It is necessary to include in our tabulation, the enervating influence, not merely of toxic substances introduced into the body as such, but of those toxins that are generated in the body, in the intestine, in abscesses, etc.
Enervation results from the continuous effort put forth by the body in overcoming toxemia from cellular waste, septic processes anywhere in the body, fermentation and putrefaction in the gastro-intestinal tract, chemical and bacterial poisons by way of the mouth, lungs, mucous membranes, or by inoculation or injection, by tea, coffee, chocolate, tobacco, alcohol, drugs, etc. The most continuous expenditure of nerve-energy, and in that sense the greatest, is the body's effort to prevent the poisons from completely overwhelming it. In view of the huge drafts made, the body, in most cases can do little more than keep even, until a time comes when resistance is completely lost, all reserve nerve energy is exhausted, and the individual is made conscious of trouble. This means that toxemia has risen above the level where it can be eliminated or neutralized, and it overflows. This is what we call a crisis--biogony.
In like manner, compensation involves a strain upon the body's nerve energy. The continuous effort to compensate for the deficiency of a damaged organ, a leaking heart, for instance, means an unceasing drain of nerve energy. This drain will not make itself felt so long as the individual's voluntary habits are good, that is, so long as he lives within his compensating capacity, but quickly becomes apparent if he practices enervating habits.