22 
MANURES. 
What is that work ? It has already been told. But, 
if it finds no acid to combine with, it then unites with 
the mould itself. It is absorbed by it. 
The mould holds it fast; it stores it up against the 
time when growing plants may need it. Now it is 
only where the abundance of ammonia produced satis¬ 
fies these actions of hastening decay, making mould 
soluble, and filling its pores without combining with 
it, that the formation of saltpetre takes place. Sq 
where animal matters, which are the great source of 
ammonia, decay, there we may expect all these ac¬ 
tions to occur. How important, then, is that action 
of mouldering, which produces ammonia. If, reader, 
you will reflect upon the consequences of this action, 
you will at once see, that if the mould is in too small 
a quantity to retain the ammonia, it may escape. If 
by a wasteful exposure, you allow your mould to dissi¬ 
pate itself in air, as #it certainly will, you not only 
incur the loss of that part of the mould, but you di¬ 
minish at the same time the chance of keeping the 
ammonia which has been formed. No doubt all cattle 
dung exposed to air, forms more ammonia than it can 
retain. Hence the necessity and the season of forming 
composts wflth this substance. u Keep what you have 
got and catch what you can,” must never be lost sight 
of in manure. The third action of mould is the pro¬ 
duction of heat. Little need be said upon this. That 
a slight degree of heat hastens the sprouting of seeds, 
you well know. That different manures produce 
different degrees of heat, that so.me are hot, some 
cold, you well know, and adapt your seed and manure 
to each other. The degree of heat depends upon the 
rapidity with which decay occurs. And this is 
affected by the quantity of ammonia which each ma¬ 
nure can afford. The great point, to which your 
attention should be directed, when considering the 
power of mouldering to produce heat, is, that it shall 
not go so far as to burn up your manure, just as hay 
will heat and take fire. 
