Absorption of Potash l»j Soils of known Composition. 349 
On analysis, this residue gave the following results : — 
Grains. 
Organic matter and ammoniacal salts 2-840 
Soluble silica -050 
Oxides of iron aud alumina, with traces of phosphoric^ .q-q 
acid / 
Sulphate of lime 1-493 
Chloride of calcium '033 
Chloride of Magnesium '261 
Chloride of sodium "110 
Chloride of potassium 27*590 
32-427 
According to these determinations, the whole solution (8 deci- 
gallons) contained : — 
Grains. 
Organic matter and salts of ammonia 8 - 088 
Soluble silica "160 
Oxides of iron and alumina, and traces of phosphoric acid - 160 
Sulphate of lime 4-777 
Chloride of calcium '105 
• Chloride of magnesium '835 
Chloride of sodium -352 
Chloride of Potassium 88-288 
102-765 
Potash. 
Chloride of 
Potassium. 
Before the experiment the whole solution - ! ^0^.550 65-957 
contained / 
After filtration through the soil, it con-j gg.ogg 5^-699 
tained / 
16-262 = 10-258 
1000 grains of sandy soil, according to this result, absorbed 
only 1'465 grains of potash. This soil thus possesses, in a much 
weaker degree, the power of separating potash from its chloride 
than any of the other kinds of soil experimented upon. The 
amount of chlorine in 104 - 55 grains of chloride of potassium 
(used in this experiment) is 49*819 grains. The residue that 
would be left on evaporation of the whole solution of chloride 
of potassium after filtration through the soil, contained, after 
heating, 42 - 976 of chlorine, namely : — 
•063 grains in combination with calcium 
•624 ,, ,, magnesium 
•213 ,, ,, sodium and 
42-076 „ ., potassium 
42-976 
VOL. XXV. 2 c 
