1918.] SOILS FERTILIZERS. 515 



cases even thin layers of less thuu 1 cm. thickness showed losses of nitrogen, 

 and it may be concluded that under field conditions where the soil could never 

 have such a large surface exposed as in these experiments, denitrification could 

 never be completely prevented. In practice, therefore, tillage and drainage of 

 peat soils may be always recommended in order to minimize denitritication, but 

 some losses must always be expected from tliat cause." 



With the second method the same apparatus was employed but the soil layers 

 were uniformly 9 cm. thick. The germicides were mixed with the soil in the 

 dry state or in solution at the rate of from 25 to 200 mg. per 60 to 70 gm. 

 of soil. 



•' Even with the maximum doses of 0.2 gm. of copper sulphate per 12 gm. of 

 dry soil, losses of nitrogen were not completely avoided. With the small doses 

 denitrification was intensified. This unexpected behavior on the part of copper 

 sulphate was probably due to the fact that the greater part of the salt is 

 precipitated as humates in a peaty soil and thus loses its toxicity. The 

 humates which are hardly ionized actually seemed to have a stimulating effect 

 on the denitrifying bacteria." 



Neither magnesium sulphate nor zinc sulphate totally inhibited denitrifica- 

 tion. Zinc sulphate diminished the action slightly, but with magnesium 

 sulphate it was nearly always slightly increased. 



" In a last series of experiments disinfectants which did not owe their 

 germicidal properties to ions were used, 1. e., carbolineum, toluene, and carbon 

 bisulphid. Where carbon bisulphid was used the period of incubation was 

 increased from two to five weeks, during which time the soil was maintained 

 at ordinary room temperature instead of at 28° C. The following results 

 were obtained : Carbolineum increased denitrification ; toluene had no stimu- 

 lating effect in whatever proportion used, but neither did it have an inhibitive 

 effect except in one single instance ; carbon bisulphid on the other hand always 

 decreased denitrification even when used in very small doses. It would there- 

 fore appear that on peaty land carbon bisulphid may be recommended as the 

 best germicide to employ." 



Utilization of the fertilizer constituents contained in cane molasses, 

 W. E. Cross and W. G. Harris (Rev. hidtis. y Agr. Tucumdn, 7 (1916), No. 3, 

 pp. 95-103; abs. in Internat. Sugar Jour., 19 (1917), No. 222, pp. 281-283; Jour. 

 Soc. Chem. Indus., 36 (1917), No. 15, pp. 897, 898).— Studies of the ash of cane 

 molasses and distillery vinasse are reported. 



Analyses of the molasses ashes show the potash content to be 45 to 50 per 

 cent. " Therefore, the ash without requiring further treatment could be used 

 or sold as a fertilizer, or sold as crude potassium carbonate for use in the 

 manufacture of glass or soft soap, in dye work, or in washing wool. . . . 



" The authors obsex'ved that by acidifying partially concentrated vinasse with 

 sulphuric acid a complete concentration can be reached, and a black, dry, 

 nonhygroscopic powder suitable for transportation in bags or barrels be 

 obtained, its composition being as follows : Phosphoric acid, P2O5, 0.75 per cent ; 

 potash, K2O, 37.5 per cent ; and no nitrogen. There must exist a good market 

 for this product, either as a concentrated potash fertilizer (containing about 

 60 per cent of potassium sulphate), or as potassium sulphate in crude form, 

 to be used as such, or converted into the pure salt. . . . 



"Fractional crystallization, employing the same method used in the case of 

 the molasses ash, was also tried in the case of a solution made from the dry 



