Animal Oeconomy.
That the Use of Exercise does conduce very much to the Preservation of
Health, that it promotes the Digestions, raises the Spirits, refreshes
the Mind, and that it strengthens and relieves the whole Man, is scarce
disputed by any; but that it should prove Curative in some particular
Distempers, and that too when scarce any thing else will prevail, seems
to obtain little Credit with most People, who tho’ they will give a
Physician the hearing when he recommends the frequent Use of Riding, or
any other sort of Exercise; yet at the bottom look upon it as a forlorn
Method, and the Effect rather of his Inability to relieve ’em, than of
his Belief that there is any great matter in what he advises: Thus by a
negligent Diffidence they deceive themselves, and let slip the Golden
Opportunities of recovering, by a diligent Struggle, what could not be
procur’d by the Use of Medicine alone.
Whether this proceeds from the Customs of these Northern Nations, so
different from those of the Ancients, and of more Southern Countries,
who seem to have plac’d almost as much in their Methods of Exercise, as
in their internal Physick; or whether from the narrow Notions most People
have conceiv’d of the Art of Physick, as if it imply’d little more than
Internals only, without considering that External, Mechanical, and all
other Means whatsoever, that give Relief, properly belong to it; this I
shall not pretend to determine, but this I think I may venture to affirm,
That most Men indulge themselves in the Expectation of more sudden
Relief, than the Nature of the Case will admit of, as if they thought
that Medicine was always to take like a Charm, without putting ’em to the
Expence of much Time or Pains; they do not consider the wonderful Variety
of the Disorders of Nature, and the Stubbornness of some Cases, which
will not permit the Sick to be wholly passive, but indispensably oblige
him to conspire with his Physician, and strive indefatigably to exalt
his Constitution to a degree requisite to supply the Defect of internal
Physick; which industrious striving on the part of the Sick, being what
is here meant by Exercise, and which it is my purpose to represent, as
more efficacious than it is generally believ’d to be; I think it proper,
first to explain what I mean by it in this place.
By _Exercise_ then, I understand all that Motion or Agitation of the
Body, of what kind soever, whether voluntary or involuntary, and all
Methods whatsoever, which without the Use of Internals, may (or without
which Internals alone may not always) suffice to enable Nature to expel
the Enemy which oppresses her; confining my self to the Consideration
of it only as it may prove Curative, not as Palliative, or barely
Preservative.
And here, before I attempt to demonstrate how Exercise proves so
beneficial in some few Cases, it may not be amiss to premise briefly
some of the ways Nature takes to relieve her self, when in danger of
being oppress’d, which may serve to illustrate my following Discourse;
as likewise some Instances of the Efforts of Nature, caus’d by external
Application, or at least by such Internals as cannot be suppos’d to
be Cordial or Vinous, or to be assimilated with the Blood and Animal
Spirits.
_First_, then; We may observe how Nature acquits her self of what we
commonly call a Cold, wherein a considerable quantity of the _Materia
perspirabilis_ is detain’d, by a sudden Constriction of the Pores of the
Skin, we shall find, that after some time the saline Particles growing
turgid, vellicate some Fibres of the fifth Pair of Nerves dispers’d
about the Nose, which by consent draw the Diaphragm into a Convulsive
Motion, by which the Air is press’d out of the Lungs thro’ the Nose with
some Violence; and by the shock the Glands of those Parts are open’d,
and the Humour, which was detain’d, is let out. This is _Sneezing_; to
which frequently is join’d _Gauping_ or _Retching_, another Method of
Nature to shake off a Load that she finds growing upon her; this is
more often repeated than _Sneezing_, and may be conceiv’d to dilate some
internal Parts by those Stretchings out of the Limbs, and more plentiful
Inspiration; _Sanctorius_ tells us in the 31st _Aphorism_ of his _fourth_
Section, that, _Corpora Oscitatione & Pandiculatione horæ dimidiæ spatio
magis perspirant, quàm tribus horis alterius temporis_, and compares it
to a Cock’s clapping his Wings after his Rest; so that it is manifest,
that even in that vulgar Affect there is an Alteration caused in the
Body, that is not Contemptible.
