JACQUES LOEB 



723 



Although in these experiments water not only diffuses from the collodion 

 bag into the beaker but electrolyte diffuses also from the beaker into 

 the collodion bag, we shall show in Chapter IV that the differences in 

 our curves are not due to differences in the rate of the diffusion of the 

 electrolytes but to differences in the rate of diffusion of water from 

 the collodion bag into the beaker. Equilibrium will be reached when 

 the solutions inside and outside of the beaker are identical, but our 

 experiments deal only with the initial rate of diffusion of water lead- 

 ing to this condition of equihbrium and not with the condition of 

 equilibrium itself. 



110 



100 



90 

 H 80 

 ^ 70 

 "i 60 

 15 50 

 c 40 

 - 30 



0) 



I 20 

 10 



5 



10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

 Time in. minutes 



Fig. 2. Curves of fall of level of water when diffusing against solutions of m/64 

 cane sugar, m/128 CaCU, m/128 NaCi, and m/192 Na2S04, showing the opposite 

 effect of increase in valency of anion and cation on the rate of diffusion of 

 water. 



Fig. 2 illustrates the influence of solutions of three neutral salts, 

 NaCl, CaCl2, and Na2S04, on the rate of diffusion of distilled water 

 from the bag into the beaker containing the salt solution. The water 

 in the bag had an initial pressure head of about 110 mm. of water. 

 Water diffuses more rapidly against a m/128 solution of NaCl and 

 still more rapidly against a m/192 Na2S04 solution than against a 

 m/64 solution of cane sugar. This difference cannot be ascribed to 

 a difference in osmotic pressure of the three solutions since their 



