OF PLANTS BY MANURING. 6% 



sion is quite overwrought. Unless plants rich in 

 potash (for example, tobacco, cabbage, turnips, pota- 

 toes, etc.) are sought to be grown in uninterrupted 

 succession, ashes and urinous liquids are almost the 

 only manures containing potash at the command of 

 the farmer ; of these, however, in the majority of 

 farms, little, comparatively speaking, comes upon the 

 land, and yet its fertility does not for this reason di- 

 minish, if in other respects it is well manured, and a 

 judicious rotation is made in the crops. By a plen- 

 tiful manuring with stable-manure, with which the 

 drainings have not been especially incorporated, we 

 give to the soil from twenty to twenty-five pounds 

 of potash per acre ; and a single good crop of clover, 

 potatoes, or beet-root produces from forty to fifty 

 pounds of this substance per acre. Here, at all 

 events, the soil locks up potash ; and it can do so, 

 for almost all kinds of earth and stone contain (Con- 

 siderable stores of potash in an insoluble state. A 

 certain quantity of this is made soluble from year 

 to year by weathering, and has a very beneficial 

 influence upon plants. Spreading the fields over 

 with burnt lime causes an increased production of 

 potash, since lime possesses the power of breaking 

 up rocks or stones containing potash, and almost 

 always itself contains small quantities of this sub- 

 stance. 



The salts of soda, amongst which common salt, 

 carbonate of soda, and Glauber salts are the most 

 generally known, influence the growth of plants 

 6 