To these may be added the _Singultus_ or Hiccough, by which the
Ventricle, when too full, endeavours to relieve her self, either by
throwing off some of the rarifi’d Contents by the Gullet, or perhaps by
the _Pylorus_.
_Lastly_, Let us consider how _Laughter_ affects us, and it will appear,
that this Contrivance of Nature, wherein the Body does sympathize with
the Mind, proves so beneficial, by the playing of the Muscles of the
_Thorax_, and the pressing out of the saline Particles, so frequently
and sensibly as it does in some chearful People, to whom it is more
habitual than others, insomuch that it comes to be Proverbially, a Cause
of Fatness. All these Instances shew, that Nature seems to receive more
Relief from the Compression or acting of the containing Parts strictly
taken, than most Men easily imagine.
As to extraordinary Efforts of Nature, to pass by what happens upon
a sudden Surprize, Fear, Passion, or the like; it is certain, that
Torture will raise the Spirits for some time very much, and there are
as great Effects follow upon Irritation, which does not come up to the
perfect Notion of Torture. What wonderful Effects do we see produc’d by
strong Emeticks given by Surgeons in some Cases of the Limbs and extreme
Parts? Where a Person so griev’d has oftentimes a robust Constitution
and perfect Health, there the Medicines, tho’ given inwardly, cannot be
suppos’d to act after the common manner of Alteratives, by passing into
the Blood, by the Spirituousness of their Parts, or the like; for the
Person being in Health needs no Alteration to be made in the Blood, and
other Juices, which are as good as they can be desir’d to be; but by the
Irritation of the Fibres in the Ventricle, the Spirits are rais’d to
the highest pitch they are capable of, and brought to communicate that
Elasticity to the whole Body, all the Springs of Life are wound up,
all the Pumps of Nature (if I may so speak) set a playing, and by these
means the Agony is extended to the extreme Part affected, and the Matter
fixt there is attenuated and brought to flow, that it may be absorb’d by
the Blood, and discharg’d in the Circulation; Nay, we may take notice
of the great Power of a more gentle Irritation of those Fibres in those
weaker _Hysterical_ People, whose Spirits are of so fine a Make, or so
scatter’d and weakened, that they can’t long bear Fasting, without very
troublesome Symptoms following upon it, for they, we may perceive, are
in a sense strengthen’d at those times that the Contents of the Stomach
happen to be so rarifi’d, as to cause a gentle _Ægritudo_, a lingring
Sickness and Nauseousness, tho’ not sufficient to cause ’em to vomit,
for they shall then dispense with the want of that Food, without which
at other times they could not possibly subsist with any tolerable Ease,
and find themselves as strong and as free from their Tremors, Shiverings,
and other ill Symptomes, as if they had eat and drank plentifully; and
likewise during that Sickness the Salts shall come off plentifully
in the Urine, which will then recover its proper Colour, tho’ it was
before as limpid as common Water; from hence it is manifest, that the
Animal Spirits may be made to expand, dilate, or in some ways act upon
themselves, without the encreasing their quantity by such internal
Medicines as may be suppos’d to be converted into their Substance.
Having premis’d these things, I shall proceed to enquire, after what
manner Nature endeavours to clear her self of some few Distempers, which
I shall consider in their proper place, and likewise how she may the
more easily succeed in those Endeavours, if duly assisted by moderate
Exercise; which Assistance, if it at first View may seem too slow and
gentle to produce so great Effects, will yet with the Allowance justly
due to all sorts of Alterative Physick, _viz._ of a Habit or frequent
Repetition, appear to be sufficient to procure those Ends I shall assign
to it.
