58 THE WEALTH OF THE SEA 



During the World War, when potassium salts 

 were so scarce, a process of recovering potassium 

 chloride from bittern was developed in California. 

 At the close of the war, when the price of potash 

 dropped, this process was discontinued. 



The discard of the bittern from the salt works 

 represents a tremendous waste. A single large solar 

 salt works near San Diego, California, produces 

 40,000 tons of salt each year. Such a plant throws 

 away 1120 tons of potassium chloride, 10,920 tons of 

 magnesium chloride, 6400 tons of magnesium sul- 

 phate, and 96 tons of bromine. At the present price 

 of bromine (40 cents per pound), this substance 

 alone would be worth $76,800. When one stops to 

 think of the tremendous amount of these salts thrown 

 away by the thousands of salines throughout the 

 world, it is difficult to conceive of the total waste. 



At one time the Stassfurt, Germany, salt mines 

 were considered to be low-grade mines because of the 

 difficulty of obtaining pure common salt from them. 

 Afler the chemists had studied the utilization of 

 potassium salts, they found that the impurities in 

 the salt, which had given so much trouble, were more 

 valuable than the salt itself. Sometime, in the same 

 way, chemists may be able to separate from the bit- 

 tern chemicals of greater value than the salt ob- 

 tained from the original sea-water. 



