156 ESSAY ON TOP DRESSINGS 



substance, and that it is essential to the growth of clover.^ 

 This may, perhaps, explain why clover so soon runs out to 

 give place to other grasses. The requisite supply of plaster 

 has been exhausted. In any case, the addition of plaster to 

 clover lands, and especially to pastures, is of the highest im- 

 portance. 



The effect of charcoal is somewhat similar to plaster. Char- 

 coal will absorb ninety times its own bulk of ammonia, which 

 is held from escaping till it is separated by water and carried 

 into the earth for the plant. When dry, the operation of fix- 

 ing the gas is repeated till the next shower sends the gas into 

 the earth, and the particles of water take its place in the char- 

 coah In this way, as a top dressing, charcoal as well as plas- 

 ter, performs the most important functions. If we take any de- 

 caying animal matter, which has begun to give off its offensive 

 and noxious odor, its ammonia, and cover it with charcoal or 

 plaster of Paris, this escaping gas is immediately stopped. No 

 infectious odor arises from it. The decay of the substance 

 has suddenly ceased. This simple fact will show the intelli- 

 gent farmer to what purposes these substances may be applied. 

 His choice of these should depend somewhat on the expense 

 of procuring them. The relative expense depends so much 

 upon circumstances, that we need not make the estimate. As 

 an absorbent and retainer of the valuable properties of manure, 

 peat mud aiid loam will also be found of essential service. If 

 used on a high and dry soil, the effect of plaster will not be 

 very apparent the first season, unless like the present, there 

 are frequent rains. 



There is an impression among many that plaster does not 

 produce so good results in the immediate vicinity of the sea 

 shore. This, we think, does not arise from the proximity to 

 the sea, but from other causes. Many of our lands do not 

 need the application of plaster. We have seen it used, to the 

 best advantage, within two miles of the sea. If thera were 

 any thing in the sea air to prevent plaster from performing its 

 usual functions of fixing the rich gases, the effect would be 

 perceived to a far greater distance inland. If any failures have 

 occurred in its use in the vicinity of the sea, they were proba- 



