236 THE SYSTEM OF FARM-YARD MANURING. 



constituents serve to restore a more suitable proportion 

 between tlie straw and corn constituents for the future 

 cereal crop, and at the same time to diminish, in the arable 

 soil, those conditions which favour the growth of weeds. 



The preceding observations relative to the produce 

 given by the Saxon fields, both in the unmanm^ed and 

 manured state, afford, in my opinion, a perfect insiglit 

 into the nature and results of cultivation by the system 

 of farm-yard manuring. In the condition of these fields 

 in their several stages, we may see reflected the history 

 of agriculture. 



In the first period, or on a \4rgin soil, corn-crop is made 

 to succeed corn-crop, and when the produce begins to fail, 

 the culture is simply transferred to a fresh field. The 

 increasing requirements of the growing population, how- 

 ever, gradually put a check upon this plan, and compel 

 a steady cultivation of the same surface ; a system of 

 alternate fallowing is now resorted to, and efforts are 

 made to restore the lost fertihty of the soil, by manur- 

 ing with the produce of the natural meadows. After 

 a time, this expedient begins to fail, and leads to the 

 cultivation of fodder-plants, the sub-soil being thus 

 turned to account as an artificial meadow. The culti- 

 vation of fodder-plants proceeds, at first, without inter- 

 ruption ; after a time, longer and longer intervals are 

 interposed between the clover and turnip crops ; finally, 

 the cultivation of fodder-plants comes to an end, and with 

 it the system of cultivation by farm-yard manuring. The 

 ultimate result is the absolute exhaustion of the soil, 

 inasmuch as the means for increasing the produce of the 

 soil gradually pass away from it by this system. 



Of course, the progress by which these difl'erent stages 

 are reached is extremely slow, and the results are felt 

 only by the third and fourth generation. Wlien there 



