PEAT. 



simple that it seems impossible not to have understood 

 it: the best answer to the whole will be a simple de- 

 tail of facts. 



Peat is produced from the ligneous matter of de- 

 composed vegetables, yet only within certain limits of 

 moisture and temperature. But the former admits of 

 considerable latitude; since it is generated under water; 

 and on the drained declivities of mountains. The range 

 of temperature cannot be exactly assigned ; because, in 

 a hot climate, it may be produced under water, when 

 it would not be formed on the soil in the same place. 

 In the tropical regions, the decomposition of vegetables 

 is so rapid and perfect, that no peat is formed in these 

 situations, except in elevated places ; while, in the 

 colder climates, it occurs even at the level of the sea. 

 I formerly used this fact as an argument against the 

 imaginary tropical nature of the plants of the coal strata. 



The varieties in the quality of peat depend chiefly 

 on the situations in which it is formed, as these relate 

 to moisture and temperature, and on the nature of the 

 plants whence it is produced. Rejecting the distinctions 

 of former writers, equally futile and insufficient, it may 

 be divided into six kinds, namely, Marsh, Lake, Forest, 

 Maritime, and Transported Peat, though the limits of 

 some of these are not always defined. The subordinate 

 distinctions, from intermixture of situations, variations 

 of drainage and temperature, differences of the original 

 vegetation, extent of decomposition, and intermixture 

 of earths, do not here require notice. 



In the simplest cases, Peat forms a single stratum, 

 on the alluvial soil or the naked rock ; while, in others, 

 it alternates with sand, gravel, or clay, or with marl, 

 or with the beds of shells whence this originates. The 

 latter case occurs in lakes and aestuaries, or in the plains 

 of tardy rivers; and thus it is sometimes deeply buried 



