We may thus justly speak of _the overwhelming healing tendency of
nature_.

Metabolism is, therefore, the one great dominant function of the body
which, accordingly, must have our especial care.

It is the blood, consequently, to which alone we can resort if we desire
to assist nature in its process and tendency of balancing and healing.

This again indicates that, notwithstanding the apparent great variety of
_constitutional diseases, they are all practically one and the same
disease. They are all disturbances of proper metabolism, by some
irregularity of the quantitative or qualitative condition of the blood_.

This governing truth the great physiologist, Prof. Jacob Moleschott, has
formulated in the memorable words: "It is one of the chief questions
which humanity must always ask of the physician: how to attain good,
healthy and active blood. And, view the question as we may, all who give
it serious thought, are forced by experience to acknowledge explicitly,
or otherwise, that _our mental and physical capacity, and likewise the
power of reproduction, are directly dependent upon our blood, and our
blood on our nutrition_."


VARIETY OF ORGANS.

Why then, you may ask, if such unity exists, why this dissimilarity in
the tissues of the respective bodily organs? How is it that a bone in
its stonelike hardness is essentially the same as the infinitely tender
tissues of the eye? This difference is due to and accounted for by the