On tlie Behavior of Nitrate in Paddy Soil. 



17 



with the rape cake flask after two weeks and with the straw flask after four 

 weeks, all the nitrate aud nitrite were reduced. In the other flasks^ 

 however, to which the nitrate was added much nitrate was still present after 

 6 weeks and in the ammonium sulphate flask also strong reactions for nitrate 

 and nitrite were noticed after three weeks. With Compost flasks (a) and (b) 

 moderately strong nitrite reactions were observed after 2-3 days from the 

 start but the reaction decreased gradually. 



The flasks for the final determinations were kept for 45 days with 

 frequent shaking until the nitrite reaction had entirely disappeared. 100 cc. 

 of supernatent clear solution were withdrawn from each flask to determine 

 the soluble nitrogenous compounds, and the remainder in the flask was 

 evaporated to dryness after adding a little sulphuric acid. The total 

 nitrogen^ nitric and ammoniacal nitrogen were determined as usual with 

 the following^ results : 



