_MADAM_
I am of your _Authors_ mind, That _heat is not the cause of digestion_;
but I dissent from him, when he says, That it is _the Ferment of the
stomach that doth cause it_: For, in my opinion, Digestion is onely
made by regular digestive motions, and ill digestion is caused by
irregular motions, and when those motions are weak, then there is no
digestion at all, but what was received, remains unaltered; but when
they are strong and quick, then they make a speedy digestion. You may
ask me, what are digestive motions? I answer, They are transchanging,
or transforming motions: but since there be many sorts of transchanging
motions, digestive motions are those, which transchange food into the
nourishment of the body, and dispose properly, fitly and usefully of
all the Parts of the food, as well of those which are converted into
nourishment, as of those which are cast forth. For give me leave to
tell you, _Madam_, that some parts of natural Matter, do force or cause
other parts of Matter to move and work according to their will, without
any change or alteration of their parts; as for example, Fire and
Metal; for Fire will cause Metal to flow, but it doth not readily alter
it from its nature of being Metal; neither doth Fire alter its nature
from being Fire. And again, some parts of Matter will cause other parts
to work and act to their own will, by forcing these over-powred parts
to alter their own natural motions into the motions of the victorious
Party, and so transforming them wholly into their own Figure; as for
example, Fire will cause Wood to move so as to take its figure, to
wit, the figure of Fire, that is, to change its own figurative motions
into the motions of Fire: and this latter kind of moving or working
is found in digestion; for the regular digestive motions do turn all
food received from its own nature or figure, into the nourishment,
figure, or nature of the body, as into flesh, blood, bones, and the
like. But when several parts of Matter meet or joyn with equal force
and power, then their several natural motions are either quite altered,
or partly mixt: As for example; some received things not agreeing with
the natural constitution of the body, the corporeal motions of the
received, and those of the receiver, do dispute or oppose each other:
for the motions of the received, not willing to change their nature
conformable to the desire of the digestive motions, do resist, and
then a War begins, whereby the body suffers most; for it causes either
a sickness in the stomack, or a pain in the head, or in the heart, or
in the bowels, or the like: Nay, if the received food gets an absolute
victory, it dissolves and alters oftentimes the whole body, it self
remaining entire and unaltered, as is evident in those that die of
surfeits. But most commonly these strifes and quarrels, if violent, do
alter and dissolve each others forms or natures. And many times it is
not the fault of the Received, but of the Receiver; as for example,
when the digestive and transforming motions are either irregular, or
weak; for they being too weak, or too few, the meat or food received
is digested onely by halves; and being irregular, it causes that which
we call corruption. But it may be observed, that the Received food is
either agreeable, or disagreeable, to the Receiver; if agreeable, then
there is a united consent of Parts, to act regularly and perfectly in
digestion; if disagreeable, then the Received acts to the Ruine, that
is, to the alteration or dissolution of the Nature of the Receiver; but
if it be neutral, that is, neither perfectly agreeable, nor perfectly
disagreeable, but between both, then the receiver, or rather the
digestive Motions of the receiver, use a double strength to alter and
transform the received. But you may ask me, _Madam_, what the reason
is, that many things received, after they are dissolved into small
parts, those parts will keep their former colour and savour? I answer;
The cause is, that either the retentive Motions in the Parts of the
received, are too strong for the digestive and alterative Motions of
the receiver, or perchance, this colour and savour is so proper to
them, as not to be transchanged: but you must observe, that those
digestive, alterative and transchanging motions, do not act or move all
after one and the same manner; for some do dissolve the natural figure
of the received, some disperse its dissolved parts into the parts of
the body, some place the dispersed parts fitly and properly for the
use, benefit, and consistence of the body; for there is so much variety
in this one act of digestion, as no man is able to conceive; and if
there be such variety in one Particular natural action, what variety
will there not be in all Nature? Wherefore, it is not, as I mentioned
in the beginning, either Ferment, or Heat, or any other thing, that
causes digestion; for if all the constitution and nature of our body
was grounded or did depend upon Ferment, then Brewers and Bakers,
and those that deal with Ferments, would be the best Physicians.
But I would fain know the cause which makes Ferment? You may say,
saltness, and sowreness. But then I ask, From whence comes saltness and
sowreness? You may say, From the Ferment. But then I shall be as wise
as before. The best way, perhaps, may be to say, with your _Author_,
that Ferment is a Primitive Cause, and a beginning or Principle of
other things, and it self proceeds from nothing. But then it is beyond
my imagination, how that can be a Principle of material things, which
it self is nothing; that is, neither a substance, nor an accident.
Good Lord! what a stir do men make about nothing! I am amazed to see
their strange Fancies and Conceptions vented for the Truest Reasons:
Wherefore I will return to my simple opinion; and as I cannot conceive
any thing that is beyond Matter, or a Body; so I believe, according to
my reason, that there is not any part in Nature, be it never so subtil
or small, but is a self-moving substance, or endued with self-motion;
and according to the regularity and irregularity of these motions,
all natural effects are produced, either perfect, or imperfect;
timely births, or untimely and monstrous births; death, health, and
diseases, good and ill dispositions, natural and extravagant Appetites
and Passions, (I say natural, that is, according to the nature of
their figures;) Sympathy and Antipathy, Peace and War, Rational and
Phantastical opinions. Nevertheless, all these motions, whether
regular or irregular, are natural; for regularity and irregularity
hath but a respect to particulars, and to our conceptions, because
those motions which move not after the ordinary, common or usual way or
manner, we call Irregular. But the curiosity and variety in Nature is
unconceiveable by any particular Creature; and so leaving it, I rest,
Madam,
_Your faithful Friend_
_and Servant._