20 On the Chemical Properties of Soils. 



2. Experiment with Solution No. 2. 



Ammonia. 

 Grains. 



Before contact with soil the solution contained .. .. 2'128 

 After contact ,, ,, .... 1*008 



1-120 



Therefore 1/120 grains of ammonia were absorbed by 1750 

 grains of soil, or 1000 grains absorbed '64 grains of ammonia. 



3. Experiment with Solution No. 3. 



Ammonia. 

 Grains. 



Before contact with soil the solution contained .. .. T232 

 After contact ,, ,, .... -777 



455 



Thus "455 grains of ammonia were absorbed by 1750 grains of 

 soil, or 1000 grains absorbed '26 grains of ammonia. 



4. Experiment with Solution No. 4. 



Before contact with soil the solution contained .. .. '616 

 After contact ,, .... *441 



175 



Therefore -175 grains of ammonia were absorbed by 1750 grains 

 of soil, or 1000 grains of soil absorbed *100 grains of ammonia. 



According to the strength of the different solutions 1000 

 grains of soil thus absorbed in 



Ammonia. 

 Grains. 



No. 1 1-32 



No. 2 -64 



No. 3 -26 



No. 4 -10 



Not only is the absolute quantity of ammonia which this soil 

 absorbs from an ammoniacal solution larger as the solution 

 employed is stronger; but very dilute solutions are relatively 

 less exhausted by it than stronger ones. 



Thus, whilst in the two first experiments, in round numbers, 

 one-half of the ammonia contained in the solutions was ab- 

 sorbed, in the 3rd Experiment about one-third, and in the 4th only 

 about one-fourth of the ammonia was retained by the soil. 



In the next place I made some additional experiments for the 

 purpose of ascertaining whether this soil, after having taken up as 

 much ammonia as it will from a weaker solution, would take up 

 more from a stronger one. 



Experiment 5. 



The solution left in the bottle from Experiment No. 2 was drawn 

 off as much as possible, the liquid remaining with the soil was 



