UPPEE INDIA. 47 



evaporation, and calcareous sand the least. The more humus, 

 therefore, that there may be in a soil, the greater will be its 

 power of preventing loss of moisture by evaporation. This, 

 then, is another reason why, in dry climates more particularly, 

 care should be taken to preserve and bury in the soil all 

 refuse vegetable matters. 



To return to our jheels. We have, by banking up the fields 

 of their drainage basins, and by deep cultivation of them, the 

 water in the subsoil instead of in or on the surface-soil merely. 

 Once there and out of danger of loss by evaporation, the water 

 will gradually find its way to the jheels by percolation or natural 

 subsoil-drainage, which process will continue throughout the 

 year; there will be a constant supply of water furnished to 

 the jheel, which will be kept within more moderate limits in 

 the rains, its bed will not be dried up and exposed to the 

 action of the sun's heat in the dry seasons of the year, and 

 thus we should get rid of a most fertile source of malaria, 

 disease, and death. At the same time that excess of moisture 

 would escape by percolation to the jheels, sufficient would 

 be held in the soil for all the requirements of plants, by 

 capillarity. 



In the same way that water by surface- drainage finds its 

 way to jheels, it also does to the minor water-courses, and 

 eventually to the rivers ; the drainage area is not increased, 

 but the action of the water wears the surface-soil into slopes 

 and channels, which facilitate the rush of the water ; the beds 

 of the water-courses and rivers are no longer able to carry off 

 the water as quickly as it is brought to them, consequently 

 they overflow their banks and spread over the low land near 

 them. Over this land, out of the influence of the main 

 current, the water is more sluggish, and it deposits on it the 

 organic, vegetable and mineral substances it has brought 

 down in suspension. As the floods subside, the action of the 



