derate Heat; for in both these cases the top of the
_Wind-pipe_ is covered over with a clammy _Tenacious Phlegm_.

There remains yet two other Symptoms of the _Voice_, which I have
undertaken to explicate, viz. why the _Voice_ sometimes leaps from one
_Eighth_ to another; and, as it is rightly said by the Vulgar
Expression, that it is broken: and why, when we strive to make our
_Voice_ either too sharp, or too flat, it at last plainly faileth us.
As to the first, let us consider when and how it cometh to pass; and
first, it's what principally happeneth to _Orators_, when they
endeavour to lift up their _Voice_ too high, or strongly; but how this
cometh to be, _Organ-pipes_, and the _Monochorde_, do teach us, _viz._
when some Impediment interposing, doth divide the _ordinary Sound_
into two; if therefore those parts are equal, either of them is by one
_Eighth_ more sharp than the former Sound, neither are they
distinguished from one another; but if they prove to be unequally
divided, then two _distinct Sounds_ are made at the same time, whereof
one is flatter than the ether, and this is commonly called a _broken
Voice_: But why our _Voice_ should fail us, when we endeavour to make
it more sharp, or more flat than it ought to be, the reason is,
because we strive either so to contract the _Cleft_ of the
_Wind-pipe_, and to press the _Spout-like Cartilage_, by help of the
_Bone of Tongue_, towards the _Epiglott_, that the going forth of the
_Voice_, and of the _Breath_, may be precluded, or else, on the
contrary, because that the said _Cleft_, through the drawing down of
the _Cartilages_, is so much widened, that the departing out of the
_Breath_, finds no hinderance.

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
inqu