26 EXPERIMENT STATION RECORD. [Vol.43 



spondins values for calcium sulphate are 0.24 and 0.1 mole, respeclively, per 

 I.O(M> mules ILO." 



Potash in J J) 18, W. 13. Hicks (U. S. Geol. Suri^eij, Min. Resources U. S., 

 1918, lit. 2. pp. n-\-385-4.'f5).— This bulletin deals with the production and use 

 of potash and potash-bearinj: materials in the United States and foreign 

 countries during 1918. and gives a general discussion of the industry in dif- 

 ferent parts of the world. 



The production of potash-bearing materials in the United States in 1918 

 amounted to 207,686 short tons, equivalent to a total content of .54,803 short 

 tons of potash. This production was nearly 70 per cent greater than in 1917 

 and represented about 22 per cent of the normal consumption in the country. 

 In 1918 the production came from 10 distinct classes of raw materials. 

 Natural brines furnished about 73 per cent of the output, the Nebraska lakes 

 alone contributing about .53 per cent and Searles Lake, Cal., the second largest 

 (piaiitity from a single source. Kelp yielded about 9 per cent of the total pro- 

 duction, follo\v(>d by smaller contributions from molasses, alunite, cement, etc. 



I'otash materials marketed in 1918 varied gi-eatly in composition and in con- 

 tent of potash. Crude mixed salts, containing from 20 to 28 per cent of potash 

 and composed largely of carbonates and sulphates of sodium and potassium, 

 constituted about 58 per cent of the output; muriate, containing 60 to 96 per 

 cent of potassiurr* chlorid, equivalent to 38 to 62 per cent of potash, about 24 

 per cent ; sulphate, containing 35 to 51 per cent of potash, 6 per cent ; and low- 

 grade chlorid, crude carbonate, caustic, potash char and ash, cement and blast- 

 furnace dust, and miscellaneous, the remainder. Most of the muriate was of 

 low grade and much of it contained borax, while the larger portion of the 

 sulphate was of high grade. Crude carbonate and caustic was largely the 

 product made from wood ashes. As marketed, much of the carbonate contained 

 about 70 per cent of potassium carbonate mixed with about 30 per cent of 

 potassium sulphate and other impurities. 



Approximately 53 per cent of the total production came from Nebraska. 34 

 per cent from California, 7 per cent from Utah, and the other 6 per cent from 

 18 other States and Porto Rico. The domestic production of reflned potassium 

 salts in 1918, exclusive of chlorids and sulphates, amounted to 53,661,676 lbs. 

 and the sales amounted to 43,833,503 lbs. 



Potassium salts (U. S. House Represent., 66 Cong., 1 Sess., Com. Ways and 

 Means ireariniis on rotassium Salts, 1919, pp. 214). — The details of the hearings 

 before the Committee on Ways and Means of the House of Representatives, 

 U. S. Congress, on a bill for the control of importation of potassium salts, are 

 given. 



Potash fertilizers (Bd. Agr. and Fisheries [London], Leaflet 335 (1920), 

 pp. 3). — Brief popular information on the price, fertilizing value, and practical 

 use of potash fertilizers in England is contained in this leaflet. 



Phosphoric acid: Facts about the most important of mineral soil con- 

 stituents, ,T. A. Brock {Faets About Sugar, 10 (1920), Nos. 3, p. 50; 4, pp. 70, 

 7/).— Brief information is given on the chemical composition of the common 

 phosphatic fertilizers, factors in their availability, and their action in soil and 

 toward plants. 



I, The relative availability of acid phosphate and the native soil phos- 

 phates in the presence of pulverized limestone. II, Future of the agri- 

 cultural lime industry, .T. L. Burgess (N. C. Dept. Agr. Bui. 4I (1920), No. 3, 

 pp. 24).— In Part I of this bulletin a review and summary of a number of 

 works by others on the availability of acid and native phosphate in the presence 

 of lime are given, from which the conclusion is drawn that while acid phosphate 



