SOILS FERTILIZERS. 723 



Red soils and phosphatic manures, J. Akik (BoI. Ayr. [Udo Paulo], 15. -ser., 

 No. 6-7 (1914), PP- o.i')-5'j5, figs. 2). — ^The author cites analyses of 48 samples 

 of red soils which show that these soils are generally deticieut in phosphoric 

 acid. He points out that although they rapidly absorb soluble phosphatic fer- 

 tilizers, the latter usually coinbiue with the irou nud aluniiuuni of the soils to 

 form insoluble comiiounds. 



He further reports exi)erinients to sliow that the absorption of phosphoric 

 acid in red soils is considerably increased by the presence of lime and humus 

 and that the solubility of the phosphates of aluminum, iron, and shig in solu- 

 tions of so-called alkaline humates increases with the concentration of the 

 solution. It is thought that the humus prevents the formation of insoluble 

 phosphatic compounds in red soils by couibining with the iihosphoric acid and 

 forniiug easily soluble so-called humo-phosjiliates. The value of liming on red 

 soils is attributed niainly to its favorable influence on bacterial activity and on 

 the solubility of potash. 



It is concluded that superphosphate may be jirofitably used on red soils if 

 accompanied by liberal additicms of organic matter and lime. 



The white phosphates of Tennessee, J. S. Hook (Resources Tenn., 5 (1915), 

 No. 1, pp. 23-33, figs. Jf). — The character, geological relations, origin, and dis- 

 tribution of the white phosiJhate deposits occurring in Perry and Decatur coun- 

 ties, Tennessee, are discussed. Sufficient investigation has not yet been made 

 to determine definitely the extent of these deposits. The deiwsits are so 

 irregular and uncertain in character that no reliable postulations can be made 

 as to the extent and size of the individual deposits, 



Phosphatic fertilizers and the deposits of apatite of Freirina, J. Brxjggen 

 (Los Ahonos Fosfatudos i los Yaciniicntos cic Apatita de Freirina. Santiago dc 

 Chile: Soc. Nac. Min., 1914, PP- 12, pJ. 1). — This article discusses briefly the 

 sources, character, and fertilizing value of various phosphatic fertilizers, and 

 describes in some detail what appear to be large deposits of high-grade apatite 

 occurring in the Department of Freirina, Chile. A considerable part of this 

 apatite contains from 25 to 29 per cent of phosphoric acid and some of it as 

 much as 35 per cent. 



American imports of potash salts {U. 8. Dept. Corn., Com. Rpts., No. 17 

 (1915), p. 293).— The import into the United States during December, 1914, 

 of muriate of potash was 8.313 tons, sulphate of potash 2,204 tons, other salts 

 503,349 tons, as compared with 28,619, 6.459, and 695,373 tons, respectively, 

 during December of the preceding year. 



The economic value of Pacific coast kelps, J. S. Burd (California 8ta. Bui. 

 248 (1915), pp. 183-215, figs. 3). — This bulletin reports in part the results of 

 an extensive series of studies on the chemistry of kelps, discussing these results 

 from the standpoint of their bearing on the commercial utilization of kelp. 



The following are the general conclusions reached: "The giant kelps contain 

 potassium, iodin. and nitrogen in amounts which will possibly justify com- 

 mercial recovery. Estimates of potash yields which are based on analyses of 

 leaves and stems and do not take into account the larger proportion of leaf to 

 stem in the growing plant are likely to be higher than can be exjiected in the 

 avei'age run of commercial recovery. Exact determinations of the moi.sture con- 

 tent of the more common of the giant kelps, hei-e presented for the first time, 

 show that weight for weight of fresh kelp Macroci/stis pyrifrra contains more 

 of each important constituent than does Nereocgstis luetkeana. 



" The efflorescence of potash salts when kelps are slowly dried can not be 

 utilized to advantage in the commercial preparation of potash if a large yield of 

 high-grade salts is desired. No technological difficulties are involved In prepar- 

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