SOILS. 23 



unfavourable indication. It is desirable to see tbe water in the 

 furrows sink down and be absorbed, instead of carrying off the 

 surface soil. If the soil be of a dull black colour, and if it pre- 

 sent upon its surface the white stones just referred to, that is 

 an unfavourable indication, as it shows that the soil has more 

 or less of peat in its composition. 



If the soil produces sub-aquatic plants, it is wet. If we find 

 that such a soil is peaty, or shallow on a retentive sub-soil, it 

 is naturally sterile. If we find that the sub-aquatic plants are 

 tall and vigorous, and the soil earthy and deep, the removal of 

 the wetness may remove the cause of infertility, and such a 

 soil may become of the richest kind. 



If we find a soil producing naturally the superior herbage 

 plants, and of a good depth, that soil we may infer to be good. 

 When soil of this kind tends to a dark hazel colour, we may 

 safely rank it among the superior soils. 



II. MEANS OF INCREASING THE PRODUCTIVE POWER OF SOILS. 



THE means at our command for increasing the productive 

 powers of soils may be comprehended under the following 

 general heads: 1. Supplying to the soil those organic and 

 earthy substances which may be required. [The grand deside- 

 ratum in many, if not most, infertile soils is calcareous mat- 

 ter, that is, carhonate of lime. The second desideratum is an 

 additional quantity of geine, that is, a larger supply of the food 

 of plants.] 2. Altering its depth, texture, and properties by 

 tillage and other means. 3. Changing its relation with respect 

 to moisture. 4. Changing its relation with respect to temper- 

 ature. 



Vegetable and animal matters, in a decomposing state, appear 

 to act in various ways in increasing the productive powers of 

 the soil. They improve its texture, and they may be supposed 

 to increase its power to absorb and retain moisture; but above 

 all, they supply that matter, which, in whatever form con- 

 veyed to the organs of plants, tends to nourish them. This 

 matter being absorbed by the roots of the plants, it must be 

 supplied when exhausted. 



Experience has in every age accordingly taught the hus- 

 bandman to supply those substances to the soil; and the doing 

 so forms one of the most important means at his command of 

 maintaining or increasing its fertility. 



Besides the animal and vegetable matter which is mixed or 

 combined with the mineral part of the soil, and is essential to 



