human longevity. It has been a
long quest, and, in the main, fruitless, though it might be said in
fairness that Brown-Sequard's method of using the expressed testicular
juice as a medicine, by mouth or injection, for the renewal of youth,
was probably the true parent of the present familiar method of using the
extracts of various glands, or the pulverized substance of the glands
themselves, notably the thyroid and the adrenal, as medicines to be
taken internally for the relief of various diseased conditions. The
constant objection to such form of medication is, of course, that when
the medicine is stopped the good results stop, so that a temporary
relief is the utmost that can be hoped for from the method. Genius is
synthetic, elliptic, sudden, but always clear and sure. Dr. Brinkley
began with a theory, and by no means a new theory. From the theory he
deduced rapidly, and acted. The results of the acts proved the truth of
the theory. That theory has been variously stated, its most familiar
form being, "In all living forms the basis of all energy is sex-energy."

Looking about for facts to confirm or disprove this assertion all
investigators have been faced with similar phenomena, such as:

When the male fowl is sterilized in order that he may grow big and fat
for the market later he loses his cock's plumage and gains in weight. In
the psychic domain the changes are still more marked. The capon is a
coward, shunning the contest for supremacy. He does not forage for the
hens, inviting them to feed upon what he has found, but looks after
himself first and last. He is lazy, sluggish, and selfish.

The stallion is a proud and beautiful animal, and Job's description of
the war-horse "He paweth in the valley and rejoiceth in his strength, He
goeth on to meet the armed men!" with its context, is still the best
word-painting we have of the majesty of the horse in full possession of
his sexual powers. The gelding is tractable and useful, and the absence
of the fiery impatience of the stallion fits the gelding for man's use.

When men are castrated, as in the East, in youth, where they are prized
as custodians of the harem, they are fat, usually large of frame, but
short-lived. The growth of hair on the head is often scant; on the face
and body it is altogether missing. The voice is high, partaking of a
treble quality. When through surgical operation or accident it happens
that a man is deprived of the testicular glands in yo