128 STALL-MANURE AND STRAW. 



under ordinary treatnnent it leaves the stable, turns 

 it to better account than by leaving it without fur- 

 ther attention to rot or ferment upon the dung-heap, 

 can no longer be doubted, since practical agricultur- 

 ists, by repeated trials and by comparative experi- 

 ments carried out upon a large scale, have very de- 

 cisively shown it to be true. What practical expe- 

 rience has established as indubitable, will always 

 accord with sound theory ; so also here. Science 

 explains this more profitable employment of fresh 

 manure in the following manner. When it is intro- 

 duced fresh below the earth, its putrefaction and de- 

 cay take place under a protecting cover, which, like 

 all porous bodies, has the power of absorbing and 

 firmly retaining the gases and other volatile sub- 

 stances thereby set at liberty, until they are taken up 

 by the roots of plants. In this manner those manur- 

 ing elements are placed at the disposal of plants, 

 which, in the common dunghill, fly off during fer- 

 mentation, and are often lost in large quantity by 

 being washed away. How considerable is this loss 

 is shown by the fact, that, in agricultural experience, 

 100 cwt. of fresh manure shrinks, by lying, to some 

 80 cwt. in a mellow or partially decomposed state ; 

 to some 60 cwt. in a saponaceous state ; and to 

 some 40 or 50 cwt. in a thoroughly decomposed 

 state. According to chemical analysis, it may be 

 assumed that, in the customary mode of treatment, 

 during the progress of this disorganization of 100 

 cwt. of fresh manure (i. e. stall-manure), there are 

 lost of its most valuable constituent, nitrogen. 



