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know very little about them up to the present time. 

 All that is actually known is, that these inorganic 

 substances, the constituents of the ashes of plants, 

 are of vital importance to the vegetable kingdom, 

 and indispensable to the existence of the plant ; 

 and it has been proved by actual experiments that 

 vegetable life cannot be supported in the absence of 

 any one of them and our knowledge ends here. 

 What functions these mineral substances have to 

 perform in vegetable life, can only be conjectured. 

 It will require indefatigable experiments and vast 

 powers of discernment to reveal to us the more 

 subtle operations of nature. 



The ashes of the different plants vary naturally 

 in the composition and proportion of their various 

 ingredients, but we find generally present first, 

 the soluble alkalis Potash and Soda, sometimes 

 combined with Chlorine; secondly, the alkaline 

 earths Lime and Magnesia, more or less in combina- 

 tion with Phosphoric and Sulphuric Acid; and 

 lastly, Silica, with a small portion of Iron, and 

 sometimes Alumina. As different plants contain 

 these substances in various proportions, and all are 

 exclusively derived from the soil, it will be admitted 

 that an analysis of the ashes of the different plants 

 is of great importance, as it will guide us in 

 the selection of the soil on which it is intended to 

 grow a certain crop. 



The knowledge of the proportion in which a 



