412 EUROPEAN AGRICULTURE. 



water peat-bog. This, however, is composed of vegetable matter 

 in the main, being altogether marine plants, which have served 

 as a kind of net-work to collect the earthy matter brought among 

 them by the tide. The quantity of salt intermixed with these 

 deposits gives them a peculiar character. They are favorable 

 to the production of plants congenial to them ; but other plants 

 cannot be made to grow upon them until they become thoroughly 

 decomposed ; and, in that case, no soils yield a more luxuriant 

 or richer vegetation. In truth, they require to be reduced to the 

 state of fine mould, and the greater portion of the saltness ex 

 hausted, which time itself will effect where they are kept from 

 the access of the tide, in order to be in a condition favorable to 

 the growth of other than marine or saline plants. 



LXXI. LOAMY SOILS. 



Next to peaty soils, I have to speak of what are called loamy 

 soils. These are not very well defined. There has been much 

 debate as to what constitutes loam or mould ; but if it be difficult 

 to define it with exactness, there is no great difficulty with prac 

 tical men in understanding what is intended by it. I suppose 

 the proper definition of mould to be decayed vegetable matter, 

 and of loam to be that portion of the soil in which this mould, or 

 decayed vegetable matter, (or humus, as it is technically called,) 

 is mixed up with other common mineral elements, such as sand, 

 clay, and lime, and in a state of fineness and equal or diffusive 

 commixture. I do not know that any great error would be com 

 mitted by considering mould and loam as synonymous, and by 

 saying that mould or loam is a rich, unctuous, dark-colored mat 

 ter, abounding in vegetable as well as mineral substances, found 

 usually on the surface of fields, especially of those which have 

 been cultivated, or those which are entirely in a state of nature ; 

 and of various depths, from inches to feet. In the rich valley of 

 the Mississippi, I have seen it extending to a depth of twelve and 

 eighteen feet, and of extraordinary richness. In cases of pure 

 sand 01 clay, little or nothing of this is to be found. In chalk 



