THE PLAJ!fT. 49 



men liav^e become shorter and less blessed with 

 health and strength, than thej were in the good old 

 days when a stone mortar and a coarse sieve made 

 a respectable flour mill. 



Another important fact concerning the ashes of 

 piants is the dift'erence of their composition in different 

 plants. Tims, the most prominent ingredient in the 

 ash of the potato is potash ; of wheat and other grains, 

 phosphoric acid ', of meadow hay, silicic acid', of clo- 

 ver, lime I of beans, jpotash^ etc. In grain, potash 

 (or soda), etc., are among the important ingredients. 



These differences are of great importance to the 

 practical farmer, as by understanding what kind of 

 plants uses tlie most of one ingredient, and what kind 

 requires another in large proportion, he can regulate 

 his crops so as to prevent his soil from being exhau-st- 

 ed more in one ingredient than in the others, and 

 can also manure his land with reference to the crop 

 which he intends to grow. The tables of analyses 

 in the fifth section will point out these differences 

 approximatel3\ The composition of ashes varies a 

 little, but not enough to affect the value of tho 

 tables for the uses of the farmer. 



CHAPTER VIII. 



RECAPITULATION. 



We have now learned as much about the plant as is 

 required for our immediate uses, and we will care- 



3 



