146 ON THE FOOD OF PLANTS. 



is immediately buried ; for, as has been stated, 

 that by burning, the solid part of the earth can- 

 not be reduced ; no more can the solid part of 

 dung be reduced by evaporation ; and the effects 

 of dung thus placed, in increasing the disposi- 

 tion of a soil to absorb moisture from the at- 

 mosphere, cannot be less, than when immedi- 

 ately buried : and what is more essential, it will 

 be less retentive of water. 



Sir Humphry Davy has fully and minutely 

 described the nature and properties of all the 

 different substances used as manures, and such 

 who wish for particular information on these 

 divided subjects, I must refer to his work. My 

 object being to establish general principles, it 

 would be superfluous to attempt following him 

 further. On the preservation of manure he 

 says, " When dung is to be preserved for any 

 " time, the situation in which it is kept is of 

 " importance; it should, if possible, be defended 

 " from the sun ; to preserve it under sheds 

 " would be of great use, or to make the site of 

 " a dunghill on the north side of a wall. The 

 " floor on which the dung is heaped should, if 

 " possible, be paved with flat stones, and there 

 " should be a little inclination from each side 

 -" towards the centre, in which there should be 

 " drains connected with a small well, furnished 



