CHAP. VI. 

 ON THE APPLICATION OF MOISTURE. 



From what has been stated in the preceeding chapter, 

 it will be sufficiently evident, that a supply of water is 

 required as a component of the soil, in which all plants 

 are grown, in order to enable them to draw from it, other 

 components, which form their food ; and that, as it is 

 necessary for them continually to take up a portion of 

 this food, so is it necessary, that moisture should be con- 

 tinually present, in order to render it available by them. 



Among other conditions to which the operation of 

 applying water to the soil should be subjected, there are 

 some which are specially important : it should never be 

 either applied in excess, or unduly withheld ; nor should 

 it ever be applied when of a temperature below that of 

 the atmosphere in which the plants to whose roots it is 

 applied, are growing at the time of its application. 



There is a liability of applying water in excess, when 

 the particular stage of growth, the peculiar state of the 

 weather, or the season of the year, are not duly regarded : 

 thus, an adult plant will consume more water than an 

 infant plant; and any plant, will decompose a larger 

 quantity of water, in sunny weather, when evaporation 

 is going on briskly, than in cloudy weather, when it is 

 scarcely perceptible; again, in the summer season, a 

 much larger quantity will be appropriated, than in the 

 winter. Water has been applied in excess, whenever the 

 soil becomes soddened or saturated therewith ; but great 

 as this evil is, it is equalled in its injurious effects, by 

 falling into the opposite extreme, and withholding a 

 quantity sufficient to render the constituents of the soil, 

 available as food to the roots of plants placed in it. 



