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NOTICES OF AUTHORS. 



assists in the process of vegetation, there can be no 

 doubt, when we consider that any kind of dung may- 

 be deprived of the greater part of its strength by 

 being long exposed to a dry atmosphere. Nor is it 

 merely by preserving its own original substance that 

 land in wood has the advantage of cultivated ground. 

 Whatever is extracted from the latter in the form 

 of vapour, falls again, when condensed, in the shape 

 of rain or dew ; but, instead of descending wholly 

 on the same spots from whence it rose, it is, of course, 

 diffused over the whole space which the clouds, con- 

 taining it, may happen to cover, and woods and 

 moors have as good a chance of receiving it on its 

 return to the earth, as the ground in tillage. The 

 part of it which falls, either on the cultivated fields 

 or the naked wastes, may be again evaporated be- 

 fore it has time to be productive of any benefit ; but 

 the portion of it which the woodlands imbibe is re- 

 tained to enrich the soil ; for, the umbrage exclud- 

 ing the rays of the sun, there is no possibility of its 

 being extracted a second time. Land covered mth 

 trees, therefore, while it never loses any thing, re- 

 ceives, with every fall of rain, or of dew, a tribute from 

 the riches of the cultivated part of the country. The 

 advantage derived from this source is greater than will 

 be credited by those who are not aware how much 



