50 



and 1898-99) believed that the use of a reducing agent was not 

 essential, but according to Otori (1904) this is a mistake. 



It is perhaps significant that the "humin" nitrogen was reduced 

 to 3.90 per cent by the presence of a reducing solution. It is not 

 known whether there was sufficient tin present to maintain a reduc- 

 ing solution throughout the hydrolysis inasmuch as the ferric iron 

 in the peat would have an oxidizing action on the stannous salt. 

 The sample was known to contain iron but the amount was not 

 determined. 



Duplicate 15 gram samples were hydrolyzed with 100 cc. hydro- 

 chloric acid (sp. gr. 1.115) for 48 hours in the presence of five and 

 ten grams of tin respectively. The tin was first partially dissolved 

 in the acid before the samples of peat were added. The deter- 

 mination of "humin" nitrogen was carried out as directed under 

 sphagnum-covered peat excepting that the digested material was 

 diluted to 500 cc. instead of to 1 liter. The nitrogen retained by 

 the barium phosphotungstate was 0.0023 gram in Sample I; and 

 0.0047 gram in Sample II. The solution containing the filtrate from 

 the bases was diluted to a volume of 300 cc. The experimental data 

 giving the grams of nitrogen found and the per cent of total 

 nitrogen are given in Table XVI. 



Table XV L Nitrogen distribution in 

 hydrolyzed in the presence of metallic tin. 



sphagnum- covered peat 



1 This result is from a single determination of nitrogen. 



13. Analysis of a 1 per cent hydrochloric acid extract of sphag- 

 num-covered peat and (in part) of calcareous black grass-peat. 

 Acid extraction was made of the two peats in direct contact with 

 1 per cent hydrochloric acid. For the extraction 125 gram por- 

 tions were placed in 2.5 liter acid bottles and two liters of 1 per 

 cent acid added. In the case of calcareous black grass-peat, how- 

 ever, the calculated amount of hydrochloric acid necessary to neu- 

 tralize the calcium oxide was first added and then sufficient dilute 

 acid to make two liters of a 1 per cent solution. Five hundred 



