his Head.  This trembling is very perceptible in most sounding Bodies, and is (if I mistake not) owing for the most part to the Springiness of the Air; which, did I not study to be brief, I could more fully explicate.  Now the Simple Breath is Air, breathed forth by the opening of the Mouth or Nostrils, simply, and without any smiting on the parts, which rather exciteth a whispering than a sound.  Hence is it, that Animals, whose Wind-pipe is cut beneath the Throat, do indeed render a Breathing, but no Voice; for the Tube of the Wind-pipe is too large, and too smooth, than that the Air can strike upon it any where; and being thus reflected on its self, it can also imprint a tremulous Motion on its neighbouring Bodies:  This the Physicians Pupils do know; who being about to dissect live Dogs, they cut their Throats, that they may not be troubled with their barking:  For Voice differs as much from a Simple Breath, as doth that hoarse Sound, which we excite, by rubbing the tops of our Fingers hard upon some Glass or Table, which is quite differing from that same soft whistling Sound, which is heard when we lightly rub with the Hand the same Glass or Table.

The Voice therefore, as it is the Voice, is generated in the Cartilages of the Wind-pipe, then afterwards is formed into such or such Letters; but that it may become a lovely Voice, it’s requisite, that those Cartilages be smooth, and lined with no mucous Matter, else the Voice will become Hoarse, and sometimes be utterly lost, viz. when they have lost their Springy power.

For Pipes; and other Wind-Instruments do most notably explain to us the nature of the Voice; for in them we see a certain Voice or Sound to be generated out of Simple Air, whilst it is as it were, rent in pieces, and forced into a tremulous Motion:  Now, that in these Instruments there is a little Tongue; or which is instead of a Tongue, the same in a Man is the Epiglott, or Cover of the Wind-pipe, and the Uvula, or Pallate of the Mouth; but the rest of the Cartilages of the Throat, besides that, they contribute much to the making of the Voice, yet are they chiefly serviceable to it, in rendering it to be more flat, and more sharp, and that especially by the Bone of the Tongue, and the adjoyning Muscles:  But I am unwilling to put from this Office the Muscles which are proper to the Wind-pipe; for they all unanimously conspire to make the Cleft of the Throat either wider, or narrower.  But above all, here is that wonderful Faculty of modifying the Voice, according to Will and Pleasure; which, even as Speech also, is not natural to us, but a Habite, contracted by long Use or Custom.  Hence it is, that the Unskilful are not only Ignorant how to Sing, but also cannot so much as imitate others who are Singing; so also such as are ignorant of any Language, do not only not understand others who are speaking that Language, but also do not know how presently to repeat that Voice which they received by their Ears.