FERTILIZERS. 1025 



and lime. On soils which j^ivo a good yield without barnyard manure 

 it does not prove proiital)lc. An application of chalk improved the 

 action of the phosphorite. How long the applu-ation of ground phos- 

 phorite may be continued with profit is a matter of doubt. When its 

 action ceases, green maiuiring should be resorted to. Other mineral 

 substances, especially marl, should be used in connection with the 

 phosphorite. 



On the utilization of fluorin gas obtained in the manufacture of 

 superphosphates, C Elschnek {Client. Zt(/.^ 21f, {1000)^ Xo. 7h^ p. 795^ 

 Jig. 1). — The gaseous lluorin products formed during the treatment of 

 mineral phosphates with sulphuric acid are conducted through a tower 

 into which a water spray is introduced, which absorbs the gases. The 

 fluorin compounds thus obtained are utilized as a preservative for 

 manure in the following way: (1) Fullers' earth and similar materials 

 are mixed with as much sulphuric acid as they will absorb without 

 destroying the powdery nature of the materials, and (2) a solution of 

 the fluorin compounds o])tained as above is treated with enough dried 

 and ground clay to convert the fluosilicic acid into stable salts. Equal 

 parts of the two preparations when mixed and sprinkled over the moist 

 manure generate fluosilicic acid. 



The guano deposits of Eritrea, (i. A.mpola [Staz. Sper. Agr. Itnl., S4 [1901), 

 Nil. 1, pp. 53-59). — Analyses and tests on different crops are reported. 



An experiment on soil improvement, C. S. Phelps ( Connecticut Storrs Sta. Rpt. 

 1899, pp. 205-208) . — This is a brief account of experiments begun in 1899 to test the 

 relative value of (1) stable manure, (2) a complete chemical fertilizer, and (3) green 

 manures, both alone and in combination with mineral fertilizers, as means of improv- 

 ing worn-out soils. The experiments are being conducted on eighth-acre plats. The 

 same crop will be grown on the whole field in the same j^ear and the crops will vary 

 from year to year in the following order of rotation: Corn, potatoes, oats and peas 

 for fodder, and soy beans. The yields of corn and stover from the different plats in 

 1899 ar(> gi\'eu without CDmment. 



The distribution of fertilizers and their effects, Berthault (Ann. Agron., 26 

 (1900), No. 9, pp. ^i7-^.;0).— Experiments at Grignon and elsewhere bearing upon 

 the effectiveness of fertilizers applied in rows, hills, and broadcast are reviewed. 

 These, it is claimed, show that fertilizers are most effective when localized in the 

 soil (as in hills and drills) and not distributed throughout its mass (as in broadcast 

 application) . By localization the fertilizing constituents are protected from absorp- 

 tion by the soil and kept available for the plant. Practical methods of securing this 

 localization under different conditions are explained. 



The phosphate industry in the United States, K. Pietru.sky ( Oesterr. Chem. 

 Ztg., 4 (1901), No. ..', pj). .'i.i-.iG) . — A brief account of this industry, compiled from 

 data reported in The Minn-nl Iiidiixtrij, volumes 1 to 8. 



The preparation of marketable superphosphates, C. Elschxer {Chem. Ztg., 

 25 (1901), Nos. 7, pp. 68, 69; 8, pp. 81, 82). — Brief descriptions are given of various 

 patented and unpatented processes (^f preparing concentrated and easily handled 

 superphosphates. 



Is the arsenic in superphosphates harmful? A. Stutzer (Deut. Landw. Presse, 

 28 (1901), No. 9, p. 61). — The percentage of arsenic in superphosphate (usually 0.011 



22065— No. 11 3 



