BOTANY. [c 



It must be clearly understood that the above equation 

 does not profess to show all the vai'ious changes under- 

 gone by the crude material during its transformation 

 into starch; all that is intended is to show the propor- 

 tions of the various chemical elements before and after 

 the change. 



Carbonic dioxide and water are both inorganic sub- 

 stances ; that is, their chemical composition is not 

 necessarily the result of life ; on the other hand, starch 

 is an organic substance, because its chemical constitution 

 is determined by a living body, or by life. 



From the above it will be seen that the material 

 composing the bodies of animals and plants is not of a 

 kind peculiar to themselves, but consists of the most 

 abundant of chemical elements forming inorganic matter, 

 so that organic matter only means the re-arrangement 

 of the elements or constituents of inorganic matter in 

 new proportions, and this is true of every organic 

 product, whether animal or vegetable. 



It will have been observed that food is indispensable 

 to the well-being of the individual; but in spite of an un- 

 diminished food supply, individuals do not continue to 

 live on for ever, but in every form of life there is a limit 

 to the existence of the individual terminating in death, 

 and which is shadowed in under normal conditions by 

 the lessened physical and chemical activity of the entire 

 organism, resulting in the liberation of less energy, which 

 to a great extent constitutes the flow of life manifested 

 during the earlier period of the existence of an indi- 

 vidual. 



The comparatively short period of time constituting 

 the life of an individual may be divided into distinct 



