64 Journal of Agricultural Research voi. vi, N0.2 



realized that the Ust is very incomplete. As opportunity to make or to 

 purchase more compounds presents itself, the investigation will be con- 

 siderably extended. From the data presented, it is observed that quite 

 varying proportions of the pure proteins, which in reality are soluble in 

 dilute alkali, are extracted. This seems to be a confirmation of the con- 

 tention that the alkali extract as a whole does not represent a definite 

 class of nitrogenous compounds. Of the simpler compounds, it is seen 

 that the more acid and more closely neutral compounds are completely 

 extracted and remain in the soluble nonprotein portion. An exception 

 to this is found in the case of nucleic acid. This is to be expected from 

 its tendency to combine with protein compounds to give insoluble 

 nucleins. The action of the purin compounds is interesting. In general 

 the more basic the compound the less the quantity recovered. 



CONCLUSIONS 



(i) If the results with the pure proteins be considered, it is probable 

 that the alkali extract as a whole contains no definite group of compounds. 



(2) From the results obtained by the precipitation of the alkali extract 

 with trichloracetic acid it would seem that the soluble nonprotein frac- 

 tion may contain most of the simpler nitrogenous compounds, and 

 therefore its determination would give an index of the degree of decom- 

 position of the organic matter in the soil. 



LITERATURE CITED 



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1912. New methods for the determination of total non-protein nitrogen, urea 



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(3) Greenwald, Isidor. 



1915. The estimation of non-protein nitrogen in blood. In Jour. Biol. Chem., 

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(7) Shorey, E. C. 



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