These mineral elements are to be found in the first instance in the
earth, but they are of no use to the body in that form. We cannot digest
and assimilate inorganic matter no matter how finely it may be
pulverized. But plants can assimilate them from the earth and organize
them in such form as to make them easily assimilable by animals and man.

If the soil on which our food is produced is itself deficient in some of
these elements, our food must also lack them. If, moreover, we cannot
for any reason add the missing elements to the soil, we must supply them
to the human system in the shape of prepared nutritive salts. It is
preferable, of course, that our food should contain all of the elements
necessary for the proper nourishment of the body.

Thus we are forced to return to consideration of the soil. It is an
established fact that our fields were originally formed from decayed
rock, and analysis shows that this primitive rock contains the same
minerals as healthy blood. But if our agriculturists are taught that
stable manure and three or four other things are all that is necessary
for the fertilization of their fields, where shall the other minerals
essential to human metabolism come from?

What a man is, largely depends upon what he eats. Hence man is very
largely a product of the fields. When the soil is denuded of any of the
elements essential to plant and animal life, it must be properly
fertilized. Incomplete or improper fertilization can have but one
result, to-wit, it will produce sickly vegetation, and this in turn must
produce unhealthy cattle, and since man is dependent upon plant and
animal life for his food a sickly race of human beings is the ultimate
result.