214 BOARD OF AGRICULTURE. 



FERTILIZERS AN* ) PLANT FOOD. 



By Prof. G. H. Whitcher, Director New Hampshire Experiment 



Station. 



Plants no less than animals require food ; the^' create nothing, 

 but simply take the compounds which exist in the air and in the 

 soil and by unknown chemical processes build up starch, sugar, 

 cellulose, vegetable acids, oils, albuminoids, etc. This power 

 belongs exclusively to plants : animals are unable to transform the 

 elements of water and carbonic acid into starch and glucose, or any 

 other organic compound. 



If plants must be fed it follows that we must have food upon 

 which to feed them. This we call plant food. 



To know what plants require we must know what they are made 

 up of. Chemical analysis alone is able to take apart the substance 

 of a plant and tell what it is composed of. A stalk of corn weighing 

 five pounds, or eighty ouuces, was analyzed at the Agricultural 

 College Laboratory and found to contain : 



Water 



Albuminoids ... 



Fat . . 



' Cane sugar 



Car bo- , Glucose . . 



hydrates, "} Starch, etc. 



i^ Fiber. . 



Ash 



Total 80 00 



Water is made up of hydrogen and oxygen. Sugar, glucose, 

 starch, fiber and oil are made up of carbon, hydrogen and oxygen, 

 and about eighty-five per cent of the albuminoids is made up of the 

 same three elements, while the remaining fifteen per cent, is nitrogen. 

 It has been shown by various experiments that all the carbon of a 

 plant comes fiom a gas called "carbonic acid gas" which exists in 

 the air ; the hydrogen and oxygen come chiefly from water. 



