AKT 8.— S. NAKAMURA. 



In such cases, if we follow Fick's theory, n satisfies the differential 



equation (2), and there is no need of reducing n to u in calculating /.•. 



I examined the relation for ZnS0 4 by Abbe's refractometer by Zeiss 



and found that it was not exactly linear. The result is given in 



Table IT. In such cases, one must reduce n to u for finding the 



value of k. 



Table II. ZuS0 4 -Solution. 



A solution of the equation (2) is 



u = e ~~'"~ !: '(A sin mx + B cos mx). 



vi being a constant. In my arrangement, the diffusion vessel is 



rectangular and closed, its height being equal to H, and at its top and 



bottom - — is equal to zero. Takiff the origin of coordinate at the 

 Ix l &o 



bottom of the vessel, the boundary conditions are, therefore, 



III 



at x=o, =o 



which grive us at once 



