ELEMENTS OF AGRICULTURE. 
67 
also destroys the acid principles in the land ; but this must 
not be in a low, wet state, or it must first be drained. 
22. Moreover, lime, when it acts, according to the 
opinion of some writers, gives additional strength to the 
straw of the different cereals, and thereby prevents them 
from falling or lodging. It corrects the defects of soils 
that are too cold and wet, and increases the porosity of 
those that are too stiff. It consequently influences,,in a 
sensible degree, the yield of crops. 
23. We have seen (No. 19) that the effect of carbonate 
of lime does not differ from that produced by quick-lime; 
this last, however, should be preferred, and for this reason: 
Calcareous substances, to produce all the effects to be ex¬ 
pected from them, should be in an earthy state. It is then 
necessary that the carbonate, before being employed, 
should be pulverized, or reduced to powder ; this is easily 
done by calcination. To pulverize it in any other way 
would be tedious and expensive. 
24. When we are assured that a soil contains no calca¬ 
reous substances, the next thing to be ascertained is the 
quantity of lime to be employed, and the time and manner 
of applying it. Here are some rules to be followed * in 
this respect. 
25. The quantity of lime to be used depends, m general—• 
1. On the durability desired to be given to the ameliora¬ 
tion. 2. The nature of the soil to be limed. 3. The na¬ 
ture of the lime that is used. It is by the examination ot 
these three causes that we can ascertain the quantity of 
lime necessary to be applied. It is, however, understood that 
clay soils, particularly those that are cold turf-lands, and the 
soils in which organic remains do not readily decompose, 
require heavier liming than light and sandy soils. On the 
last, not more than half as much is used as in the first. 
26. Lime may be applied to the land in different ways, 
and at different periods. 1. It may be laid on the surface 
