CONCLUSIONS DEBITED FROM TABLE II. 77 



cording to the above table, would be lime and mag 

 nesia; about 35 Ibs. would be potash and soda. The 

 whole quantity 72 Ibs. seems small when taken from 

 an acre, and either of the above portions of it appear 

 almost unworthy of notice; yet it is found by expe 

 rience, that if the crops are unable to obtain these 

 small and comparatively seeming unimportant parts 

 oi their whole bulk from the soil, they absolutely re 

 fuse to flourish. The farmer may furnish other manures 

 as abundantly as he pleases, but if they do not in some 

 form or other contain these missing ingredients, the 

 plant can not be forced to grow thriftily or yield 

 abundantly. The appearance of his field will say as 

 plainly as words could express it, that something is 

 needed which he has not given. How many crops 

 thus demanding food from their owners, do we see in 

 almost every neighborhood ! Should not the farmer of 

 whom such a demand is made, exert himself to supply 

 what is wanted; and if he does not already know, to 

 gain the necessary knowledge? 



Several points are established by such a table as the 

 foregoing, and these may with advantage be briefly 

 recapitulated 



1. Our cultivated plants require that all of the in 

 organic substances present in Table I. shall exist in the 

 soil. . 



2. They do not require them in the same proportion, 

 the different plants differing in the composition of 

 their ash. 



3. This composition of the ash is not accidental, but 

 each plant has a distinct character of its own. 



4. It is thus rendered obvious that land which would 

 grow one crop well, might not be able to grow an 

 other having a different composition. A crop requiring 

 little potash, for instance, might flourish luxuriantly 

 where one requiring much of this substance would fail. 

 To the principle thus indicated, we propose to return 

 in the next chapter. 7* 



