10 L. W. Öholm. (LVIII 



If we regard for instance \-n caiie sugar, its dif fusion 

 coefficient rises from the value of 0,334 when the solvent is 

 a %^-n KCl-, to 0,362 if the solvent is a 2-n KCl solution. 

 Using corresponding LiCl solutions, the said coefficient 

 diminishes from 0,324 to 0,270, In each case the change 

 seems to be linear and the both lines cross each other when 

 the salt concentration becomes zero in a point 0,328, which 

 answers to the value of the dif fusion of a I-/7 sugar solution 

 in pure water. Experimentally we have before obtained 0,325. 



The same appears in all other cases: the points of inter- 

 •section of the KCl and LiCl lines form the values of the 

 diffusion coefficients of the sugar in pure water. How well 

 these values agree with figures before experimentally obtai- 

 ned, appears from the following table: 



2-n l-n 0,25-77 0,1-n 



Cane sugar 0,275 0,325 0,369 0,38o exper. 



0,279 0,328 0,370 0,380 CXtra pol. 



We arrive to a similar result by regarding the values for 

 the diffusion of the glycerine in water, in potassium chloride 

 and lithium chloride solutions. The extrapolation to pure 

 Avater certainly here becomes more difficult since we are 

 dealing with curves, but even in this case the agreement is 

 good, as appears from the following figures: 



5-/7 2-/7 1-/7 0,25-/7 0,1-/7 



Glycerine — 0,645 0,658 0, 705 0,720 exper. 



0,590 0,645 0,662 0,700-0,710 0,715 CXtra pol. 



It is evident that the contrary influence of the two 

 ^lectrolytes upon the diffusion of the non-electrolytes in the 

 first place depends on the changes in the viscosity of the 

 solutions, caused by them. A substance, for instance LiCl, 

 added to water, generally increases its viscosity, but certain 

 substances, for instance KCl, diminishes the same. The 

 -same will take place if in the water another substance, for 

 instance sugar, has before been dissolved. The viscosity of 



