266 



analysis which we have obtained, there exists as much 

 as six tons of potash per acre, six inches deep, a supply 

 "which, with proper husbanding, will last for 600 years, 

 without any further artificial application. The province 

 of the silicates, in their effects upon the grain crops, is 

 to render the straw more stiff and healthy, and to give 

 it strength properly to sustain the ear. They communicate 

 that peculiar polish or varnish which is observable on 

 the exterior of healthy straw, and which prevents the corn 

 from being lodged or laid by rain and wind. As an 

 instance of the good effects of Lime, and to prove the 

 correctness of the theory of its action in releasing the 

 silicates, I may mention a circumstance which a few months 

 ago came to my knowledge, where one half of a field of 

 wheat was Limed, and the other not. The corn on the 

 former grew with a strong stiff and upright straw, and 

 a good ear ; — while on the latter, where no Lime was 

 applied, though the ear was also good, yet the straw 

 had not power and strength sufficient to support it, and the 

 crop was spoiled by being laid. Quick or Calcined Lime 

 also produces the beneficial effect of rendering available 

 any inert vegetable matter that may be in the soil, by 

 assisting its decomposition, when it has access also to the 

 air, and thereby renders it food for the plant, and at the 

 same time enters into combination with the acids that are 

 formed in the course of decomposition, — acids which would 

 otherwise be injurious to the growing crop ; and some 

 of the compounds thus produced, are considerably more 

 soluble and deliquescent than the Lime was in its original 

 state. 



It is an interesting question, whether, as silica is so 

 necessary a constituent of the corn crops, and is insoluble 

 except through the intervention of a caustic alkali, Quick 

 Lime being an alkaline earth, has immediately that effect ? 



