2 OF THE CONSTITUENT ELEMENTS 



derive the means of their growth and support is 

 the vegetable kingdom. 



Plants, on the other hand, find new nutritive 

 material only in inorganic substances. 



The purport of this work is to elucidate the 

 chemical processes engaged in the nutrition of 

 vegetables. 



The first part of it will be devoted to the exami- 

 nation of the matters which supply the nutriment 

 of plants, and of the changes which these matters 

 undergo in the living organism. The chemical 

 compounds which afford to plants their principal 

 constituents, viz., carbon and nitrogen, will here 

 come under consideration, as well as the relations 

 in which the vital functions of vegetables stand to 

 those of the animal economy and to other pheno- 

 mena of nature. 



The second part of the work will treat of the 

 chemical processes which effect the complete 

 destruction of plants and animals after death, such 

 as the peculiar modes of decomposition, usually 

 described as fermentation, putrefaction, and decay ; 

 and in this part the changes which organic sub- 

 stances undergo in their conversion into inorganic 

 compounds, as well as the causes which determine 

 these changes, will become matter of inquiry. 



OF THE CONSTITUENT ELEMENTS OF PLANTS. 



Carbon enters into the composition of all plants, 

 and of all their different parts or organs. 



