d may be uncovered, each one leading to
greater heights of achievement.

This phenomenon occurs not alone on the physical plane; it is
discernible in mental exertion as well. True, we seldom experience it
because we are mentally lazy and have the habit of stopping our work at
the first signs of fatigue. Did we persist, however, disregarding
fatigue and ennui, we should find ourselves tapping vast reserves of
mental power and accomplishing mental feats of astonishing brilliancy.

The occasional occurrence of the phenomenon of second-wind gives ground
for the statement that we possess more energy than we ordinarily use.
There are several lines of evidence for this statement. One is to be
found in the energizing effects of emotional excitement. Under the
impetus of anger, a man shows far greater strength than he ordinarily
uses. Similarly, a mother manifests the strength of a tigress when her
young is endangered. A second line of evidence is furnished by the
effect of stimulants. Alcohol brings to the fore surprising reserves of
physical and psychic energy. Lastly, we have innumerable instances of
accession of strength under the stimulus of an idea. Under the
domination of an all-absorbing idea, one performs feats of
extraordinary strength, utilizing stores of energy otherwise out of
reach. We have only to read of the heroic achievements of little Joan
of Arc for an example of such manifestation of reserve power.

When we examine this accession of energy we find it to be describable
in several ways--physiologically, neurologically and psychologically.
The physiological effects consist in a heightening of the bodily
functions in general. The muscles become more ready to act, the
circulation is accelerated, the breathing more rapid. Curious things
take place in various glands throughout the body. One, the adrenal
gland, has been the object of special study and has been shown, upon
the arousal of these reserves of energy, to produce a secretion of the
utmost importance in providing for sudden emergencies. This little
gland is located above the kidney, and is aroused to intense activity
at times, pouring out into the blood a fluid that goes all over the
body. Some of its effects are to furnish the blood with chemicals that
act as fuel to the muscles, assisting them to contract more vigorously,
to make the lungs more active in introducing oxygen into the system, to
make the heart more active in distributing the blood througho