII. The solubility of crystalline substances in salt solutions depends on 
the surface tensions and viscosities of the latter. In these systems the chief 
seat of action is at the limiting surfaces of the phases. Equilibrium may be 
regarded as established at the surfaces when dis-aggregation and re-ageregation 
are equal. The concentration at which this condition will exist is a function 
of the surface tension. The viscosity of the salt solution will affect the rate 
at which diffusion from the limiting surface takes place, and consequently the 
point at which equilibrium conditions are attained. 
IX. The observations of previous observers as to the greater solubility of 
serum globulin in salts of the polyvalent metals, as compared with those of 
the univalent metals is confirmed. Similar phenomena were noticed in the 
case of leucine and phenylalanine. These phenomena were less marked in the 
case of edestin, and of caffeine and benzamide, and were entirely absent in 
the case of p. toluidine. It is suggested that they are due to the direct 
attraction of the salt molecules to the surfaces of the solid or disperse phases, 
possibly owing to the different electrical charges. This would alter the 
relative tensions of solutions at these surfaces as compared with the measure- 
ments of their surface tension against air. The serum globulin is also more 
soluble in salts of polybasic acids than in salts of monobasic acids. In the 
case of edestin and of the amino acids, these substances are perhaps very 
slightly more soluble in salts of dibasic acids than in those of monobasic acid 
of similar physical properties.* In other cases these phenomena were absent. 
X. No evidence of the direct influence of the state of hydration of 
* An exact correlation of the solubility capacity with more than one physical constant 
is not possible with the data available. 
