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REVIEWS 



Fertilizer Resources of the Unted States* 



A volume issued a few months ago by the U. S. government 

 as Senate Document No. 190, with the title "Fertilizer Resources 

 of the United States," contains much that is of interest to botan- 

 ists and more particularly to students of the plants that grow in 

 the sea, although this fact might not be wholly obvious to one 

 who should go no farther than its title-page. 162 of the 290 

 pages of text in this document, 11 of the 19 plates, and all of the 

 19 maps are devoted to the marine algae and more especially to 

 the larger kelps of our Pacific Coast and to the possibilities of 

 making a practical use of these kelps as a source of potash for 

 the American farmer and gardener. Nearly all of the potash 

 that goes into the commercial fertilizers used in the United States 

 now comes from the Stassfurt region of Germany, a region that 

 represents a former sea-bottom, where certain soluble potassium 

 salts have accumulated in a solid form by the concentration and 

 final drying out of the sea-water. The Stassfurt mines are at the 

 present time the one important source of the potash supply of 

 the world, and the United States now imports from Germany 

 more than Si2,ooo,ooo worth of potash annually. Partly as a 

 result of certain recent controversies between the German 

 "Kali Syndikat" and American importers, the U. S. Congress 

 instructed the Bureau of Soils of the Department of Agriculture 

 and the U. S. Geological Survey to investigate the possibilities 

 of discovering or developing within the boundaries of the United 

 States a supply of potash that should be sufficient for the domestic 

 needs. The first and most natural steps in this search for an 

 independent American source of potash led to the alkaline basins 

 of the arid West, especially where potassium salts in the surface 

 "alkali" suggested the possibility of finding deposits of soluble 

 potassium compounds comparable to those of the Stassfurt 



* Fertilizer resources of the United States. Message from the President 

 of the United States transmitting a letter from the Secretary of Agriculture, together 

 with a preliminary report by the Bureau of Soils, on the fertilizer resources of the 

 United States. Senate Document No. 190, 62d Congress, 2d Session. Pp. 1-290. 

 pi. 1-19 + maps 0-18. Washington, 1912. 



