Oil tlia Chemical Propei'ties of Soils. 
131 
To this end, I prcpaiod ;i 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. ^ lb. 
(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 whicli the clear licjuid was drawn off, 
and the ammonia contained in it determined by distillation : — 
Ammonia. 
Graina. 
Before contact witli soil 1000 grains of solution contained .. 2'(j9G 
After contact „ „ „ 2'000 
•696 
Tlierefore '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. 
•278 
*633 
•813 
•416 
•242 
2*382 
35,000 grains of water, or ^ 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 lb. 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. 
K 2 
The first washing removed 
The second , , , , 
The third , , , , 
The fourth , , , , 
The fifth 