There is this Difference between the most compleat Productions of Humane
Artifice, and that Divine Piece of Mechanism, the Body of Man, that the
former are always the worse for wearing, and decay by Use and Motion; the
latter, notwithstanding the Tenderness of its Contexture, improves by
Exercise, and acquires by frequent Motion an Ability to last the longer;
and tho’ the Circulation, and continual and infinite Succession of
Particles, are the immediate Cause of Life, yet the Health, the Strength,
the Well-being of the Individual, is in great part owing to the Effects
of a General Motion superinduc’d to these internal Motions; which it is
so far from disordering, that it aids and assists ’em to a greater degree
than we are wont to imagine; for in our Considerations of the Animal
Oeconomy, we seem to regard Nature only as in a quiescent State, without
a due Allowance for the Alterations caus’d by the Motion of the whole,
which yet are confess’d by all to be sometimes of great Consequence:
for that General Motion acting both on the Fluids and Solids of the
Body, may sometimes prove the last and best Resort for the Restoring the
_Æquilibrium_ between ’em.
As for the Fluids; One would think the Shape and Make of the
Blood-Vessels were sufficient alone to lead us into an Opinion of the
Necessity of Exercise; by reason they all terminate in a Cone, they must
needs resist the Passage of the Blood incomparably more than they would
have done if they had been Cylindrical; and tho’ all the Branches of the
Capillary Arteries, would, if taken Collectively, make a greater Diameter
than that of the great Artery, yet the Consistence of the Blood, and
the extreme Fineness of those invisible Meanders, require the frequent
Pressure and Assistance of the Muscles to encrease the Circulation, which
accordingly we always find very much augmented by those Means; yet ’tis
the Result of this swifter Current of the Blood, which should be most
valuable to us, I mean the better Digestion and Mixture of the various
Particles convey’d into the Blood. I believe it will be allowed on all
hands, that the best way to bring an Animal Fluid to a greater degree of
Perfection, is Digestion; and the Excellency of that Operation consists
in the just Degree of Heat which causes it; or, to speak perhaps more
properly, in the just Agitation or intestine Motion of the Particles
which may be suppos’d to occasion that Heat. The Standard or Measure of
this Heat or Agitation in the Animal Oeconomy, is to be taken from what
we observe in a Man in perfect Health, and in the Prime of his Age; when
his Blood flows with its due Velocity, when there is an uninterrupted
Secretion of all that is disagreeable to it, and it is wrought up to its
florid Consistence, and a just proportion between the Serous and Grumous
parts. Now this we may successfully imitate by repeated Exercise, when
the Blood happens to be impoverish’d and Languid, we may encrease the
Velocity of the Circulation, and consequently the Heat following upon it,
by which a great many crude Particles will be attenuated and ripen’d,
either for Mixture or Secretion, and there will be an equal Distribution
of the attenuated Particles to the several Emunctories of the whole Body,
by reason of the Solids co-operating with the Fluids; whereas it is often
quite otherwise, when an internal Medicine is given design’d for one
Secretion only, which may promote that, and perhaps hinder another; as a
Medicine which agrees with the Stomach, sometimes offends the Head; for
the Nervous Parts being, as it were, Passive in the Case, the Secretions
cannot be so equally performed as when the whole Body is exercis’d.
