354 



TABLES 347-369.— DIFFFUSION, SOLUBILITY, SURFACE 

 TENSION, AND VAPOR PRESSURE 



TABLE 347.— DIFFUSION OF AN AQUEOUS SOLUTION INTO PURE WATER 



If k is the coefficient of diffusion, dS the amount of the substance which passes in the 

 time dt, at the place x, through q cm 2 of a diffusion cylinder under the influence of a drop 

 of concentration dc/dx, then 



dS = 



-kq -r- dt 

 dx 



k depends on the temperature and the concentration, c gives the gram-molecules per 

 liter. The unit of time is a day. 



SMITHSONIAN PHYSICAL TABLES 



