392 



On the Improvement of Peat Soils. 



tica), long-leaved cotton-grass (Eriophorum polystachion), and 

 the sheathed cotton-grass (Eriophorum vaginatum). 



It is of primary importance that the farmer should clearly un- 

 derstand the chemical composition of the peat with which he has 

 to contend;, and that of the watery solution with which it is usually 

 saturated. 



The common varieties of peat when dried by a moderate heat 

 lose a very considerable portion of their weight, and are materially 

 reduced in bulk. The dry mass consists chiefly of woody fibrous 

 remains of a dark-brown colour^ of which a very inconsiderable 

 portion is soluble in water ; and even by exposure to the unas- 

 sisted action of the sun and air, under the most favourable cir- 

 cumstances, it decomposes with extreme slowness. When burnt 

 to an ash the solid product thus obtained varies commonly in its 

 composition with the nature of the stratum of earth on which the 

 mass of peat rests. If this is of a gravelly or argillaceous nature, 

 the ashes are generally chiefly composed of silex, and a small 

 portion of alumina, oxide of iron, with some carbonate of lime 

 and sulphate of iron : if, however, the substratum immediately 

 under the peat is calcareous, then the ashes commonly yield a 

 considerably larger proportion of carbonate of lime, the sulphate 

 of iron (green vitriol) is absent, and the sulphate of lime (gypsum) 

 abounds in its place. 



The celebrated Dutch ashes, which are productive of such 

 large crops of clover, are composed of — 



Siliceous earth ..... 32 parts. 



Sulphate of lime (gypsum) . . . . 12 „ 



Sulphate and muriate of soda (Glauber salt and common salt) 6 „ 

 Carbonate of lime . . . . . 40 „ 



Oxide of iron . . . . . 3 „ 



Loss . . . . . , 1 ,i 



100 



The liquid with which peat is usually soaked is also equally 

 varying in its composition. It almost always contains a very small 

 portion of brown vegetable extract, a quantity of the red oxide of 

 iron, and when pyrites (sulphur and iron) are contained in the 

 gravelly or other substrata, these are gradually, by the action of 

 the water and the oxygen of the atmosphere, converted to sul- 

 phate of iron, which dissolves, and is found in the water. When, 

 however, this solution comes in contact with chalk or other calca- 

 reous matter, the lime decomposes the green vitriol, the iron is 

 precipitated, and sulphate of lime, so enriching to some of the 

 artificial grasses, is very commonly found with red oxide of iron, 

 dissolved in the peat water. 



The chemical composition of peat-soils of course varies in the 



