REASONS OP B. 



know what to do, but may not in all cases be able to 

 do it with a profit, and this with a practical man is 

 always an important distinction. 



It will be noticed in table first, that alumina, a 

 substance rarely, if ever, present in the ash of plants, 

 is quite an abundant constituent of soils. This is one 

 distinction between the inorganic part of plant:s and 

 that of the soil, alumina being a characteristic of the 

 one and absent from the other, in nearly all soils, silica 

 is the leading substance, usually constituting fully 

 two-thirds of their whole weight, and often eighty or 

 ninety pounds in every hundred. The only cases in 

 which it is not largely present are those of the f>eat 

 bogs, made up almost entirely of vegetable matter. 

 Silica forms compounds with certain of the other 

 bodies in the soil, making what are called soluble 

 silicates. The gradual formation of these compounds 

 affords a supply for the plant. 



We have now mentioned the substances which are 

 present in the soil, and have in a previous chapter 

 dwelt u|>on those which constitute the plant. Sundry 

 points of connection between the two, will alre:»dy 

 have suggi'stefl themst'lvt's to the reader or st 

 To these we must next turn our attention, in tri 

 of the various melluxls proper to be employed in 

 bringing soils to a state of fertility, and to a ••' "!'!'« ion 

 the most easy and profitable for cultivation. 



From examining table first, and from thf « xpiana- 

 tions already given, it will be perceivinl that there 

 are various points to be consideretl in he 



improvement of a soil. a. If there A 



dencioicy, that is an absence of certain constituents 

 necessary to fertility, as mcntioneil above, tin n hut 

 one course can be adopted with any hope s: 



this course is obviously to supply what i i^. 



The ways of doing this in the most advant. td 



economical manner, will be coQsid<-r< ' what 



