NITROGENOUS ORGANIC MATTERS OF THE SOIL. 279 



Carbohydrate. Ammonia. Water, Gelatine. 



C.. H,„ 0,„ + 4 NH3 - 6 11,0 + 2 (C, H,„ N, OJ. 



Afterwards Dusart, Schiitzenberger, and P. Thenard, in- 

 dependently of each otlier, obtained by exposing dextrin, 

 starcli, and glucose, to a somewhat elevated temperature 

 (300-360°F.), in contact with ammonia-water, substances 

 containing from 11 to 19° |„ of nitrogen, some soluble in 

 water and havhig properties not unlike those of gelatine, 

 others insoluble. It was observed, also, that analogous 

 compounds, containing less nitrogen, were formed at lower 

 temperatures, as at 212° F. Payen had previously observed 

 that cane sugar underwent entire alteration by prolonged 

 action of ammonia at common temperatures. 



These facts scarcely leave room to doubt that ammonia, 

 as cai-bonate, by prolonged contact with the humic acids 

 or with cellulose, and bodies of like composition, may 

 form combinations with them, from which, by the action 

 of alkalies or lime, ammonia may be regenerated. 



It has already been mentioned that when soils are boil- 

 ed with solutions of potash, they yield ammonia continu- 

 ously for a long time. 



Boussingault observed, as has been previously remarked, 

 that lime, when incorporated with the soil at the ordinary 

 temperature, causes its content of ammonia to increase. 



Soil from the Liebfrauenberg garden, mixed with 'j^ 

 its weight of lime and nearly ^ its weight of water, was 

 placed in a confined atmosphere for 8 months. On open- 

 ing the vessel, a distinct odor of ammonia was perceptible, 

 and the earth, which originally contained per kilogram, 

 11 milligrams of this substance, yielded by analysis 303 

 mgr. (See p. 265, for otlier similar results.) 



Alteration of Albuminoids in the Soil.— Albuminoids 



are carried into the soil when fresh vegetable matter is in- 

 corporated with it. They are so susceptible to alteration, 

 however, that under ordinary conditions they must speed- 



