ON VEGETABLE PHYSIOLOGY. 53 



their component or constituent parts, belongs to 

 the province of vegetable chemistry. To treat on the 

 sources by which their growth is promoted, and 

 their productions increased, comes under the head 

 of chemical agriculture, or agricultural chemistry. 

 And to class and arrange them, according to their 

 external character, so as to distinguish the one 

 from the other, in the common acceptation of the 

 term, has been termed botany ; though botany, in 

 the strictest sense, applies to a history of the 

 science, in all its different relations. 



Had it been in my power to have delivered a 

 full course of readings on the laws of the vegeta- 

 ble kingdom, I should have considered it my 

 duty to have devoted one lecture at least to each 

 of the above branches, and to have detailed all 

 the minuter parts requisite for their special illus- 

 tration. Upon the present occasion, for the rea- 

 sons obviously assigned, I must limit myself to 

 a very brief account of the structure and physio- 

 logy of vegetables. 



From the great similarity and strong analogy 

 of the laws of the vegetable and animal kingdoms, 

 many modern philosophers have considered the 

 vegetable and animal kingdoms united by one 

 link, and forming a part of the same system ; or, 

 in other words, that a vegetable is only an inferior 

 order of animal. But admitting how nearly in 

 many instances the laws of each approximate, 

 and how greatly a knowledge of the one facili- 



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