34 



hope of having some light thrown on probable constitution of the nitrog- 

 enous bodies present: 



1. 10 grams of soil were digested with 100 cubic centimeters of acid pepsin for 12 

 hours at 40° C, tillered and washed. Total nitrogen dissolved, 0.076 percent. 



2. 5 grams of soil treated with cupric hydrate according to the official method for 

 albuminoid nitrogen gave total nitrogen insoluble 0.851, or 0.011 per cent soluble. 



3. 10 grams of soil boiled for 30 minutes with 2 grams of permanganate of potash 

 and 125 cubic centimeters water; filtered and washed. Total nitrogen insoluble, 

 0.352 per cent, or 0.516 per cent soluble in neutral permanganate. 



About the only positive information obtained from the above was 

 the fact that a portion of the insoluble nitrogen could be oxidized to a 

 soluble form by neutral permanganate. By repeating the digestion 

 with an excess of permanganate the amount remaining insoluble was 

 0.22J>, or 0.539 per cent soluble. 



By the combined action of permanganate and alkali a considerable 

 portion of the nitrogen was set free as ammonia, e. g., 5 grams of soil 

 on distillation with 1.0 grams permanganate, 1.5 grams caustic soda and 

 100 cubic centimeters water, gave nitrogen as ammonia 0.162 per cent, 

 and on repeating the distillation as above with 10 grams permanganate, 

 the nitrogen set free as ammonia was 0.308 per cent. 



That in the lirst case above the nitrogen set free as ammonia, viz, 

 0.162 per cent, was due chiefly to the action of the alkali was shown as 

 follows: 5 grams of soil on distillation with 1.5 grams caustic soda and 

 100 cubic centimeters water gave nitrogen set free as ammonia 0.151 

 per cent. 



The amount of nitrogen present in the soil as ammonia determined 

 by distillation with excess of magnesia was found to be 0.007 per cent. 

 By using excess of milk of lime instead of magnesia distilling in a 

 current of steam gave nitrogen as ammonia 0.035 per cent and distilla- 

 tion by direct heat 0.053 per cent. 



The ready solubility of portion of the nitrogen in boiling acids 

 seemed to promise some information, and solutions so obtained were 

 treated by the method proposed by Osborne and Harris. « By this 

 method, which in its turn is a modification of a method proposed by 

 Hausmann,* the decomposition products which result from boiling 

 protein bodies with acids are classified. The method, briefly, is free- 

 ing the solution from excess of acid by evaporation; determination 

 of the nitrogen present as ammonia by distillation with magnesia; 

 filtering from the magnesia precipitate; determination of the nitro- 

 gen in the magnesia precipitate, the basic nitrogen in the filtrate by pre- 

 cipitation with phosphotungstic acid, and the nonbasic nitrogen by 

 difference. 



« Jour. Amer. Chem. Soc, 22 (1905), p. 323. 

 ftZtschr. Physiol. Chem., 27, p. 92. 



