114 
On the Chemical Properties of Soils. 
of the ammonia lias become neutralised by the organic matters 
in the soil. 
The deeper coloured the ammonia solution after contact with 
soil, the greater will be the error which will be made if the 
amount of ammonia is determined in the brown-coloured liquid 
in a direct manner by the alkalimetrical process. Whenever 
the solution is distinctly coloured yellow or brown, it should be 
first distilled with caustic potash, in a properly-constructed ap- 
paratus, and the free ammonia be determined in the distillate. 
Thus the same ammonia solution which yielded to 1000 
grains of this sandy soil, according to the direct process of neutral- 
isation, 1'076 grains of ammonia in one experiment, and 1'136 
grains of ammonia in a second experiment, after distillation with 
caustic potash was found to contain in 1000 grains of liquid 
'119 grains of ammonia ; consequently, subtracting as before 
•119 from '332 grains, '213 grains are removed from every 1000 
grains of liquid, or 2 '982 grains from the whole solution. 
Ammonia. 
Grains. 
In a second distillation : — ■ 
1000 strains of liquid were found to contain 'Ill 
Before contact with soil the solution contained .. .. '332 
•221 
Therefore "221 grains of ammonia were removed from every 
1000 grains of liquid, or 3"094 grains from the whole quantity. 
Ammonia. 
Grains. 
According to the first distillation : — 
1000 grains of soil absorbed "852 
According to the second distillation : — 
1000 grains of soil ab.sorbed '884 
The mean of the two direct determinations is .. .. I-IOI 
The mean of the two determinations by distillation is "868 
Difference -233 
An error, amounting to one quarter of the whole of the am- 
monia absorbed by the soil, would therefore have been com- 
mitted had the determination not been made after distilling the 
liquid with caustic potash. 
Fifth Experiment, on Pasture Land. 
The mechanical analysis of this soil yielded the following re- 
sults : — 
Moisture 2-42 
Organic matter 11-70 
Lime 1-54 
Clay 48-39 
Sand 35-95 
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