ELEMENTS OF AGRICULTURE. 
79 
peas, tobacco, etc. It has 'been recommended to win ten 
the floors of stables, to prevent the escape of the ammonia 
from the urine and manure. 
68. The application of plaster to timothy meadows is 
of doubtful utility, as it encourages the growth of the clo¬ 
vers at the expense of the other grasses. 
69. Plaster must not be confounded with other calca¬ 
reous ameliorators. These last act upon the soil by ren¬ 
dering it fit for any crop, whereas plaster in no way 
changes the nature of the soil. 
QUESTIONS. 
]. What is piaster ? 
2 How should it be applied ? 
3. What quantity to the acre ? 
4. Why is it of doubtful utility on timothy meadows ? 
LESSON X. 
PARING AND BURNING. 
70. As yet, this is a means of amelioration little used 
m the United States. Its effects are very similar to those 
of calcareous substances, and in some localities it may be 
less expensive. 
71. The object of this process is to render active all 
inert organic substances; it will consequently be of little 
use on lands containing but little vegetable matter. 
72. The operation of paring is usually done in dry 
weather, in spring or summer. The surface or sod is 
turned up with the spade or plough, to the depth of three 
inches; the sods are then set on edge to dry, and when 
dry are disposed in heaps, in a shape favorable to combus¬ 
tion. Dry brush is then put under them, and slow fires 
kept up, until the whole are reduced to ashes. 
