148 STALL-MANURE AND STRAW. 



Nevertheless, the fallen leaves and plants of the for- 

 est, of v^hich leaf-litter is composed, contain in a 

 fresh state much more potash and other soluble mat- 

 ters ; but these are washed away in the course of 

 time, and are again absorbed by the soil on which 

 they lie. For the forest this is a fortunate circum- 

 stance, since without it the removal of the litter 

 would be far more prejudicial to the growth of its 

 trees than, beyond all doubt, it generally is. In 

 this lixiviated state leaf-litter contains little more 

 than the same insoluble constituents which are 

 found in the solid excrements of cows, but lacks ex- 

 actly that which is deficient in the latter (potash and 

 azotized substances that readily disorganize) ; it can- 

 not, like straw, absorb these missing elements in 

 considerable quantity from the urine, since it takes 

 up but little of this secretion. Hence it is clear that, 

 for these reasons, the manure obtained from leaf-lit- 

 ter must be considered very imperfect. 



If the forest-soil is not exceedingly vigorous, the 

 farmer acts very foolishly who deprives his trees of 

 nourishment, and the ground on which they grow of 

 its cover and natural means of protection, in order to 

 provide his grain with a miserable food. The harm 

 thus accruing is, generally speaking, far more consid- 

 erable, and the benefit much less, than he imagines. 

 A poor, sandy soil, that is left entirely untouched, 

 obtains with difficulty in fifty or sixty years a layer of 

 humus from half an inch to an inch in depth, a weak 

 upper covering ; by once raking off this litter, there- 



