SOILS FEBTILIZEES. 519 



ditions addition of the materials appreciably promoted the ^owth of free-living 

 Azotobacter and thus increased the nitrogen content of the soil. 



A bibliography of references to the literature of the subject is given. 



The leaching of potash from freshly cut kelp, A. R. Merz and J. R. Linde- 

 HUTH (Jour. Indus, and Engiii. Chcm., 5 {1913), No. 9, pp. 129, 730). — A num- 

 ber of analyses are reported which, while not entirely conclusive, indicate 

 "that freshly cut kelp, when immersed in sea water, does not, at least at first, 

 lose its potash content very rapidly." 



The production of phosphate rock in 1912, W. C. Phalen {U. S. Geol. 

 Slurvey, Advance Chapter from Mineral Resources of the United States, Calendar 

 Year 1912, pp. 2^). — This report gives, besides statistics of production of phos- 

 phate rock for the whole country, figures showing the production of the indi- 

 vidual States for the last five years. Tables showing imports and exports 

 of fertilizer materials are also given, as well as the production of phosphate 

 rock in the principal countries of the world. The phosphate industry in the 

 different States is briefly discussed, and the author gives general information 

 of interest to those engaged in the phosphate trade. 



The phosphate rock marketed in the United States in 1912 amounted to 

 2,973,332 long tons, valued at $11,675,774. This represents a slight decrease 

 in both quantity and value, as compared with the figures for the preceding 

 year. The figures for phosphate rock mined showed, however, an increase in 

 every case except in South Carolina, the increase in Florida amounting to 

 3 per cent, in Tennessee over 12 per cent, and in the western phosphate fields 

 over 10 per cent, as compared with the amounts mined in 1911. Florida pro- 

 duced SI per cent of the entire output of the United States, Tennessee 14.2 

 per cent. South Carolina 4.4 per cent, and Idaho, Utah, and Wyoming the 

 remainder. 



Phosphate mining industry of Algeria, D. B. Mason (Daily Cons, and 

 Trade Rpts. [U. S.], 16 (1913), No. 203, pp. 1240-12Jf2) .—The important phos- 

 phate deposits of Algeria have been mined for 15 years, the production increas- 

 ing from 1,057 short tons in 1S99 to 550,000 tons in 1912. The principal mining 

 districts are near the towns of Setif and Tebessa. About 60,000 tons of phos- 

 phate was used in Algeria in 1912 in the manufacture of superphosphate. The 

 total amount exported in that year was 411,269 tons. 



On the value of Tunis phosphate for peat soils, H. von Feilitzen (Svenska 

 Mosskulturfor. Tidslcr., 21 (1913), No. 2, pp. 111-116, fig. i).— The results 

 obtained indicate that Tunis phosphate is not an economical fertilizer for peat 

 soils in comparison with Thomas slag at present market prices. 



A possible commercial utilization of nelsonite, W. H. Waggaman (Jour. 

 Indus, and Engin. Chcm., 5 (1913), No. 9, pp. 130-132). — A process of separating 

 the ilmenite, or titanic iron, and the apatite of nelsonite by means of a magnet 

 followed by extraction with 32° B. sulphuric acid is described and the com- 

 mercial possibilities of thus utilizing the mineral are discussed. 



Report on phosphatic fertilization, 1905-1910, M. K. Kkistensen and 

 H. R. Christensen (Tidsskr. Landhr. Planteavl, 20 (1918), No. 1, pp. 2^-104, 

 fig. 1). — Trials with different phosphatic fertilizers were conducted for six 

 years under a variety of conditions as to soils and special systems of fertiliza- 

 tion. 



The general conclusion drawn is that superphosphate proved the most certain 

 and quickest acting of the phosphates experimented with. If the fertilizer 

 value of the phosphorus in superphosphate be placed at 100, that of other 

 materials was on the average as follows : On grass land, Thomas slag 94, 

 bone meal 70, ground phosphate (Algiers) 68; on sandy loam soils, Thomas 

 slag 95, bone meal 65; and on clay loam soils, Thomas slag 91, bone meal 51, 



