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 their proper channel, but never suffers the least particle or drop to fall into the slit of the windpipe.  This sort of valve has a very free motion, and easily turns any way, so that by shaking on that half-opened orifice, it performs the softest modulations of the voice.  This instance is sufficient to show, by-the-by, and without entering long-winded details of anatomy, what a marvellous art there is in the frame of the inward parts.  And indeed the organ I have described is the most perfect of all musical instruments, nor have these any perfection, but so far as they imitate that.