USEFUL ALGAE — CHASE 437 



The reason for this increased interest in kelp was that the potash 

 which the farmers of the United States used for fertilizer on their 

 soil came almost exclusively from the mines in the Stassfurt region 

 in Germany. This Stassfurt region was a former sea bottom where 

 various soluble potassium salts accumulated in a solid form by the 

 concentration and final drying-out of the sea water. Up to the 

 beginning of World War I, the Stassfurt mines were the one im- 

 portant source of the potash supply of the world. The German 

 conservation laws limited the amount of potash salts that were mined 

 each year, also the amount of the annual product which was sold 

 outside of Germany. The farmers of the United States were prac- 

 tically dependent upon Germany when they began to use artificial 

 fertilizers. Previous to World War I, the United States was im- 

 porting from Germany potash valued at 12 million dollars or more 

 annually. For 3 or 4 years before the war broke out, there was disa- 

 greement between the American importers and the German Kali 

 Syndikat over the raising of the price of potash and the threatened 

 curtailment of the amount allowed to be shipped to the United States. 

 This incident, together with the fact that the United States had 

 undeveloped supplies of potash of its own, led the United States Con- 

 gress to instruct the Bureau of Soils of the Department of Agri- 

 culture to make an investigation of the possibilities of developing 

 within the boundaries of the United States a potash supply that 

 would meet the domestic requirements and make the United States 

 independent of any foreign nation in this regard. 



The investigation included a search for potash in the alkaline 

 basins of the arid West where the surface alkali includes potash salts 

 and also in the feldspar and granite rocks which contain potassium in 

 immense quantities but in the form of insoluble compounds. The 

 Washington scientists finally took into consideration the long-estab- 

 lished use of seaweeds as fertilizers for the soil and began a scientific 

 investigation of the extensive groves of kelp on the Pacific coast 

 to determine the amount of potassium salts contained in them. 



Enormous kelp beds extend along most of the Pacific coast from 

 Mexico to Alaska. The problem was to devise an economical means 

 for harvesting the kelp and then converting it into fertilizer, po- 

 tassium salts, and other valuable products. 



About half the area of the kelp beds surveyed are in the vicinity 

 of San Diego, Calif. Approximately two-thirds of the kelp that 

 was cut grew near San Diego, and was used in industrial plants near 

 that city. The amount of potash obtained from the kelp during 

 Wold War I was slight as compared to the amount previously im- 

 ported from Germany, but the kelp-potash industry was second only 

 to the industry obtaining potash from natural mines. During 1917, 



