184 uow cEors fked. 



ration are vastly more numerous and less wide than In 

 purer clays. Such a soil does not " cake," but remains 

 friable aiul powdery. 



Marly soils (containing carbonate of lime) are especially 

 prone to fall to a fine powder during drying, since the 

 carbonate of lime, which, like sand, shrinks very little, is 

 itself in a state of exti'eme division, and therefore moi-e 

 effectually separates the clayey particles. The unequal 

 shrinking of these two intimately mixed ingredients ac- 

 complishes a perfect pulverization of such soils. On the 

 cold, heavy soils of Upper Lusatia, in Germany, the appli- 

 cation of lime has been attended Avith excellent results, 

 and the larger share of the benefit is to be accounted for 

 by the improvement in the textui-e of those soils which 

 follows liming. Tlie carbonate of lime is considerably 

 soluble in water charged with carbonic acid, as is the wa- 

 ter of a soil containing vegetable matter, and this agency 

 of distribution, in connection with the mechanical opera- 

 tions of tillage, must in a short time effect an intimate 

 mixture of the lime with the whole soil. A tenacious clay 

 is thus by a heavy liming made to approach the condition 

 of a friable marl. 



Heaviu^ by Frost. — Soils which imbibe much water, 

 especially clay and peat soils, have likewise the disagree- 

 able ])roperty of being heaved by frost. The expansion, 

 by freezing, of the liquid water they contain, separates the 

 particles of soil from each other, raises, in fact, the surface 

 for a considerable height, and thus ruptures the roots of 

 grass and especially of fall-sowed grain. The lifting of 

 fence posts is due to the same cause. 



ADHESIVENESS OF THE SOIL. 



In the language of the farm a soil is said to be heavy 

 or light, not as it weighs more or less, but as it is easy or 



