But here I had almost forgot to compare the more dry, the more moist, the more solid, and the more thin Constitution of the Larynx, or Wind-pipe, which also make very much to the rendering the Voice, to be either sharp, or flat. That same humming Noise, which many flying Insects make, not so much by the Wings, (for when they are cut off, the humming still remains) as by a most swift and brisk Motion of certain Muscles, hid in the Cavity of their Breasts, seems to have somewhat of an affinity to the Voice; wherefore I desire the Learned to examine, whether those small Muscles, which are proper to the Cartilages of the Wind-pipe, cannot perform somewhat like to that.
Many more Particulars concerning the Voice might yet further be inquired into, such as, how it is, that every one may be known by his Voice? How that Sound, which in Singing is called Quavering, or Trilling, by a peculiarity, is excited, &c, But seeing that these things do not properly respect the nature of the Voice, I, for Brevities sake, do omit them.
Expounding the Nature of the Letters, and the manner how they are formed.
Hitherto we have treated concerning the Voice and Breath, and of the manner of the formation of both of them, in general; now let us see how the said Voice and Breath are, as a fit Matter for them, framed into such or such Letters; for the Voice and Breath are alone the material part of Letters, but the form of them is to be sought out from the various Configurations of those hollow Channels, thorough which they pass; Letters therefore, not as they be certain Characters, but as they are Pronounced or Spoken, are the Voice and Breath, diversly Figured by the Instruments ordained for the Speech.
But here we must be pre-admonished concerning the Letters; that there is a great Latitude almost amongst them all, and that one and the same Character is not pronounced by one and the same Configuration of the Mouth, yea, in one and the same Language; thus [a] and [e] sometimes are sounded open, and sometimes close; also [o] hath its own Latitude, so as many other Letters also may have; yea, as many as are the divers Modes, by which the Voice and Breath can be Figured, by the Organs of Speech; but the most easie, only, and the most Conspicuous are received by all Nations, whose number never almost exceedeth Twenty four, and have certain Characters annexed to them: But seeing that these Characters are not every where pronounced alike, yea, one and the same Letter sometimes is variously sounded by one and the same People, therefore I have made choice of the German Letters, which are of my Mother-Tongue, and the most Simple of all Letters, to be examined