426 On Globulins. 



compared with solutions of globulin by salts which resemble them in 

 containing large molecules, but differ in the total absence of electric layers 

 from these molecules. 



Solutions of globulins in salts introduce us to an entirely different aspect 

 of colloidal solution. Here, again, the proteid contributes nothing to the 

 osmotic pressure,* and, therefore, must be withdrawn from true molecular 

 solution ; but as all ionic interaction is suppressed by the large excess of 

 salt present, there are no double electric layers formed, and in their absence 

 viscosity is low and stable equilibrium conditions are rapidly reached. 



The origin of the mechanical stability of this system, the nature of the 

 influence which maintains the even dispersion of the proteid throughout 

 the fluid, is difficult to explain, since any factor to which we can appeal 

 seems also to involve the exertion of a finite osmotic pressure by the proteid. 



If the distribution of the energy be considered, we arrive at the 

 following : — Let the state of thorough mixing of the components be 

 established, and let a movement under the influence of any mechanical force 

 take place, so that the proteid becomes more concentrated in some region. 

 In this region, owing to the concentration of the colloidal salt, the degree of 

 hydrolysis and of ionisation will be diminished, and the available energy 

 thereby increased. 



The equation of hydrolysis which Arrheniusf gives shows that hydrolysis 

 and ionisation diminish faster than concentration increases ; therefore, with 

 unequal distribution of the proteid the gain in available energy (E — t<£) 

 will be greater in the regions of higher concentration than the loss in the 

 regions of diminished concentration. The system as a whole, therefore, 

 would gain in available energy, and the change from uniform distribution to 

 unequal distribution could not take place unless work were done on the 

 system. 



* Waymouth Keid, loc. cit. 



t ' Zeits. f. Physik. Chem., 5 vol. 5, p. 16, 1890. 



