61 
ELEMENTS OF AGRICULTURE. 
they do not know in what circumstances liming can be 
advantageously effected. 
12. To use lime as an ameliorating substance, it is 
necessary that the farmer should know how to distinguish 
the soils that would be improved by the application of cal¬ 
careous ameliorators. In effect, it is useless to add humus 
to land containing already enough ; just so is it useless to 
add lime to land that has enough. It would be a useless 
waste of labor, and might produce injurious consequences. 
13. The carbonate of lime, then, as an ameliorator, is 
only suited to such lands as do not contain calcareous prin¬ 
ciples. It is easy to recognise them: whenever an earth, 
brought in contact with an acid, produces an effervescence, 
we may be certain that it contains a sufficiency of lime to 
produce the desired effect upon such organic parts of diffi¬ 
cult decomposition as may be contained in the soil. 
14. The spontaneous vegetation, also, frequently indi¬ 
cates the lands upon which lime may be used to advantage. 
Thus, those lands upon which broom, red sheep-sorrel, 
heath, the chestnut, and resinous trees, grow spontaneously, 
are generally disposed to increase in value by the applica» 
tion of lime. 
QUESTIONS. 
1. What is the composition lime? 
2. How is it obtained 1 
3. What use is it put to 1 
4. Why is not its use more general in agriculture ? 
5. What ought the cultivator to know to make use of lime ? 
6. Are calcareous soils improved by liming ? 
7. How are calcareous soils recognised ? 
g. By what sign do we recognise the utility of liming a goal f 
