830 EXPERIMENT STATION RECORD. 



per cent of the nitrogen of the sesame cake was rendered soluble in 13 

 days, 94 per cent in 11G days. 



In the third series of experiments castor-bean cake, colza cake, and 

 wool waste (dust) were compared. In case of the first 52 per cent of 

 the nitrogen was rendered soluble in 11 days, 80 per ( - e ut in 107 days; 

 in the second case 32 and 70 per cent, respectively; and in the third 

 case and 4G per cent, respectively. 



In the fourth series of experiments the effect of previously heating 

 the soil to 100° and adding a small amount of sulphuric acid was tested. 

 In this series 2 pots received dried blood without previous treatment of 

 the soil, 1 received dried blood after the soil had been heated to 100°, 

 and another received dried blood after heating to 100° and adding a 

 small amount of acid. The heating had the effect of reducing the nitric 

 nitrogen and increasing the amount of ammoniacal and nitrous nitrogen 

 produced. Heating to 100° C, especially with the addition of acid, 

 appears to have been destructive to the nitrifying organisms. 



In the fifth series of experiments an investigation was made of the 

 progress of nitrification in soils to which mixtures of horse manure and 

 nitrate of potash or sulphate of ammonia with or without starch were 

 added. The results indicate that horse manure, especially in the pres- 

 ence of starch, tends to cause the disappearance of nitrates, but under 

 the conditions of these experiments, i. e., with a temperature of 30° 

 and a sufficient supply of air and moisture, this disappearance of 

 nitrogen is not due to an evolution of free nitrogen but largely to the 

 formation of new organic compounds of nitrogen. 



In the sixth series of experiments a comparison was made of the trans- 

 formations of nitrogen which go on in soil very rich in humus and 

 nitrogen, with and without the addition of nitric and ammoniacal 

 nitrogen. The transformations of nitrogen were somewhat slower in 

 this case than in the case of an ordinary soil. 



On the composition of natural humus substances, G. Andre 

 (Compt. Bend. Acad. Sci. Paris, 127 {1898), No. 11, pp. 411-417; abs. in 

 Ann. Agron., 24 (1898), No. 12, pp. 602-604). — In the investigations 

 here reported vegetable mold, moor soil, compost, and peat were treated 

 with (1) potash followed by hydrochloric acid and (2) hydrochloric acid 

 followed by potash. The ammonia volatilized and the nitrogen soluble 

 and insoluble in the acid and alkali were determined. The results 

 reported show the complex character of the nitrogenous matter of the 

 soil. Previous work by Berthelot and Andre ' led to the conclusion 

 that the nitrogenous matter of the soil is of an amid character. 



The lime content of soils and nitrification, F. Polzeniusz (Ztschr. 

 Landic. Versuchw. Oesterr., 1 (1898), p. 235; abs. in Centbl. Agr. Chem., 

 28 (1899), No. 1, pp. 12, 13).— Samples of 200 gin. each of a soil contain- 

 ing 0.540 per cent of lime, 0.014 per cent of which was carbonate, were 

 placed in glass dishes, and in different cases 0.0866 gm. of nitrogen in 



1 Aim. Chiin. et Phys., 6, ser., 11 (1887), ]». 368; 25 (1892), p. 314. 



