TN THE PRESENCE OF STRONGLY HYDRATED SALTS. 



49 



The depth of layer oi' the solutions given in tabic 8 was the difference 

 between 21 mm. and 1 mm., i. e., 20 mm. The depth of water used in every 

 case was the same as that of the water in the solution. 



In table 9 the depth of layer used was the difference between 11 and 1 mm., 

 i. e., 10 mm. The object of using the smaller depth of the solution was to 

 bring out more clearly in the case of hydrated salts the second water-band. 



When salts w r hich are strongly hydrated in aqueous solution are not very 

 concentrated, the difference between the transparency of the salt solution 

 and that of w T ater of the same depth of layer as the water in the solution is 

 not so pronounced. This is what would be expected, since the total amount 

 of water combined with the dissolved salt increases with the concentration of 

 the solution. The data given in table 10 bring out this fact. 



Table 9. 



