2 Ammoniacal Nitrogen oj Peats and Humus Soils 



The actual details of the experiment are as follows. 

 The apparatus consisted of a round-bottomed litre flask fitted with 

 a trap and another tube, the latter passing down to the bottom of the 

 flask. This tube after leaving the flask was bent twice at right angles 

 and tapered ofl into a fine capillary. The capillary was enclosed in 

 a small bottle through the cork of which passed a small open tube. 

 The bottle contained sulphuric acid, above the surface of which the 

 capillary terminated. This device permitted of a slow stream of 

 ammonia-free air passing into the flask during the distillation, in order 

 to avoid bumping. 



The trap in the distilling flask was connected by means of a glass 

 tap to a 100 c.c. pipette which passed through a cork fitting into a filter 

 flask containing sulphuric acid, into which the end of the pipette dipped. 

 The side-tube from the filter flask was connected to anotlier glass 

 tap, which was in turn connected to a water pump. Between the 

 tap and the pump a manometer and safety bottle were inserted 



The glass taps were found necessary when it was decided to conduct 

 three distillations in parallel, the three distilling flasks in the same 

 water bath being connected to the same capillary, and the same water 

 pump being used to evacuate the whole apparatus. 



At the end of the distillation the glass taps on either side of each 

 filter flask were turned oft\ and the pipette and flask disconnected for 

 purposes of titration. 



The preliminary determinations were made with air-dried peats, 

 30 grs. of which were found to be a convenient weight for purposes of 

 distillation. 



100 c.c. of N/100 sulphuric acid were used in the filter flasks and, 

 after the distillation, the excess of acid was determined by titration 

 with N/100 potassium hydroxide, using methyl orange as indicator. 



The method differs from that of Russell in that the distillation is only 

 continued for three hours, and the liquid is not all distilled, a procedure 

 which did not seem advisable in the case of a substance containing so 

 much nitrogenous material as these soils. 



In Table I are given the results obtained from the distillation of 

 peat in the manner described for five hours, fresh acid being used every 

 hour for the absorption of the ammonia given off. 



The results are expressed as percentage of nitrogen in air-dried peat. 

 In every case a very marked drop occurs after the second hour, 

 and after the third hour a small amount comes over which remains 

 practically constant during the fourth and fifth hours. 



