ce would look flat and
deformed, of which they are fully convinced who have happened to see
men in whom that part of the face is mutilated. It is placed just
above the mouth, that it may the more easily discern, by the odours,
whatever is most proper to feed man. The two nostrils serve at once
both for the respiration and smell. Look upon the lips: their
lively colour, freshness, figure, seat, and proportion, with the
other features, render the face most beautiful. The mouth, by the
correspondence of its motions with those of the eyes, animates,
gladdens, suddens, softens, or troubles the face, and by sensible
marks expresses every passion. The lips not only open to receive
food, but by their suppleness and the variety of their motions serve
likewise to vary the sounds that form speech. When they open they
discover a double row of teeth with which the mouth is adorned.
These teeth are little bones set in order in the two jaw-bones,
which have a spring to open and another to shut in such a manner
that the teeth grind, like a mill, the aliments in order to prepare
their digestion. But these aliments thus ground go down into the
stomach, through a pipe different from that through which we
breathe, and these two pipes, though so neighbouring, have nothing
common.

SECT. XL. Of the Tongue and Teeth.

The tongue is a contexture of small muscles and nerves so very
supple, that it winds and turns like a serpent, with unconceivable
mobility and pliantness. It performs in the mouth the same office
which either the fingers or the bow of a master of music perform on
a musical instrument: for sometimes it strikes the teeth, sometimes
the roof of the mouth. There is a pipe that goes into the inside of
the neck, called throat, from the roof of the mouth to the breast,
which is made up of cartilaginous rings nicely set one within
another, and lined within with a very smooth membrane, in order to
render the air that is pushed from the lungs more sonorous. On the
side of the roof of the mouth the end of that pipe is opened like a
flute, by a slit, that either extends, or contracts itself as is
necessary to render the voice either big or slender, hollow or
clear. But lest the aliments, which have their separate pipe,
should slide into the windpipe I have been describing, there is a
kind of valve that lies on the orifice of the organ of the voice,
and playing like a drawbridge, lets the aliments freely pass through
t