COLD AND SOUR SOILS. 67 



as is well known, when the muck is taken out and 

 dried, it becomes a valuable manure : this is because 

 air and warmth obtain access, and the process of 

 decomposition goes on again. In order to avoid mis- 

 apprehension, it ought here to be mentioned that these 

 aciils in small proportions are really useful in the soil, 

 as furnishing a portion of their food to plants. It is 

 the excess of them that does so much injury. 



It is not only in swamps that this injurious formation 

 occurs : there is much land which is too wet in the 

 early part of the season, or in which are springs that 

 saturate the surface; this land may be hard, and may 

 even bear ploughing, yet still it is what farmers call 

 cold and sour. These are exactly the proper words, 

 for they truly express its qualities. Considerable and 

 injurious quantities of these vegetable acids are 

 formed; and the water, by constant evaporation from 

 the surface, produces cold; the grass is scanty and 

 poor, while rushes show themselves in the wettest 

 spots. There are large tracts of such land as this in 

 almost every part of the country. Farmers think such 

 J and too dry for draining, and yet that is the only way 

 to make any permanent improvement upon it. It is 

 cold and late in spring, apt to bake hard in summer, 

 and to suffer from early frosts in autumn. It is not 

 in a fit condition to support good crops, and the only 

 way to bring it into a good state is to dry it. 



Some land is dry on the surface, but has a wet sub- 

 soil : when the roots of the plants get down to this, 

 they find at once injurious food, not only the acids 

 already mentioned, but inorganic substances; the pro- 

 toxide of iron, described in Chapter V., is very apt to 

 form in such places, and is at once fatal if the plant 

 can find no nutriment in other directions. In this case 

 too the only remedy is to drain. The good effects of 

 this operation on all soils suffering from any of the 

 causes above mentioned, are very remarkable, and 

 must briefly be specified before going farther 



