Table 1 60. 

 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 liquitls diffusnig uito each 

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

 an adj.icent pi.int B, and .r the distance from A to />. Then if .r is small the rate of How from A towards /i is 

 equal to A-ip — p')/.r, where /C- is the coelTicient of diffusion. Similarly for solutions of salts ditfusuiK nito the sol- 

 vent medium, p and p' bcinj; taken as the ciuantities of the salt per unit volume. The results indicate that A- depends 

 on tlie absolute density of the solution. Under c will be found the concentration in percentage of ' normal solu- 

 tion ■' of the salt; under « the number of grammes of water per gramme of salt or of acid or other liquid. 



• " Chem. Ber." vol. 15, p. 78S. 

 Smithsonian Tables. 



t "Wien. Akad. Ber.'" vol. 7S, 2. Abtli. p. 957- 



147 



