whistle is sharper than that of the wind through their narrowest
crevice. It roars louder than the lion of the desert, and it can draw
out a thread of sound as fine as the locust spins at hot noon on his
still tree-top. Its clustering columns are as a forest in which every
music-flowering tree and shrub finds its representative. It imitates all
instruments; it cheats the listener with the sound of singing choirs; it
strives for a still purer note than can be strained from human throats,
and emulates the host of heaven with its unearthly "voice of angels."
Within its breast all the passions of humanity seem to reign in turn. It
moans with the dull ache of grief, and cries with the sudden thrill of
pain; it sighs, it shouts, it laughs, it exults, it wails, it pleads, it
trembles, it shudders, it threatens, it storms, it rages, it is soothed,
it slumbers.

Such is the organ, man's nearest approach to the creation of a true
organism.

But before the audacious conception of this instrument ever entered the
imagination of man, before he had ever drawn a musical sound from pipe
or string, the chambers where the royal harmonies of his grandest vocal
mechanism were to find worthy reception were shaped in his own
marvellous structure. The _organ_ of hearing was finished by its Divine
Builder while yet the morning stars sang together, and the voices of the
young creation joined in their first choral symphony. We have seen how
the mechanism of the artificial organ takes on the likeness of life; we
shall attempt to describe the living organ in common language by the aid
of such images as our ordinary dwellings furnish us. The unscientific
reader need not take notice of the words in parentheses.

The annexed diagram may render it easier to follow the description.

[Illustration]

The structure which is to admit Sound as a visitor is protected and
ornamented at its entrance by a light movable awning (the external ear).
Beneath and within this opens a recess or passage, (_meatus auditorium
externus_,) at the farther end of which is the parchment-like
front-door, D (_membrana tympani_).

Beyond this is the hall or entry, H, (cavity of the _tympanum_,) which
has a ventilator, V, (Eustachian tube,) communicating with the outer
air, and two windows, one oval, _o_, (_fenestra ovalis_,) one round,
_r_, (_fenestra rotunda_,) both filled with parchment-like membrane, and
looking upon the inner suite of apartments (labyrinth).

This inn