Page:Aristotelous peri psuxes.djvu/287

CH. VII.] 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 ; 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 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 is said to be different from sound, and speech to be different from either; and, as