SOILS FERTILIZERS. 515 



On the fixation of phosphoric acid by the organic matter of the soil, 

 A. Petit (Compt. Rend. Acad. Nc/. [Paris], 152 (1911), No. 20, pp. ISll-tSU); 

 ahs. m Rev. 8ci. [Paris], Jf9 (1911), I, No. 21, pp. 667, 668; Chcm. Zenthl., 1911, 

 II, No. 3, pp. 157, 158; Inter nat. Inst. Agr. [Rome], Bui. Bur. Agr. Intel, and 

 Plant Diseases, 1911, No. 5, p. 1038).— The author concludes from his experi- 

 ments that in soils very rich in organic matter, such as the forest soils with 

 which he experinientetl, the fixation of phosphoric acid by hunuis was so small 

 as to be negligible. The same was true of humus extracted from soils by 

 ordinary methods. 



Changes induced by the addition of carbohydrates to soils, H. B. Hutchin- 

 son and F. S. 'SIakr (7. Internal. Cong. Appl. Ghem. [London], 1909, Sect. VII, 

 pp. 37-.',0; ahs. in Jour. Chem^ Soc. [London], 100 {1911), No. 583, II, pp. JfSO, 

 J/Sl). — Experiments are referred to in which, wheu starch was applied at the 

 rate of 1 ton per acre, the yield of barley was decreased 17.45 per cent, and an 

 equal application of sucrose resulted in a decrease in the yield of ?)1.2 per cent. 

 An examination of the soil showed a greatly increased growth of bacteria and 

 molds. In culture tests it was found that 2 per cent of starch and dextrose 

 increased the growth of bacteria and molds, but that mannitol did not produce 

 this result. 



Sewage sickness in soil, and its amelioration by partial sterilization, E. J. 

 Russell and J. Golding {Jour. Soc. Chem. Indus., 30 {1911), No. 8, pp. ^71- 

 JillJi). — Examinatious of samples of soil which had become "sick" and more or 

 less bacterially inactive as a result of continuous application of sewage showed 

 that prolonged aeration under very favorable conditions did not restore the 

 bacterial activity, but that partial sterilization by heat, carbon bisulphid, or 

 toluol did bring about this result. The authors attribute the difticulty to the 

 presence in the sewage-sick soils of large numbers of organisms which feed 

 upon the bacteria to which sewage purification is due. The number of bacteria 

 in partially sterilized soils rose to over 400.000,000 per gram, while in untreated 

 soil they only occasionally reached 4O.(X)O,0O(t. It was found that destructive 

 organisms, including amoeba?, Vorticella putrina, Euglena, and others, which 

 are found in ordinary soils, were also present in the sewage-sick soils and were 

 much more active there than in ordiiiary soils. These organisms Avere not 

 killed by aerating, liming, or resting the soil, but were destroyed by heating 

 and application of carbon bisulphid and toluol. Sewage-sick soils so treated 

 weie more effective as filters than untreated soils and did not so quickly lose 

 their efliciency. 



Carbon bisulphid as a soil improver, C. J. J. van Hall (Trj/smannia, 22 

 {1911), No. 2-3, pp. 152-162). — This is a brief review of investigations bearing 

 on this subject with references to the principal literature. 



Conservation of the purity of the soil, H. L. Bolley (Proc. Soc. Prom. Agr. 

 8ci., 31 {1910), irp. 100-106). — As in previous articles (E. S. R„ 24. p. 132) the 

 author maintains that there are large areas of wheat soils of the Northwest 

 which have declined in productiveness as a result of contamination with 

 disease-producing parasites and in this respect are analogous to old flax- 

 cropped lands. " Constant cropping has carried to the soil the various types of 

 parasites which the wlieat crop and flax crop are heir to." 



The infl.uence of the soil on plant growth, S. T. Parkinson (Jour. >^OHth- 

 cast. Agr. Col. Wye, 1910, No. 19, pp. 258-261, pi. i).— This is an account of 

 comparatively simple tests to show the character of growth made by carrots 

 on different tyiies of soil, including peat, loam, clay, sand, and chalk. The 

 experiments were made in pits tilled with the soils. 