I would not be here mis-understood, as if I suppos’d that this first
Effect of Motion, this Digestion, would avail in many Cases, as where an
ill Ferment is lodg’d in the Glands, or where the Morbifick Particles
have been long a forming, and are strongly combin’d in the Blood, but
this may take place where a greater degree of Agitation is absolutely
necessary; as when the Blood is Effete and Languid, when the Chyle comes
into it dispirited, and when even a proper Medicine proves offensive
and burthensome, and there is scarce Power enough left in the Blood to
master its Particles, and apply ’em to their proper Uses; then, I say,
’tis time to make the Solids assist the Fluids in the dispensing of this
Load which lies so hard upon ’em, which by gentle and close Exercise may
be more easily done than many imagine; besides there may be a Distemper
occasion’d by Particles of a looser Texture in the Blood, than is usual
in most Cases, where Nature may contend and struggle with the hostile
Particles, and yet not be able to get the Victory; where there may not be
a perfect Fever, nor yet a quiet Coalition between the Blood and those
foreign Particles. In such a Distemper as this, it must needs be very
proper to give a due Agitation to the Blood, to prepare those Particles
for the several Emunctories that are ready to receive ’em: and this
may be perform’d by a just Digestion, if we do but consider how much
the Body is adapted to it, and how much more Noble the Digestions are
in the Animal Oeconomy, than those produc’d by humane Contrivance. In
all artificial Digestions the Particles which are to be separated by
the Agitation of the Liquor, must either evaporate, or subside; but in
the Body there are a multitude of excretory Ducts ready to receive the
Particles, of such a determinate Figure, as renders ’em excrementitious,
and proper to be cast off; so that nothing is left but what is proper
to the Animal Fluids, and which the Vehemence of the Motion mixes and
unites at the same time that it breaks and moulds the others for their
proper excretory Chanels; so that the Agitation is in this Case (as Dr.
_Grew_ very well expresses it in his Treatise of _Mixture_) as “_carrying
the Key to and fro, till it hit the Lock; or within the Lock, till it
hit the Wards_.” How do we know the exact Degree of Agitation, that
is requisite to unite the Particles of the Fat, which are continually
flowing in a very great quantity into the Blood, with the Aqueous, by the
Means of sulphureous or saline Particles? Do we not frequently observe in
scorbutick Persons, who have lead a sedentary Life, that their Urines are
cover’d with an oily Film of several Colours? and is it not very natural
to suppose from thence, that the Blood wants a due Motion to keep those
oily Parts united with the others? But it is no wonder, if these things
are not well consider’d, when there is scarce any who makes Allowance
enough for the quantity of the fat Particles, which are continually
passing into the Blood, which must needs be very great, seeing the
whole Skin is lin’d with its Vessels, besides what is heap’d up about
the _Omentum_ and the Kidneys; so that Unctuous Medicines are copiously
intruded upon the Habit of the Body when there is a great Wasting of the
Flesh, without regarding that the Blood is not able to master the natural
_Pinguedo_, but gives it down daily, in all probability, for want of a
just degree of Agitation or Digestion, to keep it suspended in the Blood,
and to apply it to its proper Uses, and prepare it for its proper Vessels.
Besides the Power of Exercise on the Secretions of Particles purely
Excrementitious, and the better Mixture of those which are Homogeneous;
it is to be consider’d, that there are in the Oeconomy Secretions made
to return with Advantage into the Blood, out of which they are made; and
the Consideration of the Nature of these does afford us fresh Reasons
to set a Value upon the Use of Exercise, because the Body is so fram’d
and adapted, as to require it, in order to the furthering and increasing
these Operations; and if in the Business of Fermentation, which is
only a gradual Separation of the Must from the Spirituous Particles of
the Liquor, we find that the Motion of the Vessels in which the Liquor
fomenting is contain’d, does so much improve that Operation, as we are
convinc’d it does, by the Effects of the Carriage by Sea on Wines and
other Liquors in Casks; of how much greater Importance must the Motion
of the Body be, in order to the perfecting the Animal Fluids, in a System
of Mechanism so contriv’d, as to expect and demand such an Assistance?
