114 BIOLOGY OF PLANTS. 



insight into the mysteries of nature, and to be better fitted to 

 discharge our duties as citizens and as men ; our toils will 

 become lighter, because we shall find in our employment an 

 interest and a soul. 



9 



CHAPTER III. 



PRODUCTIONS OF THE VITAL PRINCIPLE THEIR CHARACTER, 



COMPOSITION, SOURCES AND ASSIMILATION. 



Having in the preceding chapters given a general account 

 of the vital principle, and the agents which act upon it, in- 

 cluding the general processes of vegetation, we come now to 

 describe the productions of this power ; for, in opposition to 

 the views of many chemists and vegetable physiologists, we 

 still insist, that this power actually/ ensts in vegetables, and 

 that we have good reasons for ascribing to it, as a principal 

 agent, the various compounds which are found in vegetable 

 bodies. The character of these compounds is wholly differ- 

 ent from that produced by a chemical or a mechanical agent. 

 Their composition cannot be accounted for by ordinary chem- 

 ical changes ; and the source and assimilation of their simple 

 constituents, teach the same doctrine. This chapter, there- 

 fore, will be devoted to the discussion of these topics. 



Sect. 1. Character and Composition of the Vegetable Pro- 

 ductions. 

 The productions of the vital power are very numerous. 

 They are called vegetable or proximate principles, such as 

 sugar, gum, and starch ; and differ, materially, in their char- 

 acter and composition, from inorganic bodies. The vegetable 

 principles exist in plants, already formed ; and the processes 

 by which they are separated, are called proximate analysis. 



