54 



Table XVIII. Nitrogen distribution in that portion of a sphag- 

 num-covered peat soluble in 4 per cent sodium hydroxide and precipi- 

 tated by hydrochloric acid and (in part) of a similar solution from a 

 calcareous black grass-peat. 



Sphagnum-covered 

 peat 



Calcareous 

 black grass-peat 



15. Ana'ysis of a portion of sphagnum-covered peat soluble 

 in 4 per cent sodium hydroxide and not precipitated by hydro- 

 chloric acid and (in part) of a similar solution from a calcareous 

 black grass-peat. The filtrate remaining from the brownish black 

 precipitate formed by acidifying the sodium hydroxide extracts 

 of the soil with hydrochloric acid (cf. section 13) were concentrated 

 in the usual manner to about 700 cc. when a heavy precipitate of 

 sodium chloride separated. On standing over night there also 

 separated a heavy flocculent brown precipitate. This may have 

 been due to the salting out effect of the sodium chloride on some 

 of the organic substances in the solution. The solution was sat- 

 urated with hydrogen chloride in the cold and the mixture then 

 divided into two portions and hydrolyzed for 48 hours. The cold 

 material after hydrolysis was united and filtered through glass 

 wool and the precipitate washed with concentrated hydrochloric 

 acid. The filtrate was allowed to stand in a tall soil beaker when 

 more salt separated, due to the increased concentration of the hydro- 

 chloric acid. The salt that separated was freed from the mother 

 liquid by packing in a centrifuge and washing with acid a number 

 of times. The salt washed as free of the solution as possible was 

 dried on the steam bath. It was nearly white in color. The glass 

 wool was dried and ground with the salt. After being sampled, 15 

 gram portions were used for Kjeldahl determinations. The results 

 were listed as nitrogen-retained-by-the-salt. 



The combined nitrates were concentrated and analyzed. After 

 the digestion of the humin nitrogen, the material in the Kjeldahl 

 flask was made to 500 cc. volume and the distillations carried out 

 on 250 cc. portions. The nitrate and washings from the humin 

 were acidified and evaporated under diminished pressure to less 

 than 200 cc. and then made to 250 cc. volume. Duplicate nitrogen 

 determinations were made on 25 cc. portions of the solution and 



