116 



BULLETIX 



3. The surface and subsoil of a heavy clay field containing 

 little sand. 



4. A sterile, sandy soil, containing much organic matter and 

 scarcely any lime. 



5. Pasture land, being a vegetable mould containing abund- 

 ance of organic matter and a fair proportion of sand and clay. 



The ammonia solution used by him contained .332 grains 

 per 1000 of NH 3 , or at the rate of 332 parts per million of 

 solution. His results follow : 



Amounts of ammonia absorbed 6.y five soils. 



When he used a still stronger solution, on the same samples 

 of soil, containing 673 parts of NH 3 per million of solution, 

 he obtained the results given in the next table. The digestion 

 was allowed to continue 3 days and 14,000 grains of the 

 stronger solution were used in each case. 



Amounts of ammonia absorbed by second treatment. 



In a third series Yoelcker used 4 solutions of different 

 strength on the same soil, which was a! moderately stiff cal- 

 careous clay. In each case 7,000 grains of solution were agi- 

 tated with 14 lb. of soil, -and after four days the solutions were 

 examined. 