Where the Solids are so fine-spun, as to determine the very Shape of the
Particles of a Fluid; and where they are so dispos’d, that a Fluid never
passes by ’em but it carries off some Melioration and Improvement, and
therefore cannot well arrive too frequently at those Passages where it
receives so happy an Alteration. Let us suppose the Blood to pass the
most extreme Parts twelve times in an Hour, when the Body is not mov’d;
if the Motion of the Body encreases this to fifteen or sixteen times in
an Hour, it will necessarily follow, that the Quantity of the Secretions
by the Liver, the Spleen, the Brain, and the rest of the Glands, which
separate the beneficial Juices, of which I am speaking; the quantity of
these, I say, must needs be augmented; which in Process of Time, when
this is brought to a Habit, must be of some Consequence. To insist but
on one of these Secretions; I take it to be no Paradox, that the more a
Man stirs himself, the more Animal Spirits are made in the Brain; tho’ it
will be strait retorted, that by the very same Motion and Exercise, there
will be a Waste of the Spirits by Perspiration, more than proportionable
to the Overplus that is made in the Brain; and tho’ I grant this, it will
not suffice to discompensate the Benefit which the Blood reaps from the
Augmentation of the Quantity of the Animal Spirits infus’d into it (if
I may so speak) from the Brain; because the true Animal Spirits have
their Work to do in the Blood, before they come to pass off at the Skin;
they are not of that Fugitive Make, which at first Thought most Men are
apt to suppose ’em to be; they seem to be destin’d to contemperate the
Acrimony of the Blood, to embrue it with a Plastick Quality, and may
serve to execute other Functions, besides that of Motion; so that it is
not at all to be wonder’d, if a Person, much accustom’d to Exercises,
notwithstanding the daily Expence of a greater Perspiration, should have
his Blood of a better Condition, and more Rich than that of another
Person living a sedentary Life, by reason of the greater Impression, the
greater Tincture (if I may be allow’d so to speak) of this most exquisite
and inimitable Fluid.
These Things are not to be stated exactly, and yet they are not to be
accounted altogether precarious; for tho’ we shall never perhaps be
able to know exactly what the Animal Spirits are, yet we may make a
shift to distinguish what they are not. According to the common Notions,
a well-prepar’d volatile Salt, after it has pass’d the Lacteals, and
comes into the Blood, might be taken to be a pure Animal Spirit; and
yet, undoubtedly, the Fluid, prepar’d by the Glands of the Brain, has
something in it transcendently preferable to any thing that can be
the Effect of Art. Whether those Glands are so dispos’d, as to unite
some Nitro-Aerial Particles with others proper to serve as a Vehicle
to ’em, is not to be determin’d by me or any Body else; but it may not
be altogether so absurd, to guess at some such thing, since we know
nothing in Nature that can afford Particles of that Elasticity as Nitre
does; and we may discern, that the Animal Spirits seem to consist of
a _Fulgur_, an _Impetum faciens_, something that is Irraditating; and
yet withal there seems to be something extremely Mild and Plastick, and
as it were Tenacious, combin’d with the Elastick. I hope I don’t run
into an _Hypothesis_; I would carry this no farther than it can be kept
in Countenance by _Phænomena_ arising in the Cure of Distempers; for
thus we see in the Nervous Atrophy, tho’ the Spirits, taken as _Impetum
facientes_, pass freely, and are not obstructed, as in the Palsie, yet
the Benign Plastick Quality seems to be wanting, because the Habit of
Body does not thrive, tho’ the Spirits are brought all over it; and
that the Spirits, when they are in their true Purity, are concern’d in
Nutrition, is plain enough; because the intercepting of ’em, by cutting
off a Nerve, always causes the wasting of the Part to which that Nerve
lead.
Thus I have endeavour’d to shew some of the secret Advantages accruing
to us from the frequent Use of Exercise; and by which it will appear,
that the Fluids of the Body are of such a Texture, as will admit of
Improvement from the greatest Rapidity of their Current, that is
consistent with the Organs thro’ which they are convey’d.
But, _Lastly_, to put these things past all Doubt, by a well-known
Observation; we need but consider what is sometimes the Effect of
too much Exercise upon taking a Purging Medicine, and that is an
_Hypercatharsis_. The Particles of the Drug being sublim’d, and render’d
more active by the greater Agitation in the Body, display a much greater
Violence than otherwise they would have done in a Person of the same
Constitution, who had given himself to Repose. This has been long ago
observ’d by _Hippocrates_, in the _fourteenth_ and _fifteenth Aphorisms_
of his _fourth Section_; From whence it naturally follows, that the
Motion of the Body may cause great Alterations in the Blood; may very
much improve any Juices that are convey’d into it; and that in some nice
Cases, where the Alterative Physick is very mild, and perhaps given in
too small a Quantity, it is absolutely necessary to have Recourse to
the Use of Exercise, to give an Energy to it, that it may produce the
desired Effect.
