J. 0. B. Ellis and C. G. T. Morison 



The ammonia which is most easily removable comes over in the first 

 two hours. Distillations for three hours would make certain of the 

 removal of the whole of the nitrogen arising from the decomposition 

 of the more unstable compounds present, while as little as possible of 

 the nitrogen from more stable compounds would be included in this 

 result. 



The nitrogen should come from ammonia present either as ammonium 

 compounds and absorbed ammonia, or from organic compounds which 

 are hydrolysed with comparative ease. 



The amount of magnesia taken was fixed at three grams as a result 

 of a set of determinations of which Table II contains examples. 



These determinations w^ere made by distilling the peat for three 

 hours with 1 gram of magnesia, then adding a second gram and con- 

 tinuing the distillation for another three hours, and similarly for a 

 third gram. 



Table II. 



Nitrogen per cent. 



Soil(l) SoU (2) Soil (3) 



1st gr. MgO -005866 -007863 -006878 



2nd „ -001471 -000475 -000984 



3rd „ -000992 -000345 -000051 



Determinations were then made of the amounts of ammonia set 

 free in this way from a series of humus soils. 



The origin of the soils and the results are given in Table III. 



It will be seen from these results that large quantities of ammonia 



may be set free from humus soils, which quantities are very much 



larger than the amounts set free from ordinary soils when treated in 



a similar way. To demonstrate this determinations were made in 



three ordinary soils: 



N as NHg, per cent. 



(1) A coarse sand in rough permanent grass. |-00060 



(2) Arable soil on limestone gravel subsoil. 1-00037 



(3) Arable alluvial soil on gravel subsoil. 1-00046 



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