16 HINTS ON SOILS AND FERTILIZERS 
bination, known as carbon dioxide. This is the 
same gas that people exhale in breathing, and 
is mildly poisonous, but the plant breathes in 
this gas, and immediately separates the two, 
retaining the carbon, and releasing the oxygen. 
To sum up: A plant will grow under some 
conditions, and will fail to grow under others. 
The soil is largely the determining factor as 
to the success or failure of a crop, and the 
physical and chemical condition of the soil is 
the point that needs the greatest emphasis. 
Before proceeding further in the mysteries of 
the soil, perhaps it would be best to first con¬ 
sider something about the soil in its relation to 
plant growth. 
HOW SOILS AFFECT PLANT GROWTH 
Let us first start with a seed, and get a clear 
idea of just what a seed is, and then we can 
follow the young seedling up through its 
growth, and learn some of the mysteries of 
the plant and its relation to the soil. A seed 
is usually defined as a young, miniature plant 
that is in the dormant, or resting stage, with 
enough plant* food surrounding it to nourish it 
until it is capable of sending out roots to gather 
its own food. These seeds are usually com¬ 
posed, then, of two major parts; the miniature 
plant, sometimes called the embryo, and the 
plant food surrounding the embryo. 
Next, let us plant this seed in the soil, and 
note what takes place. We will find that if 
the soil is fairly warm, and if a sufficient 
