HINTS ON SOILS AND FERTILIZERS 19 
comparatively small amount of plant food. This 
is what happens: The leaves evaporate all this 
surplus water, and retain only the elements 
that the plant needs for growth. It is amaz¬ 
ing to learn the amount of water that is evap¬ 
orated by various plants to produce just one 
bushel of grain. For instance, a number of 
corn plants, sufficient to produce one bushel 
of matured corn, will evaporate during one sea¬ 
son, over one hundred and fifty barrels of 
water. A rather startling assertion, is it not? 
Now, let us stay with the plant a little longer, 
and see what happens. Did you ever wonder 
why practically all plants have green leaves? 
As the breakfast food poet would say, “There’s 
a reason.” The plant has a reason for green 
foliage, or leaves. These plants all contain a 
substance known to the botonist as chlorophyll, 
or green coloring matter. Now this green color¬ 
ing matter, or chlorophyll, has the ability, in 
the presence of sunlight, to combine the ele¬ 
ments that present themselves in the leaves, 
and manufacture them into food for the plant. 
For instance, it takes the carbon that is 
breathed in by the plant in the form of carbon 
dioxide, it takes the oxygen from the same 
source, or from water, it takes hydrogen from 
the water, and it takes the nitrogen from the 
solution, as well as all the other mineral ele¬ 
ments that enter the leaves in the water solu¬ 
tion, throws off what it does not need, and uses 
the elements that it does need, making up 
various combinations of these elements, which 
go to nourish the rest of the plant. This 
process cannot take place unless in the presence 
