88 GKALL.E. 



of the country which but for them would become driving 

 dust in summer, and so susceptible to cold in winter, that 

 they would be continually drawing the moisture from the 

 surrounding fields in the hot and dry months, and chilling 

 them with nipping winds at the other times of the year. 



Sunbeams never fall idly : and if the nature of any surface 

 is such that they cannot fall upon it for good, they are 

 certain to fall for evil. If there is a vegetable covering, it 

 clothes as a mantle, or cools by its evaporation ; and if there 

 is vegetable matter in the mould, the decomposition of that 

 finds the sunbeams in employment, and the gaseous pro- 

 ducts which they evolve enter into new combinations, and 

 the waste which takes place there is merely a transfer to 

 other places. 



But if there is nothing but the powder of the earths, or of 

 metallic and other mineral substances, there is nothing but 

 the idle operations of nature's chemistry heating and dry- 

 ing, cooling and wetting, both running to extremes with the 

 seasons, and both tending to spread their effects. 



Any one who has observed, but for one season, the progress 

 of vegetation upon the margin of a plantless waste, and com- 

 pared it with that upon ground of the same quality, elevation, 

 and aspect, which had not the misfortune of so bad a neigh- 

 bour, must have seen what would have been the advantage 

 of having that ground covered with vegetation of any kind. 

 When matters are in that state, there are of course no de- 

 stroying insects ; for they too must perish in the ruin of which 

 they are the authors, and which they would always accom- 

 plish to a certain extent, were it not for the birds that feed 

 upon the ground. 



These birds take up the ground where the field birds end, 

 and occupy it as far as there is food and as a walking foot can 

 go, to the uppermost part of the hill that will bear bent and 

 rushes, to the farthest shallow in the lake and' the river; 



