24 On the Chemical Properties of Soils. 



The soil used in these experiments was the same as that em- 

 ployed in the Fourth Series. 



1st Experiment. A strong solution of pure ammonia in dis- 

 tilled water was prepared, and its strength accurately determined. 

 An imperial gallon contained 194*39 grains of ammonia, or 

 1000 grains 2*777 grains. J Ib. soil (1750 grains) was placed 

 in a well-stoppered bottle, and 7000 grains of the ammonia solu- 

 tion of the above strength were added. The bottle and contents 

 were repeatedly shaken, and then the whole left to subside for 

 three days. The clear liquid was drawn off and weighed, and 

 its strength determined in the usual way. 



Grains. 



Before contact with the soil 1000 grains of the solution) ,- 



contained H 



After contact , 2-112 



665 



Thus *665 grains of ammonia were removed from every 1000 

 grains of solution, or 4*655 grains were removed from the whole 

 solution employed (7000 grains) and retained by 1750 grains of 

 soil. 1000 grains of soil consequently absorbed 2*66 grains of 

 ammonia. The quantity of liquid drawn off weighed 4916 grains, 

 and contained 10*382 grains of ammonia. 



The residue in the bottle was next shaken up with 7000 grains 

 of distilled water ; after three days the clear liquid was drawn 

 off, weighed, and its strength determined as before. 1000 

 grains of the liquid were found to contain *510 grains of ammonia. 

 The amount of liquid left in the bottle before the addition of 

 7000 grains of water, and its strength, being known,' this result 

 will show whether or not the addition of water has had any effect 

 upon the ammonia retained by the soil from a strong ammoniacal 

 solution. 



Had the effect of the water simply resulted in the dilution of the 

 ammonia-solution, which could not be poured off from the soil in 

 a clear state, its strength would have been "484 grains of am- 

 monia in every 1000 grains ; but it was *510 grains of ammonia, 

 consequently *026 grains of ammonia were removed by every 

 1000 grains of liquid, or *236 grains by the whole quantity of 

 liquid employed in the experiment, from 4*655 grains of ammonia 

 previously absorbed by \ Ib. of soil. 



2nd Experiment. 7000 grains of distilled water were added to 

 the residue in the bottle from the preceding experiment, and 

 after three days the clear liquid was drawn off, weighed, and 

 the strength determined. 1000 grains of liquid contained *192 

 grains. If this second addition of water had not acted upon the 



