22 AMERICAN AGRICULTURE. 



ceeded ; and few are more profitable for cultivation or 

 grazing. 



ALLUVIAL SOILS, are such as have been formed from the 

 washing of streams. They vary in their characteristics, 

 from a mixed clay to an almost pure sand ; but gene rally, they 

 combine the components of soils in such proportions as are 

 designated by loamy soils, or sandy loams. "When thus 

 formed they are exceedingly fertile ; and if subject to the an- 

 nual overflow of a stream, having its sources far above them, 

 they usually receive such an addition to their productiveness, 

 as enables them to yield large crops perpetually, without 

 further manuring. 



They are for the most part easily worked, and are suited 

 to the various purposes of tillage and meadows ; but when 

 exposed to overflowing, it is safer to keep them in grass, as 

 this crop is less liable to injury by a freshet ; and where sub- 

 ject to washing from the same cause, a well-matted sod is 

 the best protection which can be offered against it. Many 

 of the natural grasses which are found in these meadows, 

 yield a fodder of the highest value. 



PEATY SOILS. These are composed almost wholly of peat, 

 and are frequently called vegetable soils. They are exten- 

 sively diffused between the latitudes of 40 and 60 north, 

 at a level with the ocean, and are frequently found in much 

 lower latitudes, when the elevation of the surface produces 

 a corresponding temperature. They generally occupy low 

 swampy levels, but sometimes exist on slight, northern 

 declivities, where the water in its descent is arrested by a 

 succession of basin-shaped cavities. 



Their peaty character is acquired, by the growth and par- 

 tial decay, through successive ages, of various aquatic plants, 

 the principal being the sphagnums and lichens. In swamps, 

 many of which were probably small lakes in their origin, 

 the peat is found of an unknown depth, reaching in some 

 instances, beyond 30 and 40 feet. On declivities and occa- 

 sional levels, the peat is sometimes only a few inches in 

 thickness. It is of a blackish or dark brown color, and exists 

 in various stages of decay, from the almost perfect state of 

 fallen stumps and leaves, to an imperfectly defined, ligneous 

 mass, or even an impalpable powder. 



In its natural state, it is totally unfit for any profitable 

 vegetation, being saturated with water, of an antiseptic na- 

 ture, which, for an almost indefinite time, resists putrefaction 

 or decay. When thrown out of its native bed and exposed 



