vibration may be communicated to the sense. Aristotle
may perhaps have been led, notwithstanding the unstable
opinions of his age upon the air, to conclude that, as
sound "is present in the air," air must be connected with
the hearing, and, if so, be contained, naturally, within its
organ. The succeeding passages hardly admit of comment,
on account of their evident want of anatomical know-
ledge; but they prove that the tympanic membrane had
been made out, as also that it may be so injured, as to
admit fluid from without into the ear. And this disease
of the membrane is aptly compared to ulceration and
consequent opacity of the eye's membrane, (the cornea,)
whereby the rays of light are precluded from entering
the eye and producing vision.
Note 5, p. 102. But proof is afforded, &c.] This
somewhat puerile experiment is still extant. It seems
strange that the very obvious cause of this phenomenon
did not occur to one who had surmised, without ana-
tomical proof, that there is air within the tympanum; it
had escaped Aristotle, besides, that, in a former passage,
he had made the air which is immured within the ear to
be immovable.
Note 6, p. 104. The voice is a sound, &c.] This passage is a clear definition of the voice, and it points, although indistinctly, to the parts and functions concerned in its formation. The voice[1] is said to be different from sound, and speech to be different from either; and, as
- ↑ Hist. Animalm, iv. 9. i.