Having thus briefly consider’d the Power of the Use of Exercise, I come
now to shew, after what manner it affects the Solids; and that I take to
be, _first_, by giving a greater Tension to ’em, or restoring the true
Tone of the Parts, by curing the Relaxation by which they were weakned.
That I may explain what I mean by this _Tension_ or _Tone_ of the Parts,
it will be necessary to consider, _first_, how great is the Benefit
we daily receive by only changing the Position of our Bodies, from an
Horizontal to an Erect Position when we quit our Beds, where in the
time of Sleep the Body has been relaxed; and this will appear best by
the ill Consequences which follow upon a Person’s being confin’d by an
Accident to keep his Bed for a few days; for such a one always finds upon
his getting up again, that his Spirits are disorder’d; he finds himself
Vertiginous in some measure, and a great deal weaker than he was, before
he betook himself to that Posture: From whence it evidently appears,
that Standing or Sitting, the familiar Exercises (if I may so call ’em)
of the most sedentary Life, are absolutely requisite to keep up the
Balance on the part of the Solids, even in a State of Health, and that
more violent Exercises are as requisite to recover this Balance, when
sunk by Sickness. I know it may be objected here, that this Observation
is chiefly owing to the Custom of changing the Posture of the Body
alternately, in such a space of time, and that the breaking of that
Custom occasions those Disorders; but this will not suffice; for an erect
Position is essential to the well being of the Body of Man: and if the
Infant was not at such an Age brought to it by degrees by the Nurse,
tho’ it might grow up to the Bulk of a Man, and live many Years, yet it
would be a kind of bedridden Creature; Paralytick, as to the Use of its
Limbs, tho’ with the Sense of Feeling; and much weaker internally, for
want of that Advantage, which the Fluids receive from the Solids by this
most familiar degree of Tension; which we experience in Standing, which
Posture has ever been esteem’d as a Tonick Motion.
But the Stiffness or Strength of the solid Parts will appear more evident
by that sensible encrease of the Strength, which Men experience when
they set themselves upon any vigorous Exercise; which continues, till
thro’ the Greatness of the Perspiration they grow tyr’d, and relax
again; or, to borrow an Illustration from Beasts, It will appear by what
_Jockeys_ observe, who when they design to take the Bearings of a Running
Horse, that is, measure the Extent of his Stroaks, they usually let him
gallop a Mile or more first, as supposing that he can’t come upon his
Legs (as they term it) till he has run a considerable time; that is, he
can’t strike out so far, tho’ press’d ever so much to it, upon his first
setting out, as he can after he has run some time: which explains what
I assert, That a proper or due degree of Exercise, enables the Nerves
to dilate themselves sufficiently to take a greater Quantity of Animal
Spirits, or some other way, to us unknown, gives ’em a better Tone, or
Elater, and consequently fits ’em for more vigorous Actions.
But to bring the Sense of this Tension nearer to a Case of Sickness; Let
any Man reflect, how he found himself after an Acute Distemper, wherein
the solid Parts were mightily relax’d by the Heat of the Fever; when a
Man in that Case rises first from his sick Bed, and makes a shift to walk
a very little in his Chamber, tho’ he quickly grows faint, and wants
some Cordial to refresh him; that is, Tho’ his Vital Spirits sink, as
the Antients lov’d to express it, yet he perceives a certain Stiffness,
Tension, or Strength in the solid Parts, by that first attempt to walk,
which never leaves him, but encreases daily, till he recover his perfect
Health.
