46 



ABSORPTION OF LIGHT BY WATER CHANGED 



We selected for these substances with little or no hydrating power, salts 

 of potassium and ammonium. The potassium salts studied were the chlo- 

 ride and nitrate. Ammonium chloride and nitrate were also investigated. 

 For the salts with large hydrating power, calcium chloride, magnesium 

 chloride, and aluminium sulphate were used. These salts were shown, from 

 our earlier work, to be among the most strongly hydrated substances with 

 which we are familiar. Two depths of layer of each solution of every 



Table 6. 



