206 ANNUAL EEPOETS OF THE DEPAETMENT OF AGKICULTUEE. 



mercial demand created by the stoppage of the normal supplies from 

 Germany. Of these four, the giant kelps of the Pacific coast appear 

 to rank first. There are about 400 square miles of commercially 

 available kelp beds, but if only those on the coast of the State of 

 California and those on Puget Sound, which are readily accessible to 

 manufacturing sites, were worked they could meet the normal need 

 of the country and leave a margin for export. The technical prob- 

 lems of producing dried kelp, kelp ash, or a pure potassium chloride 

 are sufficiently advanced to justify commercial exploitation, but the 

 beds are all under the control of the States, and apparently there are 

 no State laws or regulations governing the harvesting of kelp, so that 

 capital has been timid. 



It is quite feasible to obtain potassium salts from feldspar and 

 other potassium silicates, of which great quantities are to be found in 

 nearly every section of the United States. But the practicability of 

 mining on a large scale a product with a sufficiently high content of 

 potassium to justify further manipulation and at a sufficiently low 

 cost has yet to be demonstrated. Disinterested investigators agree 

 that ''jDotash from feldspar" is a commercial possibihty if the by- 

 product is also salable. The most practical suggestion is that the 

 residue from which the potassium has been extracted should be 

 employed in making cement. Apparently, very good cements can 

 be thus prepared. But they do not meet the standard specifications 

 upon which the great bulk of cement is purchased in the United 

 States. Consequently, the cement manufacturers have been loath 

 to remodel their plants, retrain their working forces, and reeducate 

 their buyuig public in an effort to secure an industry worth but a 

 small fraction of their existing business. 



The production of potassium sulphate from alunite is technically 

 quite feasible, but the only known deposit of massive alunite capable 

 of commercial development is near Marysvale, Utah, a geographical 

 location somewhat unfortunate for the fertifizer industry, which is the 

 main consumer for potassium salts. 



One of the by-products in "potash from alunite" is anhydrous 

 sulphuric acid. The alunite deposits being situated in the Fillmore 

 National Forest, the sulphuric-acid fumes can not be allowed to escape 

 unchecked, and there is little or no sale for the sulphuric acid in Utah. 

 Instead of being an asset, its disposal is a serious charge. The other 

 by-product is alumina, from which alummum might be produced 

 and has been produced in an experimental way. But the only com- 

 mercial producer of aluminum in the United States is amply sup- 

 plied with large deposits of bauxite and is not interested in develop- 

 ing another source. To enter this field would mvolve adjustment of 

 patent rights and the securing of a source of cheap power. Abrasives, 

 refractories, and possibly other substances might be made from the 

 alumma, but for these the market does not yet exist. In spite of 

 these handicaps the pressure for potash salts is so great that plants 

 for the working of alunite are m course of construction which wiU 

 shortly produce potassium sulphate in the interest of certain ferti- 

 lizer manufacturers. Since the greater part of the Marysvale 

 alunite kno^^^l to be workable is owned by two private interests, it 

 is doubtful if "potash from alunite" is to be of interest to the fertilizer 

 industry generally. 



