On the Chemical Properties of Soils. 29 



To this end, I prepared a solution of sulphate of ammonia, 

 which contained 188*720 grains of ammonia in the gallon, or 

 2*696 grains of ammonia in 1000 grains of liquid. J Ib. 

 (1750 grains) of calcareous soil used in First Series was mixed in 

 a stoppered bottle with 7000 grains of this solution, then left at 

 rest for three days, after which the clear liquid was drawn off, 

 and the ammonia contained in it determined by distillation : 



Ammonia. 

 Grains. 



Before contact with soil 1000 grains of solution contained .. 2*696 

 After contact 2-000 



696 



Therefore "696 grains of ammonia were removed from every 

 1000 grains of liquid, or 4*872 grains were removed from the 

 whole solution, and retained by 1750 grains of soil; 1000 grains 

 of soil thus absorbed 2*784 grains of ammonia. 



A comparison of this result with the amount of ammonia 

 absorbed from sulphate of ammonia in the preceding experi- 

 ments, shows that much more ammonia is removed by soil from 

 the stronger ammoniacal solution than from the weaker one. 



The liquid was drawn off as much as possible, and the amount 

 of that which could not be removed ascertained by weight ; 

 7000 grains of pure distilled water were next added ; after three 

 days the clear liquid was drawn off and weighed, and the am- 

 monia in it determined by distillation in the usual way. 



Proceeding in this manner, the soil which had absorbed 4*872 

 grains of ammonia from a strong solution of sulphate of ammonia 

 was washed five times with 7000 grains of water each time : 



Ammonia. 

 Grains. 



T lie first washing removed '278 



The second ,, ,, -fioo 



The third ,, ., , '813 



The fourth ,, ,, '416 



The fifth -242 



2-382 



35,000 grains of water, or J gallon, thus removed 2*382 grains 

 of ammonia from the soil, which had absorbed 4*872 grains of 

 ammonia. At the conclusion of the experiment the quantity of 

 ammonia which remained in J Ib. of soil amounted to 2*490 

 grains, or very nearly half the quantity which it absorbed in the 

 first place. 



These results are conformable with those obtained in the 

 Retention Experiments, where a solution of free ammonia was 

 employed. 