These are some familiar Instances of the Sense we have, after what manner
we come to acquire more Strength upon the Use of Exercise, and which
every Man almost may recollect, that he has experienc’d more or less in
himself; tho’ in other Cases the solid Parts are always strengthening
by Exercise, without so plain a Sense of it, as in the Instances above
mention’d; as we see what excessive Strength some Men gradually acquire
by a constant Practice of vehement Motions, begun when they are young,
which growing upon ’em by degrees, they are not so sensible of the
Encrease of it. This is the Case of Tumblers, Rope-dancers, and the like,
in whom the Nervous and Solid Parts must be incomparably more wound up,
more tense than in other People; and thus we see the strongest Men are
often thin and Raw-bon’d, as we call it; that is, tho’ daily hard Labour,
and great Perspiration carry off a great deal of the grosser Fluids of
the Body; yet are the Muscles not Flaccid, but Tense and Firm, capable
of greater Actions than the Muscles of those who seem to have a better
Habit of Body; which plainly indicates, that Exercise does communicate
some Strength to the Nervous Parts, which cannot be any other way
procur’d; and that we may argue from the greater to the less; that if
healthy Persons may acquire such monstrous Strength by Use, People that
are Valetudinary may, by setting themselves upon a resolute and diligent
Practice of moderate Exercise, obtain a proportionable Increase of
Strength.
It may be expected, perhaps, that I should endeavour to explain, how the
Fibres come to receive a greater Power to act, by being often put upon
Action, and to shew wherein the Elater, the Spring of the Solids, does
consist; but this has been attempted so largely by an Eminent Author, Dr.
_Baglivi_, and so much to the Disgust of very many, that it’s better to
rest contented with plain Experience, than to frame an _Hypothesis_ for
the _Modus_ of so abstruse a Method of Nature, which, in all likelyhood,
Mankind will ever be ignorant of; but as far as we may reasonably guess,
by frequent Distension the Nerves receive a greater quantity of Animal
Spirits, because the Limb which is most us’d, grows biggest; and there
is reason to induce us to suspect, that the Fibre it self strengthens
by Use, has a peculiar Faculty to exert it self more and more, as often
as the _Imperium Voluntatis_, the _Fiat of the Will_, sets it upon
Motion. But unless we knew the Bond of Union, and understood how the
Rational Soul acts upon the Animal Powers, we must be content to be most
ignorant, the nearer we approach in our Disquisitions to that Union; but
the Experimental Knowledge of these Parts sufficiently reproves those
who hope to be deliver’d from some Distempers seated in the Solids,
without acting suitably to the Nature of the Solids, the Subject of
their Distempers: As for Instance; Suppose a Person, by frequent and
unnecessary Use of the Bagnio, and more unnecessary Bleedings; by the
Use of hot Liquors, and a perfect Disuse of all Bodily Exercise; by
Passions of the Mind, and other Irregularities, is brought into the very
worst of Hysterick Symptomes, with a Flaccidity and Relaxation of the
whole Nervous System; How ridiculous is it, for such a Person to expect
to be perfectly restor’d to a firm Habit of Body by internal Alteratives,
and Methods little different from those things which occasion’d the
Distemper; which tho’ they may give wonderful Relief in the Paroxysm,
yet can never restore the Tone of the Solids, which must be treated in
a manner proper to themselves, by Frictions, Exercise of the Body, the
Cold Bath, and the like; which are very likely to be able to succeed to
a perfect Cure? For why ought we not to suppose, that as all Fluids have
more or less a Tendency to purifie and exalt themselves by Fermentation,
the Solids should otherwise have a Propensity proper to their Make, to
recover themselves by a due Tension? And what can be more reasonable
and natural, than to conclude, that if a Supine and Luxurious Course
of Life has enervated the Body, an Active and Vigorous one should
restore it? If it be objected, That gentle Emeticks have gone a great
way towards procuring a perfect Recovery from some Hysterick Cases; I
have premis’d already, that they act upon the Fibres, and put ’em upon
