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APPENDIX. 



as common salts, soaper's spent leys, consisting chiefly of muriate of 

 potash mixed with a peculiar organic compound called glyceine, salt- 

 petre, ashes leeched or fresh, urine, containing abundant phosphates 

 and aramoniacal salts, soot ; containing both ammonia and geine ; third, 

 lime, in all its forms, marl, shells, chalk, marble, air-slacked lime, plas- 

 ter, bones. 



3. Silicates. — To have a distinct idea of this division of soil, let 

 ue tabulate the composition of argillite, and of the several simple min- 

 erals, whose aggregate composes primitive rocks. Though analyses, 

 imperfect as they are, have not yet discovered phosphoric acid in all 

 these aggregates, yet I doubt not, that accurate investigation will de- 

 tect its presence in all granitic sand. Phosphate of lime is by no 

 means an uncommon mineral in primitive rocks, and chlorides are 

 widely diffused. 



Table of the constituents of the elements of silicated soils or granitic sand. 



Argillite contains notable portions of carbon. The source of this 

 not only in this, but in other primitive rocks, I shall show elsewhere, is 

 the geine and geates, held in solution in the water, from which these 

 sedimentary rocks were deposited. 



Sulphuretof iron is abundant in primitive rocks. Its decomposition 

 produces with the silicates, sulphates of alkalies, earths, and oxides. 

 Keeping in view the remark on phosphates and muriates, and we have 

 then, at a glance, the inorganic elements of all plants. 



Burning reduces these constituents to two classes : ashes and vola- 

 tile salts. The last are found in soot. The ashes are formed of salts 

 and silicates. These vary in quantity and quality, not only in different 

 plants, but, as is well known, in different parts of the same plant. Let 

 us take oak, beech, basswood, birch, as the types of the composition of 



