SILEX. Ill 



vegetable products that have been given in 

 treating of this subject, must convince even the 

 most skeptical, how all-important these sub- 

 stances are; and that no plant or vegetable 

 structure can ever exist without the agency of 

 the simples thus imperfectly described. 



Farther experience will probably tend to 

 elucidate much that is now obscure in the pro- 

 cesses nature employs, and each fresh dis- 

 covery that is made not only simplifies the 

 subject, but is a double step in advance; as 

 such discovery not only tends to simplify what 

 is already comprehended, but gives us a firmer 

 footing on v^hich to base our future operations. 



