ON GARDENING 



combine certain inorganic elements into nutritious 

 foods, a feat that no human chemist can perform. 



But on the other hand, we do know, thanks to 

 the analysis of the chemist — who can sometimes 

 tear things to pieces and find out what they are 

 made of even when he cannot put them together 

 again — what the chlorophyll granule accomplishes, 

 even though we cannot understand just how or 

 why it is able to perform its work. 

 Chlorophyll at Work 



What takes place within the structure of the 

 leaf, then, with the aid of the wonderful green 

 workmen, is this : A certain number of molecules 

 of water, brought to the leaf from root and stem, 

 are taken in hand and compounded with a certain 

 number of molecules of carbon extracted from the 

 air that has been brought into the leaf laboratory 

 through its mouths or stomata from the outside 

 atmosphere. 



When the compound has been effected, we still 

 have the atoms of hydrogen and oxygen that com- 

 posed the water molecules and the atoms of 

 carbon, but they are so marvelously put together 

 that they no longer constitute the liquid water or 

 the gas in which the carbon was imported. They 

 now constitute an altogether new substance which 

 is termed sugar. 



Thus only three elements are dealt with and 



[31] 



