JOHN P. NORTON'S ADDRESS. 393 



all wild uncultivated land. In situations where no counteract- 

 ing influences are at work, a thin soil is thus at last collected, 

 even on extremely poor land that is in a state of nature. I 

 have seen land once good, so exhausted by cropping that even 

 weeds would scarcely grow upon it. On soils naturally fertile, 

 as at the west, this annual growth and decay produces in time 

 a rich deposit of great depth, and of almost inexhaustible fer- 

 tility. 



It will be remembered, that these plants, whose remains form 

 in this manner a new soil, contain, beside much organic matter, 

 also some inorganic substances, or ash. This is, of course, 

 drawn wholly from the soil. There are, in every soil, stores 

 of inorganic substances, suitable for plants, that lie in what 

 chemists call an insoluble state ; that is, they cannot be dis- 

 solved, either in water or acids. Gradual changes are, howev- 

 er, always going on, by which these compounds are becoming 

 soluble, a small quantity being thus changed every year ; the 

 rapidity of this change is doubtless accelerated, by the presence 

 of the roots of growing plants. Stiff" clays are especially ben- 

 efitted, by ploughing in heavy green crops, as they are thereby 

 lightened and mellowed, so that air and warmth can have ac- 

 cess, and aid in the work of decomposition. The roots of 

 growing plants penetrate into the subsoil, and bring up thence, 

 mineral food. Some of the deep rooted green crops go very 

 far down, and bring up stores, quite inaccessible to our ordinary 

 cultivated crops. When the green crop dies, or is ploughed in, 

 this inorganic matter is deposited within the reach of succeed- 

 ing crops. Thus, the ground is at last prepared for valuable 

 plants ; those which grow first, may not contain particular sub- 

 stances, necessary for particular plants ; but when crop has suc- 

 ceeded crop, each adding a little to the stock, — aided, mean- 

 while, by natural decomposition, — a sufficient quantity may 

 have accumulated, for the support of the more valuable crop. 



It is easy to see, how much faster the land must gain, by this 

 system of green cropping, than by naked fallowing. In the 

 naked fallow, by means of constant stirring and ploughing, the 

 decomposition of insoluble inorganic substances is hastened, 

 and a store collected for the next season. The same end is 



