98 



ON THE FOOD OF PLANTS. 



THE food of plants has for a long time been 

 considered an object of importance, by natural 

 philosophers, and a great variety of experiments 

 have been made, to ascertain what it consists of, 

 and in what state of preparation it is most 

 readily and effectually applied ^ and many con- 

 clusions have been drawn, and conjectures 

 formed. As before explained, the earth, ani- 

 mals, and vegetables, have been analyzed, and 

 their component parts minutely described, by 

 men of the greatest talents and learning ; but as 

 yet no one has arranged and described such a 

 system of cultivation as will enable a person to 

 trace effects to their causes on just scientific 

 principles. Much has been founded on conjee 

 ture, and much still remains to be determined 

 by practical observation and demonstration. 



Vegetables, like animals, vary in their natuie 

 and habits, and like them have their peculiar 

 food; and although the food of plants may ge- 

 nerally be composed of the same elements, it 

 varies in the proportion of its composition, and 

 thereby becomes adapted to different purposes : 

 thus we find that a soil, which will furnish food 



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