frequent Contractions, much after the same manner as a total Exercise of
the Body; and therefore in this last Case, where the first Passages are
not in Fault, their way of acting illustrates what I assert, that the
Solids must be made to strengthen themselves, and recover their Spring
by frequent Endeavours. But for Alteratives, strictly taken, I think
it may be justly a Question, Whether there is that Medicine in Nature,
that can remove this Distemper, when it has been of long continuance,
tho’ the World has been taught above an Age ago by _Paracelsus_ and his
Followers, to expect what I fear is not within the Extent of Nature; and
the Impudence of Empiricks is so great, as to promise every thing that
is absurd and Romantick; which keeps People up with hopes, that they
may be so happy as to meet with that mighty Secret, which even in the
quantity of a few drops, shall as it were charm away the most troublesome
and riveted Distemper, and so instead of being Cur’d, they are Kill’d
by Expectation; when the Power of Recovering their Health was in their
own hands, if they had resolutely set about the proper means; like the
Country-Fellow in the Fable, who when his Cart stuck fast in the Mire,
must needs be calling upon _Hercules_ to come and help him, when with
setting his own Shoulders to the Wheels, he might easily have got clear.
But moreover, a second Advantage arising from Exercise, is, that it
gives the Solid and Nervous Parts a grateful Sensation, which in some
Cases is not contemptible; a gentle Agitation of the Spirits being able
to remove some Pain situated in those Parts, which perhaps nothing else
would remove so surely and so soon. To explain the manner of this by a
trivial Observation (if any thing in Nature can be so) let us consider,
how we can separate the _Cuticle_ from the true _Cutis_ without Pain;
it can’t be done with an Instrument without extream Pain, it can’t be
done by Vesicatories without some Pain; but it may be done with Chafing
without any Pain at all, or rather with some Pleasure, till you leave
off Rubbing, and the Air comes to act upon the naked Fibres. Now this
can’t be attributed to the Heat of the Part only, for then hot Medicines
apply’d to the Skin; would do it as easily but must be suppos’d to be
owing to a certain Agitation of the Spirits in the Extremity of the
Fibres, which affects ’em with so agreeable a Sensation, as to surmount
even the Pain of a Separation of their Covering, the Scarf-Skin. Now
it will be allow’d by all, that whatsoever Sensation there is in the
Extremity of the Fibre, the same there is at the Origine of it in the
Brain; so that a pleasant Sensation in the Extremity, must needs be
the same in the common _Sensorium_; and therefore ’tis easie to account
for the good Effects of Frictions of the Limbs in some sort of Fits, by
giving a new and different Motion to the Spirits, and thereby disengaging
’em from their disorderly Motions. And then if acting thus upon the
Extremity of the Fibres produces such an Effect in ’em, ’tis natural
to imagine, that that Motion, or gentle Concussion, which much after
the same manner, in some proportion acts upon the whole Body of the
Nerves, must affect ’em with a Sensation proportionably agreeable, and
may prove sufficient to dispose the Spirits to leave their Displosions,
and irregular Motions, when they happen to be so discompos’d, and
consequently remove the troublesome Watchings and painful Symptomes
occasion’d by those Displosions, when other Means prove ineffectual. Thus
we see how natural it is for those Hysterick Persons, who are vexed with
obstinate Watchings, to fall into a true and refreshing Slumber, by the
Motion of a Chariot, when Opiats will have no effect upon ’em, but rather
encrease their Watchings: The Spirits being the most stubborn Part of the
Animal Oeconomy, and not always to be compel’d, even by that potent Drug.
The abstruse Nature of this Part of the Animal Oeconomy, will not permit
us to come at a fair Explication of these Phænomena, any otherwise, than
by what we at different times experience; for we must first understand,
as the Author of the _Dispensary_ very well expresses it.
_How the same Nerves are fashion’d to sustain_
_The greatest Pleasure, and the greatest Pain._