TABLE 160. 

 DIFFUSION OF LIQUIDS AND SOLUTIONS OF SALTS INTO WATER. 



The coefficient of diffusion as tabulated below is the constant which multiplied by the rate of change of concentration 

 in any direction gives the rate of flow in that direction in C. G. S. units. Suppose two liquids diffusing into each 

 other, and let p be the quantity of one of them per unit volume at a point A , and p' the quantity per unit volume at 

 an adjacent point S, and x the distance from A to B. Then if jr is small the rate of flow from A towards B is 

 equal to k (p P')/JC, where k is the coefficient of diffusion. Similarly for solutions of salts diffusing into the sol- 

 vent medium, p and p' being taken as the quantities of the salt per unit volume. The results indicate that k depends 

 on ihe absolute density of the solution. Under c will be found the concentration in grammes of the salt per loo cu. 

 cms. of the solution ; under the number of gramme-molecules of water per gramme-molecule of salt or of acid or 

 other liquid. 



* " Z. fiir Phys. Chem." 2, p. 390. 

 SMITHSONIAN TABLES. 



t " Wien. Akad. Ber." vol. 79, 2. Abth. p. 603. 



147 



