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THE OLIVE
ing, the flowers fall off and the tree gives its strength to wood.
The hygroscopicity of a soil, or the property of retaining moisture, is of great value in a hot and dry country. It is well known that the more a soil is manured and cultivated, the more moisture it retains. The following table will show the percentage of water contained in different soils.
| Silicious sand | .25 |
| Gypsum | .27 |
| Calcareous sand | .29 |
| Dry chalk | .40 |
| Chalk, somewhat more fertile | .50 |
| Clay soil | .60 |
| Clay, pure | .70 |
| Calcareous soil | .85 |
| Manure | 1.90 |
| Garden soil | .89 |
| Arable land | .52 |
The capacity to absorb humidity from the atmosphere varies with different soils. The following are the results of experiments.
| Silicious sand | .0 of water |
| Calcareous sand | 1.5 " " |
| Gypsum | 0.5 " " |
| Dry chalk | 13.0 " " |
| Chalky earth | 15.0 " " |
| Clayey earth | 18.0 " " |
| Clay | 21.0 " " |
| Fine calcareous earth | 15.5 " " |
| Magnesia | 38.0 " " |
| Manure | 48.5 " " |
| Garden earth | 22.5 " " |
| Ordinary earth | 11.0 " " |
